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34 Commits

Author SHA1 Message Date
Yicheng Qin
654eaba5a1 *: bump to v0.4.9+git 2015-03-31 13:59:10 -07:00
Yicheng Qin
9fa3bea5a2 *: bump to v0.4.9 2015-03-31 13:54:58 -07:00
Xiang Li
2fc8304300 Merge pull request #2586 from xiang90/047snap
server: introduce /v2/migration/snapshot endpoint
2015-03-27 17:42:19 -07:00
Xiang Li
087ba30a90 server: introduce /v2/migration/snapshot endpoint 2015-03-27 17:42:06 -07:00
Yicheng Qin
e1df265dc5 Merge pull request #2595 from yichengq/revert-upgrade-related
Revert upgrade related commits
2015-03-27 16:23:40 -07:00
Yicheng Qin
8059598332 Revert "server: add version monitoring"
This reverts commit 4f1f003d04.
2015-03-27 16:09:11 -07:00
Yicheng Qin
e1e2daa205 Revert "etcd: register usable versions when bootstrap"
This reverts commit 9f70568a02.
2015-03-27 16:09:04 -07:00
Yicheng Qin
399931cec9 Revert "next-version-handler"
This reverts commit f36d55f062.
2015-03-27 16:08:54 -07:00
Yicheng Qin
49715173cb Revert "server: add internal version"
This reverts commit 9a2d82854e.

Conflicts:
	server/version.go
2015-03-27 16:06:31 -07:00
Yicheng Qin
ad4f231b40 Revert "server: standby exits when detecting v2 is running"
This reverts commit ebb8d781b5.
2015-03-27 16:04:40 -07:00
Yicheng Qin
55263bc6b5 Revert "etcd: add -internal-dir flag"
This reverts commit 03a99cf9b1.
2015-03-27 16:03:49 -07:00
Yicheng Qin
262d769168 *: bump to v0.4.8+git 2015-03-23 14:20:09 -07:00
Yicheng Qin
2f6ea0a0e5 *: bump to v0.4.8 2015-03-23 13:47:10 -07:00
Kelsey Hightower
fc8020b7d6 Merge pull request #2546 from kelseyhightower/add-internal-dir-flag
etcd: add -internal-dir flag
2015-03-20 10:36:36 -07:00
Kelsey Hightower
03a99cf9b1 etcd: add -internal-dir flag
etcd supports setting the path to the etcd binary directory used for
running legacy mode and upgrades.

etcd no longer limits internal version checking to GOOS=linux.
2015-03-19 20:01:47 -07:00
Kelsey Hightower
eae1e18500 Merge pull request #2418 from kelseyhightower/release-0.4
Documentation: make -bind-addr and -peer-bind-addr docs match the code
2015-03-11 15:35:08 -07:00
Kelsey Hightower
6666b20d91 Documentation: make -bind-addr and -peer-bind-addr docs match the code
Fixes #2072.
2015-03-11 15:31:38 -07:00
Yicheng Qin
2d4592e8c5 Merge pull request #2416 from aeneby/etcd_trace_fix
config: Capitalise strTrace field name
2015-03-03 21:05:23 -08:00
Aaron Sowry
12fec1f936 config: Capitalise strTrace field name
Field names not beginning with a capital letter will not be exported
and therefore cannot be assigned values. This breaks the usage of
ETCD_TRACE when debugging.

Fixes #1970
2015-03-03 14:52:08 +01:00
Yicheng Qin
d6523fe463 bump to v0.4.7 2015-02-10 15:59:33 -08:00
Yicheng Qin
c25127a699 Merge pull request #2262 from yichengq/047
server: forbid /v2/stats/leader on follower
2015-02-09 22:29:48 -08:00
Yicheng Qin
9f031e6218 server: forbid /v2/stats/leader on follower 2015-02-09 14:50:34 -08:00
Yicheng Qin
e55724e959 Merge pull request #2260 from yichengq/047
server: refresh commit index when someone rejoins
2015-02-09 14:35:00 -08:00
Yicheng Qin
29af192e3d server: refresh commit index when someone rejoins
Update commit index when rejoin happens, because 2.0 doesn't accept
more than one uncommitted config entry.
2015-02-09 14:28:30 -08:00
Yicheng Qin
2fc79912c2 Merge pull request #2194 from yichengq/o3
server: standby exits when detecting v2 is running
2015-01-30 09:32:19 -08:00
Yicheng Qin
ebb8d781b5 server: standby exits when detecting v2 is running 2015-01-29 16:26:47 -08:00
Xiang Li
2e30b3c17f Merge pull request #2130 from xiang90/047-version
server: add internal version
2015-01-22 15:23:38 -08:00
Xiang Li
9a2d82854e server: add internal version 2015-01-22 15:23:15 -08:00
Xiang Li
b077dcf6c4 Merge pull request #2125 from xiang90/047-handler
next-version-handler
2015-01-22 11:40:54 -08:00
Yicheng Qin
2b572cb6e8 Merge pull request #2126 from yichengq/o1
etcd: register usable versions when bootstrap
2015-01-22 11:32:23 -08:00
Xiang Li
f36d55f062 next-version-handler 2015-01-22 11:20:52 -08:00
Yicheng Qin
9f70568a02 etcd: register usable versions when bootstrap 2015-01-22 11:08:58 -08:00
Xiang Li
1ca7d1e064 Merge pull request #2124 from xiang90/047-version
server: add version monitoring
2015-01-22 10:38:27 -08:00
Xiang Li
4f1f003d04 server: add version monitoring 2015-01-22 10:23:15 -08:00
1750 changed files with 98113 additions and 331719 deletions

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.git

5
.gitignore vendored
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@@ -1,11 +1,6 @@
/coverage
/gopath
/go-bindata
/machine*
/bin
.vagrant
*.etcd
/etcd
*.swp
/hack/insta-discovery/.env
*.test

1
.godir
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github.com/coreos/etcd

33
.header
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@@ -1,13 +1,20 @@
// Copyright 2014 CoreOS, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
/*
Copyright 2013 CoreOS Inc.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package x
import (
)

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@@ -1,11 +0,0 @@
language: go
sudo: false
go:
- 1.4
- 1.5
install:
- go get github.com/barakmich/go-nyet
script:
- INTEGRATION=y ./test

87
CHANGELOG Normal file
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v0.4.6
* Fix long-term timer leak (#900, #875, #868, #904)
* Fix `Running` field in standby_info file (#881)
* Add `quorum=true` query parameter for GET requests (#866, #883)
* Add `Access-Control-Allow-Headers` header for CORS requests (#886)
* Various documentation improvements (#907, #882)
v0.4.5
* Flush headers immediatly on `wait=true` requests (#877)
* Add `ETCD_HTTP_READ_TIMEOUT` and `ETCD_HTTP_WRITE_TIMEOUT` (#880)
* Add `ETCDCTL_PEERS` configuration to etcdctl (#95)
* etcdctl takes stdin for mk (#91)
v0.4.4
* Fix `--no-sync` flag in etcdctl (#83)
* Improved logging for machine removal (#844)
* Various documentation improvements (#858, #851, #847)
v0.4.3
* Avoid panic() on truncated or unexpected log data (#834, #833)
* Fix missing stats field (#807)
* Lengthen default peer removal delay to 30mins (#835)
* Reduce logging on heartbeat timeouts (#836)
v0.4.2
* Improvements to the clustering documents
* Set content-type properly on errors (#469)
* Standbys re-join if they should be part of the cluster (#810, #815, #818)
v0.4.1
* Re-introduce DELETE on the machines endpoint
* Document the machines endpoint
v0.4.0
* Introduced standby mode
* Added HEAD requests
* Set logs NOCOW flag when BTRFS is detected to avoid fsync overhead
* Fix all known data races, and pass Go race detector (TODO: re-run race detector)
* Fixed timeouts when using HTTPS
* Improved snapshot stability
* Migration of machine names to new IPs
* Updated peer discovery ordering
v0.3.0
* Add Compare-and-Delete support.
* Added prevNode to response objects.
* Added Discovery API.
* Add tracing and debug endpoints (Documentation/debugging.md).
* Improved logging of cluster events.
* go get github.com/coreos/etcd works.
* info file is no longer used.
* Snapshots are on by default.
* Statistics APIs documented.
v0.2.0
* Support directory creation and removal.
* Add Compare-and-Swap (CAS) support.
* Support recursive GETs.
* Support fully consistent GETs.
* Allow clients to watch specific paths.
* Allow clients to watch for key expiration.
* Unique key generation.
* Support hidden paths.
* Refactor low-level data store.
* Modularize store, server and API code.
* Integrate Gorilla Web Toolkit.
* Add tiered configuration (command line args, env variables, config file).
* Add peer protocol versioning.
* Add rolling upgrade support for future versions.
* Sync key expiration across cluster.
* Significantly improve test coverage.
* Improve migration testing.
* Configurable snapshot count.
* Reduce TCP connection count.
* Fix TCP connection leak.
* Bug Fixes: https://github.com/coreos/etcd/issues?milestone=1&state=closed
Contributors:
* Xiang Li (@xiangli-cmu)
* Ben Johnson (@benbjohnson)
* Brandon Philips (@philips)
* Yifan (@yifan-gu)
* Rob Szumski
* Hongchao Deng (@fengjingchao)
* Kelsey Hightower (@kelseyhightower)
* Adrián (@adrianlzt)
* Antonio Terreno (@aterreno)

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# How to contribute
etcd is Apache 2.0 licensed and accepts contributions via GitHub pull requests. This document outlines some of the conventions on commit message formatting, contact points for developers and other resources to make getting your contribution into etcd easier.
etcd is Apache 2.0 licensed and accepts contributions via Github pull requests. This document outlines some of the conventions on commit message formatting, contact points for developers and other resources to make getting your contribution into etcd easier.
# Email and chat
@@ -12,14 +12,6 @@ etcd is Apache 2.0 licensed and accepts contributions via GitHub pull requests.
- Fork the repository on GitHub
- Read the README.md for build instructions
## Reporting Bugs and Creating Issues
Reporting bugs is one of the best ways to contribute. However, a good bug report
has some very specific qualities, so please read over our short document on
[reporting bugs](https://github.com/coreos/etcd/blob/master/Documentation/reporting_bugs.md)
before you submit your bug report. This document might contain links known
issues, another good reason to take a look there, before reporting your bug.
## Contribution flow
This is a rough outline of what a contributor's workflow looks like:
@@ -29,13 +21,12 @@ This is a rough outline of what a contributor's workflow looks like:
- Make sure your commit messages are in the proper format (see below).
- Push your changes to a topic branch in your fork of the repository.
- Submit a pull request to coreos/etcd.
- Your PR must receive a LGTM from two maintainers found in the MAINTAINERS file.
Thanks for your contributions!
### Code style
The coding style suggested by the Golang community is used in etcd. See the [style doc](https://code.google.com/p/go-wiki/wiki/CodeReviewComments) for details.
The coding style suggested by the Golang community is used in etcd. See [style doc](https://code.google.com/p/go-wiki/wiki/Style) for details.
Please follow this style to make etcd easy to review, maintain and develop.

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FROM golang:onbuild
EXPOSE 4001 7001 2379 2380
FROM ubuntu:12.04
# Let's install go just like Docker (from source).
RUN apt-get update -q
RUN DEBIAN_FRONTEND=noninteractive apt-get install -qy build-essential curl git
RUN curl -s https://storage.googleapis.com/golang/go1.3.src.tar.gz | tar -v -C /usr/local -xz
RUN cd /usr/local/go/src && ./make.bash --no-clean 2>&1
ENV PATH /usr/local/go/bin:$PATH
ADD . /opt/etcd
RUN cd /opt/etcd && ./build
EXPOSE 4001 7001
ENTRYPOINT ["/opt/etcd/bin/etcd"]

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## Snapshot Migration
You can migrate a snapshot of your data from a v0.4.9+ cluster into a new etcd 2.2 cluster using a snapshot migration. After snapshot migration, the etcd indexes of your data will change. Many etcd applications rely on these indexes to behave correctly. This operation should only be done while all etcd applications are stopped.
To get started get the newest data snapshot from the 0.4.9+ cluster:
```
curl http://cluster.example.com:4001/v2/migration/snapshot > backup.snap
```
Now, import the snapshot into your new cluster:
```
etcdctl --endpoint new_cluster.example.com import --snap backup.snap
```
If you have a large amount of data, you can specify more concurrent works to copy data in parallel by using `-c` flag.
If you have hidden keys to copy, you can use `--hidden` flag to specify.
And the data will quickly copy into the new cluster:
```
entering dir: /
entering dir: /foo
entering dir: /foo/bar
copying key: /foo/bar/1 1
entering dir: /
entering dir: /foo2
entering dir: /foo2/bar2
copying key: /foo2/bar2/2 2
```

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## Administration
### Data Directory
#### Lifecycle
When first started, etcd stores its configuration into a data directory specified by the data-dir configuration parameter.
Configuration is stored in the write ahead log and includes: the local member ID, cluster ID, and initial cluster configuration.
The write ahead log and snapshot files are used during member operation and to recover after a restart.
Having a dedicated disk to store wal files can improve the throughput and stabilize the cluster.
It is highly recommended to dedicate a wal disk and set `--wal-dir` to point to a directory on that device for a production cluster deployment.
If a members data directory is ever lost or corrupted then the user should [remove][remove-a-member] the etcd member from the cluster using `etcdctl` tool.
A user should avoid restarting an etcd member with a data directory from an out-of-date backup.
Using an out-of-date data directory can lead to inconsistency as the member had agreed to store information via raft then re-joins saying it needs that information again.
For maximum safety, if an etcd member suffers any sort of data corruption or loss, it must be removed from the cluster.
Once removed the member can be re-added with an empty data directory.
[remove-a-member]: runtime-configuration.md#remove-a-member
#### Contents
The data directory has two sub-directories in it:
1. wal: write ahead log files are stored here. For details see the [wal package documentation][wal-pkg]
2. snap: log snapshots are stored here. For details see the [snap package documentation][snap-pkg]
If `--wal-dir` flag is set, etcd will write the write ahead log files to the specified directory instead of data directory.
[wal-pkg]: http://godoc.org/github.com/coreos/etcd/wal
[snap-pkg]: http://godoc.org/github.com/coreos/etcd/snap
### Cluster Management
#### Lifecycle
If you are spinning up multiple clusters for testing it is recommended that you specify a unique initial-cluster-token for the different clusters.
This can protect you from cluster corruption in case of mis-configuration because two members started with different cluster tokens will refuse members from each other.
#### Monitoring
It is important to monitor your production etcd cluster for healthy information and runtime metrics.
##### Health Monitoring
At lowest level, etcd exposes health information via HTTP at `/health` in JSON format. If it returns `{"health": "true"}`, then the cluster is healthy. Please note the `/health` endpoint is still an experimental one as in etcd 2.2.
```
$ curl -L http://127.0.0.1:2379/health
{"health": "true"}
```
You can also use etcdctl to check the cluster-wide health information. It will contact all the members of the cluster and collect the health information for you.
```
$./etcdctl cluster-health
member 8211f1d0f64f3269 is healthy: got healthy result from http://127.0.0.1:12379
member 91bc3c398fb3c146 is healthy: got healthy result from http://127.0.0.1:22379
member fd422379fda50e48 is healthy: got healthy result from http://127.0.0.1:32379
cluster is healthy
```
##### Runtime Metrics
etcd uses [Prometheus](http://prometheus.io/) for metrics reporting in the server. You can read more through the runtime metrics [doc](metrics.md).
#### Debugging
Debugging a distributed system can be difficult. etcd provides several ways to make debug
easier.
##### Enabling Debug Logging
When you want to debug etcd without stopping it, you can enable debug logging at runtime.
etcd exposes logging configuration at `/config/local/log`.
```
$ curl http://127.0.0.1:2379/config/local/log -XPUT -d '{"Level":"DEBUG"}'
$ # debug logging enabled
$
$ curl http://127.0.0.1:2379/config/local/log -XPUT -d '{"Level":"INFO"}'
$ # debug logging disabled
```
##### Debugging Variables
Debug variables are exposed for real-time debugging purposes. Developers who are familiar with etcd can utilize these variables to debug unexpected behavior. etcd exposes debug variables via HTTP at `/debug/vars` in JSON format. The debug variables contains
`cmdline`, `file_descriptor_limit`, `memstats` and `raft.status`.
`cmdline` is the command line arguments passed into etcd.
`file_descriptor_limit` is the max number of file descriptors etcd can utilize.
`memstats` is well explained [here](http://golang.org/pkg/runtime/#MemStats).
`raft.status` is useful when you want to debug low level raft issues if you are familiar with raft internals. In most cases, you do not need to check `raft.status`.
```json
{
"cmdline": ["./etcd"],
"file_descriptor_limit": 0,
"memstats": {"Alloc":4105744,"TotalAlloc":42337320,"Sys":12560632,"...":"..."},
"raft.status": {"id":"ce2a822cea30bfca","term":5,"vote":"ce2a822cea30bfca","commit":23509,"lead":"ce2a822cea30bfca","raftState":"StateLeader","progress":{"ce2a822cea30bfca":{"match":23509,"next":23510,"state":"ProgressStateProbe"}}}
}
```
#### Optimal Cluster Size
The recommended etcd cluster size is 3, 5 or 7, which is decided by the fault tolerance requirement. A 7-member cluster can provide enough fault tolerance in most cases. While larger cluster provides better fault tolerance the write performance reduces since data needs to be replicated to more machines.
#### Fault Tolerance Table
It is recommended to have an odd number of members in a cluster. Having an odd cluster size doesn't change the number needed for majority, but you gain a higher tolerance for failure by adding the extra member. You can see this in practice when comparing even and odd sized clusters:
| Cluster Size | Majority | Failure Tolerance |
|--------------|------------|-------------------|
| 1 | 1 | 0 |
| 3 | 2 | 1 |
| 4 | 3 | 1 |
| 5 | 3 | **2** |
| 6 | 4 | 2 |
| 7 | 4 | **3** |
| 8 | 5 | 3 |
| 9 | 5 | **4** |
As you can see, adding another member to bring the size of cluster up to an odd size is always worth it. During a network partition, an odd number of members also guarantees that there will almost always be a majority of the cluster that can continue to operate and be the source of truth when the partition ends.
#### Changing Cluster Size
After your cluster is up and running, adding or removing members is done via [runtime reconfiguration](runtime-configuration.md#cluster-reconfiguration-operations), which allows the cluster to be modified without downtime. The `etcdctl` tool has a `member list`, `member add` and `member remove` commands to complete this process.
### Member Migration
When there is a scheduled machine maintenance or retirement, you might want to migrate an etcd member to another machine without losing the data and changing the member ID.
The data directory contains all the data to recover a member to its point-in-time state. To migrate a member:
* Stop the member process
* Copy the data directory of the now-idle member to the new machine
* Update the peer URLs for that member to reflect the new machine according to the [runtime configuration] [change peer url]
* Start etcd on the new machine, using the same configuration and the copy of the data directory
This example will walk you through the process of migrating the infra1 member to a new machine:
|Name|Peer URL|
|------|--------------|
|infra0|10.0.1.10:2380|
|infra1|10.0.1.11:2380|
|infra2|10.0.1.12:2380|
```sh
$ export ETCDCTL_PEERS=http://10.0.1.10:2379,http://10.0.1.11:2379,http://10.0.1.12:2379
```
```sh
$ etcdctl member list
84194f7c5edd8b37: name=infra0 peerURLs=http://10.0.1.10:2380 clientURLs=http://127.0.0.1:2379,http://10.0.1.10:2379
b4db3bf5e495e255: name=infra1 peerURLs=http://10.0.1.11:2380 clientURLs=http://127.0.0.1:2379,http://10.0.1.11:2379
bc1083c870280d44: name=infra2 peerURLs=http://10.0.1.12:2380 clientURLs=http://127.0.0.1:2379,http://10.0.1.12:2379
```
#### Stop the member etcd process
```sh
$ ssh 10.0.1.11
```
```sh
$ kill `pgrep etcd`
```
#### Copy the data directory of the now-idle member to the new machine
```
$ tar -cvzf infra1.etcd.tar.gz %data_dir%
```
```sh
$ scp infra1.etcd.tar.gz 10.0.1.13:~/
```
#### Update the peer URLs for that member to reflect the new machine
```sh
$ curl http://10.0.1.10:2379/v2/members/b4db3bf5e495e255 -XPUT \
-H "Content-Type: application/json" -d '{"peerURLs":["http://10.0.1.13:2380"]}'
```
Or use `etcdctl member update` command
```sh
$ etcdctl member update b4db3bf5e495e255 http://10.0.1.13:2380
```
#### Start etcd on the new machine, using the same configuration and the copy of the data directory
```sh
$ ssh 10.0.1.13
```
```sh
$ tar -xzvf infra1.etcd.tar.gz -C %data_dir%
```
```
etcd -name infra1 \
-listen-peer-urls http://10.0.1.13:2380 \
-listen-client-urls http://10.0.1.13:2379,http://127.0.0.1:2379 \
-advertise-client-urls http://10.0.1.13:2379,http://127.0.0.1:2379
```
[change peer url]: runtime-configuration.md#update-a-member
### Disaster Recovery
etcd is designed to be resilient to machine failures. An etcd cluster can automatically recover from any number of temporary failures (for example, machine reboots), and a cluster of N members can tolerate up to _(N-1)/2_ permanent failures (where a member can no longer access the cluster, due to hardware failure or disk corruption). However, in extreme circumstances, a cluster might permanently lose enough members such that quorum is irrevocably lost. For example, if a three-node cluster suffered two simultaneous and unrecoverable machine failures, it would be normally impossible for the cluster to restore quorum and continue functioning.
To recover from such scenarios, etcd provides functionality to backup and restore the datastore and recreate the cluster without data loss.
#### Backing up the datastore
**NB:** Windows users must stop etcd before running the backup command.
The first step of the recovery is to backup the data directory on a functioning etcd node. To do this, use the `etcdctl backup` command, passing in the original data directory used by etcd. For example:
```sh
etcdctl backup \
--data-dir %data_dir% \
--backup-dir %backup_data_dir%
```
This command will rewrite some of the metadata contained in the backup (specifically, the node ID and cluster ID), which means that the node will lose its former identity. In order to recreate a cluster from the backup, you will need to start a new, single-node cluster. The metadata is rewritten to prevent the new node from inadvertently being joined onto an existing cluster.
#### Restoring a backup
To restore a backup using the procedure created above, start etcd with the `-force-new-cluster` option and pointing to the backup directory. This will initialize a new, single-member cluster with the default advertised peer URLs, but preserve the entire contents of the etcd data store. Continuing from the previous example:
```sh
etcd \
-data-dir=%backup_data_dir% \
-force-new-cluster \
...
```
Now etcd should be available on this node and serving the original datastore.
Once you have verified that etcd has started successfully, shut it down and move the data back to the previous location (you may wish to make another copy as well to be safe):
```sh
pkill etcd
rm -fr %data_dir%
mv %backup_data_dir% %data_dir%
etcd \
-data-dir=%data_dir% \
...
```
#### Restoring the cluster
Now that if the node is running successfully, you should [change its advertised peer URLs](runtime-configuration.md#update-a-member), as the `--force-new-cluster` has set the peer URL to the default (listening on localhost).
You can then add more nodes to the cluster and restore resiliency. See the [add a new member](runtime-configuration.md#add-a-new-member) guide for more details. **NB:** If you are trying to restore your cluster using old failed etcd nodes, please make sure you have stopped old etcd instances and removed their old data directories specified by the data-dir configuration parameter.
### Client Request Timeout
etcd sets different timeouts for various types of client requests. The timeout value is not tunable now, which will be improved soon (https://github.com/coreos/etcd/issues/2038).
#### Get requests
Timeout is not set for get requests, because etcd serves the result locally in a non-blocking way.
**Note**: QuorumGet request is a different type, which is mentioned in the following sections.
#### Watch requests
Timeout is not set for watch requests. etcd will not stop a watch request until client cancels it, or the connection is broken.
#### Delete, Put, Post, QuorumGet requests
The default timeout is 5 seconds. It should be large enough to allow all key modifications if the majority of cluster is functioning.
If the request times out, it indicates two possibilities:
1. the server the request sent to was not functioning at that time.
2. the majority of the cluster is not functioning.
If timeout happens several times continuously, administrators should check status of cluster and resolve it as soon as possible.
### Best Practices
#### Maximum OS threads
By default, etcd uses the default configuration of the Go 1.4 runtime, which means that at most one operating system thread will be used to execute code simultaneously. (Note that this default behavior [may change in Go 1.5](https://docs.google.com/document/d/1At2Ls5_fhJQ59kDK2DFVhFu3g5mATSXqqV5QrxinasI/edit)).
When using etcd in heavy-load scenarios on machines with multiple cores it will usually be desirable to increase the number of threads that etcd can utilize. To do this, simply set the environment variable `GOMAXPROCS` to the desired number when starting etcd. For more information on this variable, see the Go [runtime](https://golang.org/pkg/runtime) documentation.

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# v2 Auth and Security
## etcd Resources
There are three types of resources in etcd
1. permission resources: users and roles in the user store
2. key-value resources: key-value pairs in the key-value store
3. settings resources: security settings, auth settings, and dynamic etcd cluster settings (election/heartbeat)
### Permission Resources
#### Users
A user is an identity to be authenticated. Each user can have multiple roles. The user has a capability (such as reading or writing) on the resource if one of the roles has that capability.
A user named `root` is required before authentication can be enabled, and it always has the ROOT role. The ROOT role can be granted to multiple users, but `root` is required for recovery purposes.
#### Roles
Each role has exact one associated Permission List. An permission list exists for each permission on key-value resources.
The special static ROOT (named `root`) role has a full permissions on all key-value resources, the permission to manage user resources and settings resources. Only the ROOT role has the permission to manage user resources and modify settings resources. The ROOT role is built-in and does not need to be created.
There is also a special GUEST role, named 'guest'. These are the permissions given to unauthenticated requests to etcd. This role will be created automatically, and by default allows access to the full keyspace due to backward compatability. (etcd did not previously authenticate any actions.). This role can be modified by a ROOT role holder at any time, to reduce the capabilities of unauthenticated users.
#### Permissions
There are two types of permissions, `read` and `write`. All management and settings require the ROOT role.
A Permission List is a list of allowed patterns for that particular permission (read or write). Only ALLOW prefixes are supported. DENY becomes more complicated and is TBD.
### Key-Value Resources
A key-value resource is a key-value pairs in the store. Given a list of matching patterns, permission for any given key in a request is granted if any of the patterns in the list match.
Only prefixes or exact keys are supported. A prefix permission string ends in `*`.
A permission on `/foo` is for that exact key or directory, not its children or recursively. `/foo*` is a prefix that matches `/foo` recursively, and all keys thereunder, and keys with that prefix (eg. `/foobar`. Contrast to the prefix `/foo/*`). `*` alone is permission on the full keyspace.
### Settings Resources
Specific settings for the cluster as a whole. This can include adding and removing cluster members, enabling or disabling authentication, replacing certificates, and any other dynamic configuration by the administrator (holder of the ROOT role).
## v2 Auth
### Basic Auth
We only support [Basic Auth](http://en.wikipedia.org/wiki/Basic_access_authentication) for the first version. Client needs to attach the basic auth to the HTTP Authorization Header.
### Authorization field for operations
Added to requests to /v2/keys, /v2/auth
Add code 401 Unauthorized to the set of responses from the v2 API
Authorization: Basic {encoded string}
### Future Work
Other types of auth can be considered for the future (eg, signed certs, public keys) but the `Authorization:` header allows for other such types
### Things out of Scope for etcd Permissions
* Pluggable AUTH backends like LDAP (other Authorization tokens generated by LDAP et al may be a possibility)
* Very fine-grained access controls (eg: users modifying keys outside work hours)
## API endpoints
An Error JSON corresponds to:
{
"name": "ErrErrorName",
"description" : "The longer helpful description of the error."
}
#### Enable and Disable Authentication
**Get auth status**
GET /v2/auth/enable
Sent Headers:
Possible Status Codes:
200 OK
200 Body:
{
"enabled": true
}
**Enable auth**
PUT /v2/auth/enable
Sent Headers:
Put Body: (empty)
Possible Status Codes:
200 OK
400 Bad Request (if root user has not been created)
409 Conflict (already enabled)
200 Body: (empty)
**Disable auth**
DELETE /v2/auth/enable
Sent Headers:
Authorization: Basic <RootAuthString>
Possible Status Codes:
200 OK
401 Unauthorized (if not a root user)
409 Conflict (already disabled)
200 Body: (empty)
#### Users
The User JSON object is formed as follows:
```
{
"user": "userName",
"password": "password",
"roles": [
"role1",
"role2"
],
"grant": [],
"revoke": []
}
```
Password is only passed when necessary.
**Get a list of users**
GET/HEAD /v2/auth/users
Sent Headers:
Authorization: Basic <BasicAuthString>
Possible Status Codes:
200 OK
401 Unauthorized
200 Headers:
Content-type: application/json
200 Body:
{
"users": ["alice", "bob", "eve"]
}
**Get User Details**
GET/HEAD /v2/auth/users/alice
Sent Headers:
Authorization: Basic <BasicAuthString>
Possible Status Codes:
200 OK
401 Unauthorized
404 Not Found
200 Headers:
Content-type: application/json
200 Body:
{
"user" : "alice",
"roles" : ["fleet", "etcd"]
}
**Create Or Update A User**
A user can be created with initial roles, if filled in. However, no roles are required; only the username and password fields
PUT /v2/auth/users/charlie
Sent Headers:
Authorization: Basic <BasicAuthString>
Put Body:
JSON struct, above, matching the appropriate name
* Starting password and roles when creating.
* Grant/Revoke/Password filled in when updating (to grant roles, revoke roles, or change the password).
Possible Status Codes:
200 OK
201 Created
400 Bad Request
401 Unauthorized
404 Not Found (update non-existent users)
409 Conflict (when granting duplicated roles or revoking non-existent roles)
200 Headers:
Content-type: application/json
200 Body:
JSON state of the user
**Remove A User**
DELETE /v2/auth/users/charlie
Sent Headers:
Authorization: Basic <BasicAuthString>
Possible Status Codes:
200 OK
401 Unauthorized
403 Forbidden (remove root user when auth is enabled)
404 Not Found
200 Headers:
200 Body: (empty)
#### Roles
A full role structure may look like this. A Permission List structure is used for the "permissions", "grant", and "revoke" keys.
```
{
"role" : "fleet",
"permissions" : {
"kv" : {
"read" : [ "/fleet/" ],
"write": [ "/fleet/" ]
}
},
"grant" : {"kv": {...}},
"revoke": {"kv": {...}}
}
```
**Get a list of Roles**
GET/HEAD /v2/auth/roles
Sent Headers:
Authorization: Basic <BasicAuthString>
Possible Status Codes:
200 OK
401 Unauthorized
200 Headers:
Content-type: application/json
200 Body:
{
"roles": ["fleet", "etcd", "quay"]
}
**Get Role Details**
GET/HEAD /v2/auth/roles/fleet
Sent Headers:
Authorization: Basic <BasicAuthString>
Possible Status Codes:
200 OK
401 Unauthorized
404 Not Found
200 Headers:
Content-type: application/json
200 Body:
{
"role" : "fleet",
"permissions" : {
"kv" : {
"read": [ "/fleet/" ],
"write": [ "/fleet/" ]
}
}
}
**Create Or Update A Role**
PUT /v2/auth/roles/rkt
Sent Headers:
Authorization: Basic <BasicAuthString>
Put Body:
Initial desired JSON state, including the role name for verification and:
* Starting permission set if creating
* Granted/Revoked permission set if updating
Possible Status Codes:
200 OK
201 Created
400 Bad Request
401 Unauthorized
404 Not Found (update non-existent roles)
409 Conflict (when granting duplicated permission or revoking non-existent permission)
200 Body:
JSON state of the role
**Remove A Role**
DELETE /v2/auth/roles/rkt
Sent Headers:
Authorization: Basic <BasicAuthString>
Possible Status Codes:
200 OK
401 Unauthorized
403 Forbidden (remove root)
404 Not Found
200 Headers:
200 Body: (empty)
## Example Workflow
Let's walk through an example to show two tenants (applications, in our case) using etcd permissions.
### Create root role
```
PUT /v2/auth/users/root
Put Body:
{"user" : "root", "password": "betterRootPW!"}
```
### Enable auth
```
PUT /v2/auth/enable
```
### Modify guest role (revoke write permission)
```
PUT /v2/auth/roles/guest
Headers:
Authorization: Basic <root:betterRootPW!>
Put Body:
{
"role" : "guest",
"revoke" : {
"kv" : {
"write": [
"*"
]
}
}
}
```
### Create Roles for the Applications
Create the rkt role fully specified:
```
PUT /v2/auth/roles/rkt
Headers:
Authorization: Basic <root:betterRootPW!>
Body:
{
"role" : "rkt",
"permissions" : {
"kv": {
"read": [
"/rkt/*"
],
"write": [
"/rkt/*"
]
}
}
}
```
But let's make fleet just a basic role for now:
```
PUT /v2/auth/roles/fleet
Headers:
Authorization: Basic <root:betterRootPW!>
Body:
{
"role" : "fleet"
}
```
### Optional: Grant some permissions to the roles
Well, we finally figured out where we want fleet to live. Let's fix it.
(Note that we avoided this in the rkt case. So this step is optional.)
```
PUT /v2/auth/roles/fleet
Headers:
Authorization: Basic <root:betterRootPW!>
Put Body:
{
"role" : "fleet",
"grant" : {
"kv" : {
"read": [
"/rkt/fleet",
"/fleet/*"
]
}
}
}
```
### Create Users
Same as before, let's use rocket all at once and fleet separately
```
PUT /v2/auth/users/rktuser
Headers:
Authorization: Basic <root:betterRootPW!>
Body:
{"user" : "rktuser", "password" : "rktpw", "roles" : ["rkt"]}
```
```
PUT /v2/auth/users/fleetuser
Headers:
Authorization: Basic <root:betterRootPW!>
Body:
{"user" : "fleetuser", "password" : "fleetpw"}
```
### Optional: Grant Roles to Users
Likewise, let's explicitly grant fleetuser access.
```
PUT /v2/auth/users/fleetuser
Headers:
Authorization: Basic <root:betterRootPW!>
Body:
{"user": "fleetuser", "grant": ["fleet"]}
```
#### Start to use fleetuser and rktuser
For example:
```
PUT /v2/keys/rkt/RktData
Headers:
Authorization: Basic <rktuser:rktpw>
Body:
value=launch
```
Reads and writes outside the prefixes granted will fail with a 401 Unauthorized.

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# Authentication Guide
**NOTE: The authentication feature is considered experimental. We may change workflow without warning in future releases.**
## Overview
Authentication -- having users and roles in etcd -- was added in etcd 2.1. This guide will help you set up basic authentication in etcd.
etcd before 2.1 was a completely open system; anyone with access to the API could change keys. In order to preserve backward compatibility and upgradability, this feature is off by default.
For a full discussion of the RESTful API, see [the authentication API documentation](auth_api.md)
## Special Users and Roles
There is one special user, `root`, and there are two special roles, `root` and `guest`.
### User `root`
User `root` must be created before security can be activated. It has the `root` role and allows for the changing of anything inside etcd. The idea behind the `root` user is for recovery purposes -- a password is generated and stored somewhere -- and the root role is granted to the administrator accounts on the system. In the future, for troubleshooting and recovery, we will need to assume some access to the system, and future documentation will assume this root user (though anyone with the role will suffice).
### Role `root`
Role `root` cannot be modified, but it may be granted to any user. Having access via the root role not only allows global read-write access (as was the case before 2.1) but allows modification of the authentication policy and all administrative things, like modifying the cluster membership.
### Role `guest`
The `guest` role defines the permissions granted to any request that does not provide an authentication. This will be created on security activation (if it doesn't already exist) to have full access to all keys, as was true in etcd 2.0. It may be modified at any time, and cannot be removed.
## Working with users
The `user` subcommand for `etcdctl` handles all things having to do with user accounts.
A listing of users can be found with
```
$ etcdctl user list
```
Creating a user is as easy as
```
$ etcdctl user add myusername
```
And there will be prompt for a new password.
Roles can be granted and revoked for a user with
```
$ etcdctl user grant myusername -roles foo,bar,baz
$ etcdctl user revoke myusername -roles bar,baz
```
We can look at this user with
```
$ etcdctl user get myusername
```
And the password for a user can be changed with
```
$ etcdctl user passwd myusername
```
Which will prompt again for a new password.
To delete an account, there's always
```
$ etcdctl user remove myusername
```
## Working with roles
The `role` subcommand for `etcdctl` handles all things having to do with access controls for particular roles, as were granted to individual users.
A listing of roles can be found with
```
$ etcdctl role list
```
A new role can be created with
```
$ etcdctl role add myrolename
```
A role has no password; we are merely defining a new set of access rights.
Roles are granted access to various parts of the keyspace, a single path at a time.
Reading a path is simple; if the path ends in `*`, that key **and all keys prefixed with it**, are granted to holders of this role. If it does not end in `*`, only that key and that key alone is granted.
Access can be granted as either read, write, or both, as in the following examples:
```
# Give read access to keys under the /foo directory
$ etcdctl role grant myrolename -path '/foo/*' -read
# Give write-only access to the key at /foo/bar
$ etcdctl role grant myrolename -path '/foo/bar' -write
# Give full access to keys under /pub
$ etcdctl role grant myrolename -path '/pub/*' -readwrite
```
Beware that
```
# Give full access to keys under /pub??
$ etcdctl role grant myrolename -path '/pub*' -readwrite
```
Without the slash may include keys under `/publishing`, for example. To do both, grant `/pub` and `/pub/*`
To see what's granted, we can look at the role at any time:
```
$ etcdctl role get myrolename
```
Revocation of permissions is done the same logical way:
```
$ etcdctl role revoke myrolename -path '/foo/bar' -write
```
As is removing a role entirely
```
$ etcdctl role remove myrolename
```
## Enabling authentication
The minimal steps to enabling auth follow. The administrator can set up users and roles before or after enabling authentication, as a matter of preference.
Make sure the root user is created:
```
$ etcdctl user add root
New password:
```
And enable authentication
```
$ etcdctl auth enable
```
After this, etcd is running with authentication enabled. To disable it for any reason, use the reciprocal command:
```
$ etcdctl -u root:rootpw auth disable
```
It would also be good to check what guests (unauthenticated users) are allowed to do:
```
$ etcdctl -u root:rootpw role get guest
```
And modify this role appropriately, depending on your policies.
## Using `etcdctl` to authenticate
`etcdctl` supports a similar flag as `curl` for authentication.
```
$ etcdctl -u user:password get foo
```
or if you prefer to be prompted:
```
$ etcdctl -u user get foo
```
Otherwise, all `etcdctl` commands remain the same. Users and roles can still be created and modified, but require authentication by a user with the root role.

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# Backward Compatibility
The main goal of etcd 2.0 release is to improve cluster safety around bootstrapping and dynamic reconfiguration. To do this, we deprecated the old error-prone APIs and provide a new set of APIs.
The other main focus of this release was a more reliable Raft implementation, but as this change is internal it should not have any notable effects to users.
## Command Line Flags Changes
The major flag changes are to mostly related to bootstrapping. The `initial-*` flags provide an improved way to specify the required criteria to start the cluster. The advertised URLs now support a list of values instead of a single value, which allows etcd users to gracefully migrate to the new set of IANA-assigned ports (2379/client and 2380/peers) while maintaining backward compatibility with the old ports.
- `-addr` is replaced by `-advertise-client-urls`.
- `-bind-addr` is replaced by `-listen-client-urls`.
- `-peer-addr` is replaced by `-initial-advertise-peer-urls`.
- `-peer-bind-addr` is replaced by `-listen-peer-urls`.
- `-peers` is replaced by `-initial-cluster`.
- `-peers-file` is replaced by `-initial-cluster`.
- `-peer-heartbeat-interval` is replaced by `-heartbeat-interval`.
- `-peer-election-timeout` is replaced by `-election-timeout`.
The documentation of new command line flags can be found at
https://github.com/coreos/etcd/blob/master/Documentation/configuration.md.
## Data Directory Naming
The default data dir location has changed from {$hostname}.etcd to {name}.etcd.
## Key-Value API
### Read consistency flag
The consistent flag for read operations is removed in etcd 2.0.0. The normal read operations provides the same consistency guarantees with the 0.4.6 read operations with consistent flag set.
The read consistency guarantees are:
The consistent read guarantees the sequential consistency within one client that talks to one etcd server. Read/Write from one client to one etcd member should be observed in order. If one client write a value to a etcd server successfully, it should be able to get the value out of the server immediately.
Each etcd member will proxy the request to leader and only return the result to user after the result is applied on the local member. Thus after the write succeed, the user is guaranteed to see the value on the member it sent the request to.
Reads do not provide linearizability. If you want linearizable read, you need to set quorum option to true.
**Previous behavior**
We added an option for a consistent read in the old version of etcd since etcd 0.x redirects the write request to the leader. When the user get back the result from the leader, the member it sent the request to originally might not apply the write request yet. With the consistent flag set to true, the client will always send read request to the leader. So one client should be able to see its last write when consistent=true is enabled. There is no order guarantees among different clients.
## Standby
etcd 0.4s standby mode has been deprecated. [Proxy mode][proxymode] is introduced to solve a subset of problems standby was solving.
Standby mode was intended for large clusters that had a subset of the members acting in the consensus process. Overall this process was too magical and allowed for operators to back themselves into a corner.
Proxy mode in 2.0 will provide similar functionality, and with improved control over which machines act as proxies due to the operator specifically configuring them. Proxies also support read only or read/write modes for increased security and durability.
[proxymode]: proxy.md
## Discovery Service
A size key needs to be provided inside a [discovery token][discoverytoken].
[discoverytoken]: clustering.md#custom-etcd-discovery-service
## HTTP Admin API
`v2/admin` on peer url and `v2/keys/_etcd` are unified under the new [v2/member API][memberapi] to better explain which machines are part of an etcd cluster, and to simplify the keyspace for all your use cases.
[memberapi]: other_apis.md
## HTTP Key Value API
- The follower can now transparently proxy write requests to the leader. Clients will no longer see 307 redirections to the leader from etcd.
- Expiration time is in UTC instead of local time.

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# Benchmarks
etcd benchmarks will be published regularly and tracked for each release below:
- [etcd v2.1.0-alpha](./etcd-2-1-0-alpha-benchmarks.md)
- [etcd v2.2.0-rc](./etcd-2-2-0-rc-benchmarks.md)
- [etcd v3 demo](./etcd-3-demo-benchmarks.md)
# Memory Usage Benchmarks
It records expected memory usage in different scenarios.
- [etcd v2.2.0-rc](./etcd-2-2-0-rc-memory-benchmarks.md)

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## Physical machines
GCE n1-highcpu-2 machine type
- 1x dedicated local SSD mounted under /var/lib/etcd
- 1x dedicated slow disk for the OS
- 1.8 GB memory
- 2x CPUs
- etcd version 2.1.0 alpha
## etcd Cluster
3 etcd members, each runs on a single machine
## Testing
Bootstrap another machine and use benchmark tool [boom](https://github.com/rakyll/boom) to send requests to each etcd member.
## Performance
### reading one single key
| key size in bytes | number of clients | target etcd server | read QPS | 90th Percentile Latency (ms) |
|-------------------|-------------------|--------------------|----------|---------------|
| 64 | 1 | leader only | 1534 | 0.7 |
| 64 | 64 | leader only | 10125 | 9.1 |
| 64 | 256 | leader only | 13892 | 27.1 |
| 256 | 1 | leader only | 1530 | 0.8 |
| 256 | 64 | leader only | 10106 | 10.1 |
| 256 | 256 | leader only | 14667 | 27.0 |
| 64 | 64 | all servers | 24200 | 3.9 |
| 64 | 256 | all servers | 33300 | 11.8 |
| 256 | 64 | all servers | 24800 | 3.9 |
| 256 | 256 | all servers | 33000 | 11.5 |
### writing one single key
| key size in bytes | number of clients | target etcd server | write QPS | 90th Percentile Latency (ms) |
|-------------------|-------------------|--------------------|-----------|---------------|
| 64 | 1 | leader only | 60 | 21.4 |
| 64 | 64 | leader only | 1742 | 46.8 |
| 64 | 256 | leader only | 3982 | 90.5 |
| 256 | 1 | leader only | 58 | 20.3 |
| 256 | 64 | leader only | 1770 | 47.8 |
| 256 | 256 | leader only | 4157 | 105.3 |
| 64 | 64 | all servers | 1028 | 123.4 |
| 64 | 256 | all servers | 3260 | 123.8 |
| 256 | 64 | all servers | 1033 | 121.5 |
| 256 | 256 | all servers | 3061 | 119.3 |

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## Physical machines
GCE n1-highcpu-2 machine type
- 1x dedicated local SSD mounted under /var/lib/etcd
- 1x dedicated slow disk for the OS
- 1.8 GB memory
- 2x CPUs
## etcd Cluster
3 etcd 2.2.0-rc members, each runs on a single machine.
Detailed versions:
```
etcd Version: 2.2.0-alpha.1+git
Git SHA: 59a5a7e
Go Version: go1.4.2
Go OS/Arch: linux/amd64
```
Also, we use 3 etcd 2.1.0 alpha-stage members to form cluster to get base performance. etcd's commit head is at [c7146bd5](https://github.com/coreos/etcd/commits/c7146bd5f2c73716091262edc638401bb8229144), which is the same as the one that we use in [etcd 2.1 benchmark](./etcd-2-1-0-benchmarks.md).
## Testing
Bootstrap another machine and use benchmark tool [boom](https://github.com/rakyll/boom) to send requests to each etcd member. Check [here](../../hack/benchmark/) for instructions.
## Performance
### reading one single key
| key size in bytes | number of clients | target etcd server | read QPS | 90th Percentile Latency (ms) |
|-------------------|-------------------|--------------------|----------|---------------|
| 64 | 1 | leader only | 2804 (-5%) | 0.4 (+0%) |
| 64 | 64 | leader only | 17816 (+0%) | 5.7 (-6%) |
| 64 | 256 | leader only | 18667 (-6%) | 20.4 (+2%) |
| 256 | 1 | leader only | 2181 (-15%) | 0.5 (+25%) |
| 256 | 64 | leader only | 17435 (-7%) | 6.0 (+9%) |
| 256 | 256 | leader only | 18180 (-8%) | 21.3 (+3%) |
| 64 | 64 | all servers | 46965 (-4%) | 2.1 (+0%) |
| 64 | 256 | all servers | 55286 (-6%) | 7.4 (+6%) |
| 256 | 64 | all servers | 46603 (-6%) | 2.1 (+5%) |
| 256 | 256 | all servers | 55291 (-6%) | 7.3 (+4%) |
### writing one single key
| key size in bytes | number of clients | target etcd server | write QPS | 90th Percentile Latency (ms) |
|-------------------|-------------------|--------------------|-----------|---------------|
| 64 | 1 | leader only | 76 (+22%) | 19.4 (-15%) |
| 64 | 64 | leader only | 2461 (+45%) | 31.8 (-32%) |
| 64 | 256 | leader only | 4275 (+1%) | 69.6 (-10%) |
| 256 | 1 | leader only | 64 (+20%) | 16.7 (-30%) |
| 256 | 64 | leader only | 2385 (+30%) | 31.5 (-19%) |
| 256 | 256 | leader only | 4353 (-3%) | 74.0 (+9%) |
| 64 | 64 | all servers | 2005 (+81%) | 49.8 (-55%) |
| 64 | 256 | all servers | 4868 (+35%) | 81.5 (-40%) |
| 256 | 64 | all servers | 1925 (+72%) | 47.7 (-59%) |
| 256 | 256 | all servers | 4975 (+36%) | 70.3 (-36%) |
### performance changes explanation
- read QPS in most scenarios is decreased by 5~8%. The reason is that etcd records store metrics for each store operation. The metrics is important for monitoring and debugging, so this is acceptable.
- write QPS to leader is increased by 20~30%. This is because we decouple raft main loop and entry apply loop, which avoids them blocking each other.
- write QPS to all servers is increased by 30~80% because follower could receive latest commit index earlier and commit proposals faster.

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## Physical machine
GCE n1-standard-2 machine type
- 1x dedicated local SSD mounted under /var/lib/etcd
- 1x dedicated slow disk for the OS
- 7.5 GB memory
- 2x CPUs
## etcd
```
etcd Version: 2.2.0-rc.0+git
Git SHA: 103cb5c
Go Version: go1.5
Go OS/Arch: linux/amd64
```
## Testing
Start 3-member etcd cluster, each of which uses 2 cores.
The length of key name is always 64 bytes, which is a reasonable length of average key bytes.
## Memory Maximal Usage
- etcd may use maximal memory if one follower is dead and the leader keeps sending snapshots.
- `max RSS` is the maximal memory usage recorded in 3 runs.
| value bytes | key number | data size(MB) | max RSS(MB) | max RSS/data rate on leader |
|-------------|-------------|---------------|-------------|-----------------------------|
| 128 | 50000 | 6 | 433 | 72x |
| 128 | 100000 | 12 | 659 | 54x |
| 128 | 200000 | 24 | 1466 | 61x |
| 1024 | 50000 | 48 | 1253 | 26x |
| 1024 | 100000 | 96 | 2344 | 24x |
| 1024 | 200000 | 192 | 4361 | 22x |
## Data Size Threshold
- When etcd reaches data size threshold, it may trigger leader election easily and drop part of proposals.
- At most cases, etcd cluster should work smoothly if it doesn't hit the threshold. If it doesn't work well due to insufficient resources, you need to decrease its data size.
| value bytes | key number limitation | suggested data size threshold(MB) | consumed RSS(MB) |
|-------------|-----------------------|-----------------------------------|------------------|
| 128 | 400K | 48 | 2400 |
| 1024 | 300K | 292 | 6500 |

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## Physical machines
GCE n1-highcpu-2 machine type
- 1x dedicated local SSD mounted under /var/lib/etcd
- 1x dedicated slow disk for the OS
- 1.8 GB memory
- 2x CPUs
- etcd version 2.2.0
## etcd Cluster
1 etcd member running in v3 demo mode
## Testing
Use [etcd v3 benchmark tool](../../hack/v3benchmark/).
## Performance
### reading one single key
| key size in bytes | number of clients | read QPS | 90th Percentile Latency (ms) |
|-------------------|-------------------|----------|---------------|
| 256 | 1 | 2716 | 0.4 |
| 256 | 64 | 16623 | 6.1 |
| 256 | 256 | 16622 | 21.7 |
The performance is nearly the same as the one with empty server handler.
### reading one single key after putting
| key size in bytes | number of clients | read QPS | 90th Percentile Latency (ms) |
|-------------------|-------------------|----------|---------------|
| 256 | 1 | 2269 | 0.5 |
| 256 | 64 | 13582 | 8.6 |
| 256 | 256 | 13262 | 47.5 |
The performance with empty server handler is not affected by one put. So the
performance downgrade should be caused by storage package.

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@@ -1,24 +0,0 @@
## Branch Management
### Guide
- New development occurs on the [master branch](https://github.com/coreos/etcd/tree/master)
- Master branch should always have a green build!
- Backwards-compatible bug fixes should target the master branch and subsequently be ported to stable branches
- Once the master branch is ready for release, it will be tagged and become the new stable branch.
The etcd team has adopted a _rolling release model_ and supports one stable version of etcd.
### Master branch
The `master` branch is our development branch. All new features land here first.
If you want to try new features, pull `master` and play with it. Note that `master` may not be stable because new features may introduce bugs.
Before the release of the next stable version, feature PRs will be frozen. We will focus on the testing, bug-fix and documentation for one to two weeks.
### Stable branches
All branches with prefix `release-` are considered _stable_ branches.
After every minor release (http://semver.org/), we will have a new stable branch for that release. We will keep fixing the backwards-compatible bugs for the latest stable release, but not previous releases. The _patch_ release, incorporating any bug fixes, will be once every two weeks, given any patches.

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# Client libraries support matrix for etcd
As etcd features support is really uneven between client libraries, a compatibility matrix can be important.
We will consider in detail only the features of clients supporting the v2 API. Clients still supporting the v1 API *only* are listed below.
## v1-only clients
Clients supporting only the API version 1
- [justinsb/jetcd](https://github.com/justinsb/jetcd) Java
- [transitorykris/etcd-py](https://github.com/transitorykris/etcd-py) Python
- [russellhaering/txetcd](https://github.com/russellhaering/txetcd) Python
- [iconara/etcd-rb](https://github.com/iconara/etcd-rb) Ruby
- [jpfuentes2/etcd-ruby](https://github.com/jpfuentes2/etcd-ruby) Ruby
- [aterreno/etcd-clojure](https://github.com/aterreno/etcd-clojure) Clojure
- [marshall-lee/etcd.erl](https://github.com/marshall-lee/etcd.erl) Erlang
## v2 clients
The v2 API has a lot of features, we will categorize them in a few categories:
- **HTTPS Auth**: Support for SSL-certificate based authentication
- **Reconnect**: If the client is able to reconnect automatically to another server if one fails.
- **Mod/Lock**: Support for the locking module
- **Mod/Leader**: Support for the leader election module
- **GET,PUT,POST,DEL Features**: Support for all the modifiers when calling the etcd server with said HTTP method.
### Supported features matrix
| Client| [go-etcd](https://github.com/coreos/go-etcd) | [jetcd](https://github.com/diwakergupta/jetcd) | [python-etcd](https://github.com/jplana/python-etcd) | [python-etcd-client](https://github.com/dsoprea/PythonEtcdClient) | [node-etcd](https://github.com/stianeikeland/node-etcd) | [nodejs-etcd](https://github.com/lavagetto/nodejs-etcd) | [etcd-ruby](https://github.com/ranjib/etcd-ruby) | [etcd-api](https://github.com/jdarcy/etcd-api) | [cetcd](https://github.com/dwwoelfel/cetcd) | [clj-etcd](https://github.com/rthomas/clj-etcd) | [etcetera](https://github.com/drusellers/etcetera)| [Etcd.jl](https://github.com/forio/Etcd.jl) | [p5-etcd](https://metacpan.org/release/Etcd)
| --- | :---: | :---: | :---: | :---: | :---: | :---: | :---: | :---: | :---: | :---: | :---: | :---: | :---: |
| **HTTPS Auth** | Y | Y | Y | Y | Y | Y | - | - | - | - | - | - | - |
| **Reconnect** | Y | - | Y | Y | - | - | - | Y | - | - | - | - | - |
| **Mod/Lock** | - | - | Y | Y | - | - | - | - | - | - | - | Y | - |
| **Mod/Leader** | - | - | - | Y | - | - | - | - | - | - | - | Y | - |
| **GET Features** | F | B | F | F | F | F | F | B | F | G | F | F | F |
| **PUT Features** | F | B | F | F | F | F | F | G | F | G | F | F | F |
| **POST Features** | F | - | F | F | - | F | F | - | - | - | F | F | F |
| **DEL Features** | F | B | F | F | F | F | F | B | G | B | F | F | F |
**Legend**
**F**: Full support **G**: Good support **B**: Basic support
**Y**: Feature supported **-**: Feature not supported

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# Cluster Discovery
## Overview
Starting an etcd cluster requires that each node knows another in the cluster. If you are trying to bring up a cluster all at once, say using a cloud formation, you also need to coordinate who will be the initial cluster leader. The discovery protocol helps you by providing an automated way to discover other existing peers in a cluster.
For more information on how etcd can locate the cluster, see the [finding the cluster][cluster-finding] documentation.
Please note - at least 3 nodes are required for [cluster availability][optimal-cluster-size].
[cluster-finding]: https://github.com/coreos/etcd/blob/master/Documentation/design/cluster-finding.md
[optimal-cluster-size]: https://github.com/coreos/etcd/blob/master/Documentation/optimal-cluster-size.md
## Using discovery.etcd.io
### Create a Token
To use the discovery API, you must first create a token for your etcd cluster. Visit [https://discovery.etcd.io/new](https://discovery.etcd.io/new) to create a new token.
You can inspect the list of peers by viewing `https://discovery.etcd.io/<token>`.
### Start etcd With the Discovery Flag
Specify the `-discovery` flag when you start each etcd instance. The list of existing peers in the cluster will be downloaded and configured. If the instance is the first peer, it will start as the leader of the cluster.
Here's a full example:
```
TOKEN=$(curl https://discovery.etcd.io/new)
./etcd -name instance1 -peer-addr 10.1.2.3:7001 -addr 10.1.2.3:4001 -discovery $TOKEN
./etcd -name instance2 -peer-addr 10.1.2.4:7001 -addr 10.1.2.4:4001 -discovery $TOKEN
./etcd -name instance3 -peer-addr 10.1.2.5:7001 -addr 10.1.2.5:4001 -discovery $TOKEN
```
## Running Your Own Discovery Endpoint
The discovery API communicates with a separate etcd cluster to store and retrieve the list of peers. CoreOS provides [https://discovery.etcd.io](https://discovery.etcd.io) as a free service, but you can easily run your own etcd cluster for this purpose. Here's an example using an etcd cluster located at `10.10.10.10:4001`:
```
TOKEN="testcluster"
./etcd -name instance1 -peer-addr 10.1.2.3:7001 -addr 10.1.2.3:4001 -discovery http://10.10.10.10:4001/v2/keys/$TOKEN
./etcd -name instance2 -peer-addr 10.1.2.4:7001 -addr 10.1.2.4:4001 -discovery http://10.10.10.10:4001/v2/keys/$TOKEN
./etcd -name instance3 -peer-addr 10.1.2.5:7001 -addr 10.1.2.5:4001 -discovery http://10.10.10.10:4001/v2/keys/$TOKEN
```
If you're interested in how to discovery API works behind the scenes, read about the [Discovery Protocol](https://github.com/coreos/etcd/blob/master/Documentation/discovery-protocol.md).
## Setting Peer Addresses Correctly
The Discovery API submits the `-peer-addr` of each etcd instance to the configured Discovery endpoint. It's important to select an address that *all* peers in the cluster can communicate with. For example, if you're located in two regions of a cloud provider, configuring a private `10.x` address will not work between the two regions, and communication will not be possible between all peers.
## Stale Peers
The discovery API will automatically clean up the address of a stale peer that is no longer part of the cluster. The TTL for this process is a week, which should be long enough to handle any extremely long outage you may encounter. There is no harm in having stale peers in the list until they are cleaned up, since an etcd instance only needs to connect to one valid peer in the cluster to join.
## Lifetime of a Discovery URL
A discovery URL identifies a single etcd cluster. Do not re-use discovery URLs for new clusters.
When a machine starts with a new discovery URL the discovery URL will be activated and record the machine's metadata. If you destroy the whole cluster and attempt to bring the cluster back up with the same discovery URL it will fail. This is intentional because all of the registered machines are gone including their logs so there is nothing to recover the killed cluster.

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# Clustering Guide
## Clustering
## Overview
### Example cluster of three machines
Starting an etcd cluster statically requires that each member knows another in the cluster. In a number of cases, you might not know the IPs of your cluster members ahead of time. In these cases, you can bootstrap an etcd cluster with the help of a discovery service.
Let's explore the use of etcd clustering.
We use Raft as the underlying distributed protocol which provides consistency and persistence of the data across all of the etcd instances.
Once an etcd cluster is up and running, adding or removing members is done via [runtime reconfiguration](runtime-configuration.md). To better understand the design behind runtime reconfiguration, we suggest you read [this](runtime-reconf-design.md).
Let start by creating 3 new etcd instances.
This guide will cover the following mechanisms for bootstrapping an etcd cluster:
We use `-peer-addr` to specify server port and `-addr` to specify client port and `-data-dir` to specify the directory to store the log and info of the machine in the cluster:
* [Static](#static)
* [etcd Discovery](#etcd-discovery)
* [DNS Discovery](#dns-discovery)
```sh
./etcd -peer-addr 127.0.0.1:7001 -addr 127.0.0.1:4001 -data-dir machines/machine1 -name machine1
```
Each of the bootstrapping mechanisms will be used to create a three machine etcd cluster with the following details:
**Note:** If you want to run etcd on an external IP address and still have access locally, you'll need to add `-bind-addr 0.0.0.0` so that it will listen on both external and localhost addresses.
A similar argument `-peer-bind-addr` is used to setup the listening address for the server port.
|Name|Address|Hostname|
|------|---------|------------------|
|infra0|10.0.1.10|infra0.example.com|
|infra1|10.0.1.11|infra1.example.com|
|infra2|10.0.1.12|infra2.example.com|
Let's join two more machines to this cluster using the `-peers` argument. A single connection to any peer will allow a new machine to join, but multiple can be specified for greater resiliency.
## Static
```sh
./etcd -peer-addr 127.0.0.1:7002 -addr 127.0.0.1:4002 -peers 127.0.0.1:7001,127.0.0.1:7003 -data-dir machines/machine2 -name machine2
./etcd -peer-addr 127.0.0.1:7003 -addr 127.0.0.1:4003 -peers 127.0.0.1:7001,127.0.0.1:7002 -data-dir machines/machine3 -name machine3
```
As we know the cluster members, their addresses and the size of the cluster before starting, we can use an offline bootstrap configuration by setting the `initial-cluster` flag. Each machine will get either the following command line or environment variables:
We can retrieve a list of machines in the cluster using the HTTP API:
```sh
curl -L http://127.0.0.1:4001/v2/machines
```
We should see there are three machines in the cluster
```
ETCD_INITIAL_CLUSTER="infra0=http://10.0.1.10:2380,infra1=http://10.0.1.11:2380,infra2=http://10.0.1.12:2380"
ETCD_INITIAL_CLUSTER_STATE=new
http://127.0.0.1:4001, http://127.0.0.1:4002, http://127.0.0.1:4003
```
The machine list is also available via the main key API:
```sh
curl -L http://127.0.0.1:4001/v2/keys/_etcd/machines
```
```json
{
"action": "get",
"node": {
"createdIndex": 1,
"dir": true,
"key": "/_etcd/machines",
"modifiedIndex": 1,
"nodes": [
{
"createdIndex": 1,
"key": "/_etcd/machines/machine1",
"modifiedIndex": 1,
"value": "raft=http://127.0.0.1:7001&etcd=http://127.0.0.1:4001"
},
{
"createdIndex": 2,
"key": "/_etcd/machines/machine2",
"modifiedIndex": 2,
"value": "raft=http://127.0.0.1:7002&etcd=http://127.0.0.1:4002"
},
{
"createdIndex": 3,
"key": "/_etcd/machines/machine3",
"modifiedIndex": 3,
"value": "raft=http://127.0.0.1:7003&etcd=http://127.0.0.1:4003"
}
]
}
}
```
We can also get the current leader in the cluster:
```
curl -L http://127.0.0.1:4001/v2/leader
```
The first server we set up should still be the leader unless it has died during these commands.
```
http://127.0.0.1:7001
```
Now we can do normal SET and GET operations on keys as we explored earlier.
```sh
curl -L http://127.0.0.1:4001/v2/keys/foo -XPUT -d value=bar
```
```json
{
"action": "set",
"node": {
"createdIndex": 4,
"key": "/foo",
"modifiedIndex": 4,
"value": "bar"
}
}
```
### Rejoining to the Cluster
If one machine disconnects from the cluster, it could rejoin the cluster automatically when the communication is recovered.
If one machine is killed, it could rejoin the cluster when started with old name. If the peer address is changed, etcd will treat the new peer address as the refreshed one, which benefits instance migration, or virtual machine boot with different IP. The peer-address-changing functionality is only supported when the majority of the cluster is alive, because this behavior needs the consensus of the etcd cluster.
**Note:** For now, it is user responsibility to ensure that the machine doesn't join the cluster that has the member with the same name. Or unexpected error will happen. It would be improved sooner or later.
### Killing Nodes in the Cluster
Now if we kill the leader of the cluster, we can get the value from one of the other two machines:
```sh
curl -L http://127.0.0.1:4002/v2/keys/foo
```
We can also see that a new leader has been elected:
```
curl -L http://127.0.0.1:4002/v2/leader
```
```
-initial-cluster infra0=http://10.0.1.10:2380,infra1=http://10.0.1.11:2380,infra2=http://10.0.1.12:2380 \
-initial-cluster-state new
http://127.0.0.1:7002
```
Note that the URLs specified in `initial-cluster` are the _advertised peer URLs_, i.e. they should match the value of `initial-advertise-peer-urls` on the respective nodes.
If you are spinning up multiple clusters (or creating and destroying a single cluster) with same configuration for testing purpose, it is highly recommended that you specify a unique `initial-cluster-token` for the different clusters. By doing this, etcd can generate unique cluster IDs and member IDs for the clusters even if they otherwise have the exact same configuration. This can protect you from cross-cluster-interaction, which might corrupt your clusters.
etcd listens on [`listen-client-urls`](configuration.md#-listen-client-urls) to accept client traffic. etcd member advertises the URLs specified in [`advertise-client-urls`](configuration.md#-advertise-client-urls) to other members, proxies, clients. Please make sure the `advertise-client-urls` are reachable from intended clients. A common mistake is setting `advertise-client-urls` to localhost or leave it as default when you want the remote clients to reach etcd.
On each machine you would start etcd with these flags:
or
```
$ etcd -name infra0 -initial-advertise-peer-urls http://10.0.1.10:2380 \
-listen-peer-urls http://10.0.1.10:2380 \
-listen-client-urls http://10.0.1.10:2379,http://127.0.0.1:2379 \
-advertise-client-urls http://10.0.1.10:2379 \
-initial-cluster-token etcd-cluster-1 \
-initial-cluster infra0=http://10.0.1.10:2380,infra1=http://10.0.1.11:2380,infra2=http://10.0.1.12:2380 \
-initial-cluster-state new
```
```
$ etcd -name infra1 -initial-advertise-peer-urls http://10.0.1.11:2380 \
-listen-peer-urls http://10.0.1.11:2380 \
-listen-client-urls http://10.0.1.11:2379,http://127.0.0.1:2379 \
-advertise-client-urls http://10.0.1.11:2379 \
-initial-cluster-token etcd-cluster-1 \
-initial-cluster infra0=http://10.0.1.10:2380,infra1=http://10.0.1.11:2380,infra2=http://10.0.1.12:2380 \
-initial-cluster-state new
```
```
$ etcd -name infra2 -initial-advertise-peer-urls http://10.0.1.12:2380 \
-listen-peer-urls http://10.0.1.12:2380 \
-listen-client-urls http://10.0.1.12:2379,http://127.0.0.1:2379 \
-advertise-client-urls http://10.0.1.12:2379 \
-initial-cluster-token etcd-cluster-1 \
-initial-cluster infra0=http://10.0.1.10:2380,infra1=http://10.0.1.11:2380,infra2=http://10.0.1.12:2380 \
-initial-cluster-state new
http://127.0.0.1:7003
```
The command line parameters starting with `-initial-cluster` will be ignored on subsequent runs of etcd. You are free to remove the environment variables or command line flags after the initial bootstrap process. If you need to make changes to the configuration later (for example, adding or removing members to/from the cluster), see the [runtime configuration](runtime-configuration.md) guide.
### Error Cases
### Testing Persistence
In the following example, we have not included our new host in the list of enumerated nodes. If this is a new cluster, the node _must_ be added to the list of initial cluster members.
Next we'll kill all the machines to test persistence.
Type `CTRL-C` on each terminal and then rerun the same command you used to start each machine.
```
$ etcd -name infra1 -initial-advertise-peer-urls http://10.0.1.11:2380 \
-listen-peer-urls https://10.0.1.11:2380 \
-listen-client-urls http://10.0.1.11:2379,http://127.0.0.1:2379 \
-advertise-client-urls http://10.0.1.11:2379 \
-initial-cluster infra0=http://10.0.1.10:2380 \
-initial-cluster-state new
etcd: infra1 not listed in the initial cluster config
exit 1
Your request for the `foo` key will return the correct value:
```sh
curl -L http://127.0.0.1:4002/v2/keys/foo
```
In this example, we are attempting to map a node (infra0) on a different address (127.0.0.1:2380) than its enumerated address in the cluster list (10.0.1.10:2380). If this node is to listen on multiple addresses, all addresses _must_ be reflected in the "initial-cluster" configuration directive.
```
$ etcd -name infra0 -initial-advertise-peer-urls http://127.0.0.1:2380 \
-listen-peer-urls http://10.0.1.10:2380 \
-listen-client-urls http://10.0.1.10:2379,http://127.0.0.1:2379 \
-advertise-client-urls http://10.0.1.10:2379 \
-initial-cluster infra0=http://10.0.1.10:2380,infra1=http://10.0.1.11:2380,infra2=http://10.0.1.12:2380 \
-initial-cluster-state=new
etcd: error setting up initial cluster: infra0 has different advertised URLs in the cluster and advertised peer URLs list
exit 1
```json
{
"action": "get",
"node": {
"createdIndex": 4,
"key": "/foo",
"modifiedIndex": 4,
"value": "bar"
}
}
```
If you configure a peer with a different set of configuration and attempt to join this cluster you will get a cluster ID mismatch and etcd will exit.
```
$ etcd -name infra3 -initial-advertise-peer-urls http://10.0.1.13:2380 \
-listen-peer-urls http://10.0.1.13:2380 \
-listen-client-urls http://10.0.1.13:2379,http://127.0.0.1:2379 \
-advertise-client-urls http://10.0.1.13:2379 \
-initial-cluster infra0=http://10.0.1.10:2380,infra1=http://10.0.1.11:2380,infra3=http://10.0.1.13:2380 \
-initial-cluster-state=new
etcd: conflicting cluster ID to the target cluster (c6ab534d07e8fcc4 != bc25ea2a74fb18b0). Exiting.
exit 1
```
### Using HTTPS between servers
## Discovery
In the previous example we showed how to use SSL client certs for client-to-server communication.
Etcd can also do internal server-to-server communication using SSL client certs.
To do this just change the `-*-file` flags to `-peer-*-file`.
In a number of cases, you might not know the IPs of your cluster peers ahead of time. This is common when utilizing cloud providers or when your network uses DHCP. In these cases, rather than specifying a static configuration, you can use an existing etcd cluster to bootstrap a new one. We call this process "discovery".
There two methods that can be used for discovery:
* etcd discovery service
* DNS SRV records
### etcd Discovery
To better understand the design about discovery service protocol, we suggest you read [this](./discovery_protocol.md).
#### Lifetime of a Discovery URL
A discovery URL identifies a unique etcd cluster. Instead of reusing a discovery URL, you should always create discovery URLs for new clusters.
Moreover, discovery URLs should ONLY be used for the initial bootstrapping of a cluster. To change cluster membership after the cluster is already running, see the [runtime reconfiguration][runtime] guide.
[runtime]: runtime-configuration.md
#### Custom etcd Discovery Service
Discovery uses an existing cluster to bootstrap itself. If you are using your own etcd cluster you can create a URL like so:
```
$ curl -X PUT https://myetcd.local/v2/keys/discovery/6c007a14875d53d9bf0ef5a6fc0257c817f0fb83/_config/size -d value=3
```
By setting the size key to the URL, you create a discovery URL with an expected cluster size of 3.
If you bootstrap an etcd cluster using discovery service with more than the expected number of etcd members, the extra etcd processes will [fall back][fall-back] to being [proxies][proxy] by default.
The URL you will use in this case will be `https://myetcd.local/v2/keys/discovery/6c007a14875d53d9bf0ef5a6fc0257c817f0fb83` and the etcd members will use the `https://myetcd.local/v2/keys/discovery/6c007a14875d53d9bf0ef5a6fc0257c817f0fb83` directory for registration as they start.
Each member must have a different name flag specified. Or discovery will fail due to duplicated name.
Now we start etcd with those relevant flags for each member:
```
$ etcd -name infra0 -initial-advertise-peer-urls http://10.0.1.10:2380 \
-listen-peer-urls http://10.0.1.10:2380 \
-listen-client-urls http://10.0.1.10:2379,http://127.0.0.1:2379 \
-advertise-client-urls http://10.0.1.10:2379 \
-discovery https://myetcd.local/v2/keys/discovery/6c007a14875d53d9bf0ef5a6fc0257c817f0fb83
```
```
$ etcd -name infra1 -initial-advertise-peer-urls http://10.0.1.11:2380 \
-listen-peer-urls http://10.0.1.11:2380 \
-listen-client-urls http://10.0.1.11:2379,http://127.0.0.1:2379 \
-advertise-client-urls http://10.0.1.11:2379 \
-discovery https://myetcd.local/v2/keys/discovery/6c007a14875d53d9bf0ef5a6fc0257c817f0fb83
```
```
$ etcd -name infra2 -initial-advertise-peer-urls http://10.0.1.12:2380 \
-listen-peer-urls http://10.0.1.12:2380 \
-listen-client-urls http://10.0.1.12:2379,http://127.0.0.1:2379 \
-advertise-client-urls http://10.0.1.12:2379 \
-discovery https://myetcd.local/v2/keys/discovery/6c007a14875d53d9bf0ef5a6fc0257c817f0fb83
```
This will cause each member to register itself with the custom etcd discovery service and begin the cluster once all machines have been registered.
#### Public etcd Discovery Service
If you do not have access to an existing cluster, you can use the public discovery service hosted at `discovery.etcd.io`. You can create a private discovery URL using the "new" endpoint like so:
```
$ curl https://discovery.etcd.io/new?size=3
https://discovery.etcd.io/3e86b59982e49066c5d813af1c2e2579cbf573de
```
This will create the cluster with an initial expected size of 3 members. If you do not specify a size, a default of 3 will be used.
If you bootstrap an etcd cluster using discovery service with more than the expected number of etcd members, the extra etcd processes will [fall back][fall-back] to being [proxies][proxy] by default.
[fall-back]: proxy.md#fallback-to-proxy-mode-with-discovery-service
[proxy]: proxy.md
```
ETCD_DISCOVERY=https://discovery.etcd.io/3e86b59982e49066c5d813af1c2e2579cbf573de
```
```
-discovery https://discovery.etcd.io/3e86b59982e49066c5d813af1c2e2579cbf573de
```
Each member must have a different name flag specified. Or discovery will fail due to duplicated name.
Now we start etcd with those relevant flags for each member:
```
$ etcd -name infra0 -initial-advertise-peer-urls http://10.0.1.10:2380 \
-listen-peer-urls http://10.0.1.10:2380 \
-listen-client-urls http://10.0.1.10:2379,http://127.0.0.1:2379 \
-advertise-client-urls http://10.0.1.10:2379 \
-discovery https://discovery.etcd.io/3e86b59982e49066c5d813af1c2e2579cbf573de
```
```
$ etcd -name infra1 -initial-advertise-peer-urls http://10.0.1.11:2380 \
-listen-peer-urls http://10.0.1.11:2380 \
-listen-client-urls http://10.0.1.11:2379,http://127.0.0.1:2379 \
-advertise-client-urls http://10.0.1.11:2379 \
-discovery https://discovery.etcd.io/3e86b59982e49066c5d813af1c2e2579cbf573de
```
```
$ etcd -name infra2 -initial-advertise-peer-urls http://10.0.1.12:2380 \
-listen-peer-urls http://10.0.1.12:2380 \
-listen-client-urls http://10.0.1.12:2379,http://127.0.0.1:2379 \
-advertise-client-urls http://10.0.1.12:2379 \
-discovery https://discovery.etcd.io/3e86b59982e49066c5d813af1c2e2579cbf573de
```
This will cause each member to register itself with the discovery service and begin the cluster once all members have been registered.
You can use the environment variable `ETCD_DISCOVERY_PROXY` to cause etcd to use an HTTP proxy to connect to the discovery service.
#### Error and Warning Cases
##### Discovery Server Errors
```
$ etcd -name infra0 -initial-advertise-peer-urls http://10.0.1.10:2380 \
-listen-peer-urls http://10.0.1.10:2380 \
-listen-client-urls http://10.0.1.10:2379,http://127.0.0.1:2379 \
-advertise-client-urls http://10.0.1.10:2379 \
-discovery https://discovery.etcd.io/3e86b59982e49066c5d813af1c2e2579cbf573de
etcd: error: the cluster doesnt have a size configuration value in https://discovery.etcd.io/3e86b59982e49066c5d813af1c2e2579cbf573de/_config
exit 1
```
##### User Errors
This error will occur if the discovery cluster already has the configured number of members, and `discovery-fallback` is explicitly disabled
```
$ etcd -name infra0 -initial-advertise-peer-urls http://10.0.1.10:2380 \
-listen-peer-urls http://10.0.1.10:2380 \
-listen-client-urls http://10.0.1.10:2379,http://127.0.0.1:2379 \
-advertise-client-urls http://10.0.1.10:2379 \
-discovery https://discovery.etcd.io/3e86b59982e49066c5d813af1c2e2579cbf573de \
-discovery-fallback exit
etcd: discovery: cluster is full
exit 1
```
##### Warnings
This is a harmless warning notifying you that the discovery URL will be
ignored on this machine.
```
$ etcd -name infra0 -initial-advertise-peer-urls http://10.0.1.10:2380 \
-listen-peer-urls http://10.0.1.10:2380 \
-listen-client-urls http://10.0.1.10:2379,http://127.0.0.1:2379 \
-advertise-client-urls http://10.0.1.10:2379 \
-discovery https://discovery.etcd.io/3e86b59982e49066c5d813af1c2e2579cbf573de
etcdserver: discovery token ignored since a cluster has already been initialized. Valid log found at /var/lib/etcd
```
### DNS Discovery
DNS [SRV records](http://www.ietf.org/rfc/rfc2052.txt) can be used as a discovery mechanism.
The `-discovery-srv` flag can be used to set the DNS domain name where the discovery SRV records can be found.
The following DNS SRV records are looked up in the listed order:
* _etcd-server-ssl._tcp.example.com
* _etcd-server._tcp.example.com
If `_etcd-server-ssl._tcp.example.com` is found then etcd will attempt the bootstrapping process over SSL.
#### Create DNS SRV records
```
$ dig +noall +answer SRV _etcd-server._tcp.example.com
_etcd-server._tcp.example.com. 300 IN SRV 0 0 2380 infra0.example.com.
_etcd-server._tcp.example.com. 300 IN SRV 0 0 2380 infra1.example.com.
_etcd-server._tcp.example.com. 300 IN SRV 0 0 2380 infra2.example.com.
```
```
$ dig +noall +answer infra0.example.com infra1.example.com infra2.example.com
infra0.example.com. 300 IN A 10.0.1.10
infra1.example.com. 300 IN A 10.0.1.11
infra2.example.com. 300 IN A 10.0.1.12
```
#### Bootstrap the etcd cluster using DNS
etcd cluster members can listen on domain names or IP address, the bootstrap process will resolve DNS A records.
The resolved address in `-initial-advertise-peer-urls` *must match* one of the resolved addresses in the SRV targets. The etcd member reads the resolved address to find out if it belongs to the cluster defined in the SRV records.
```
$ etcd -name infra0 \
-discovery-srv example.com \
-initial-advertise-peer-urls http://infra0.example.com:2380 \
-initial-cluster-token etcd-cluster-1 \
-initial-cluster-state new \
-advertise-client-urls http://infra0.example.com:2379 \
-listen-client-urls http://infra0.example.com:2379 \
-listen-peer-urls http://infra0.example.com:2380
```
```
$ etcd -name infra1 \
-discovery-srv example.com \
-initial-advertise-peer-urls http://infra1.example.com:2380 \
-initial-cluster-token etcd-cluster-1 \
-initial-cluster-state new \
-advertise-client-urls http://infra1.example.com:2379 \
-listen-client-urls http://infra1.example.com:2379 \
-listen-peer-urls http://infra1.example.com:2380
```
```
$ etcd -name infra2 \
-discovery-srv example.com \
-initial-advertise-peer-urls http://infra2.example.com:2380 \
-initial-cluster-token etcd-cluster-1 \
-initial-cluster-state new \
-advertise-client-urls http://infra2.example.com:2379 \
-listen-client-urls http://infra2.example.com:2379 \
-listen-peer-urls http://infra2.example.com:2380
```
You can also bootstrap the cluster using IP addresses instead of domain names:
```
$ etcd -name infra0 \
-discovery-srv example.com \
-initial-advertise-peer-urls http://10.0.1.10:2380 \
-initial-cluster-token etcd-cluster-1 \
-initial-cluster-state new \
-advertise-client-urls http://10.0.1.10:2379 \
-listen-client-urls http://10.0.1.10:2379 \
-listen-peer-urls http://10.0.1.10:2380
```
```
$ etcd -name infra1 \
-discovery-srv example.com \
-initial-advertise-peer-urls http://10.0.1.11:2380 \
-initial-cluster-token etcd-cluster-1 \
-initial-cluster-state new \
-advertise-client-urls http://10.0.1.11:2379 \
-listen-client-urls http://10.0.1.11:2379 \
-listen-peer-urls http://10.0.1.11:2380
```
```
$ etcd -name infra2 \
-discovery-srv example.com \
-initial-advertise-peer-urls http://10.0.1.12:2380 \
-initial-cluster-token etcd-cluster-1 \
-initial-cluster-state new \
-advertise-client-urls http://10.0.1.12:2379 \
-listen-client-urls http://10.0.1.12:2379 \
-listen-peer-urls http://10.0.1.12:2380
```
#### etcd proxy configuration
DNS SRV records can also be used to configure the list of peers for an etcd server running in proxy mode:
```
$ etcd --proxy on -discovery-srv example.com
```
#### Error Cases
You might see the an error like `cannot find local etcd $name from SRV records.`. That means the etcd member fails to find itself from the cluster defined in SRV records. The resolved address in `-initial-advertise-peer-urls` *must match* one of the resolved addresses in the SRV targets.
# 0.4 to 2.0+ Migration Guide
In etcd 2.0 we introduced the ability to listen on more than one address and to advertise multiple addresses. This makes using etcd easier when you have complex networking, such as private and public networks on various cloud providers.
To make understanding this feature easier, we changed the naming of some flags, but we support the old flags to make the migration from the old to new version easier.
|Old Flag |New Flag |Migration Behavior |
|-----------------------|-----------------------|---------------------------------------------------------------------------------------|
|-peer-addr |-initial-advertise-peer-urls |If specified, peer-addr will be used as the only peer URL. Error if both flags specified.|
|-addr |-advertise-client-urls |If specified, addr will be used as the only client URL. Error if both flags specified.|
|-peer-bind-addr |-listen-peer-urls |If specified, peer-bind-addr will be used as the only peer bind URL. Error if both flags specified.|
|-bind-addr |-listen-client-urls |If specified, bind-addr will be used as the only client bind URL. Error if both flags specified.|
|-peers |none |Deprecated. The -initial-cluster flag provides a similar concept with different semantics. Please read this guide on cluster startup.|
|-peers-file |none |Deprecated. The -initial-cluster flag provides a similar concept with different semantics. Please read this guide on cluster startup.|
If you are using SSL for server-to-server communication, you must use it on all instances of etcd.

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@@ -1,264 +1,135 @@
## Configuration Flags
# Etcd Configuration
etcd is configurable through command-line flags and environment variables. Options set on the command line take precedence over those from the environment.
## Node Configuration
The format of environment variable for flag `-my-flag` is `ETCD_MY_FLAG`. It applies to all flags.
Individual node configuration options can be set in three places:
To start etcd automatically using custom settings at startup in Linux, using a [systemd][systemd-intro] unit is highly recommended.
1. Command line flags
2. Environment variables
3. Configuration file
[systemd-intro]: http://freedesktop.org/wiki/Software/systemd/
Options set on the command line take precedence over all other sources.
Options set in environment variables take precedence over options set in
configuration files.
### Member Flags
## Cluster Configuration
##### -name
+ Human-readable name for this member.
+ default: "default"
+ env variable: ETCD_NAME
+ This value is referenced as this node's own entries listed in the `-initial-cluster` flag (Ex: `default=http://localhost:2380` or `default=http://localhost:2380,default=http://localhost:7001`). This needs to match the key used in the flag if you're using [static boostrapping](clustering.md#static).
Cluster-wide settings are configured via the `/config` admin endpoint and additionally in the configuration file. Values contained in the configuration file will seed the cluster setting with the provided value. After the cluster is running, only the admin endpoint is used.
##### -data-dir
+ Path to the data directory.
+ default: "${name}.etcd"
+ env variable: ETCD_DATA_DIR
The full documentation is contained in the [API docs](https://github.com/coreos/etcd/blob/master/Documentation/api.md#cluster-config).
##### -wal-dir
+ Path to the dedicated wal directory. If this flag is set, etcd will write the WAL files to the walDir rather than the dataDir. This allows a dedicated disk to be used, and helps avoid io competition between logging and other IO operations.
+ default: ""
+ env variable: ETCD_WAL_DIR
* `activeSize` - the maximum number of peers that can participate in the consensus protocol. Other peers will join as standbys.
* `removeDelay` - the minimum time in seconds that a machine has been observed to be unresponsive before it is removed from the cluster.
* `syncInterval` - the amount of time in seconds between cluster sync when it runs in standby mode.
##### -snapshot-count
+ Number of committed transactions to trigger a snapshot to disk.
+ default: "10000"
+ env variable: ETCD_SNAPSHOT_COUNT
## Command Line Flags
##### -heartbeat-interval
+ Time (in milliseconds) of a heartbeat interval.
+ default: "100"
+ env variable: ETCD_HEARTBEAT_INTERVAL
### Required
##### -election-timeout
+ Time (in milliseconds) for an election to timeout. See [Documentation/tuning.md](tuning.md#time-parameters) for details.
+ default: "1000"
+ env variable: ETCD_ELECTION_TIMEOUT
* `-name` - The node name. Defaults to a UUID.
##### -listen-peer-urls
+ List of URLs to listen on for peer traffic. This flag tells the etcd to accept incoming requests from its peers on the specified scheme://IP:port combinations. Scheme can be either http or https.If 0.0.0.0 is specified as the IP, etcd listens to the given port on all interfaces. If an IP address is given as well as a port, etcd will listen on the given port and interface. Multiple URLs may be used to specify a number of addresses and ports to listen on. The etcd will respond to requests from any of the listed addresses and ports.
+ default: "http://localhost:2380,http://localhost:7001"
+ env variable: ETCD_LISTEN_PEER_URLS
+ example: "http://10.0.0.1:2380"
+ invalid example: "http://example.com:2380" (domain name is invalid for binding)
### Optional
##### -listen-client-urls
+ List of URLs to listen on for client traffic. This flag tells the etcd to accept incoming requests from the clients on the specified scheme://IP:port combinations. Scheme can be either http or https. If 0.0.0.0 is specified as the IP, etcd listens to the given port on all interfaces. If an IP address is given as well as a port, etcd will listen on the given port and interface. Multiple URLs may be used to specify a number of addresses and ports to listen on. The etcd will respond to requests from any of the listed addresses and ports.
+ default: "http://localhost:2379,http://localhost:4001"
+ env variable: ETCD_LISTEN_CLIENT_URLS
+ example: "http://10.0.0.1:2379"
+ invalid example: "http://example.com:2379" (domain name is invalid for binding)
* `-addr` - The advertised public hostname:port for client communication. Defaults to `127.0.0.1:4001`.
* `-discovery` - A URL to use for discovering the peer list. (i.e `"https://discovery.etcd.io/your-unique-key"`).
* `-http-read-timeout` - The number of seconds before an HTTP read operation is timed out.
* `-http-write-timeout` - The number of seconds before an HTTP write operation is timed out.
* `-bind-addr` - The listening hostname for client communication. Defaults to 0.0.0.0 and the advertised port.
* `-peers` - A comma separated list of peers in the cluster (i.e `"203.0.113.101:7001,203.0.113.102:7001"`).
* `-peers-file` - The file path containing a comma separated list of peers in the cluster.
* `-ca-file` - The path of the client CAFile. Enables client cert authentication when present.
* `-cert-file` - The cert file of the client.
* `-key-file` - The key file of the client.
* `-config` - The path of the etcd configuration file. Defaults to `/etc/etcd/etcd.conf`.
* `-cors` - A comma separated white list of origins for cross-origin resource sharing.
* `-cpuprofile` - The path to a file to output CPU profile data. Enables CPU profiling when present.
* `-data-dir` - The directory to store log and snapshot. Defaults to the current working directory.
* `-max-result-buffer` - The max size of result buffer. Defaults to `1024`.
* `-max-retry-attempts` - The max retry attempts when trying to join a cluster. Defaults to `3`.
* `-peer-addr` - The advertised public hostname:port for server communication. Defaults to `127.0.0.1:7001`.
* `-peer-bind-addr` - The listening hostname for server communication. Defaults to 0.0.0.0 and the advertised peer port.
* `-peer-ca-file` - The path of the CAFile. Enables client/peer cert authentication when present.
* `-peer-cert-file` - The cert file of the server.
* `-peer-key-file` - The key file of the server.
* `-peer-election-timeout` - The number of milliseconds to wait before the leader is declared unhealthy.
* `-peer-heartbeat-interval` - The number of milliseconds in between heartbeat requests
* `-snapshot=false` - Disable log snapshots. Defaults to `true`.
* `-cluster-active-size` - The expected number of instances participating in the consensus protocol. Only applied if the etcd instance is the first peer in the cluster.
* `-cluster-remove-delay` - The number of seconds before one node is removed from the cluster since it cannot be connected at all. Only applied if the etcd instance is the first peer in the cluster.
* `-cluster-sync-interval` - The number of seconds between synchronization for standby-mode instance with the cluster. Only applied if the etcd instance is the first peer in the cluster.
* `-v` - Enable verbose logging. Defaults to `false`.
* `-vv` - Enable very verbose logging. Defaults to `false`.
* `-version` - Print the version and exit.
##### -max-snapshots
+ Maximum number of snapshot files to retain (0 is unlimited)
+ default: 5
+ env variable: ETCD_MAX_SNAPSHOTS
+ The default for users on Windows is unlimited, and manual purging down to 5 (or your preference for safety) is recommended.
## Configuration File
##### -max-wals
+ Maximum number of wal files to retain (0 is unlimited)
+ default: 5
+ env variable: ETCD_MAX_WALS
+ The default for users on Windows is unlimited, and manual purging down to 5 (or your preference for safety) is recommended.
The etcd configuration file is written in [TOML](https://github.com/mojombo/toml)
and read from `/etc/etcd/etcd.conf` by default.
##### -cors
+ Comma-separated white list of origins for CORS (cross-origin resource sharing).
+ default: none
+ env variable: ETCD_CORS
```TOML
addr = "127.0.0.1:4001"
bind_addr = "127.0.0.1:4001"
ca_file = ""
cert_file = ""
cors = []
cpu_profile_file = ""
data_dir = "."
discovery = "http://etcd.local:4001/v2/keys/_etcd/registry/examplecluster"
http_read_timeout = 10
http_write_timeout = 10
key_file = ""
peers = []
peers_file = ""
max_cluster_size = 9
max_result_buffer = 1024
max_retry_attempts = 3
name = "default-name"
snapshot = false
verbose = false
very_verbose = false
### Clustering Flags
[peer]
addr = "127.0.0.1:7001"
bind_addr = "127.0.0.1:7001"
ca_file = ""
cert_file = ""
key_file = ""
`-initial` prefix flags are used in bootstrapping ([static bootstrap][build-cluster], [discovery-service bootstrap][discovery] or [runtime reconfiguration][reconfig]) a new member, and ignored when restarting an existing member.
[cluster]
active_size = 9
remove_delay = 1800.0
sync_interval = 5.0
```
`-discovery` prefix flags need to be set when using [discovery service][discovery].
## Environment Variables
##### -initial-advertise-peer-urls
+ List of this member's peer URLs to advertise to the rest of the cluster. These addresses are used for communicating etcd data around the cluster. At least one must be routable to all cluster members. These URLs can contain domain names.
+ default: "http://localhost:2380,http://localhost:7001"
+ env variable: ETCD_INITIAL_ADVERTISE_PEER_URLS
+ example: "http://example.com:2380, http://10.0.0.1:2380"
##### -initial-cluster
+ Initial cluster configuration for bootstrapping.
+ default: "default=http://localhost:2380,default=http://localhost:7001"
+ env variable: ETCD_INITIAL_CLUSTER
+ The key is the value of the `-name` flag for each node provided. The default uses `default` for the key because this is the default for the `-name` flag.
##### -initial-cluster-state
+ Initial cluster state ("new" or "existing"). Set to `new` for all members present during initial static or DNS bootstrapping. If this option is set to `existing`, etcd will attempt to join the existing cluster. If the wrong value is set, etcd will attempt to start but fail safely.
+ default: "new"
+ env variable: ETCD_INITIAL_CLUSTER_STATE
[static bootstrap]: clustering.md#static
##### -initial-cluster-token
+ Initial cluster token for the etcd cluster during bootstrap.
+ default: "etcd-cluster"
+ env variable: ETCD_INITIAL_CLUSTER_TOKEN
##### -advertise-client-urls
+ List of this member's client URLs to advertise to the rest of the cluster. These URLs can contain domain names.
+ default: "http://localhost:2379,http://localhost:4001"
+ env variable: ETCD_ADVERTISE_CLIENT_URLS
+ example: "http://example.com:2379, http://10.0.0.1:2379"
+ Be careful if you are advertising URLs such as http://localhost:2379 from a cluster member and are using the proxy feature of etcd. This will cause loops, because the proxy will be forwarding requests to itself until its resources (memory, file descriptors) are eventually depleted.
##### -discovery
+ Discovery URL used to bootstrap the cluster.
+ default: none
+ env variable: ETCD_DISCOVERY
##### -discovery-srv
+ DNS srv domain used to bootstrap the cluster.
+ default: none
+ env variable: ETCD_DISCOVERY_SRV
##### -discovery-fallback
+ Expected behavior ("exit" or "proxy") when discovery services fails.
+ default: "proxy"
+ env variable: ETCD_DISCOVERY_FALLBACK
##### -discovery-proxy
+ HTTP proxy to use for traffic to discovery service.
+ default: none
+ env variable: ETCD_DISCOVERY_PROXY
### Proxy Flags
`-proxy` prefix flags configures etcd to run in [proxy mode][proxy].
##### -proxy
+ Proxy mode setting ("off", "readonly" or "on").
+ default: "off"
+ env variable: ETCD_PROXY
##### -proxy-failure-wait
+ Time (in milliseconds) an endpoint will be held in a failed state before being reconsidered for proxied requests.
+ default: 5000
+ env variable: ETCD_PROXY_FAILURE_WAIT
##### -proxy-refresh-interval
+ Time (in milliseconds) of the endpoints refresh interval.
+ default: 30000
+ env variable: ETCD_PROXY_REFRESH_INTERVAL
##### -proxy-dial-timeout
+ Time (in milliseconds) for a dial to timeout or 0 to disable the timeout
+ default: 1000
+ env variable: ETCD_PROXY_DIAL_TIMEOUT
##### -proxy-write-timeout
+ Time (in milliseconds) for a write to timeout or 0 to disable the timeout.
+ default: 5000
+ env variable: ETCD_PROXY_WRITE_TIMEOUT
##### -proxy-read-timeout
+ Time (in milliseconds) for a read to timeout or 0 to disable the timeout.
+ Don't change this value if you use watches because they are using long polling requests.
+ default: 0
+ env variable: ETCD_PROXY_READ_TIMEOUT
### Security Flags
The security flags help to [build a secure etcd cluster][security].
##### -ca-file [DEPRECATED]
+ Path to the client server TLS CA file. `-ca-file ca.crt` could be replaced by `-trusted-ca-file ca.crt -client-cert-auth` and etcd will perform the same.
+ default: none
+ env variable: ETCD_CA_FILE
##### -cert-file
+ Path to the client server TLS cert file.
+ default: none
+ env variable: ETCD_CERT_FILE
##### -key-file
+ Path to the client server TLS key file.
+ default: none
+ env variable: ETCD_KEY_FILE
##### -client-cert-auth
+ Enable client cert authentication.
+ default: false
+ env variable: ETCD_CLIENT_CERT_AUTH
##### -trusted-ca-file
+ Path to the client server TLS trusted CA key file.
+ default: none
+ env variable: ETCD_TRUSTED_CA_FILE
##### -peer-ca-file [DEPRECATED]
+ Path to the peer server TLS CA file. `-peer-ca-file ca.crt` could be replaced by `-peer-trusted-ca-file ca.crt -peer-client-cert-auth` and etcd will perform the same.
+ default: none
+ env variable: ETCD_PEER_CA_FILE
##### -peer-cert-file
+ Path to the peer server TLS cert file.
+ default: none
+ env variable: ETCD_PEER_CERT_FILE
##### -peer-key-file
+ Path to the peer server TLS key file.
+ default: none
+ env variable: ETCD_PEER_KEY_FILE
##### -peer-client-cert-auth
+ Enable peer client cert authentication.
+ default: false
+ env variable: ETCD_PEER_CLIENT_CERT_AUTH
##### -peer-trusted-ca-file
+ Path to the peer server TLS trusted CA file.
+ default: none
+ env variable: ETCD_PEER_TRUSTED_CA_FILE
### Logging Flags
##### -debug
+ Drop the default log level to DEBUG for all subpackages.
+ default: false (INFO for all packages)
+ env variable: ETCD_DEBUG
##### -log-package-levels
+ Set individual etcd subpackages to specific log levels. An example being `etcdserver=WARNING,security=DEBUG`
+ default: none (INFO for all packages)
+ env variable: ETCD_LOG_PACKAGE_LEVELS
### Unsafe Flags
Please be CAUTIOUS when using unsafe flags because it will break the guarantees given by the consensus protocol.
For example, it may panic if other members in the cluster are still alive.
Follow the instructions when using these flags.
##### -force-new-cluster
+ Force to create a new one-member cluster. It commits configuration changes in force to remove all existing members in the cluster and add itself. It needs to be set to [restore a backup][restore].
+ default: false
+ env variable: ETCD_FORCE_NEW_CLUSTER
### Experimental Flags
##### -experimental-v3demo
+ Enable experimental [v3 demo API](rfc/v3api.proto).
+ default: false
+ env variable: ETCD_EXPERIMENTAL_V3DEMO
### Miscellaneous Flags
##### -version
+ Print the version and exit.
+ default: false
[build-cluster]: clustering.md#static
[reconfig]: runtime-configuration.md
[discovery]: clustering.md#discovery
[proxy]: proxy.md
[security]: security.md
[restore]: admin_guide.md#restoring-a-backup
* `ETCD_ADDR`
* `ETCD_BIND_ADDR`
* `ETCD_CA_FILE`
* `ETCD_CERT_FILE`
* `ETCD_CORS_ORIGINS`
* `ETCD_CONFIG`
* `ETCD_CPU_PROFILE_FILE`
* `ETCD_DATA_DIR`
* `ETCD_DISCOVERY`
* `ETCD_CLUSTER_HTTP_READ_TIMEOUT`
* `ETCD_CLUSTER_HTTP_WRITE_TIMEOUT`
* `ETCD_KEY_FILE`
* `ETCD_PEERS`
* `ETCD_PEERS_FILE`
* `ETCD_MAX_CLUSTER_SIZE`
* `ETCD_MAX_RESULT_BUFFER`
* `ETCD_MAX_RETRY_ATTEMPTS`
* `ETCD_NAME`
* `ETCD_SNAPSHOT`
* `ETCD_VERBOSE`
* `ETCD_VERY_VERBOSE`
* `ETCD_PEER_ADDR`
* `ETCD_PEER_BIND_ADDR`
* `ETCD_PEER_CA_FILE`
* `ETCD_PEER_CERT_FILE`
* `ETCD_PEER_KEY_FILE`
* `ETCD_PEER_ELECTION_TIMEOUT`
* `ETCD_CLUSTER_ACTIVE_SIZE`
* `ETCD_CLUSTER_REMOVE_DELAY`
* `ETCD_CLUSTER_SYNC_INTERVAL`

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# Debugging etcd
Diagnosing issues in a distributed application is hard.
etcd will help as much as it can - just enable these debug features using the CLI flag `-trace=*` or the config option `trace=*`.
## Logging
Log verbosity can be increased to the max using either the `-vvv` CLI flag or the `very_very_verbose=true` config option.
The only supported logging mode is to stdout.
## Metrics
etcd itself can generate a set of metrics.
These metrics represent many different internal data points that can be helpful when debugging etcd servers.
#### Metrics reference
Each individual metric name is prefixed with `etcd.<NAME>`, where \<NAME\> is the configured name of the etcd server.
* `timer.appendentries.handle`: amount of time a peer takes to process an AppendEntriesRequest from the POV of the peer itself
* `timer.peer.<PEER>.heartbeat`: amount of time a peer heartbeat operation takes from the POV of the leader that initiated that operation for peer \<PEER\>
* `timer.command.<COMMAND>`: amount of time a given command took to be processed through the local server's raft state machine. This does not include time waiting on locks.
#### Fetching metrics over HTTP
Once tracing has been enabled on a given etcd server, all metric data is available at the server's `/debug/metrics` HTTP endpoint (i.e. `http://127.0.0.1:4001/debug/metrics`).
Executing a GET HTTP command against the metrics endpoint will yield the current state of all metrics in the etcd server.
#### Sending metrics to Graphite
etcd supports [Graphite's Carbon plaintext protocol](https://graphite.readthedocs.org/en/latest/feeding-carbon.html#the-plaintext-protocol) - a TCP wire protocol designed for shipping metric data to an aggregator.
To send metrics to a Graphite endpoint using this protocol, use of the `-graphite-host` CLI flag or the `graphite_host` config option (i.e. `graphite_host=172.17.0.19:2003`).
See an [example graphite deploy script](https://github.com/coreos/etcd/contrib/graphite).
#### Generating additional metrics with Collectd
[Collectd](http://collectd.org/documentation.shtml) gathers metrics from the host running etcd.
While these aren't metrics generated by etcd itself, it can be invaluable to compare etcd's view of the world to that of a separate process running next to etcd.
See an [example collectd deploy script](https://github.com/coreos/etcd/contrib/collectd).
## Profiling
etcd exposes profiling information from the Go pprof package over HTTP.
The basic browsable interface is served by etcd at the `/debug/pprof` HTTP endpoint (i.e. `http://127.0.0.1:4001/debug/pprof`).
For more information on using profiling tools, see http://blog.golang.org/profiling-go-programs.
**NOTE**: In the following examples you need to ensure that the `./bin/etcd` is identical to the `./bin/etcd` that you are targeting (same git hash, arch, platform, etc).
#### Heap memory profile
```
go tool pprof ./bin/etcd http://127.0.0.1:4001/debug/pprof/heap
```
#### CPU profile
```
go tool pprof ./bin/etcd http://127.0.0.1:4001/debug/pprof/profile
```
#### Blocked goroutine profile
```
go tool pprof ./bin/etcd http://127.0.0.1:4001/debug/pprof/block
```

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## Cluster Finding Process
Peer discovery uses the following sources in this order: log data in `-data-dir`, `-discovery` and `-peers`.
If log data is provided, etcd will concatenate possible peers from three sources: the log data, the `-discovery` option, and `-peers`. Then it tries to join cluster through them one by one. If all connection attempts fail (which indicates that the majority of the cluster is currently down), it will restart itself based on the log data, which helps the cluster to recover from a full outage.
Without log data, the instance is assumed to be a brand new one. If possible targets are provided by `-discovery` and `-peers`, etcd will make a best effort attempt to join them, and if none is reachable it will exit. Otherwise, if no `-discovery` or `-peers` option is provided, a new cluster will always be started.
This ensures that users can always restart the node safely with the same command (without --force), and etcd will either reconnect to the old cluster if it is still running or recover its cluster from a outage.
## Logical Workflow
Start an etcd machine:
```
If log data is given:
Try to join via peers in previous cluster
Try to join via peers found in discover URL
Try to join via peers in peer list
Restart the previous cluster which is down
return
If discover URL is given:
Fetch peers through discover URL
If Success:
Join via peers found
return
If peer list is given:
Join as follower via peers in peer list
return
Start as the leader of a new cluster
```

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## Standbys
Adding peers in an etcd cluster adds network, CPU, and disk overhead to the leader since each one requires replication.
Peers primarily provide resiliency in the event of a leader failure but the benefit of more failover nodes decreases as the cluster size increases.
A lightweight alternative is the standby.
Standbys are a way for an etcd node to forward requests along to the cluster but the standbys are not part of the Raft cluster themselves.
This provides an easier API for local applications while reducing the overhead required by a regular peer node.
Standbys also act as standby nodes in the event that a peer node in the cluster has not recovered after a long duration.
## Configuration Parameters
There are three configuration parameters used by standbys: active size, remove delay and standby sync interval.
The active size specifies a target size for the number of peers in the cluster.
If there are not enough peers to meet the active size, standbys will send join requests until the peer count is equal to the active size.
If there are more peers than the target active size then peers are removed by the leader and will become standbys.
The remove delay specifies how long the cluster should wait before removing a dead peer.
By default this is 30 minutes.
If a peer is inactive for 30 minutes then the peer is removed.
The standby sync interval specifies the synchronization interval of standbys with the cluster.
By default this is 5 seconds.
After each interval, standbys synchronize information with cluster.
## Logical Workflow
### Start a etcd machine
#### Main logic
```
If find existing standby cluster info:
Goto standby loop
Find cluster as required
If determine to start peer server:
Goto peer loop
Else:
Goto standby loop
Peer loop:
Start peer mode
If running:
Wait for stop
Goto standby loop
Standby loop:
Start standby mode
If running:
Wait for stop
Goto peer loop
```
#### [Cluster finding logic][cluster-finding.md]
#### Join request logic:
```
Fetch machine info
If cannot match version:
return false
If active size <= peer count:
return false
If it has existed in the cluster:
return true
If join request fails:
return false
return true
```
**Note**
1. [TODO] The running mode cannot be determined by log, because the log may be outdated. But the log could be used to estimate its state.
2. Even if sync cluster fails, it will restart still for recovery from full outage.
#### Peer mode start logic
```
Start raft server
Start other helper routines
```
#### Peer mode auto stop logic
```
When removed from the cluster:
Stop raft server
Stop other helper routines
```
#### Standby mode run logic
```
Loop:
Sleep for some time
Sync cluster, and write cluster info into disk
Check active size and send join request if needed
If succeed:
Clear cluster info from disk
Return
```
#### Serve Requests as Standby
Return '404 Page Not Found' always on peer address. This is because peer address is used for raft communication and cluster management, which should not be used in standby mode.
Serve requests from client:
```
Redirect all requests to client URL of leader
```
**Note**
1. The leader here implies the one in raft cluster when doing the latest successful synchronization.
2. [IDEA] We could extend HTTP Redirect to multiple possible targets.
### Join Request Handling
```
If machine has existed in the cluster:
Return
If peer count < active size:
Add peer
Increase peer count
```
### Remove Request Handling
```
If machine exists in the cluster:
Remove peer
Decrease peer count
```
## Cluster Monitor Logic
### Active Size Monitor:
This is only run by current cluster leader.
```
Loop:
Sleep for some time
If peer count > active size:
Remove randomly selected peer
```
### Peer Activity Monitor
This is only run by current cluster leader.
```
Loop:
Sleep for some time
For each peer:
If peer last activity time > remove delay:
Remove the peer
Goto Loop
```
## Cluster Cases
### Create Cluster with Thousands of Instances
First few machines run in peer mode.
All the others check the status of the cluster and run in standby mode.
### Recover from full outage
Machines with log data restart with join failure.
Machines in peer mode recover heartbeat between each other.
Machines in standby mode always sync the cluster. If sync fails, it uses the first address from data log as redirect target.
### Kill one peer machine
Leader of the cluster lose the connection with the peer.
When the time exceeds remove delay, it removes the peer from the cluster.
Machine in standby mode finds one available place of the cluster. It sends join request and joins the cluster.
**Note**
1. [TODO] Machine which was divided from majority and was removed from the cluster will distribute running of the cluster if the new node uses the same name.
### Kill one standby machine
No change for the cluster.
## Cons
1. New instance cannot join immediately after one peer is kicked out of the cluster, because the leader doesn't know the info about the standby instances.
2. It may introduce join collision
3. Cluster needs a good interval setting to balance the join delay and join collision.
## Future Attack Plans
1. Based on heartbeat miss and remove delay, standby could adjust its next check time.
2. Preregister the promotion target when heartbeat miss happens.
3. Get the estimated cluster size from the check happened in the sync interval, and adjust sync interval dynamically.
4. Accept join requests based on active size and alive peers.

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# etcd release guide
The guide talks about how to release a new version of etcd.
The procedure includes some manual steps for sanity checking but it can probably be further scripted. Please keep this document up-to-date if you want to make changes to the release process.
## Prepare Release
Set desired version as environment variable for following steps. Here is an example to release 2.1.3:
```
export VERSION=v2.1.3
export PREV_VERSION=v2.1.2
```
All releases version numbers follow the format of [semantic versioning 2.0.0](http://semver.org/).
### Major, Minor Version Release, or its Pre-release
- Ensure the relevant milestone on GitHub is complete. All referenced issues should be closed, or moved elsewhere.
- Remove this release from [roadmap](https://github.com/coreos/etcd/blob/master/ROADMAP.md), if necessary.
- Ensure the latest upgrade documentation is available.
- Bump [hardcoded MinClusterVerion in the repository](https://github.com/coreos/etcd/blob/master/version/version.go#L29), if necessary.
- Add feature capability maps for the new version, if necessary.
### Patch Version Release
- Discuss about commits that are backported to the patch release. The commits should not include merge commits.
- Cherry-pick these commits starting from the oldest one into stable branch.
## Write Release Note
- Write introduction for the new release. For example, what major bug we fix, what new features we introduce or what performance improvement we make.
- Write changelog for the last release. ChangeLog should be straightforward and easy to understand for the end-user.
- Put `[GH XXXX]` at the head of change line to reference Pull Request that introduces the change. Moreover, add a link on it to jump to the Pull Request.
## Tag Version
- Bump [hardcoded Version in the repository](https://github.com/coreos/etcd/blob/master/version/version.go#L30) to the latest version `${VERSION}`.
- Ensure all tests on CI system are passed.
- Manually check etcd is buildable in Linux, Darwin and Windows.
- Manually check upgrade etcd cluster of previous minor version works well.
- Manually check new features work well.
- Add a signed tag through `git tag -s ${VERSION}`.
- Sanity check tag correctness through `git show tags/$VERSION`.
- Push the tag to GitHub through `git push origin tags/$VERSION`. This assumes `origin` corresponds to "https://github.com/coreos/etcd".
## Build Release Binaries and Images
- Ensure `actool` is available, or installing it through `go get github.com/appc/spec/actool`.
- Ensure `docker` is available.
Run release script in root directory:
```
./scripts/release.sh ${VERSION}
```
It generates all release binaries and images under directory ./release.
## Sign Binaries and Images
Choose appropriate private key to sign the generated binaries and images.
The following commands are used for public release sign:
```
cd release
# personal GPG is okay for now
for i in etcd-*{.zip,.tar.gz}; do gpg --sign ${i}; done
# use `CoreOS ACI Builder <release@coreos.com>` secret key
gpg -u 88182190 -a --output etcd-${VERSION}-linux-amd64.aci.asc --detach-sig etcd-${VERSION}-linux-amd64.aci
```
## Publish Release Page in GitHub
- Set release title as the version name.
- Follow the format of previous release pages.
- Attach the generated binaries, aci image and signatures.
- Select whether it is a pre-release.
- Publish the release!
## Publish Docker Image in Quay.io
- Push docker image:
```
docker login quay.io
docker push quay.io/coreos/etcd:${VERSION}
```
- Add `latest` tag to the new image on [quay.io](https://quay.io/repository/coreos/etcd?tag=latest&tab=tags) if this is a stable release.
## Announce to etcd-dev Googlegroup
- Follow the format of [previous release emails](https://groups.google.com/forum/#!forum/etcd-dev).
- Make sure to include a list of authors that contributed since the previous release - something like the following might be handy:
```
git log ...${PREV_VERSION} --pretty=format:"%an" | sort | uniq | tr '\n' ',' | sed -e 's#,#, #g' -e 's#, $##'
```
- Send email to etcd-dev@googlegroups.com
## Post Release
- Create new stable branch through `git push origin ${VERSION_MAJOR}.${VERSION_MINOR}` if this is a major stable release. This assumes `origin` corresponds to "https://github.com/coreos/etcd".
- Bump [hardcoded Version in the repository](https://github.com/coreos/etcd/blob/master/version/version.go#L30) to the version `${VERSION}+git`.

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# Development tools
## Vagrant
For fast start you can use Vagrant. `vagrant up` will make etcd build and running on virtual machine. Required Vagrant version is 1.5.0.
Next lets set a single key and then retrieve it:
```
curl -L http://127.0.0.1:4001/v2/keys/mykey -XPUT -d value="this is awesome"
curl -L http://127.0.0.1:4001/v2/keys/mykey
```

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# Discovery Protocol
Starting a new etcd cluster can be painful since each machine needs to know of at least one live machine in the cluster. If you are trying to bring up a new cluster all at once, say using an AWS cloud formation, you also need to coordinate who will be the initial cluster leader. The discovery protocol uses an existing running etcd cluster to start a second etcd cluster.
To use this feature you add the command line flag `-discovery` to your etcd args. In this example we will use `http://example.com/v2/keys/_etcd/registry` as the URL prefix.
## The Protocol
By convention the etcd discovery protocol uses the key prefix `_etcd/registry`. A full URL to the keyspace will be `http://example.com/v2/keys/_etcd/registry`.
### Creating a New Cluster
Generate a unique token that will identify the new cluster. This will be used as a key prefix in the following steps. An easy way to do this is to use uuidgen:
```
UUID=$(uuidgen)
```
### Bringing up Machines
Now that you have your cluster ID you can start bringing up machines. Every machine will follow this protocol internally in etcd if given a `-discovery`.
### Registering your Machine
The first thing etcd must do is register your machine. This is done by using the machine name (from the `-name` arg) and posting it with a long TTL to the given key.
```
curl -X PUT "http://example.com/v2/keys/_etcd/registry/${UUID}/${etcd_machine_name}?ttl=604800" -d value=${peer_addr}
```
### Discovering Peers
Now that this etcd machine is registered it must discover its peers.
But, the tricky bit of starting a new cluster is that one machine needs to assume the initial role of leader and will have no peers. To figure out if another machine has already started the cluster etcd needs to create the `_state` key and set its value to "started":
```
curl -X PUT "http://example.com/v2/keys/_etcd/registry/${UUID}/_state?prevExist=false" -d value=started
```
If this returns a `200 OK` response then this machine is the initial leader and should start with no peers configured. If, however, this returns a `412 Precondition Failed` then you need to find all of the registered peers:
```
curl -X GET "http://example.com/v2/keys/_etcd/registry/${UUID}?recursive=true"
```
```
{
"action": "get",
"node": {
"createdIndex": 11,
"dir": true,
"key": "/_etcd/registry/9D4258A5-A1D3-4074-8837-31C1E091131D",
"modifiedIndex": 11,
"nodes": [
{
"createdIndex": 16,
"expiration": "2014-02-03T13:19:57.631253589-08:00",
"key": "/_etcd/registry/9D4258A5-A1D3-4074-8837-31C1E091131D/peer1",
"modifiedIndex": 16,
"ttl": 604765,
"value": "127.0.0.1:7001"
},
{
"createdIndex": 17,
"expiration": "2014-02-03T13:19:57.631253589-08:00",
"key": "/_etcd/registry/9D4258A5-A1D3-4074-8837-31C1E091131D/peer2",
"modifiedIndex": 17,
"ttl": 604765,
"value": "127.0.0.1:7002"
}
]
}
}
```
Using this information you can connect to the rest of the peers in the cluster.
### Heartbeating
At this point etcd will start heart beating to your registration URL. The
protocol uses a heartbeat so permanently deleted nodes get slowly removed from
the discovery information cluster.
The heartbeat interval is about once per day and the TTL is one week. This
should give a sufficiently wide window to protect against a discovery service
taking a temporary outage yet provide adequate cleanup.

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# Discovery Service Protocol
Discovery service protocol helps new etcd member to discover all other members in cluster bootstrap phase using a shared discovery URL.
Discovery service protocol is _only_ used in cluster bootstrap phase, and cannot be used for runtime reconfiguration or cluster monitoring.
The protocol uses a new discovery token to bootstrap one _unique_ etcd cluster. Remember that one discovery token can represent only one etcd cluster. As long as discovery protocol on this token starts, even if fails halfway, it must not be used to bootstrap another etcd cluster.
The rest of this article will walk through the discovery process with examples that correspond to a self-hosted discovery cluster. The public discovery service, discovery.etcd.io, functions the same way, but with a layer of polish to abstract away ugly URLs, generate UUIDs automatically, and provide some protections against excessive requests. At its core, the public discovery service still uses an etcd cluster as the data store as described in this document.
## The Protocol Workflow
The idea of discovery protocol is to use an internal etcd cluster to coordinate bootstrap of a new cluster. First, all new members interact with discovery service and help to generate the expected member list. Then each new member bootstraps its server using this list, which performs the same functionality as -initial-cluster flag.
In the following example workflow, we will list each step of protocol in curl format for ease of understanding.
By convention the etcd discovery protocol uses the key prefix `_etcd/registry`. If `http://example.com` hosts a etcd cluster for discovery service, a full URL to discovery keyspace will be `http://example.com/v2/keys/_etcd/registry`. We will use this as the URL prefix in the example.
### Creating a New Discovery Token
Generate a unique token that will identify the new cluster. This will be used as a unique prefix in discovery keyspace in the following steps. An easy way to do this is to use `uuidgen`:
```
UUID=$(uuidgen)
```
### Specifying the Expected Cluster Size
You need to specify the expected cluster size for this discovery token. The size is used by the discovery service to know when it has found all members that will initially form the cluster.
```
curl -X PUT http://example.com/v2/keys/_etcd/registry/${UUID}/_config/size -d value=${cluster_size}
```
Usually the cluster size is 3, 5 or 7. Check [optimal cluster size](admin_guide.md#optimal-cluster-size) for more details.
### Bringing up etcd Processes
Now that you have your discovery URL, you can use it as `-discovery` flag and bring up etcd processes. Every etcd process will follow this next few steps internally if given a `-discovery` flag.
### Registering itself
The first thing for etcd process is to register itself into the discovery URL as a member. This is done by creating member ID as a key in the discovery URL.
```
curl -X PUT http://example.com/v2/keys/_etcd/registry/${UUID}/${member_id}?prevExist=false -d value="${member_name}=${member_peer_url_1}&${member_name}=${member_peer_url_2}"
```
### Checking the Status
It checks the expected cluster size and registration status in discovery URL, and decides what the next action is.
```
curl -X GET http://example.com/v2/keys/_etcd/registry/${UUID}/_config/size
curl -X GET http://example.com/v2/keys/_etcd/registry/${UUID}
```
If registered members are still not enough, it will wait for left members to appear.
If the number of registered members is bigger than the expected size N, it treats the first N registered members as the member list for the cluster. If the member itself is in the member list, the discovery procedure succeeds and it fetches all peers through the member list. If it is not in the member list, the discovery procedure finishes with the failure that the cluster has been full.
In etcd implementation, the member may check the cluster status even before registering itself. So it could fail quickly if the cluster has been full.
### Waiting for All Members
The wait process is described in details [here](https://github.com/coreos/etcd/blob/master/Documentation/api.md#waiting-for-a-change).
```
curl -X GET http://example.com/v2/keys/_etcd/registry/${UUID}?wait=true&waitIndex=${current_etcd_index}
```
It keeps waiting until finding all members.
## Public Discovery Service
CoreOS Inc. hosts a public discovery service at https://discovery.etcd.io/ , which provides some nice features for ease of use.
### Mask Key Prefix
Public discovery service will redirect `https://discovery.etcd.io/${UUID}` to etcd cluster behind for the key at `/v2/keys/_etcd/registry`. It masks register key prefix for short and readable discovery url.
### Get new token
```
GET /new
Sent query:
size=${cluster_size}
Possible status codes:
200 OK
400 Bad Request
200 Body:
generated discovery url
```
The generation process in the service follows the step from [Creating a New Discovery Token](#creating-a-new-discovery-token) to [Specifying the Expected Cluster Size](#specifying-the-expected-cluster-size).
### Check Discovery Status
```
GET /${UUID}
```
You can check the status for this discovery token, including the machines that have been registered, by requesting the value of the UUID.
### Open-source repository
The repository is located at https://github.com/coreos/discovery.etcd.io. You could use it to build your own public discovery service.

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# Running etcd under Docker
The following guide will show you how to run etcd under Docker using the [static bootstrap process](clustering.md#static).
## Running etcd in standalone mode
In order to expose the etcd API to clients outside of the Docker host you'll need use the host IP address when configuring etcd.
```
export HostIP="192.168.12.50"
```
The following `docker run` command will expose the etcd client API over ports 4001 and 2379, and expose the peer port over 2380.
```
docker run -d -v /usr/share/ca-certificates/:/etc/ssl/certs -p 4001:4001 -p 2380:2380 -p 2379:2379 \
--name etcd quay.io/coreos/etcd:v2.0.8 \
-name etcd0 \
-advertise-client-urls http://${HostIP}:2379,http://${HostIP}:4001 \
-listen-client-urls http://0.0.0.0:2379,http://0.0.0.0:4001 \
-initial-advertise-peer-urls http://${HostIP}:2380 \
-listen-peer-urls http://0.0.0.0:2380 \
-initial-cluster-token etcd-cluster-1 \
-initial-cluster etcd0=http://${HostIP}:2380 \
-initial-cluster-state new
```
Configure etcd clients to use the Docker host IP and one of the listening ports from above.
```
etcdctl -C http://192.168.12.50:2379 member list
```
```
etcdctl -C http://192.168.12.50:4001 member list
```
## Running a 3 node etcd cluster
Using Docker to setup a multi-node cluster is very similar to the standalone mode configuration.
The main difference being the value used for the `-initial-cluster` flag, which must contain the peer urls for each etcd member in the cluster.
### etcd0
```
docker run -d -v /usr/share/ca-certificates/:/etc/ssl/certs -p 4001:4001 -p 2380:2380 -p 2379:2379 \
--name etcd quay.io/coreos/etcd:v2.0.8 \
-name etcd0 \
-advertise-client-urls http://192.168.12.50:2379,http://192.168.12.50:4001 \
-listen-client-urls http://0.0.0.0:2379,http://0.0.0.0:4001 \
-initial-advertise-peer-urls http://192.168.12.50:2380 \
-listen-peer-urls http://0.0.0.0:2380 \
-initial-cluster-token etcd-cluster-1 \
-initial-cluster etcd0=http://192.168.12.50:2380,etcd1=http://192.168.12.51:2380,etcd2=http://192.168.12.52:2380 \
-initial-cluster-state new
```
### etcd1
```
docker run -d -v /usr/share/ca-certificates/:/etc/ssl/certs -p 4001:4001 -p 2380:2380 -p 2379:2379 \
--name etcd quay.io/coreos/etcd:v2.0.8 \
-name etcd1 \
-advertise-client-urls http://192.168.12.51:2379,http://192.168.12.51:4001 \
-listen-client-urls http://0.0.0.0:2379,http://0.0.0.0:4001 \
-initial-advertise-peer-urls http://192.168.12.51:2380 \
-listen-peer-urls http://0.0.0.0:2380 \
-initial-cluster-token etcd-cluster-1 \
-initial-cluster etcd0=http://192.168.12.50:2380,etcd1=http://192.168.12.51:2380,etcd2=http://192.168.12.52:2380 \
-initial-cluster-state new
```
### etcd2
```
docker run -d -v /usr/share/ca-certificates/:/etc/ssl/certs -p 4001:4001 -p 2380:2380 -p 2379:2379 \
--name etcd quay.io/coreos/etcd:v2.0.8 \
-name etcd2 \
-advertise-client-urls http://192.168.12.52:2379,http://192.168.12.52:4001 \
-listen-client-urls http://0.0.0.0:2379,http://0.0.0.0:4001 \
-initial-advertise-peer-urls http://192.168.12.52:2380 \
-listen-peer-urls http://0.0.0.0:2380 \
-initial-cluster-token etcd-cluster-1 \
-initial-cluster etcd0=http://192.168.12.50:2380,etcd1=http://192.168.12.51:2380,etcd2=http://192.168.12.52:2380 \
-initial-cluster-state new
```
Once the cluster has been bootstrapped etcd clients can be configured with a list of etcd members:
```
etcdctl -C http://192.168.12.50:2379,http://192.168.12.51:2379,http://192.168.12.52:2379 member list
```

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Error Code
======
This document describes the error code used in key space '/v2/keys'. Feel free to import 'github.com/coreos/etcd/error' to use.
This document describes the error code in **Etcd** project.
It's categorized into four groups:
- Command Related Error
| name | code | strerror |
|----------------------|------|-----------------------|
| EcodeKeyNotFound | 100 | "Key not found" |
| EcodeTestFailed | 101 | "Compare failed" |
| EcodeNotFile | 102 | "Not a file" |
| EcodeNotDir | 104 | "Not a directory" |
| EcodeNodeExist | 105 | "Key already exists" |
| EcodeRootROnly | 107 | "Root is read only" |
| EcodeDirNotEmpty | 108 | "Directory not empty" |
- Post Form Related Error
| name | code | strerror |
|--------------------------|------|------------------------------------------------|
| EcodePrevValueRequired | 201 | "PrevValue is Required in POST form" |
| EcodeTTLNaN | 202 | "The given TTL in POST form is not a number" |
| EcodeIndexNaN | 203 | "The given index in POST form is not a number" |
| EcodeInvalidField | 209 | "Invalid field" |
| EcodeInvalidForm | 210 | "Invalid POST form" |
- Raft Related Error
| name | code | strerror |
|-------------------|------|--------------------------|
| EcodeRaftInternal | 300 | "Raft Internal Error" |
| EcodeLeaderElect | 301 | "During Leader Election" |
- Etcd Related Error
| name | code | strerror |
|-------------------------|------|--------------------------------------------------------|
| EcodeWatcherCleared | 400 | "watcher is cleared due to etcd recovery" |
| EcodeEventIndexCleared | 401 | "The event in requested index is outdated and cleared" |
Error code corresponding strerror
------
const (
EcodeKeyNotFound = 100
EcodeTestFailed = 101
EcodeNotFile = 102
EcodeNoMorePeer = 103
EcodeNotDir = 104
EcodeNodeExist = 105
EcodeKeyIsPreserved = 106
EcodeRootROnly = 107
EcodeValueRequired = 200
EcodePrevValueRequired = 201
EcodeTTLNaN = 202
EcodeIndexNaN = 203
EcodeRaftInternal = 300
EcodeLeaderElect = 301
EcodeWatcherCleared = 400
EcodeEventIndexCleared = 401
)
// command related errors
errors[100] = "Key Not Found"
errors[101] = "Test Failed" //test and set
errors[102] = "Not A File"
errors[103] = "Reached the max number of peers in the cluster"
errors[104] = "Not A Directory"
errors[105] = "Already exists" // create
errors[106] = "The prefix of given key is a keyword in etcd"
errors[107] = "Root is read only"
// Post form related errors
errors[200] = "Value is Required in POST form"
errors[201] = "PrevValue is Required in POST form"
errors[202] = "The given TTL in POST form is not a number"
errors[203] = "The given index in POST form is not a number"
// raft related errors
errors[300] = "Raft Internal Error"
errors[301] = "During Leader Election"
// etcd related errors
errors[400] = "watcher is cleared due to etcd recovery"
errors[401] = "The event in requested index is outdated and cleared"

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#Etcd File System
## Structure
[TODO]
![alt text](./img/etcd_fs_structure.jpg "etcd file system structure")
## Node
In **etcd**, the **node** is the base from which the filesystem is constructed.
**etcd**'s file system is Unix-like with two kinds of nodes: file and directories.
- A **file node** has data associated with it.
- A **directory node** has child nodes associated with it.
All nodes, regardless of type, have the following attributes and operations:
### Attributes:
- **Expiration Time** [optional]
The node will be deleted when it expires.
- **ACL**
The path to the node's access control list.
### Operation:
- **Get** (path, recursive, sorted)
Get the content of the node
- If the node is a file, the data of the file will be returned.
- If the node is a directory, the child nodes of the directory will be returned.
- If recursive is true, it will recursively get the nodes of the directory.
- If sorted is true, the result will be sorted based on the path.
- **Create** (path, value[optional], ttl [optional])
Create a file. Create operation will help to create intermediate directories with no expiration time.
- If the file already exists, create will fail.
- If the value is given, set will create a file.
- If the value is not given, set will crate a directory.
- If ttl is given, the node will be deleted when it expires.
- **Update** (path, value[optional], ttl [optional])
Update the content of the node.
- If the value is given, the value of the key will be updated.
- If ttl is given, the expiration time of the node will be updated.
- **Delete** (path, recursive)
Delete the node of given path.
- If the node is a directory:
- If recursive is true, the operation will delete all nodes under the directory.
- If recursive is false, error will be returned.
- **TestAndSet** (path, prevValue [prevIndex], value, ttl)
Atomic *test and set* value to a file. If test succeeds, this operation will change the previous value of the file to the given value.
- If the prevValue is given, it will test against previous value of
the node.
- If the prevValue is empty, it will test if the node is not existing.
- If the prevValue is not empty, it will test if the prevValue is equal to the current value of the file.
- If the prevIndex is given, it will test if the create/last modified index of the node is equal to prevIndex.
- **Renew** (path, ttl)
Set the node's expiration time to (current time + ttl)
## ACL
### Theory
Etcd exports a Unix-like file system interface consisting of files and directories, collectively called nodes.
Each node has various meta-data, including three names of the access control lists used to control reading, writing and changing (change ACL names for the node).
We are storing the ACL names for nodes under a special *ACL* directory.
Each node has ACL name corresponding to one file within *ACL* dir.
Unless overridden, a node naturally inherits the ACL names of its parent directory on creation.
For each ACL name, it has three children: *R (Reading)*, *W (Writing)*, *C (Changing)*
Each permission is also a node. Under the node it contains the users who have this permission for the file referring to this ACL name.
### Example
[TODO]
### Diagram
[TODO]
### Interface
Testing permissions:
- (node *Node) get_perm()
- (node *Node) has_perm(perm string, user string)
Setting/Changing permissions:
- (node *Node) set_perm(perm string)
- (node *Node) change_ACLname(aclname string)
## User Group
[TODO]

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@@ -1,80 +0,0 @@
# FAQ
## 1) How come I can read an old version of the data when a majority of the members are down?
In situations where a client connects to a minority, etcd
favors by default availability over consistency. This means that even though
data might be “out of date”, it is still better to return something versus
nothing.
In order to confirm that a read is up to date with a majority of the cluster,
the client can use the `quorum=true` parameter on reads of keys. This means
that a majority of the cluster is checked on reads before returning the data,
otherwise the read will timeout and fail.
## 2) With quorum=false, doesnt this mean that if my client switched the member it was connected to, that it could experience a logical ordering where the cluster goes backwards in time?
Yes, but this could be handled at the etcd client implementation via
remembering the last seen index. The “index” is the cluster's single
irrevocable sequence of the entire modification history. The client could
remember the last seen index, and determine via comparing the index returned on
the GET whether or not the state of the key-value pair is before or after its
last seen state.
## 3) What happens if a watch is registered on a minority member?
The watch will stay untriggered, even as modifications are occurring in the
majority quorum. This is an open issue, and is being addressed in v3. There are
multiple ways to work around the watch trigger not firing.
1) build a signaling mechanism independent of etcd. This could be as simple as
a “pulse” to the client to reissue a GET with quorum=true for the most recent
version of the data.
2) poll on the `/v2/keys` endpoint and check that the raft-index is increasing every
timeout.
## 4) What is a proxy used for?
A proxy is a redirection server to the etcd cluster. The proxy handles the
redirection of a client to the current configuration of the etcd cluster. A
typical usecase is to start a proxy on a machine, and on first boot up of the
proxy specify both the `--proxy` flag and the `--initial-cluster` flag.
From there, any etcdctl client that starts up automatically speaks to the local
proxy and the proxy redirects operations to the current configuration of the
cluster it was originally paired with.
In the v2 spec of etcd, proxies cannot be promoted to members of the cluster.
They also cannot be promoted to followers or at any point become part of the
replication of the etcd cluster itself.
## 5) How is cluster membership and health handled in etcd v2?
The design goal of etcd is that reconfiguration is simply an API, and health
monitoring and addition/removal of members is up to the individual application
and their integration with the reconfiguration API.
Thus, a member that is down, even infinitely, will never be automatically
removed from the etcd cluster member list.
This makes sense because its usually an application level / administrative
action to determine whether a reconfiguration should happen based on health.
For more information, refer to [Documentation/runtime-reconfiguration.md].
## 6) how does --peers work with etcdctl?
The `--peers` flag can specify any number of etcd cluster members in a comma
separated list. This list might be a subset, equal to, or more than the actual
etcd cluster member list itself.
If only one peer is specified via the `--peers` flag, the etcdctl discovers the
rest of the cluster via the member list of that one peer, and then it randomly
chooses a member to use. Again, the client can use the `quorum=true` flag on
reads, which will always fail when using a member in the minority.
If peers from multiple clusters are specified via the `--peers` flag, etcdctl
will randomly choose a peer, and the request will simply get routed to one of
the clusters. This is probably not what you want.

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@@ -1,35 +0,0 @@
## Glossary
This document defines the various terms used in etcd documentation, command line and source code.
### Node
Node is an instance of raft state machine.
It has a unique identification, and records other nodes' progress internally when it is the leader.
### Member
Member is an instance of etcd. It hosts a node, and provides service to clients.
### Cluster
Cluster consists of several members.
The node in each member follows raft consensus protocol to replicate logs. Cluster receives proposals from members, commits them and apply to local store.
### Peer
Peer is another member of the same cluster.
### Proposal
A proposal is a request (for example a write request, a configuration change request) that needs to go through raft protocol.
### Client
Client is a caller of the cluster's HTTP API.
### Machine (deprecated)
The alternative of Member in etcd before 2.0

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# FAQ
## Initial Bootstrapping UX
etcd initial bootstrapping is done via command line flags such as
`--initial-cluster` or `--discovery`. These flags can safely be left on the
command line after your cluster is running but they will be ignored if you have
a non-empty data dir. So, why did we decide to have this sort of odd UX?
One of the design goals of etcd is easy bringup of clusters using a one-shot
static configuration like AWS Cloud Formation, PXE booting, etc. Essentially we
want to describe several virtual machines and bring them all up at once into an
etcd cluster.
To achieve this sort of hands-free cluster bootstrap we had two other options:
**API to bootstrap**
This is problematic because it cannot be coordinated from a single service file
and we didn't want to have the etcd socket listening but unresponsive to
clients for an unbound period of time.
It would look something like this:
```
ExecStart=/usr/bin/etcd
ExecStartPost/usr/bin/etcd init localhost:2379 --cluster=
```
**etcd init subcommand**
```
etcd init --cluster='default=http://localhost:2380,default=http://localhost:7001'...
etcd init --discovery https://discovery-example.etcd.io/193e4
```
Then after running an init step you would execute `etcd`. This however
introduced problems: we now have to define a hand-off protocol between the etcd
init process and the etcd binary itself. This is hard to coordinate in a single
service file such as:
```
ExecStartPre=/usr/bin/etcd init --cluster=....
ExecStart=/usr/bin/etcd
```
There are several error cases:
0) Init has already ran and the data directory is already configured
1) Discovery fails because of network timeout, etc
2) Discovery fails because the cluster is already full and etcd needs to fall back to proxy
3) Static cluster configuration fails because of conflict, misconfiguration or timeout
In hindsight we could have made this work by doing:
```
rc status
0 Init already ran
1 Discovery fails on network timeout, etc
0 Discovery fails for cluster full, coordinate via proxy state file
1 Static cluster configuration failed
```
Perhaps we can add the init command in a future version and deprecate if the UX
continues to confuse people.

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@@ -3,13 +3,8 @@
**Tools**
- [etcdctl](https://github.com/coreos/etcdctl) - A command line client for etcd
- [etcd-backup](https://github.com/fanhattan/etcd-backup) - A powerful command line utility for dumping/restoring etcd - Supports v2
- [etcd-dump](https://npmjs.org/package/etcd-dump) - Command line utility for dumping/restoring etcd.
- [etcd-fs](https://github.com/xetorthio/etcd-fs) - FUSE filesystem for etcd
- [etcd-browser](https://github.com/henszey/etcd-browser) - A web-based key/value editor for etcd using AngularJS
- [etcd-lock](https://github.com/datawisesystems/etcd-lock) - Master election & distributed r/w lock implementation using etcd - Supports v2
- [etcd-console](https://github.com/matishsiao/etcd-console) - A web-base key/value editor for etcd using PHP
- [etcd-viewer](https://github.com/nikfoundas/etcd-viewer) - An etcd key-value store editor/viewer written in Java
**Go libraries**
@@ -17,24 +12,19 @@
**Java libraries**
- [boonproject/etcd](https://github.com/boonproject/boon/blob/master/etcd/README.md) - Supports v2, Async/Sync and waits
- [justinsb/jetcd](https://github.com/justinsb/jetcd)
- [diwakergupta/jetcd](https://github.com/diwakergupta/jetcd) - Supports v2
- [jurmous/etcd4j](https://github.com/jurmous/etcd4j) - Supports v2, Async/Sync, waits and SSL
- [AdoHe/etcd4j](http://github.com/AdoHe/etcd4j) - Supports v2 (enhance for real production cluster)
**Python libraries**
- [jplana/python-etcd](https://github.com/jplana/python-etcd) - Supports v2
- [russellhaering/txetcd](https://github.com/russellhaering/txetcd) - a Twisted Python library
- [cholcombe973/autodock](https://github.com/cholcombe973/autodock) - A docker deployment automation tool
- [lisael/aioetcd](https://github.com/lisael/aioetcd) - (Python 3.4+) Asyncio coroutines client (Supports v2)
**Node libraries**
- [stianeikeland/node-etcd](https://github.com/stianeikeland/node-etcd) - Supports v2 (w Coffeescript)
- [lavagetto/nodejs-etcd](https://github.com/lavagetto/nodejs-etcd) - Supports v2
- [deedubs/node-etcd-config](https://github.com/deedubs/node-etcd-config) - Supports v2
**Ruby libraries**
@@ -45,10 +35,6 @@
**C libraries**
- [jdarcy/etcd-api](https://github.com/jdarcy/etcd-api) - Supports v2
- [shafreeck/cetcd](https://github.com/shafreeck/cetcd) - Supports v2
**C++ libraries**
- [edwardcapriolo/etcdcpp](https://github.com/edwardcapriolo/etcdcpp) - Supports v2
**Clojure libraries**
@@ -72,14 +58,6 @@
- [wereHamster/etcd-hs](https://github.com/wereHamster/etcd-hs)
**R libraries**
- [ropensci/etseed](https://github.com/ropensci/etseed)
**Tcl libraries**
- [efrecon/etcd-tcl](https://github.com/efrecon/etcd-tcl) - Supports v2, except wait.
A detailed recap of client functionalities can be found in the [clients compatibility matrix][clients-matrix.md].
[clients-matrix.md]: https://github.com/coreos/etcd/blob/master/Documentation/clients-matrix.md
@@ -114,8 +92,3 @@ A detailed recap of client functionalities can be found in the [clients compatib
- [GoogleCloudPlatform/kubernetes](https://github.com/GoogleCloudPlatform/kubernetes) - Container cluster manager.
- [mailgun/vulcand](https://github.com/mailgun/vulcand) - HTTP proxy that uses etcd as a configuration backend.
- [duedil-ltd/discodns](https://github.com/duedil-ltd/discodns) - Simple DNS nameserver using etcd as a database for names and records.
- [skynetservices/skydns](https://github.com/skynetservices/skydns) - RFC compliant DNS server
- [xordataexchange/crypt](https://github.com/xordataexchange/crypt) - Securely store values in etcd using GPG encryption
- [spf13/viper](https://github.com/spf13/viper) - Go configuration library, reads values from ENV, pflags, files, and etcd with optional encryption
- [lytics/metafora](https://github.com/lytics/metafora) - Go distributed task library
- [ryandoyle/nss-etcd](https://github.com/ryandoyle/nss-etcd) - A GNU libc NSS module for resolving names from etcd.

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## Metrics
**NOTE: The metrics feature is considered as an experimental. We might add/change/remove metrics without warning in the future releases.**
etcd uses [Prometheus](http://prometheus.io/) for metrics reporting in the server. The metrics can be used for real-time monitoring and debugging.
The simplest way to see the available metrics is to cURL the metrics endpoint `/metrics` of etcd. The format is described [here](http://prometheus.io/docs/instrumenting/exposition_formats/).
You can also follow the doc [here](http://prometheus.io/docs/introduction/getting_started/) to start a Promethus server and monitor etcd metrics.
The naming of metrics follows the suggested [best practice of Promethus](http://prometheus.io/docs/practices/naming/). A metric name has an `etcd` prefix as its namespace and a subsystem prefix (for example `wal` and `etcdserver`).
etcd now exposes the following metrics:
### etcdserver
| Name | Description | Type |
|-----------------------------------------|--------------------------------------------------|---------|
| file_descriptors_used_total | The total number of file descriptors used | Gauge |
| proposal_durations_milliseconds | The latency distributions of committing proposal | Summary |
| pending_proposal_total | The total number of pending proposals | Gauge |
| proposal_failed_total | The total number of failed proposals | Counter |
High file descriptors (`file_descriptors_used_total`) usage (near the file descriptors limitation of the process) indicates a potential out of file descriptors issue. That might cause etcd fails to create new WAL files and panics.
[Proposal](glossary.md#proposal) durations (`proposal_durations_milliseconds`) give you an summary about the proposal commit latency. Latency can be introduced into this process by network and disk IO.
Pending proposal (`pending_proposal_total`) gives you an idea about how many proposal are in the queue and waiting for commit. An increasing pending number indicates a high client load or an unstable cluster.
Failed proposals (`proposal_failed_total`) are normally related to two issues: temporary failures related to a leader election or longer duration downtime caused by a loss of quorum in the cluster.
### store
These metrics describe the accesses into the data store of etcd members that exist in the cluster. They
are useful to count what kind of actions are taken by users. It is also useful to see and whether all etcd members
"see" the same set of data mutations, and whether reads and watches (which are local) are equally distributed.
All these metrics are prefixed with `etcd_store_`.
| Name | Description | Type |
|---------------------------|------------------------------------------------------------------------------------------|--------------------|
| reads_total | Total number of reads from store, should differ among etcd members (local reads). | Counter(action) |
| writes_total | Total number of writes to store, should be same among all etcd members. | Counter(action) |
| reads_failed_total | Number of failed reads from store (e.g. key missing) on local reads. | Counter(action) |
| writes_failed_total | Number of failed writes to store (e.g. failed compare and swap). | Counter(action) |
| expires_total | Total number of expired keys (due to TTL).   | Counter |
| watch_requests_totals | Total number of incoming watch requests to this etcd member (local watches). | Counter |
| watchers | Current count of active watchers on this etcd member. | Gauge |
Both `reads_total` and `writes_total` count both successful and failed requests. `reads_failed_total` and
`writes_failed_total` count failed requests. A lot of failed writes indicate possible contentions on keys (e.g. when
doing `compareAndSet`), and read failures indicate that some clients try to access keys that don't exist.
Example Prometheus queries that may be useful from these metrics (across all etcd members):
* `sum(rate(etcd_store_reads_total{job="etcd"}[1m])) by (action)`
`max(rate(etcd_store_writes_total{job="etcd"}[1m])) by (action)`
Rate of reads and writes by action, across all servers across a time window of `1m`. The reason why `max` is used
for writes as opposed to `sum` for reads is because all of etcd nodes in the cluster apply all writes to their stores.
Shows the rate of successfull readonly/write queries across all servers, across a time window of `1m`.
* `sum(rate(etcd_store_watch_requests_total{job="etcd"}[1m]))`
Shows rate of new watch requests per second. Likely driven by how often watched keys change.
* `sum(etcd_store_watchers{job="etcd"})`
Number of active watchers across all etcd servers.
### wal
| Name | Description | Type |
|------------------------------------|--------------------------------------------------|---------|
| fsync_durations_microseconds | The latency distributions of fsync called by wal | Summary |
| last_index_saved | The index of the last entry saved by wal | Gauge |
Abnormally high fsync duration (`fsync_durations_microseconds`) indicates disk issues and might cause the cluster to be unstable.
### snapshot
| Name | Description | Type |
|--------------------------------------------|------------------------------------------------------------|---------|
| snapshot_save_total_durations_microseconds | The total latency distributions of save called by snapshot | Summary |
Abnormally high snapshot duration (`snapshot_save_total_durations_microseconds`) indicates disk issues and might cause the cluster to be unstable.
### rafthttp
| Name | Description | Type | Labels |
|-----------------------------------|--------------------------------------------|---------|--------------------------------|
| message_sent_latency_microseconds | The latency distributions of messages sent | Summary | sendingType, msgType, remoteID |
| message_sent_failed_total | The total number of failed messages sent | Summary | sendingType, msgType, remoteID |
Abnormally high message duration (`message_sent_latency_microseconds`) indicates network issues and might cause the cluster to be unstable.
An increase in message failures (`message_sent_failed_total`) indicates more severe network issues and might cause the cluster to be unstable.
Label `sendingType` is the connection type to send messages. `message`, `msgapp` and `msgappv2` use HTTP streaming, while `pipeline` does HTTP request for each message.
Label `msgType` is the type of raft message. `MsgApp` is log replication message; `MsgSnap` is snapshot install message; `MsgProp` is proposal forward message; the others are used to maintain raft internal status. If you have a large snapshot, you would expect a long msgSnap sending latency. For other types of messages, you would expect low latency, which is comparable to your ping latency if you have enough network bandwidth.
Label `remoteID` is the member ID of the message destination.
### proxy
etcd members operating in proxy mode do not do store operations. They forward all requests
to cluster instances.
Tracking the rate of requests coming from a proxy allows one to pin down which machine is performing most reads/writes.
All these metrics are prefixed with `etcd_proxy_`
| Name | Description | Type |
|---------------------------|-----------------------------------------------------------------------------------------|--------------------|
| requests_total | Total number of requests by this proxy instance. . | Counter(method) |
| handled_total | Total number of fully handled requests, with responses from etcd members. | Counter(method) |
| dropped_total | Total number of dropped requests due to forwarding errors to etcd members.  | Counter(method,error) |
| handling_duration_seconds | Bucketed handling times by HTTP method, including round trip to member instances. | Histogram(method) |
Example Prometheus queries that may be useful from these metrics (across all etcd servers):
* `sum(rate(etcd_proxy_handled_total{job="etcd"}[1m])) by (method)`
Rate of requests (by HTTP method) handled by all proxies, across a window of `1m`.
* `histogram_quantile(0.9, sum(increase(etcd_proxy_events_handling_time_seconds_bucket{job="etcd",method="GET"}[5m])) by (le))`
`histogram_quantile(0.9, sum(increase(etcd_proxy_events_handling_time_seconds_bucket{job="etcd",method!="GET"}[5m])) by (le))`
Show the 0.90-tile latency (in seconds) of handling of user requestsacross all proxy machines, with a window of `5m`.
* `sum(rate(etcd_proxy_dropped_total{job="etcd"}[1m])) by (proxying_error)`
Number of failed request on the proxy. This should be 0, spikes here indicate connectivity issues to etcd cluster.

118
Documentation/modules.md Normal file
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## Modules
etcd has a number of modules that are built on top of the core etcd API.
These modules provide things like dashboards, locks and leader election (removed).
**Warning**: Modules are deprecated from v0.4 until we have a solid base we can apply them back onto.
For now, we are choosing to focus on raft algorithm and core etcd to make sure that it works correctly and fast.
And it is time consuming to maintain these modules in this period, given that etcd's API changes from time to time.
Moreover, the lock module has some unfixed bugs, which may mislead users.
But we also notice that these modules are popular and useful, and plan to add them back with full functionality as soon as possible.
### Dashboard
An HTML dashboard can be found at `http://127.0.0.1:4001/mod/dashboard/`.
This dashboard is compiled into the etcd binary and uses the same API as regular etcd clients.
Use the `-cors='*'` flag to allow your browser to request information from the current master as it changes.
### Lock
The Lock module implements a fair lock that can be used when lots of clients want access to a single resource.
A lock can be associated with a value.
The value is unique so if a lock tries to request a value that is already queued for a lock then it will find it and watch until that value obtains the lock.
You may supply a `timeout` which will cancel the lock request if it is not obtained within `timeout` seconds. If `timeout` is not supplied, it is presumed to be infinite. If `timeout` is `0`, the lock request will fail if it is not immediately acquired.
If you lock the same value on a key from two separate curl sessions they'll both return at the same time.
Here's the API:
**Acquire a lock (with no value) for "customer1"**
```sh
curl -X POST http://127.0.0.1:4001/mod/v2/lock/customer1?ttl=60
```
**Acquire a lock for "customer1" that is associated with the value "bar"**
```sh
curl -X POST http://127.0.0.1:4001/mod/v2/lock/customer1?ttl=60 -d value=bar
```
**Acquire a lock for "customer1" that is associated with the value "bar" only if it is done within 2 seconds**
```sh
curl -X POST http://127.0.0.1:4001/mod/v2/lock/customer1?ttl=60 -d value=bar -d timeout=2
```
**Renew the TTL on the "customer1" lock for index 2**
```sh
curl -X PUT http://127.0.0.1:4001/mod/v2/lock/customer1?ttl=60 -d index=2
```
**Renew the TTL on the "customer1" lock for value "bar"**
```sh
curl -X PUT http://127.0.0.1:4001/mod/v2/lock/customer1?ttl=60 -d value=bar
```
**Retrieve the current value for the "customer1" lock.**
```sh
curl http://127.0.0.1:4001/mod/v2/lock/customer1
```
**Retrieve the current index for the "customer1" lock**
```sh
curl http://127.0.0.1:4001/mod/v2/lock/customer1?field=index
```
**Delete the "customer1" lock with the index 2**
```sh
curl -X DELETE http://127.0.0.1:4001/mod/v2/lock/customer1?index=2
```
**Delete the "customer1" lock with the value "bar"**
```sh
curl -X DELETE http://127.0.0.1:4001/mod/v2/lock/customer1?value=bar
```
### Leader Election (Deprecated and Removed in 0.4)
The Leader Election module wraps the Lock module to allow clients to come to consensus on a single value.
This is useful when you want one server to process at a time but allow other servers to fail over.
The API is similar to the Lock module but is limited to simple strings values.
Here's the API:
**Attempt to set a value for the "order_processing" leader key:**
```sh
curl -X PUT http://127.0.0.1:4001/mod/v2/leader/order_processing?ttl=60 -d name=myserver1.foo.com
```
**Retrieve the current value for the "order_processing" leader key:**
```sh
curl http://127.0.0.1:4001/mod/v2/leader/order_processing
myserver1.foo.com
```
**Remove a value from the "order_processing" leader key:**
```sh
curl -X DELETE http://127.0.0.1:4001/mod/v2/leader/order_processing?name=myserver1.foo.com
```
If multiple clients attempt to set the value for a key then only one will succeed.
The other clients will hang until the current value is removed because of TTL or because of a `DELETE` operation.
Multiple clients can submit the same value and will all be notified when that value succeeds.
To update the TTL of a value simply reissue the same `PUT` command that you used to set the value.

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@@ -0,0 +1,38 @@
# Optimal etcd Cluster Size
etcd's Raft consensus algorithm is most efficient in small clusters between 3 and 9 peers. For clusters larger than 9, etcd will select a subset of instances to participate in the algorithm in order to keep it efficient. The end of this document briefly explores how etcd works internally and why these choices have been made.
## Cluster Management
You can manage the active cluster size through the [cluster config API](https://github.com/coreos/etcd/blob/master/Documentation/api.md#cluster-config). `activeSize` represents the etcd peers allowed to actively participate in the consensus algorithm.
If the total number of etcd instances exceeds this number, additional peers are started as [standbys](https://github.com/coreos/etcd/blob/master/Documentation/design/standbys.md), which can be promoted to active participation if one of the existing active instances has failed or been removed.
## Internals of etcd
### Writing to etcd
Writes to an etcd peer are always redirected to the leader of the cluster and distributed to all of the peers immediately. A write is only considered successful when a majority of the peers acknowledge the write.
For example, in a cluster with 5 peers, a write operation is only as fast as the 3rd fastest machine. This is the main reason for keeping the number of active peers below 9. In practice, you only need to worry about write performance in high latency environments such as a cluster spanning multiple data centers.
### Leader Election
The leader election process is similar to writing a key &mdash; a majority of the active peers must acknowledge the new leader before cluster operations can continue. The longer each peer takes to elect a new leader means you have to wait longer before you can write to the cluster again. In low latency environments this process takes milliseconds.
### Odd Active Cluster Size
The other important cluster optimization is to always have an odd active cluster size (i.e. `activeSize`). Adding an odd node to the number of peers doesn't change the size of the majority and therefore doesn't increase the total latency of the majority as described above. But, you gain a higher tolerance for peer failure by adding the extra machine. You can see this in practice when comparing two even and odd sized clusters:
| Active Peers | Majority | Failure Tolerance |
|--------------|------------|-------------------|
| 1 peers | 1 peers | None |
| 3 peers | 2 peers | 1 peer |
| 4 peers | 3 peers | 1 peer |
| 5 peers | 3 peers | **2 peers** |
| 6 peers | 4 peers | 2 peers |
| 7 peers | 4 peers | **3 peers** |
| 8 peers | 5 peers | 3 peers |
| 9 peers | 5 peers | **4 peers** |
As you can see, adding another peer to bring the number of active peers up to an odd size is always worth it. During a network partition, an odd number of active peers also guarantees that there will almost always be a majority of the cluster that can continue to operate and be the source of truth when the partition ends.

View File

@@ -1,119 +0,0 @@
## Members API
* [List members](#list-members)
* [Add a member](#add-a-member)
* [Delete a member](#delete-a-member)
* [Change the peer urls of a member](#change-the-peer-urls-of-a-member)
## List members
Return an HTTP 200 OK response code and a representation of all members in the etcd cluster.
### Request
```
GET /v2/members HTTP/1.1
```
### Example
```sh
curl http://10.0.0.10:2379/v2/members
```
```json
{
"members": [
{
"id": "272e204152",
"name": "infra1",
"peerURLs": [
"http://10.0.0.10:2380"
],
"clientURLs": [
"http://10.0.0.10:2379"
]
},
{
"id": "2225373f43",
"name": "infra2",
"peerURLs": [
"http://10.0.0.11:2380"
],
"clientURLs": [
"http://10.0.0.11:2379"
]
},
]
}
```
## Add a member
Returns an HTTP 201 response code and the representation of added member with a newly generated a memberID when successful. Returns a string describing the failure condition when unsuccessful.
If the POST body is malformed an HTTP 400 will be returned. If the member exists in the cluster or existed in the cluster at some point in the past an HTTP 409 will be returned. If any of the given peerURLs exists in the cluster an HTTP 409 will be returned. If the cluster fails to process the request within timeout an HTTP 500 will be returned, though the request may be processed later.
### Request
```
POST /v2/members HTTP/1.1
{"peerURLs": ["http://10.0.0.10:2380"]}
```
### Example
```sh
curl http://10.0.0.10:2379/v2/members -XPOST \
-H "Content-Type: application/json" -d '{"peerURLs":["http://10.0.0.10:2380"]}'
```
```json
{
"id": "3777296169",
"peerURLs": [
"http://10.0.0.10:2380"
]
}
```
## Delete a member
Remove a member from the cluster. The member ID must be a hex-encoded uint64.
Returns 204 with empty content when successful. Returns a string describing the failure condition when unsuccessful.
If the member does not exist in the cluster an HTTP 500(TODO: fix this) will be returned. If the cluster fails to process the request within timeout an HTTP 500 will be returned, though the request may be processed later.
### Request
```
DELETE /v2/members/<id> HTTP/1.1
```
### Example
```sh
curl http://10.0.0.10:2379/v2/members/272e204152 -XDELETE
```
## Change the peer urls of a member
Change the peer urls of a given member. The member ID must be a hex-encoded uint64. Returns 204 with empty content when successful. Returns a string describing the failure condition when unsuccessful.
If the POST body is malformed an HTTP 400 will be returned. If the member does not exist in the cluster an HTTP 404 will be returned. If any of the given peerURLs exists in the cluster an HTTP 409 will be returned. If the cluster fails to process the request within timeout an HTTP 500 will be returned, though the request may be processed later.
#### Request
```
PUT /v2/members/<id> HTTP/1.1
{"peerURLs": ["http://10.0.0.10:2380"]}
```
#### Example
```sh
curl http://10.0.0.10:2379/v2/members/272e204152 -XPUT \
-H "Content-Type: application/json" -d '{"peerURLs":["http://10.0.0.10:2380"]}'
```

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@@ -2,3 +2,6 @@ etcd is being used successfully by many companies in production. It is,
however, under active development and systems like etcd are difficult to get
correct. If you are comfortable with bleeding-edge software please use etcd and
provide us with the feedback and testing young software needs.
When the etcd team feels confident removing this warning we will release etcd
1.0.

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@@ -1,37 +0,0 @@
## Proxy
etcd can now run as a transparent proxy. Running etcd as a proxy allows for easily discovery of etcd within your infrastructure, since it can run on each machine as a local service. In this mode, etcd acts as a reverse proxy and forwards client requests to an active etcd cluster. The etcd proxy does not participate in the consensus replication of the etcd cluster, thus it neither increases the resilience nor decreases the write performance of the etcd cluster.
etcd currently supports two proxy modes: `readwrite` and `readonly`. The default mode is `readwrite`, which forwards both read and write requests to the etcd cluster. A `readonly` etcd proxy only forwards read requests to the etcd cluster, and returns `HTTP 501` to all write requests.
The proxy will shuffle the list of cluster members periodically to avoid sending all connections to a single member.
The member list used by proxy consists of all client URLs advertised within the cluster, as specified in each members' `-advertise-client-urls` flag. If this flag is set incorrectly, requests sent to the proxy are forwarded to wrong addresses and then fail. Including URLs in the `-advertise-client-urls` flag that point to the proxy itself, e.g. http://localhost:2379, is even more problematic as it will cause loops, because the proxy keeps trying to forward requests to itself until its resources (memory, file descriptors) are eventually depleted. The fix for this problem is to restart etcd member with correct `-advertise-client-urls` flag. After client URLs list in proxy is recalculated, which happens every 30 seconds, requests will be forwarded correctly.
### Using an etcd proxy
To start etcd in proxy mode, you need to provide three flags: `proxy`, `listen-client-urls`, and `initial-cluster` (or `discovery`).
To start a readwrite proxy, set `-proxy on`; To start a readonly proxy, set `-proxy readonly`.
The proxy will be listening on `listen-client-urls` and forward requests to the etcd cluster discovered from in `initial-cluster` or `discovery` url.
#### Start an etcd proxy with a static configuration
To start a proxy that will connect to a statically defined etcd cluster, specify the `initial-cluster` flag:
```
etcd -proxy on -listen-client-urls http://127.0.0.1:8080 -initial-cluster infra0=http://10.0.1.10:2380,infra1=http://10.0.1.11:2380,infra2=http://10.0.1.12:2380
```
#### Start an etcd proxy with the discovery service
If you bootstrap an etcd cluster using the [discovery service][discovery-service], you can also start the proxy with the same `discovery`.
To start a proxy using the discovery service, specify the `discovery` flag. The proxy will wait until the etcd cluster defined at the `discovery` url finishes bootstrapping, and then start to forward the requests.
```
etcd -proxy on -listen-client-urls http://127.0.0.1:8080 -discovery https://discovery.etcd.io/3e86b59982e49066c5d813af1c2e2579cbf573de
```
#### Fallback to proxy mode with discovery service
If you bootstrap a etcd cluster using [discovery service][discovery-service] with more than the expected number of etcd members, the extra etcd processes will fall back to being `readwrite` proxies by default. They will forward the requests to the cluster as described above. For example, if you create a discovery url with `size=5`, and start ten etcd processes using that same discovery url, the result will be a cluster with five etcd members and five proxies. Note that this behaviour can be disabled with the `proxy-fallback` flag.
[discovery-service]: clustering.md#discovery

View File

@@ -1,43 +0,0 @@
## Reporting Bugs
If you find bugs or documentation mistakes in etcd project, please let us know by [opening an issue](https://github.com/coreos/etcd/issues/new). We treat bugs and mistakes very seriously and believe no issue is too small. Before creating a bug report, please check there that one does not already exist.
To make your bug report accurate and easy to understand, please try to create bug reports that are:
- Specific. Include as much details as possible: which version, what environment, what configuration, etc. You can also attach etcd log (the starting log with etcd configuration is especially important).
- Reproducible. Include the steps to reproduce the problem. We understand some issues might be hard to reproduce, please includes the steps that might lead to the problem. You can also attach the affected etcd data dir and stack strace to the bug report.
- Isolated. Please try to isolate and reproduce the bug with minimum dependencies. It would significantly slow down the speed to fix a bug if too many dependencies are involved in a bug report. Debugging external systems that rely on etcd is out of scope, but we are happy to point you in the right direction or help you interact with etcd in the correct manner.
- Unique. Do not duplicate existing bug report.
- Scoped. One bug per report. Do not follow up with another bug inside one report.
You might also want to read [Elika Etemads article on filing good bug reports](http://fantasai.inkedblade.net/style/talks/filing-good-bugs/) before creating a bug report.
We might ask you for further information to locate a bug. A duplicated bug report will be closed.
## Frequently Asked Questions
### How to get stack trace
``` bash
$ kill -QUIT $PID
```
### How to get etcd version
``` bash
$ etcd --version
```
### How to get etcd configuration and log when it runs as systemd service etcd2.service
``` bash
$ sudo systemctl cat etcd2
$ sudo journalctl -u etcd2
```
Due to an upstream systemd bug, journald may miss the last few log lines when its process exit. If journalctl tells you that etcd stops without fatal or panic message, you could try `sudo journalctl -f -t etcd2` to get full log.

View File

@@ -1,191 +0,0 @@
## Design
1. Flatten binary key-value space
2. Keep the event history until compaction
- access to old version of keys
- user controlled history compaction
3. Support range query
- Pagination support with limit argument
- Support consistency guarantee across multiple range queries
4. Replace TTL key with Lease
- more efficient/ low cost keep alive
- a logical group of TTL keys
5. Replace CAS/CAD with multi-object Txn
- MUCH MORE powerful and flexible
6. Support efficient watching with multiple ranges
7. RPC API supports the completed set of APIs.
- more efficient than JSON/HTTP
- additional txn/lease support
8. HTTP API supports a subset of APIs.
- easy for people to try out etcd
- easy for people to write simple etcd application
## Protobuf Defined API
[protobuf](./v3api.proto)
### Examples
#### Put a key (foo=bar)
```
// A put is always successful
Put( PutRequest { key = foo, value = bar } )
PutResponse {
cluster_id = 0x1000,
member_id = 0x1,
revision = 1,
raft_term = 0x1,
}
```
#### Get a key (assume we have foo=bar)
```
Get ( RangeRequest { key = foo } )
RangeResponse {
cluster_id = 0x1000,
member_id = 0x1,
revision = 1,
raft_term = 0x1,
kvs = {
{
key = foo,
value = bar,
create_revision = 1,
mod_revision = 1,
version = 1;
},
},
}
```
#### Range over a key space (assume we have foo0=bar0… foo100=bar100)
```
Range ( RangeRequest { key = foo, end_key = foo80, limit = 30 } )
RangeResponse {
cluster_id = 0x1000,
member_id = 0x1,
revision = 100,
raft_term = 0x1,
kvs = {
{
key = foo0,
value = bar0,
create_revision = 1,
mod_revision = 1,
version = 1;
},
...,
{
key = foo30,
value = bar30,
create_revision = 30,
mod_revision = 30,
version = 1;
},
},
}
```
#### Finish a txn (assume we have foo0=bar0, foo1=bar1)
```
Txn(TxnRequest {
// mod_revision of foo0 is equal to 1, mod_revision of foo1 is greater than 1
compare = {
{compareType = equal, key = foo0, mod_revision = 1},
{compareType = greater, key = foo1, mod_revision = 1}}
},
// if the comparison succeeds, put foo2 = bar2
success = {PutRequest { key = foo2, value = success }},
// if the comparison fails, put foo2=fail
failure = {PutRequest { key = foo2, value = failure }},
)
TxnResponse {
cluster_id = 0x1000,
member_id = 0x1,
revision = 3,
raft_term = 0x1,
succeeded = true,
responses = {
// response of PUT foo2=success
{
cluster_id = 0x1000,
member_id = 0x1,
revision = 3,
raft_term = 0x1,
}
}
}
```
#### Watch on a key/range
```
Watch( WatchRequest{
key = foo,
end_key = fop, // prefix foo
start_revision = 20,
end_revision = 10000,
// server decided notification frequency
progress_notification = true,
}
… // this can be a watch request stream
)
// put (foo0=bar0) event at 3
WatchResponse {
cluster_id = 0x1000,
member_id = 0x1,
revision = 3,
raft_term = 0x1,
event_type = put,
kv = {
key = foo0,
value = bar0,
create_revision = 1,
mod_revision = 1,
version = 1;
},
}
// a notification at 2000
WatchResponse {
cluster_id = 0x1000,
member_id = 0x1,
revision = 2000,
raft_term = 0x1,
// nil event as notification
}
// put (foo0=bar3000) event at 3000
WatchResponse {
cluster_id = 0x1000,
member_id = 0x1,
revision = 3000,
raft_term = 0x1,
event_type = put,
kv = {
key = foo0,
value = bar3000,
create_revision = 1,
mod_revision = 3000,
version = 2;
},
}
```

View File

@@ -1,285 +0,0 @@
syntax = "proto3";
// Interface exported by the server.
service etcd {
// Range gets the keys in the range from the store.
rpc Range(RangeRequest) returns (RangeResponse) {}
// Put puts the given key into the store.
// A put request increases the revision of the store,
// and generates one event in the event history.
rpc Put(PutRequest) returns (PutResponse) {}
// Delete deletes the given range from the store.
// A delete request increase the revision of the store,
// and generates one event in the event history.
rpc DeleteRange(DeleteRangeRequest) returns (DeleteRangeResponse) {}
// Txn processes all the requests in one transaction.
// A txn request increases the revision of the store,
// and generates events with the same revision in the event history.
rpc Txn(TxnRequest) returns (TxnResponse) {}
// Watch watches the events happening or happened in etcd. Both input and output
// are stream. One watch rpc can watch for multiple ranges and get a stream of
// events. The whole events history can be watched unless compacted.
rpc WatchRange(stream WatchRangeRequest) returns (stream WatchRangeResponse) {}
// Compact compacts the event history in etcd. User should compact the
// event history periodically, or it will grow infinitely.
rpc Compact(CompactionRequest) returns (CompactionResponse) {}
// LeaseCreate creates a lease. A lease has a TTL. The lease will expire if the
// server does not receive a keepAlive within TTL from the lease holder.
// All keys attached to the lease will be expired and deleted if the lease expires.
// The key expiration generates an event in event history.
rpc LeaseCreate(LeaseCreateRequest) returns (LeaseCreateResponse) {}
// LeaseRevoke revokes a lease. All the key attached to the lease will be expired and deleted.
rpc LeaseRevoke(LeaseRevokeRequest) returns (LeaseRevokeResponse) {}
// LeaseAttach attaches keys with a lease.
rpc LeaseAttach(LeaseAttachRequest) returns (LeaseAttachResponse) {}
// LeaseTxn likes Txn. It has two addition success and failure LeaseAttachRequest list.
// If the Txn is successful, then the success list will be executed. Or the failure list
// will be executed.
rpc LeaseTxn(LeaseTxnRequest) returns (LeaseTxnResponse) {}
// KeepAlive keeps the lease alive.
rpc LeaseKeepAlive(stream LeaseKeepAliveRequest) returns (stream LeaseKeepAliveResponse) {}
}
message ResponseHeader {
// an error type message?
string error = 1;
uint64 cluster_id = 2;
uint64 member_id = 3;
// revision of the store when the request was applied.
int64 revision = 4;
// term of raft when the request was applied.
uint64 raft_term = 5;
}
message RangeRequest {
// if the range_end is not given, the request returns the key.
bytes key = 1;
// if the range_end is given, it gets the keys in range [key, range_end).
bytes range_end = 2;
// limit the number of keys returned.
int64 limit = 3;
// range over the store at the given revision.
// if revision is less or equal to zero, range over the newest store.
// if the revision has been compacted, ErrCompaction will be returned in
// response.
int64 revision = 4;
}
message RangeResponse {
ResponseHeader header = 1;
repeated storagepb.KeyValue kvs = 2;
// more indicates if there are more keys to return in the requested range.
bool more = 3;
}
message PutRequest {
bytes key = 1;
bytes value = 2;
}
message PutResponse {
ResponseHeader header = 1;
}
message DeleteRangeRequest {
// if the range_end is not given, the request deletes the key.
bytes key = 1;
// if the range_end is given, it deletes the keys in range [key, range_end).
bytes range_end = 2;
}
message DeleteRangeResponse {
ResponseHeader header = 1;
}
message RequestUnion {
oneof request {
RangeRequest request_range = 1;
PutRequest request_put = 2;
DeleteRangeRequest request_delete_range = 3;
}
}
message ResponseUnion {
oneof response {
RangeResponse response_range = 1;
PutResponse response_put = 2;
DeleteRangeResponse response_delete_range = 3;
}
}
message Compare {
enum CompareResult {
EQUAL = 0;
GREATER = 1;
LESS = 2;
}
enum CompareTarget {
VERSION = 0;
CREATE = 1;
MOD = 2;
VALUE= 3;
}
CompareResult result = 1;
CompareTarget target = 2;
// key path
bytes key = 3;
oneof target_union {
// version of the given key
int64 version = 4;
// create revision of the given key
int64 create_revision = 5;
// last modified revision of the given key
int64 mod_revision = 6;
// value of the given key
bytes value = 7;
}
}
// If the comparisons succeed, then the success requests will be processed in order,
// and the response will contain their respective responses in order.
// If the comparisons fail, then the failure requests will be processed in order,
// and the response will contain their respective responses in order.
// From google paxosdb paper:
// Our implementation hinges around a powerful primitive which we call MultiOp. All other database
// operations except for iteration are implemented as a single call to MultiOp. A MultiOp is applied atomically
// and consists of three components:
// 1. A list of tests called guard. Each test in guard checks a single entry in the database. It may check
// for the absence or presence of a value, or compare with a given value. Two different tests in the guard
// may apply to the same or different entries in the database. All tests in the guard are applied and
// MultiOp returns the results. If all tests are true, MultiOp executes t op (see item 2 below), otherwise
// it executes f op (see item 3 below).
// 2. A list of database operations called t op. Each operation in the list is either an insert, delete, or
// lookup operation, and applies to a single database entry. Two different operations in the list may apply
// to the same or different entries in the database. These operations are executed
// if guard evaluates to
// true.
// 3. A list of database operations called f op. Like t op, but executed if guard evaluates to false.
message TxnRequest {
repeated Compare compare = 1;
repeated RequestUnion success = 2;
repeated RequestUnion failure = 3;
}
message TxnResponse {
ResponseHeader header = 1;
bool succeeded = 2;
repeated ResponseUnion responses = 3;
}
message KeyValue {
bytes key = 1;
int64 create_revision = 2;
// mod_revision is the last modified revision of the key.
int64 mod_revision = 3;
// version is the version of the key. A deletion resets
// the version to zero and any modification of the key
// increases its version.
int64 version = 4;
bytes value = 5;
}
message WatchRangeRequest {
// if the range_end is not given, the request returns the key.
bytes key = 1;
// if the range_end is given, it gets the keys in range [key, range_end).
bytes range_end = 2;
// start_revision is an optional revision (including) to watch from. No start_revision is "now".
int64 start_revision = 3;
// end_revision is an optional revision (excluding) to end watch. No end_revision is "forever".
int64 end_revision = 4;
bool progress_notification = 5;
}
message WatchRangeResponse {
ResponseHeader header = 1;
repeated Event events = 2;
}
message Event {
enum EventType {
PUT = 0;
DELETE = 1;
EXPIRE = 2;
}
EventType event_type = 1;
// a put event contains the current key-value
// a delete/expire event contains the previous
// key-value
KeyValue kv = 2;
}
// Compaction compacts the kv store upto the given revision (including).
// It removes the old versions of a key. It keeps the newest version of
// the key even if its latest modification revision is smaller than the given
// revision.
message CompactionRequest {
int64 revision = 1;
}
message CompactionResponse {
ResponseHeader header = 1;
}
message LeaseCreateRequest {
// advisory ttl in seconds
int64 ttl = 1;
}
message LeaseCreateResponse {
ResponseHeader header = 1;
int64 lease_id = 2;
// server decided ttl in second
int64 ttl = 3;
string error = 4;
}
message LeaseRevokeRequest {
int64 lease_id = 1;
}
message LeaseRevokeResponse {
ResponseHeader header = 1;
}
message LeaseTxnRequest {
TxnRequest request = 1;
repeated LeaseAttachRequest success = 2;
repeated LeaseAttachRequest failure = 3;
}
message LeaseTxnResponse {
ResponseHeader header = 1;
TxnResponse response = 2;
repeated LeaseAttachResponse attach_responses = 3;
}
message LeaseAttachRequest {
int64 lease_id = 1;
bytes key = 2;
}
message LeaseAttachResponse {
ResponseHeader header = 1;
}
message LeaseKeepAliveRequest {
int64 lease_id = 1;
}
message LeaseKeepAliveResponse {
ResponseHeader header = 1;
int64 lease_id = 2;
int64 ttl = 3;
}

View File

@@ -1,163 +0,0 @@
## Runtime Reconfiguration
etcd comes with support for incremental runtime reconfiguration, which allows users to update the membership of the cluster at run time.
Reconfiguration requests can only be processed when the the majority of the cluster members are functioning. It is **highly recommended** to always have a cluster size greater than two in production. It is unsafe to remove a member from a two member cluster. The majority of a two member cluster is also two. If there is a failure during the removal process, the cluster might not able to make progress and need to [restart from majority failure][majority failure].
To better understand the design behind runtime reconfiguration, we suggest you read [this](runtime-reconf-design.md).
[majority failure]: #restart-cluster-from-majority-failure
## Reconfiguration Use Cases
Let us walk through some common reasons for reconfiguring a cluster. Most of these just involve combinations of adding or removing a member, which are explained below under [Cluster Reconfiguration Operations](#cluster-reconfiguration-operations).
### Cycle or Upgrade Multiple Machines
If you need to move multiple members of your cluster due to planned maintenance (hardware upgrades, network downtime, etc.), it is recommended to modify members one at a time.
It is safe to remove the leader, however there is a brief period of downtime while the election process takes place. If your cluster holds more than 50MB, it is recommended to [migrate the member's data directory][member migration].
[member migration]: admin_guide.md#member-migration
### Change the Cluster Size
Increasing the cluster size can enhance [failure tolerance][fault tolerance table] and provide better read performance. Since clients can read from any member, increasing the number of members increases the overall read throughput.
Decreasing the cluster size can improve the write performance of a cluster, with a trade-off of decreased resilience. Writes into the cluster are replicated to a majority of members of the cluster before considered committed. Decreasing the cluster size lowers the majority, and each write is committed more quickly.
[fault tolerance table]: admin_guide.md#fault-tolerance-table
### Replace A Failed Machine
If a machine fails due to hardware failure, data directory corruption, or some other fatal situation, it should be replaced as soon as possible. Machines that have failed but haven't been removed adversely affect your quorum and reduce the tolerance for an additional failure.
To replace the machine, follow the instructions for [removing the member][remove member] from the cluster, and then [add a new member][add member] in its place. If your cluster holds more than 50MB, it is recommended to [migrate the failed member's data directory][member migration] if you can still access it.
[remove member]: #remove-a-member
[add member]: #add-a-new-member
### Restart Cluster from Majority Failure
If the majority of your cluster is lost or all of your nodes have changed IP addresses, then you need to take manual action in order to recover safely.
The basic steps in the recovery process include [creating a new cluster using the old data][disaster recovery], forcing a single member to act as the leader, and finally using runtime configuration to [add new members][add member] to this new cluster one at a time.
[add member]: #add-a-new-member
[disaster recovery]: admin_guide.md#disaster-recovery
## Cluster Reconfiguration Operations
Now that we have the use cases in mind, let us lay out the operations involved in each.
Before making any change, the simple majority (quorum) of etcd members must be available.
This is essentially the same requirement as for any other write to etcd.
All changes to the cluster are done one at a time:
* To update a single member peerURLs you will make an update operation
* To replace a single member you will make an add then a remove operation
* To increase from 3 to 5 members you will make two add operations
* To decrease from 5 to 3 you will make two remove operations
All of these examples will use the `etcdctl` command line tool that ships with etcd.
If you want to use the member API directly you can find the documentation [here](other_apis.md).
### Update a Member
If you would like to update a member IP address (peerURLs), first, we need to find the target member's ID. You can list all members with `etcdctl`:
```sh
$ etcdctl member list
6e3bd23ae5f1eae0: name=node2 peerURLs=http://localhost:23802 clientURLs=http://127.0.0.1:23792
924e2e83e93f2560: name=node3 peerURLs=http://localhost:23803 clientURLs=http://127.0.0.1:23793
a8266ecf031671f3: name=node1 peerURLs=http://localhost:23801 clientURLs=http://127.0.0.1:23791
```
In this example let's `update` a8266ecf031671f3 member ID and change its peerURLs value to http://10.0.1.10:2380
```sh
$ etcdctl member update a8266ecf031671f3 http://10.0.1.10:2380
Updated member with ID a8266ecf031671f3 in cluster
```
### Remove a Member
Let us say the member ID we want to remove is a8266ecf031671f3.
We then use the `remove` command to perform the removal:
```sh
$ etcdctl member remove a8266ecf031671f3
Removed member a8266ecf031671f3 from cluster
```
The target member will stop itself at this point and print out the removal in the log:
```
etcd: this member has been permanently removed from the cluster. Exiting.
```
It is safe to remove the leader, however the cluster will be inactive while a new leader is elected. This duration is normally the period of election timeout plus the voting process.
### Add a New Member
Adding a member is a two step process:
* Add the new member to the cluster via the [members API](other_apis.md#post-v2members) or the `etcdctl member add` command.
* Start the new member with the new cluster configuration, including a list of the updated members (existing members + the new member).
Using `etcdctl` let's add the new member to the cluster by specifying its [name](configuration.md#-name) and [advertised peer URLs](configuration.md#-initial-advertise-peer-urls):
```sh
$ etcdctl member add infra3 http://10.0.1.13:2380
added member 9bf1b35fc7761a23 to cluster
ETCD_NAME="infra3"
ETCD_INITIAL_CLUSTER="infra0=http://10.0.1.10:2380,infra1=http://10.0.1.11:2380,infra2=http://10.0.1.12:2380,infra3=http://10.0.1.13:2380"
ETCD_INITIAL_CLUSTER_STATE=existing
```
`etcdctl` has informed the cluster about the new member and printed out the environment variables needed to successfully start it.
Now start the new etcd process with the relevant flags for the new member:
```sh
$ export ETCD_NAME="infra3"
$ export ETCD_INITIAL_CLUSTER="infra0=http://10.0.1.10:2380,infra1=http://10.0.1.11:2380,infra2=http://10.0.1.12:2380,infra3=http://10.0.1.13:2380"
$ export ETCD_INITIAL_CLUSTER_STATE=existing
$ etcd -listen-client-urls http://10.0.1.13:2379 -advertise-client-urls http://10.0.1.13:2379 -listen-peer-urls http://10.0.1.13:2380 -initial-advertise-peer-urls http://10.0.1.13:2380 -data-dir %data_dir%
```
The new member will run as a part of the cluster and immediately begin catching up with the rest of the cluster.
If you are adding multiple members the best practice is to configure a single member at a time and verify it starts correctly before adding more new members.
If you add a new member to a 1-node cluster, the cluster cannot make progress before the new member starts because it needs two members as majority to agree on the consensus. You will only see this behavior between the time `etcdctl member add` informs the cluster about the new member and the new member successfully establishing a connection to the existing one.
#### Error Cases
In the following case we have not included our new host in the list of enumerated nodes.
If this is a new cluster, the node must be added to the list of initial cluster members.
```sh
$ etcd -name infra3 \
-initial-cluster infra0=http://10.0.1.10:2380,infra1=http://10.0.1.11:2380,infra2=http://10.0.1.12:2380 \
-initial-cluster-state existing
etcdserver: assign ids error: the member count is unequal
exit 1
```
In this case we give a different address (10.0.1.14:2380) to the one that we used to join the cluster (10.0.1.13:2380).
```sh
$ etcd -name infra4 \
-initial-cluster infra0=http://10.0.1.10:2380,infra1=http://10.0.1.11:2380,infra2=http://10.0.1.12:2380,infra4=http://10.0.1.14:2380 \
-initial-cluster-state existing
etcdserver: assign ids error: unmatched member while checking PeerURLs
exit 1
```
When we start etcd using the data directory of a removed member, etcd will exit automatically if it connects to any alive member in the cluster:
```sh
$ etcd
etcd: this member has been permanently removed from the cluster. Exiting.
exit 1
```

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@@ -1,47 +0,0 @@
### Design of Runtime Reconfiguration
Runtime reconfiguration is one of the hardest and most error prone features in a distributed system, especially in a consensus based system like etcd.
Read on to learn about the design of etcd's runtime reconfiguration commands and how we tackled these problems.
### Two Phase Config Changes Keep you Safe
In etcd, every runtime reconfiguration has to go through [two phases](Documentation/runtime-configuration.md#add-a-new-member) for safety reasons. For example, to add a member you need to first inform cluster of new configuration and then start the new member.
Phase 1 - Inform cluster of new configuration
To add a member into etcd cluster, you need to make an API call to request a new member to be added to the cluster. And this is only way that you can add a new member into an existing cluster. The API call returns when the cluster agrees on the configuration change.
Phase 2 - Start new member
To join the etcd member into the existing cluster, you need to specify the correct `initial-cluster` and set `initial-cluster-state` to `existing`. When the member starts, it will contact the existing cluster first and verify the current cluster configuration matches the expected one specified in `initial-cluster`. When the new member successfully starts, you know your cluster reached the expected configuration.
By splitting the process into two discrete phases users are forced to be explicit regarding cluster membership changes. This actually gives users more flexibility and makes things easier to reason about. For example, if there is an attempt to add a new member with the same ID as an existing member in an etcd cluster, the action will fail immediately during phase one without impacting the running cluster. Similar protection is provided to prevent adding new members by mistake. If a new etcd member attempts to join the cluster before the cluster has accepted the configuration change,, it will not be accepted by the cluster.
Without the explicit workflow around cluster membership etcd would be vulnerable to unexpected cluster membership changes. For example, if etcd is running under an init system such as systemd, etcd would be restarted after being removed via the membership API, and attempt to rejoin the cluster on startup. This cycle would continue every time a member is removed via the API and systemd is set to restart etcd after failing, which is unexpected.
We think runtime reconfiguration should be a low frequent operation. We made the decision to keep it explicit and user-driven to ensure configuration safety and keep your cluster always running smoothly under your control.
### Permanent Loss of Quorum Requires New Cluster
If a cluster permanently loses a majority of its members, a new cluster will need to be started from an old data directory to recover the previous state.
It is entirely possible to force removing the failed members from the existing cluster to recover. However, we decided not to support this method since it bypasses the normal consensus committing phase, which is unsafe. If the member to remove is not actually dead or you force to remove different members through different members in the same cluster, you will end up with diverged cluster with same clusterID. This is very dangerous and hard to debug/fix afterwards.
If you have a correct deployment, the possibility of permanent majority lose is very low. But it is a severe enough problem that worth special care. We strongly suggest you to read the [disaster recovery documentation](admin_guide.md#disaster-recovery) and prepare for permanent majority lose before you put etcd into production.
### Do Not Use Public Discovery Service For Runtime Reconfiguration
The public discovery service should only be used for bootstrapping a cluster. To join member into an existing cluster, you should use runtime reconfiguration API.
Discovery service is designed for bootstrapping an etcd cluster in the cloud environment, when you do not know the IP addresses of all the members beforehand. After you successfully bootstrap a cluster, the IP addresses of all the members are known. Technically, you should not need the discovery service any more.
It seems that using public discovery service is a convenient way to do runtime reconfiguration, after all discovery service already has all the cluster configuration information. However relying on public discovery service brings troubles:
1. it introduces a external dependencies for the entire life-cycle of your cluster, not just bootstrap time. If there is a network issue between your cluster and public discover service, your cluster will suffer from it.
2. public discovery service must reflect correct runtime configuration of your cluster during it life-cycle. It has to provide security mechanism to avoid bad actions, and it is hard.
3. public discovery service has to keep tens of thousands of cluster configurations. Our public discovery service backend is not ready for that workload.
If you want to have a discovery service that supports runtime reconfiguration, the best choice is to build your private one.

View File

@@ -1,60 +1,34 @@
# security model
# Reading and Writing over HTTPS
etcd supports SSL/TLS as well as authentication through client certificates, both for clients to server as well as peer (server to server / cluster) communication.
## Transport Security with HTTPS
To get up and running you first need to have a CA certificate and a signed key pair for one member. It is recommended to create and sign a new key pair for every member in a cluster.
For convenience the [cfssl](https://github.com/cloudflare/cfssl) tool provides an easy interface to certificate generation, and we provide a full example using the tool at [here](../hack/tls-setup). Alternatively this site provides a good reference on how to generate self-signed key pairs:
Etcd supports SSL/TLS and client cert authentication for clients to server, as well as server to server communication.
First, you need to have a CA cert `clientCA.crt` and signed key pair `client.crt`, `client.key`.
This site has a good reference for how to generate self-signed key pairs:
http://www.g-loaded.eu/2005/11/10/be-your-own-ca/
Or you could use [etcd-ca](https://github.com/coreos/etcd-ca) to generate certs and keys.
## Basic setup
For testing you can use the certificates in the `fixtures/ca` directory.
etcd takes several certificate related configuration options, either through command-line flags or environment variables:
**Client-to-server communication:**
`--cert-file=<path>`: Certificate used for SSL/TLS connections **to** etcd. When this option is set, you can set advertise-client-urls using HTTPS schema.
`--key-file=<path>`: Key for the certificate. Must be unencrypted.
`--client-cert-auth`: When this is set etcd will check all incoming HTTPS requests for a client certificate signed by the trusted CA, requests that don't supply a valid client certificate will fail.
`--trusted-ca-file=<path>`: Trusted certificate authority.
**Peer (server-to-server / cluster) communication:**
The peer options work the same way as the client-to-server options:
`--peer-cert-file=<path>`: Certificate used for SSL/TLS connections between peers. This will be used both for listening on the peer address as well as sending requests to other peers.
`--peer-key-file=<path>`: Key for the certificate. Must be unencrypted.
`--peer-client-cert-auth`: When set, etcd will check all incoming peer requests from the cluster for valid client certificates signed by the supplied CA.
`--peer-trusted-ca-file=<path>`: Trusted certificate authority.
If either a client-to-server or peer certificate is supplied the key must also be set. All of these configuration options are also available through the environment variables, `ETCD_CA_FILE`, `ETCD_PEER_CA_FILE` and so on.
## Example 1: Client-to-server transport security with HTTPS
For this you need your CA certificate (`ca.crt`) and signed key pair (`server.crt`, `server.key`) ready.
Let us configure etcd to provide simple HTTPS transport security step by step:
Let's configure etcd to use this keypair:
```sh
$ etcd -name infra0 -data-dir infra0 \
-cert-file=/path/to/server.crt -key-file=/path/to/server.key \
-advertise-client-urls=https://127.0.0.1:2379 -listen-client-urls=https://127.0.0.1:2379
./etcd -f -name machine0 -data-dir machine0 -cert-file=./fixtures/ca/server.crt -key-file=./fixtures/ca/server.key.insecure
```
This should start up fine and you can now test the configuration by speaking HTTPS to etcd:
There are a few new options we're using:
* `-f` - forces a new machine configuration, even if an existing configuration is found. (WARNING: data loss!)
* `-cert-file` and `-key-file` specify the location of the cert and key files to be used for for transport layer security between the client and server.
You can now test the configuration using HTTPS:
```sh
$ curl --cacert /path/to/ca.crt https://127.0.0.1:2379/v2/keys/foo -XPUT -d value=bar -v
curl --cacert ./fixtures/ca/server-chain.pem https://127.0.0.1:4001/v2/keys/foo -XPUT -d value=bar -v
```
You should be able to see the handshake succeed. Because we use self-signed certificates with our own certificate authorities you need to provide the CA to curl using the `--cacert` option. Another possibility would be to add your CA certificate to the trusted certificates on your system (usually in `/etc/ssl/certs`).
You should be able to see the handshake succeed.
**OSX 10.9+ Users**: curl 7.30.0 on OSX 10.9+ doesn't understand certificates passed in on the command line.
Instead you must import the dummy ca.crt directly into the keychain or add the `-k` flag to curl to ignore errors.
@@ -62,27 +36,42 @@ If you want to test without the `-k` flag run `open ./fixtures/ca/ca.crt` and fo
Please remove this certificate after you are done testing!
If you know of a workaround let us know.
## Example 2: Client-to-server authentication with HTTPS client certificates
For now we've given the etcd client the ability to verify the server identity and provide transport security. We can however also use client certificates to prevent unauthorized access to etcd.
The clients will provide their certificates to the server and the server will check whether the cert is signed by the supplied CA and decide whether to serve the request.
You need the same files mentioned in the first example for this, as well as a key pair for the client (`client.crt`, `client.key`) signed by the same certificate authority.
```sh
$ etcd -name infra0 -data-dir infra0 \
-client-cert-auth -trusted-ca-file=/path/to/ca.crt -cert-file=/path/to/server.crt -key-file=/path/to/server.key \
-advertise-client-urls https://127.0.0.1:2379 -listen-client-urls https://127.0.0.1:2379
```
...
SSLv3, TLS handshake, Finished (20):
...
```
Now try the same request as above to this server:
And also the response from the etcd server:
```sh
$ curl --cacert /path/to/ca.crt https://127.0.0.1:2379/v2/keys/foo -XPUT -d value=bar -v
```json
{
"action": "set",
"key": "/foo",
"modifiedIndex": 3,
"value": "bar"
}
```
The request should be rejected by the server:
## Authentication with HTTPS Client Certificates
We can also do authentication using CA certs.
The clients will provide their cert to the server and the server will check whether the cert is signed by the CA and decide whether to serve the request.
```sh
./etcd -f -name machine0 -data-dir machine0 -ca-file=./fixtures/ca/ca.crt -cert-file=./fixtures/ca/server.crt -key-file=./fixtures/ca/server.key.insecure
```
```-ca-file``` is the path to the CA cert.
Try the same request to this server:
```sh
curl --cacert ./fixtures/ca/server-chain.pem https://127.0.0.1:4001/v2/keys/foo -XPUT -d value=bar -v
```
The request should be rejected by the server.
```
...
@@ -90,11 +79,10 @@ routines:SSL3_READ_BYTES:sslv3 alert bad certificate
...
```
To make it succeed, we need to give the CA signed client certificate to the server:
We need to give the CA signed cert to the server.
```sh
$ curl --cacert /path/to/ca.crt --cert /path/to/client.crt --key /path/to/client.key \
-L https://127.0.0.1:2379/v2/keys/foo -XPUT -d value=bar -v
curl --key ./fixtures/ca/server2.key.insecure --cert ./fixtures/ca/server2.crt --cacert ./fixtures/ca/server-chain.pem -L https://127.0.0.1:4001/v2/keys/foo -XPUT -d value=bar -v
```
You should able to see:
@@ -120,41 +108,7 @@ And also the response from the server:
}
```
## Example 3: Transport security & client certificates in a cluster
etcd supports the same model as above for **peer communication**, that means the communication between etcd members in a cluster.
Assuming we have our `ca.crt` and two members with their own keypairs (`member1.crt` & `member1.key`, `member2.crt` & `member2.key`) signed by this CA, we launch etcd as follows:
```sh
DISCOVERY_URL=... # from https://discovery.etcd.io/new
# member1
$ etcd -name infra1 -data-dir infra1 \
-peer-client-cert-auth -peer-trusted-ca-file=/path/to/ca.crt -peer-cert-file=/path/to/member1.crt -peer-key-file=/path/to/member1.key \
-initial-advertise-peer-urls=https://10.0.1.10:2380 -listen-peer-urls=https://10.0.1.10:2380 \
-discovery ${DISCOVERY_URL}
# member2
$ etcd -name infra2 -data-dir infra2 \
-peer-client-cert-atuh -peer-trusted-ca-file=/path/to/ca.crt -peer-cert-file=/path/to/member2.crt -peer-key-file=/path/to/member2.key \
-initial-advertise-peer-urls=https://10.0.1.11:2380 -listen-peer-urls=https://10.0.1.11:2380 \
-discovery ${DISCOVERY_URL}
```
The etcd members will form a cluster and all communication between members in the cluster will be encrypted and authenticated using the client certificates. You will see in the output of etcd that the addresses it connects to use HTTPS.
## Frequently Asked Questions
### My cluster is not working with peer tls configuration?
The internal protocol of etcd v2.0.x uses a lot of short-lived HTTP connections.
So, when enabling TLS you may need to increase the heartbeat interval and election timeouts to reduce internal cluster connection churn.
A reasonable place to start are these values: ` --heartbeat-interval 500 --election-timeout 2500`.
This issues is resolved in the etcd v2.1.x series of releases which uses fewer connections.
### I'm seeing a SSLv3 alert handshake failure when using SSL client authentication?
### Why SSLv3 alert handshake failure when using SSL client auth?
The `crypto/tls` package of `golang` checks the key usage of the certificate public key before using it.
To use the certificate public key to do client auth, we need to add `clientAuth` to `Extended Key Usage` when creating the certificate public key.
@@ -173,10 +127,5 @@ Add the following section to your openssl.cnf:
When creating the cert be sure to reference it in the `-extensions` flag:
```
$ openssl ca -config openssl.cnf -policy policy_anything -extensions ssl_client -out certs/machine.crt -infiles machine.csr
openssl ca -config openssl.cnf -policy policy_anything -extensions ssl_client -out certs/machine.crt -infiles machine.csr
```
### With peer certificate authentication I receive "certificate is valid for 127.0.0.1, not $MY_IP"
Make sure that you sign your certificates with a Subject Name your member's public IP address. The `etcd-ca` tool for example provides an `--ip=` option for its `new-cert` command.
If you need your certificate to be signed for your member's FQDN in its Subject Name then you could use Subject Alternative Names (short IP SANs) to add your IP address. The `etcd-ca` tool provides `--domain=` option for its `new-cert` command, and openssl can make [it](http://wiki.cacert.org/FAQ/subjectAltName) too.

View File

@@ -3,49 +3,50 @@
The default settings in etcd should work well for installations on a local network where the average network latency is low.
However, when using etcd across multiple data centers or over networks with high latency you may need to tweak the heartbeat interval and election timeout settings.
The network isn't the only source of latency. Each request and response may be impacted by slow disks on both the leader and follower. Each of these timeouts represents the total time from request to successful response from the other machine.
### Time Parameters
The underlying distributed consensus protocol relies on two separate time parameters to ensure that nodes can handoff leadership if one stalls or goes offline.
The first parameter is called the *Heartbeat Interval*.
This is the frequency with which the leader will notify followers that it is still the leader.
For best pratices, the parameter should be set around round-trip time between members.
By default, etcd uses a `100ms` heartbeat interval.
etcd batches commands together for higher throughput so this heartbeat interval is also a delay for how long it takes for commands to be committed.
By default, etcd uses a `50ms` heartbeat interval.
The second parameter is the *Election Timeout*.
This timeout is how long a follower node will go without hearing a heartbeat before attempting to become leader itself.
By default, etcd uses a `1000ms` election timeout.
By default, etcd uses a `200ms` election timeout.
Adjusting these values is a trade off.
The value of heartbeat interval is recommended to be around the maximum of average round-trip time (RTT) between members, normally around 0.5-1.5x the round-trip time.
If heartbeat interval is too low, etcd will send unnecessary messages that increase the usage of CPU and network resources.
On the other side, a too high heartbeat interval leads to high election timeout. Higher election timeout takes longer time to detect a leader failure.
The easiest way to measure round-trip time (RTT) is to use [PING utility](https://en.wikipedia.org/wiki/Ping_(networking_utility)).
Lowering the heartbeat interval will cause individual commands to be committed faster but it will lower the overall throughput of etcd.
If your etcd instances have low utilization then lowering the heartbeat interval can improve your command response time.
The election timeout should be set based on the heartbeat interval and average round-trip time between members.
Election timeouts must be at least 10 times the round-trip time so it can account for variance in your network.
For example, if the round-trip time between your members is 10ms then you should have at least a 100ms election timeout.
The election timeout should be set based on the heartbeat interval and your network ping time between nodes.
Election timeouts should be at least 10 times your ping time so it can account for variance in your network.
For example, if the ping time between your nodes is 10ms then you should have at least a 100ms election timeout.
The upper limit of election timeout is 50000ms, which should only be used when deploying global etcd cluster. First, 5s is the upper limit of average global round-trip time. A reasonable round-trip time for the continental united states is 130ms, and the time between US and japan is around 350-400ms. Because package gets delayed a lot, and network situation may be terrible, 5s is a safe value for it. Then, because election timeout should be an order of magnitude bigger than broadcast time, 50s becomes its maximum.
You should also set your election timeout to at least 5 to 10 times your heartbeat interval to account for variance in leader replication.
For a heartbeat interval of 50ms you should set your election timeout to at least 250ms - 500ms.
The heartbeat interval and election timeout value should be the same for all members in one cluster. Setting different values for etcd members may disrupt cluster stability.
You should also set your election timeout to at least 4 to 5 times your heartbeat interval to account for variance in leader replication.
For a heartbeat interval of 50ms you should set your election timeout to at least 200ms - 250ms.
You can override the default values on the command line:
```sh
# Command line arguments:
$ etcd -heartbeat-interval=100 -election-timeout=500
$ etcd -peer-heartbeat-interval=100 -peer-election-timeout=500
# Environment variables:
$ ETCD_HEARTBEAT_INTERVAL=100 ETCD_ELECTION_TIMEOUT=500 etcd
$ ETCD_PEER_HEARTBEAT_INTERVAL=100 ETCD_PEER_ELECTION_TIMEOUT=500 etcd
```
Or you can set the values within the configuration file:
```toml
[peer]
heartbeat_interval = 100
election_timeout = 100
```
The values are specified in milliseconds.
### Snapshots
etcd appends all key changes to a log file.
@@ -68,3 +69,25 @@ $ etcd -snapshot-count=5000
# Environment variables:
$ ETCD_SNAPSHOT_COUNT=5000 etcd
```
Or you can change the setting in the configuration file:
```toml
snapshot_count = 5000
```
You can also disable snapshotting by adding the following to your command line:
```sh
# Command line arguments:
$ etcd -snapshot false
# Environment variables:
$ ETCD_SNAPSHOT=false etcd
```
You can also disable snapshotting within the configuration file:
```toml
snapshot = false
```

17
Documentation/upgrade.md Normal file
View File

@@ -0,0 +1,17 @@
# Upgrading an Existing Cluster
etcd clusters can be upgraded by doing a rolling upgrade or all at once. We make every effort to test this process, but please be sure to backup your data [by etcd-dump](https://github.com/AaronO/etcd-dump), or make a copy of data directory beforehand.
## Upgrade Process
- Stop the old etcd processes
- Upgrade the etcd binary
- Restart the etcd instance using the original --name, --address, --peer-address and --data-dir.
## Rolling Upgrade
During an upgrade, etcd clusters are designed to continue working in a mix of old and new versions. It's recommended to converge on the new version quickly. Using new API features before the entire cluster has been upgraded is only supported as a best effort. Each instance's version can be found with `curl http://127.0.0.1:4001/version`.
## All at Once
If downtime is not an issue, the easiest way to upgrade your cluster is to shutdown all of the etcd instances and restart them with the new binary. The current state of the cluster is saved to disk and will be loaded into the cluster when it restarts.

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@@ -1,112 +0,0 @@
## Upgrade etcd to 2.1
In the general case, upgrading from etcd 2.0 to 2.1 can be a zero-downtime, rolling upgrade:
- one by one, stop the etcd v2.0 processes and replace them with etcd v2.1 processes
- after you are running all v2.1 processes, new features in v2.1 are available to the cluster
Before [starting an upgrade](#upgrade-procedure), read through the rest of this guide to prepare.
### Upgrade Checklists
#### Upgrade Requirement
To upgrade an existing etcd deployment to 2.1, you must be running 2.0. If youre running a version of etcd before 2.0, you must upgrade to [2.0](https://github.com/coreos/etcd/releases/tag/v2.0.13) before upgrading to 2.1.
Also, to ensure a smooth rolling upgrade, your running cluster must be healthy. You can check the health of the cluster by using `etcdctl cluster-health` command.
#### Preparedness
Before upgrading etcd, always test the services relying on etcd in a staging environment before deploying the upgrade to the production environment.
You might also want to [backup your data directory](admin_guide.md#backing-up-the-datastore) for a potential [downgrade](#downgrade).
etcd 2.1 introduces a new [authentication](auth_api.md) feature, which is disabled by default. If your deployment depends on these, you may want to test the auth features before enabling them in production.
#### Mixed Versions
While upgrading, an etcd cluster supports mixed versions of etcd members. The cluster is only considered upgraded once all its members are upgraded to 2.1.
Internally, etcd members negotiate with each other to determine the overall etcd cluster version, which controls the reported cluster version and the supported features. For example, if you are mid-upgrade, any 2.1 features (such as the the authentication feature mentioned above) wont be available.
#### Limitations
If you encounter any issues during the upgrade, you can attempt to restart the etcd process in trouble using a newer v2.1 binary to solve the problem. One known issue is that etcd v2.0.0 and v2.0.2 may panic during rolling upgrades due to an existing bug, which has been fixed since etcd v2.0.3.
It might take up to 2 minutes for the newly upgraded member to catch up with the existing cluster when the total data size is larger than 50MB (You can check the size of the existing snapshot to know about the rough data size). In other words, it is safest to wait for 2 minutes before upgrading the next member.
If you have even more data, this might take more time. If you have a data size larger than 100MB you should contact us before upgrading, so we can make sure the upgrades work smoothly.
#### Downgrade
If all members have been upgraded to v2.1, the cluster will be upgraded to v2.1, and downgrade is **not possible**. If any member is still v2.0, the cluster will remain in v2.0, and you can go back to use v2.0 binary.
Please [backup your data directory](admin_guide.md#backing-up-the-datastore) of all etcd members if you want to downgrade the cluster, even if it is upgraded.
### Upgrade Procedure
#### 1. Check upgrade requirements.
```
$ etcdctl cluster-health
cluster is healthy
member 6e3bd23ae5f1eae0 is healthy
member 924e2e83e93f2560 is healthy
member a8266ecf031671f3 is healthy
$ curl http://127.0.0.1:4001/version
etcd 2.0.x
```
#### 2. Stop the existing etcd process
You will see similar error logging from other etcd processes in your cluster. This is normal, since you just shut down a member.
```
2015/06/23 15:45:09 sender: error posting to 6e3bd23ae5f1eae0: dial tcp 127.0.0.1:7002: connection refused
2015/06/23 15:45:09 sender: the connection with 6e3bd23ae5f1eae0 became inactive
2015/06/23 15:45:11 rafthttp: encountered error writing to server log stream: write tcp 127.0.0.1:53783: broken pipe
2015/06/23 15:45:11 rafthttp: server streaming to 6e3bd23ae5f1eae0 at term 2 has been stopped
2015/06/23 15:45:11 stream: error sending message: stopped
2015/06/23 15:45:11 stream: stopping the stream server...
```
You could [backup your data directory](https://github.com/coreos/etcd/blob/7f7e2cc79d9c5c342a6eb1e48c386b0223cf934e/Documentation/admin_guide.md#backing-up-the-datastore) for data safety.
```
$ etcdctl backup \
--data-dir /var/lib/etcd \
--backup-dir /tmp/etcd_backup
```
#### 3. Drop-in etcd v2.1 binary and start the new etcd process
You will see the etcd publish its information to the cluster.
```
2015/06/23 15:45:39 etcdserver: published {Name:infra2 ClientURLs:[http://localhost:4002]} to cluster e9c7614f68f35fb2
```
You could verify the cluster becomes healthy.
```
$ etcdctl cluster-health
cluster is healthy
member 6e3bd23ae5f1eae0 is healthy
member 924e2e83e93f2560 is healthy
member a8266ecf031671f3 is healthy
```
#### 4. Repeat step 2 to step 3 for all other members
#### 5. Finish
When all members are upgraded, you will see the cluster is upgraded to 2.1 successfully:
```
2015/06/23 15:46:35 etcdserver: updated the cluster version from 2.0.0 to 2.1.0
```
```
$ curl http://127.0.0.1:4001/version
{"etcdserver":"2.1.x","etcdcluster":"2.1.0"}
```

View File

@@ -1,128 +0,0 @@
## Upgrade etcd from 2.1 to 2.2
In the general case, upgrading from etcd 2.1 to 2.2 can be a zero-downtime, rolling upgrade:
- one by one, stop the etcd v2.1 processes and replace them with etcd v2.2 processes
- after you are running all v2.2 processes, new features in v2.2 are available to the cluster
Before [starting an upgrade](#upgrade-procedure), read through the rest of this guide to prepare.
### Upgrade Checklists
#### Upgrade Requirement
To upgrade an existing etcd deployment to 2.2, you must be running 2.1. If youre running a version of etcd before 2.1, you must upgrade to [2.1](https://github.com/coreos/etcd/releases/tag/v2.1.2) before upgrading to 2.2.
Also, to ensure a smooth rolling upgrade, your running cluster must be healthy. You can check the health of the cluster by using `etcdctl cluster-health` command.
#### Preparedness
Before upgrading etcd, always test the services relying on etcd in a staging environment before deploying the upgrade to the production environment.
You might also want to [backup your data directory](admin_guide.md#backing-up-the-datastore) for a potential [downgrade](#downgrade).
#### Mixed Versions
While upgrading, an etcd cluster supports mixed versions of etcd members. The cluster is only considered upgraded once all its members are upgraded to 2.2.
Internally, etcd members negotiate with each other to determine the overall etcd cluster version, which controls the reported cluster version and the supported features.
#### Limitations
If you have a data size larger than 100MB you should contact us before upgrading, so we can make sure the upgrades work smoothly.
Every etcd 2.2 member will do health checking across the cluster periodically. etcd 2.1 member does not support health checking. During the upgrade, etcd 2.2 member will log warning about the unhealthy state of etcd 2.1 member. You can ignore the warning.
#### Downgrade
If all members have been upgraded to v2.2, the cluster will be upgraded to v2.2, and downgrade is **not possible**. If any member is still v2.1, the cluster will remain in v2.1, and you can go back to use v2.1 binary.
Please [backup your data directory](admin_guide.md#backing-up-the-datastore) of all etcd members if you want to downgrade the cluster, even if it is upgraded.
### Upgrade Procedure
In the example, we upgrade a three member v2.1 cluster running on local machine.
#### 1. Check upgrade requirements.
```
$ etcdctl cluster-health
member 6e3bd23ae5f1eae0 is healthy: got healthy result from http://localhost:22379
member 924e2e83e93f2560 is healthy: got healthy result from http://localhost:32379
member a8266ecf031671f3 is healthy: got healthy result from http://localhost:12379
cluster is healthy
$ curl http://localhost:4001/version
{"etcdserver":"2.1.x","etcdcluster":"2.1.0"}
```
#### 2. Stop the existing etcd process
You will see similar error logging from other etcd processes in your cluster. This is normal, since you just shut down a member and the connection is broken.
```
2015/09/2 09:48:35 etcdserver: failed to reach the peerURL(http://localhost:12380) of member a8266ecf031671f3 (Get http://localhost:12380/version: dial tcp [::1]:12380: getsockopt: connection refused)
2015/09/2 09:48:35 etcdserver: cannot get the version of member a8266ecf031671f3 (Get http://localhost:12380/version: dial tcp [::1]:12380: getsockopt: connection refused)
2015/09/2 09:48:35 rafthttp: failed to write a8266ecf031671f3 on stream Message (write tcp 127.0.0.1:32380->127.0.0.1:64394: write: broken pipe)
2015/09/2 09:48:35 rafthttp: failed to write a8266ecf031671f3 on pipeline (dial tcp [::1]:12380: getsockopt: connection refused)
2015/09/2 09:48:40 etcdserver: failed to reach the peerURL(http://localhost:7001) of member a8266ecf031671f3 (Get http://localhost:7001/version: dial tcp [::1]:12380: getsockopt: connection refused)
2015/09/2 09:48:40 etcdserver: cannot get the version of member a8266ecf031671f3 (Get http://localhost:12380/version: dial tcp [::1]:12380: getsockopt: connection refused)
2015/09/2 09:48:40 rafthttp: failed to heartbeat a8266ecf031671f3 on stream MsgApp v2 (write tcp 127.0.0.1:32380->127.0.0.1:64393: write: broken pipe)
```
You will see logging output like this from ungraded member due to a mixed version cluster. You can ignore this while upgrading.
```
2015/09/2 09:48:45 etcdserver: the etcd version 2.1.2+git is not up-to-date
2015/09/2 09:48:45 etcdserver: member a8266ecf031671f3 has a higher version &{2.2.0-rc.0+git 2.1.0}
```
You will also see logging output like this from the newly upgraded member, since etcd 2.1 member does not support health checking. You can ignore this while upgrading.
```
2015-09-02 09:55:42.691384 W | rafthttp: the connection to peer 6e3bd23ae5f1eae0 is unhealthy
2015-09-02 09:55:42.705626 W | rafthttp: the connection to peer 924e2e83e93f2560 is unhealthy
```
You could [backup your data directory](https://github.com/coreos/etcd/blob/7f7e2cc79d9c5c342a6eb1e48c386b0223cf934e/Documentation/admin_guide.md#backing-up-the-datastore) for data safety.
```
$ etcdctl backup \
--data-dir /var/lib/etcd \
--backup-dir /tmp/etcd_backup
```
#### 3. Drop-in etcd v2.2 binary and start the new etcd process
Now, you can start the etcd v2.2 binary with the previous configuration.
You will see the etcd start and publish its information to the cluster.
```
2015-09-02 09:56:46.117609 I | etcdserver: published {Name:infra2 ClientURLs:[http://localhost:22380]} to cluster e9c7614f68f35fb2
```
You could verify the cluster becomes healthy.
```
$ etcdctl cluster-health
member 6e3bd23ae5f1eae0 is healthy: got healthy result from http://localhost:22379
member 924e2e83e93f2560 is healthy: got healthy result from http://localhost:32379
member a8266ecf031671f3 is healthy: got healthy result from http://localhost:12379
cluster is healthy
```
#### 4. Repeat step 2 to step 3 for all other members
#### 5. Finish
When all members are upgraded, you will see the cluster is upgraded to 2.2 successfully:
```
2015-09-02 09:56:54.896848 N | etcdserver: updated the cluster version from 2.1 to 2.2
```
```
$ curl http://127.0.0.1:4001/version
{"etcdserver":"2.2.x","etcdcluster":"2.2.0"}
```

157
Godeps/Godeps.json generated
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@@ -1,157 +0,0 @@
{
"ImportPath": "github.com/coreos/etcd",
"GoVersion": "go1.4.2",
"Packages": [
"./..."
],
"Deps": [
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{
"ImportPath": "github.com/coreos/go-semver/semver",
"Rev": "568e959cd89871e61434c1143528d9162da89ef2"
},
{
"ImportPath": "github.com/coreos/go-systemd/daemon",
"Comment": "v3-6-gcea488b",
"Rev": "cea488b4e6855fee89b6c22a811e3c5baca861b6"
},
{
"ImportPath": "github.com/coreos/go-systemd/journal",
"Comment": "v3-6-gcea488b",
"Rev": "cea488b4e6855fee89b6c22a811e3c5baca861b6"
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{
"ImportPath": "github.com/coreos/go-systemd/util",
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"Rev": "5677a0e3d5e89854c9974e1256839ee23f8233ca"
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"ImportPath": "github.com/google/btree",
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{
"ImportPath": "github.com/jonboulle/clockwork",
"Rev": "72f9bd7c4e0c2a40055ab3d0f09654f730cce982"
},
{
"ImportPath": "github.com/matttproud/golang_protobuf_extensions/pbutil",
"Rev": "fc2b8d3a73c4867e51861bbdd5ae3c1f0869dd6a"
},
{
"ImportPath": "github.com/prometheus/client_golang/prometheus",
"Comment": "0.7.0-52-ge51041b",
"Rev": "e51041b3fa41cece0dca035740ba6411905be473"
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"ImportPath": "github.com/prometheus/client_model/go",
"Comment": "model-0.0.2-12-gfa8ad6f",
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"ImportPath": "github.com/prometheus/procfs",
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"ImportPath": "github.com/rakyll/pb",
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"ImportPath": "github.com/xiang90/probing",
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}

5
Godeps/Readme generated
View File

@@ -1,5 +0,0 @@
This directory tree is generated automatically by godep.
Please do not edit.
See https://github.com/tools/godep for more information.

2
Godeps/_workspace/.gitignore generated vendored
View File

@@ -1,2 +0,0 @@
/pkg
/bin

View File

@@ -1,13 +0,0 @@
include $(GOROOT)/src/Make.inc
TARG=bitbucket.org/ww/goautoneg
GOFILES=autoneg.go
include $(GOROOT)/src/Make.pkg
format:
gofmt -w *.go
docs:
gomake clean
godoc ${TARG} > README.txt

View File

@@ -1,67 +0,0 @@
PACKAGE
package goautoneg
import "bitbucket.org/ww/goautoneg"
HTTP Content-Type Autonegotiation.
The functions in this package implement the behaviour specified in
http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
Copyright (c) 2011, Open Knowledge Foundation Ltd.
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the
distribution.
Neither the name of the Open Knowledge Foundation Ltd. nor the
names of its contributors may be used to endorse or promote
products derived from this software without specific prior written
permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
FUNCTIONS
func Negotiate(header string, alternatives []string) (content_type string)
Negotiate the most appropriate content_type given the accept header
and a list of alternatives.
func ParseAccept(header string) (accept []Accept)
Parse an Accept Header string returning a sorted list
of clauses
TYPES
type Accept struct {
Type, SubType string
Q float32
Params map[string]string
}
Structure to represent a clause in an HTTP Accept Header
SUBDIRECTORIES
.hg

View File

@@ -1,162 +0,0 @@
/*
HTTP Content-Type Autonegotiation.
The functions in this package implement the behaviour specified in
http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
Copyright (c) 2011, Open Knowledge Foundation Ltd.
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the
distribution.
Neither the name of the Open Knowledge Foundation Ltd. nor the
names of its contributors may be used to endorse or promote
products derived from this software without specific prior written
permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package goautoneg
import (
"sort"
"strconv"
"strings"
)
// Structure to represent a clause in an HTTP Accept Header
type Accept struct {
Type, SubType string
Q float64
Params map[string]string
}
// For internal use, so that we can use the sort interface
type accept_slice []Accept
func (accept accept_slice) Len() int {
slice := []Accept(accept)
return len(slice)
}
func (accept accept_slice) Less(i, j int) bool {
slice := []Accept(accept)
ai, aj := slice[i], slice[j]
if ai.Q > aj.Q {
return true
}
if ai.Type != "*" && aj.Type == "*" {
return true
}
if ai.SubType != "*" && aj.SubType == "*" {
return true
}
return false
}
func (accept accept_slice) Swap(i, j int) {
slice := []Accept(accept)
slice[i], slice[j] = slice[j], slice[i]
}
// Parse an Accept Header string returning a sorted list
// of clauses
func ParseAccept(header string) (accept []Accept) {
parts := strings.Split(header, ",")
accept = make([]Accept, 0, len(parts))
for _, part := range parts {
part := strings.Trim(part, " ")
a := Accept{}
a.Params = make(map[string]string)
a.Q = 1.0
mrp := strings.Split(part, ";")
media_range := mrp[0]
sp := strings.Split(media_range, "/")
a.Type = strings.Trim(sp[0], " ")
switch {
case len(sp) == 1 && a.Type == "*":
a.SubType = "*"
case len(sp) == 2:
a.SubType = strings.Trim(sp[1], " ")
default:
continue
}
if len(mrp) == 1 {
accept = append(accept, a)
continue
}
for _, param := range mrp[1:] {
sp := strings.SplitN(param, "=", 2)
if len(sp) != 2 {
continue
}
token := strings.Trim(sp[0], " ")
if token == "q" {
a.Q, _ = strconv.ParseFloat(sp[1], 32)
} else {
a.Params[token] = strings.Trim(sp[1], " ")
}
}
accept = append(accept, a)
}
slice := accept_slice(accept)
sort.Sort(slice)
return
}
// Negotiate the most appropriate content_type given the accept header
// and a list of alternatives.
func Negotiate(header string, alternatives []string) (content_type string) {
asp := make([][]string, 0, len(alternatives))
for _, ctype := range alternatives {
asp = append(asp, strings.SplitN(ctype, "/", 2))
}
for _, clause := range ParseAccept(header) {
for i, ctsp := range asp {
if clause.Type == ctsp[0] && clause.SubType == ctsp[1] {
content_type = alternatives[i]
return
}
if clause.Type == ctsp[0] && clause.SubType == "*" {
content_type = alternatives[i]
return
}
if clause.Type == "*" && clause.SubType == "*" {
content_type = alternatives[i]
return
}
}
}
return
}

View File

@@ -1,33 +0,0 @@
package goautoneg
import (
"testing"
)
var chrome = "application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5"
func TestParseAccept(t *testing.T) {
alternatives := []string{"text/html", "image/png"}
content_type := Negotiate(chrome, alternatives)
if content_type != "image/png" {
t.Errorf("got %s expected image/png", content_type)
}
alternatives = []string{"text/html", "text/plain", "text/n3"}
content_type = Negotiate(chrome, alternatives)
if content_type != "text/html" {
t.Errorf("got %s expected text/html", content_type)
}
alternatives = []string{"text/n3", "text/plain"}
content_type = Negotiate(chrome, alternatives)
if content_type != "text/plain" {
t.Errorf("got %s expected text/plain", content_type)
}
alternatives = []string{"text/n3", "application/rdf+xml"}
content_type = Negotiate(chrome, alternatives)
if content_type != "text/n3" {
t.Errorf("got %s expected text/n3", content_type)
}
}

View File

@@ -1,63 +0,0 @@
package quantile
import (
"testing"
)
func BenchmarkInsertTargeted(b *testing.B) {
b.ReportAllocs()
s := NewTargeted(Targets)
b.ResetTimer()
for i := float64(0); i < float64(b.N); i++ {
s.Insert(i)
}
}
func BenchmarkInsertTargetedSmallEpsilon(b *testing.B) {
s := NewTargeted(TargetsSmallEpsilon)
b.ResetTimer()
for i := float64(0); i < float64(b.N); i++ {
s.Insert(i)
}
}
func BenchmarkInsertBiased(b *testing.B) {
s := NewLowBiased(0.01)
b.ResetTimer()
for i := float64(0); i < float64(b.N); i++ {
s.Insert(i)
}
}
func BenchmarkInsertBiasedSmallEpsilon(b *testing.B) {
s := NewLowBiased(0.0001)
b.ResetTimer()
for i := float64(0); i < float64(b.N); i++ {
s.Insert(i)
}
}
func BenchmarkQuery(b *testing.B) {
s := NewTargeted(Targets)
for i := float64(0); i < 1e6; i++ {
s.Insert(i)
}
b.ResetTimer()
n := float64(b.N)
for i := float64(0); i < n; i++ {
s.Query(i / n)
}
}
func BenchmarkQuerySmallEpsilon(b *testing.B) {
s := NewTargeted(TargetsSmallEpsilon)
for i := float64(0); i < 1e6; i++ {
s.Insert(i)
}
b.ResetTimer()
n := float64(b.N)
for i := float64(0); i < n; i++ {
s.Query(i / n)
}
}

View File

@@ -1,121 +0,0 @@
// +build go1.1
package quantile_test
import (
"bufio"
"fmt"
"log"
"os"
"strconv"
"time"
"github.com/coreos/etcd/Godeps/_workspace/src/github.com/beorn7/perks/quantile"
)
func Example_simple() {
ch := make(chan float64)
go sendFloats(ch)
// Compute the 50th, 90th, and 99th percentile.
q := quantile.NewTargeted(map[float64]float64{
0.50: 0.005,
0.90: 0.001,
0.99: 0.0001,
})
for v := range ch {
q.Insert(v)
}
fmt.Println("perc50:", q.Query(0.50))
fmt.Println("perc90:", q.Query(0.90))
fmt.Println("perc99:", q.Query(0.99))
fmt.Println("count:", q.Count())
// Output:
// perc50: 5
// perc90: 16
// perc99: 223
// count: 2388
}
func Example_mergeMultipleStreams() {
// Scenario:
// We have multiple database shards. On each shard, there is a process
// collecting query response times from the database logs and inserting
// them into a Stream (created via NewTargeted(0.90)), much like the
// Simple example. These processes expose a network interface for us to
// ask them to serialize and send us the results of their
// Stream.Samples so we may Merge and Query them.
//
// NOTES:
// * These sample sets are small, allowing us to get them
// across the network much faster than sending the entire list of data
// points.
//
// * For this to work correctly, we must supply the same quantiles
// a priori the process collecting the samples supplied to NewTargeted,
// even if we do not plan to query them all here.
ch := make(chan quantile.Samples)
getDBQuerySamples(ch)
q := quantile.NewTargeted(map[float64]float64{0.90: 0.001})
for samples := range ch {
q.Merge(samples)
}
fmt.Println("perc90:", q.Query(0.90))
}
func Example_window() {
// Scenario: We want the 90th, 95th, and 99th percentiles for each
// minute.
ch := make(chan float64)
go sendStreamValues(ch)
tick := time.NewTicker(1 * time.Minute)
q := quantile.NewTargeted(map[float64]float64{
0.90: 0.001,
0.95: 0.0005,
0.99: 0.0001,
})
for {
select {
case t := <-tick.C:
flushToDB(t, q.Samples())
q.Reset()
case v := <-ch:
q.Insert(v)
}
}
}
func sendStreamValues(ch chan float64) {
// Use your imagination
}
func flushToDB(t time.Time, samples quantile.Samples) {
// Use your imagination
}
// This is a stub for the above example. In reality this would hit the remote
// servers via http or something like it.
func getDBQuerySamples(ch chan quantile.Samples) {}
func sendFloats(ch chan<- float64) {
f, err := os.Open("exampledata.txt")
if err != nil {
log.Fatal(err)
}
sc := bufio.NewScanner(f)
for sc.Scan() {
b := sc.Bytes()
v, err := strconv.ParseFloat(string(b), 64)
if err != nil {
log.Fatal(err)
}
ch <- v
}
if sc.Err() != nil {
log.Fatal(sc.Err())
}
close(ch)
}

File diff suppressed because it is too large Load Diff

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@@ -1,292 +0,0 @@
// Package quantile computes approximate quantiles over an unbounded data
// stream within low memory and CPU bounds.
//
// A small amount of accuracy is traded to achieve the above properties.
//
// Multiple streams can be merged before calling Query to generate a single set
// of results. This is meaningful when the streams represent the same type of
// data. See Merge and Samples.
//
// For more detailed information about the algorithm used, see:
//
// Effective Computation of Biased Quantiles over Data Streams
//
// http://www.cs.rutgers.edu/~muthu/bquant.pdf
package quantile
import (
"math"
"sort"
)
// Sample holds an observed value and meta information for compression. JSON
// tags have been added for convenience.
type Sample struct {
Value float64 `json:",string"`
Width float64 `json:",string"`
Delta float64 `json:",string"`
}
// Samples represents a slice of samples. It implements sort.Interface.
type Samples []Sample
func (a Samples) Len() int { return len(a) }
func (a Samples) Less(i, j int) bool { return a[i].Value < a[j].Value }
func (a Samples) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
type invariant func(s *stream, r float64) float64
// NewLowBiased returns an initialized Stream for low-biased quantiles
// (e.g. 0.01, 0.1, 0.5) where the needed quantiles are not known a priori, but
// error guarantees can still be given even for the lower ranks of the data
// distribution.
//
// The provided epsilon is a relative error, i.e. the true quantile of a value
// returned by a query is guaranteed to be within (1±Epsilon)*Quantile.
//
// See http://www.cs.rutgers.edu/~muthu/bquant.pdf for time, space, and error
// properties.
func NewLowBiased(epsilon float64) *Stream {
ƒ := func(s *stream, r float64) float64 {
return 2 * epsilon * r
}
return newStream(ƒ)
}
// NewHighBiased returns an initialized Stream for high-biased quantiles
// (e.g. 0.01, 0.1, 0.5) where the needed quantiles are not known a priori, but
// error guarantees can still be given even for the higher ranks of the data
// distribution.
//
// The provided epsilon is a relative error, i.e. the true quantile of a value
// returned by a query is guaranteed to be within 1-(1±Epsilon)*(1-Quantile).
//
// See http://www.cs.rutgers.edu/~muthu/bquant.pdf for time, space, and error
// properties.
func NewHighBiased(epsilon float64) *Stream {
ƒ := func(s *stream, r float64) float64 {
return 2 * epsilon * (s.n - r)
}
return newStream(ƒ)
}
// NewTargeted returns an initialized Stream concerned with a particular set of
// quantile values that are supplied a priori. Knowing these a priori reduces
// space and computation time. The targets map maps the desired quantiles to
// their absolute errors, i.e. the true quantile of a value returned by a query
// is guaranteed to be within (Quantile±Epsilon).
//
// See http://www.cs.rutgers.edu/~muthu/bquant.pdf for time, space, and error properties.
func NewTargeted(targets map[float64]float64) *Stream {
ƒ := func(s *stream, r float64) float64 {
var m = math.MaxFloat64
var f float64
for quantile, epsilon := range targets {
if quantile*s.n <= r {
f = (2 * epsilon * r) / quantile
} else {
f = (2 * epsilon * (s.n - r)) / (1 - quantile)
}
if f < m {
m = f
}
}
return m
}
return newStream(ƒ)
}
// Stream computes quantiles for a stream of float64s. It is not thread-safe by
// design. Take care when using across multiple goroutines.
type Stream struct {
*stream
b Samples
sorted bool
}
func newStream(ƒ invariant) *Stream {
x := &stream{ƒ: ƒ}
return &Stream{x, make(Samples, 0, 500), true}
}
// Insert inserts v into the stream.
func (s *Stream) Insert(v float64) {
s.insert(Sample{Value: v, Width: 1})
}
func (s *Stream) insert(sample Sample) {
s.b = append(s.b, sample)
s.sorted = false
if len(s.b) == cap(s.b) {
s.flush()
}
}
// Query returns the computed qth percentiles value. If s was created with
// NewTargeted, and q is not in the set of quantiles provided a priori, Query
// will return an unspecified result.
func (s *Stream) Query(q float64) float64 {
if !s.flushed() {
// Fast path when there hasn't been enough data for a flush;
// this also yields better accuracy for small sets of data.
l := len(s.b)
if l == 0 {
return 0
}
i := int(float64(l) * q)
if i > 0 {
i -= 1
}
s.maybeSort()
return s.b[i].Value
}
s.flush()
return s.stream.query(q)
}
// Merge merges samples into the underlying streams samples. This is handy when
// merging multiple streams from separate threads, database shards, etc.
//
// ATTENTION: This method is broken and does not yield correct results. The
// underlying algorithm is not capable of merging streams correctly.
func (s *Stream) Merge(samples Samples) {
sort.Sort(samples)
s.stream.merge(samples)
}
// Reset reinitializes and clears the list reusing the samples buffer memory.
func (s *Stream) Reset() {
s.stream.reset()
s.b = s.b[:0]
}
// Samples returns stream samples held by s.
func (s *Stream) Samples() Samples {
if !s.flushed() {
return s.b
}
s.flush()
return s.stream.samples()
}
// Count returns the total number of samples observed in the stream
// since initialization.
func (s *Stream) Count() int {
return len(s.b) + s.stream.count()
}
func (s *Stream) flush() {
s.maybeSort()
s.stream.merge(s.b)
s.b = s.b[:0]
}
func (s *Stream) maybeSort() {
if !s.sorted {
s.sorted = true
sort.Sort(s.b)
}
}
func (s *Stream) flushed() bool {
return len(s.stream.l) > 0
}
type stream struct {
n float64
l []Sample
ƒ invariant
}
func (s *stream) reset() {
s.l = s.l[:0]
s.n = 0
}
func (s *stream) insert(v float64) {
s.merge(Samples{{v, 1, 0}})
}
func (s *stream) merge(samples Samples) {
// TODO(beorn7): This tries to merge not only individual samples, but
// whole summaries. The paper doesn't mention merging summaries at
// all. Unittests show that the merging is inaccurate. Find out how to
// do merges properly.
var r float64
i := 0
for _, sample := range samples {
for ; i < len(s.l); i++ {
c := s.l[i]
if c.Value > sample.Value {
// Insert at position i.
s.l = append(s.l, Sample{})
copy(s.l[i+1:], s.l[i:])
s.l[i] = Sample{
sample.Value,
sample.Width,
math.Max(sample.Delta, math.Floor(s.ƒ(s, r))-1),
// TODO(beorn7): How to calculate delta correctly?
}
i++
goto inserted
}
r += c.Width
}
s.l = append(s.l, Sample{sample.Value, sample.Width, 0})
i++
inserted:
s.n += sample.Width
r += sample.Width
}
s.compress()
}
func (s *stream) count() int {
return int(s.n)
}
func (s *stream) query(q float64) float64 {
t := math.Ceil(q * s.n)
t += math.Ceil(s.ƒ(s, t) / 2)
p := s.l[0]
var r float64
for _, c := range s.l[1:] {
r += p.Width
if r+c.Width+c.Delta > t {
return p.Value
}
p = c
}
return p.Value
}
func (s *stream) compress() {
if len(s.l) < 2 {
return
}
x := s.l[len(s.l)-1]
xi := len(s.l) - 1
r := s.n - 1 - x.Width
for i := len(s.l) - 2; i >= 0; i-- {
c := s.l[i]
if c.Width+x.Width+x.Delta <= s.ƒ(s, r) {
x.Width += c.Width
s.l[xi] = x
// Remove element at i.
copy(s.l[i:], s.l[i+1:])
s.l = s.l[:len(s.l)-1]
xi -= 1
} else {
x = c
xi = i
}
r -= c.Width
}
}
func (s *stream) samples() Samples {
samples := make(Samples, len(s.l))
copy(samples, s.l)
return samples
}

View File

@@ -1,188 +0,0 @@
package quantile
import (
"math"
"math/rand"
"sort"
"testing"
)
var (
Targets = map[float64]float64{
0.01: 0.001,
0.10: 0.01,
0.50: 0.05,
0.90: 0.01,
0.99: 0.001,
}
TargetsSmallEpsilon = map[float64]float64{
0.01: 0.0001,
0.10: 0.001,
0.50: 0.005,
0.90: 0.001,
0.99: 0.0001,
}
LowQuantiles = []float64{0.01, 0.1, 0.5}
HighQuantiles = []float64{0.99, 0.9, 0.5}
)
const RelativeEpsilon = 0.01
func verifyPercsWithAbsoluteEpsilon(t *testing.T, a []float64, s *Stream) {
sort.Float64s(a)
for quantile, epsilon := range Targets {
n := float64(len(a))
k := int(quantile * n)
lower := int((quantile - epsilon) * n)
if lower < 1 {
lower = 1
}
upper := int(math.Ceil((quantile + epsilon) * n))
if upper > len(a) {
upper = len(a)
}
w, min, max := a[k-1], a[lower-1], a[upper-1]
if g := s.Query(quantile); g < min || g > max {
t.Errorf("q=%f: want %v [%f,%f], got %v", quantile, w, min, max, g)
}
}
}
func verifyLowPercsWithRelativeEpsilon(t *testing.T, a []float64, s *Stream) {
sort.Float64s(a)
for _, qu := range LowQuantiles {
n := float64(len(a))
k := int(qu * n)
lowerRank := int((1 - RelativeEpsilon) * qu * n)
upperRank := int(math.Ceil((1 + RelativeEpsilon) * qu * n))
w, min, max := a[k-1], a[lowerRank-1], a[upperRank-1]
if g := s.Query(qu); g < min || g > max {
t.Errorf("q=%f: want %v [%f,%f], got %v", qu, w, min, max, g)
}
}
}
func verifyHighPercsWithRelativeEpsilon(t *testing.T, a []float64, s *Stream) {
sort.Float64s(a)
for _, qu := range HighQuantiles {
n := float64(len(a))
k := int(qu * n)
lowerRank := int((1 - (1+RelativeEpsilon)*(1-qu)) * n)
upperRank := int(math.Ceil((1 - (1-RelativeEpsilon)*(1-qu)) * n))
w, min, max := a[k-1], a[lowerRank-1], a[upperRank-1]
if g := s.Query(qu); g < min || g > max {
t.Errorf("q=%f: want %v [%f,%f], got %v", qu, w, min, max, g)
}
}
}
func populateStream(s *Stream) []float64 {
a := make([]float64, 0, 1e5+100)
for i := 0; i < cap(a); i++ {
v := rand.NormFloat64()
// Add 5% asymmetric outliers.
if i%20 == 0 {
v = v*v + 1
}
s.Insert(v)
a = append(a, v)
}
return a
}
func TestTargetedQuery(t *testing.T) {
rand.Seed(42)
s := NewTargeted(Targets)
a := populateStream(s)
verifyPercsWithAbsoluteEpsilon(t, a, s)
}
func TestLowBiasedQuery(t *testing.T) {
rand.Seed(42)
s := NewLowBiased(RelativeEpsilon)
a := populateStream(s)
verifyLowPercsWithRelativeEpsilon(t, a, s)
}
func TestHighBiasedQuery(t *testing.T) {
rand.Seed(42)
s := NewHighBiased(RelativeEpsilon)
a := populateStream(s)
verifyHighPercsWithRelativeEpsilon(t, a, s)
}
// BrokenTestTargetedMerge is broken, see Merge doc comment.
func BrokenTestTargetedMerge(t *testing.T) {
rand.Seed(42)
s1 := NewTargeted(Targets)
s2 := NewTargeted(Targets)
a := populateStream(s1)
a = append(a, populateStream(s2)...)
s1.Merge(s2.Samples())
verifyPercsWithAbsoluteEpsilon(t, a, s1)
}
// BrokenTestLowBiasedMerge is broken, see Merge doc comment.
func BrokenTestLowBiasedMerge(t *testing.T) {
rand.Seed(42)
s1 := NewLowBiased(RelativeEpsilon)
s2 := NewLowBiased(RelativeEpsilon)
a := populateStream(s1)
a = append(a, populateStream(s2)...)
s1.Merge(s2.Samples())
verifyLowPercsWithRelativeEpsilon(t, a, s2)
}
// BrokenTestHighBiasedMerge is broken, see Merge doc comment.
func BrokenTestHighBiasedMerge(t *testing.T) {
rand.Seed(42)
s1 := NewHighBiased(RelativeEpsilon)
s2 := NewHighBiased(RelativeEpsilon)
a := populateStream(s1)
a = append(a, populateStream(s2)...)
s1.Merge(s2.Samples())
verifyHighPercsWithRelativeEpsilon(t, a, s2)
}
func TestUncompressed(t *testing.T) {
q := NewTargeted(Targets)
for i := 100; i > 0; i-- {
q.Insert(float64(i))
}
if g := q.Count(); g != 100 {
t.Errorf("want count 100, got %d", g)
}
// Before compression, Query should have 100% accuracy.
for quantile := range Targets {
w := quantile * 100
if g := q.Query(quantile); g != w {
t.Errorf("want %f, got %f", w, g)
}
}
}
func TestUncompressedSamples(t *testing.T) {
q := NewTargeted(map[float64]float64{0.99: 0.001})
for i := 1; i <= 100; i++ {
q.Insert(float64(i))
}
if g := q.Samples().Len(); g != 100 {
t.Errorf("want count 100, got %d", g)
}
}
func TestUncompressedOne(t *testing.T) {
q := NewTargeted(map[float64]float64{0.99: 0.01})
q.Insert(3.14)
if g := q.Query(0.90); g != 3.14 {
t.Error("want PI, got", g)
}
}
func TestDefaults(t *testing.T) {
if g := NewTargeted(map[float64]float64{0.99: 0.001}).Query(0.99); g != 0 {
t.Errorf("want 0, got %f", g)
}
}

View File

@@ -1,2 +0,0 @@
example/example
example/example.exe

View File

@@ -1,201 +0,0 @@
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risks associated with Your exercise of permissions under this License.
8. Limitation of Liability. In no event and under no legal theory,
whether in tort (including negligence), contract, or otherwise,
unless required by applicable law (such as deliberate and grossly
negligent acts) or agreed to in writing, shall any Contributor be
liable to You for damages, including any direct, indirect, special,
incidental, or consequential damages of any character arising as a
result of this License or out of the use or inability to use the
Work (including but not limited to damages for loss of goodwill,
work stoppage, computer failure or malfunction, or any and all
other commercial damages or losses), even if such Contributor
has been advised of the possibility of such damages.
9. Accepting Warranty or Additional Liability. While redistributing
the Work or Derivative Works thereof, You may choose to offer,
and charge a fee for, acceptance of support, warranty, indemnity,
or other liability obligations and/or rights consistent with this
License. However, in accepting such obligations, You may act only
on Your own behalf and on Your sole responsibility, not on behalf
of any other Contributor, and only if You agree to indemnify,
defend, and hold each Contributor harmless for any liability
incurred by, or claims asserted against, such Contributor by reason
of your accepting any such warranty or additional liability.
END OF TERMS AND CONDITIONS
APPENDIX: How to apply the Apache License to your work.
To apply the Apache License to your work, attach the following
boilerplate notice, with the fields enclosed by brackets "[]"
replaced with your own identifying information. (Don't include
the brackets!) The text should be enclosed in the appropriate
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Copyright [2013] [the CloudFoundry Authors]
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

View File

@@ -1,30 +0,0 @@
# Speakeasy
This package provides cross-platform Go (#golang) helpers for taking user input
from the terminal while not echoing the input back (similar to `getpasswd`). The
package uses syscalls to avoid any dependence on cgo, and is therefore
compatible with cross-compiling.
[![GoDoc](https://godoc.org/github.com/bgentry/speakeasy?status.png)][godoc]
## Unicode
Multi-byte unicode characters work successfully on Mac OS X. On Windows,
however, this may be problematic (as is UTF in general on Windows). Other
platforms have not been tested.
## License
The code herein was not written by me, but was compiled from two separate open
source packages. Unix portions were imported from [gopass][gopass], while
Windows portions were imported from the [CloudFoundry Go CLI][cf-cli]'s
[Windows terminal helpers][cf-ui-windows].
The [license for the windows portion](./LICENSE_WINDOWS) has been copied exactly
from the source (though I attempted to fill in the correct owner in the
boilerplate copyright notice).
[cf-cli]: https://github.com/cloudfoundry/cli "CloudFoundry Go CLI"
[cf-ui-windows]: https://github.com/cloudfoundry/cli/blob/master/src/cf/terminal/ui_windows.go "CloudFoundry Go CLI Windows input helpers"
[godoc]: https://godoc.org/github.com/bgentry/speakeasy "speakeasy on Godoc.org"
[gopass]: https://code.google.com/p/gopass "gopass"

View File

@@ -1,18 +0,0 @@
package main
import (
"fmt"
"os"
"github.com/coreos/etcd/Godeps/_workspace/src/github.com/bgentry/speakeasy"
)
func main() {
password, err := speakeasy.Ask("Please enter a password: ")
if err != nil {
fmt.Println(err)
os.Exit(1)
}
fmt.Printf("Password result: %q\n", password)
fmt.Printf("Password len: %d\n", len(password))
}

View File

@@ -1,47 +0,0 @@
package speakeasy
import (
"fmt"
"io"
"os"
"strings"
)
// Ask the user to enter a password with input hidden. prompt is a string to
// display before the user's input. Returns the provided password, or an error
// if the command failed.
func Ask(prompt string) (password string, err error) {
return FAsk(os.Stdout, prompt)
}
// Same as the Ask function, except it is possible to specify the file to write
// the prompt to.
func FAsk(file *os.File, prompt string) (password string, err error) {
if prompt != "" {
fmt.Fprint(file, prompt) // Display the prompt.
}
password, err = getPassword()
// Carriage return after the user input.
fmt.Fprintln(file, "")
return
}
func readline() (value string, err error) {
var valb []byte
var n int
b := make([]byte, 1)
for {
// read one byte at a time so we don't accidentally read extra bytes
n, err = os.Stdin.Read(b)
if err != nil && err != io.EOF {
return "", err
}
if n == 0 || b[0] == '\n' {
break
}
valb = append(valb, b[0])
}
return strings.TrimSuffix(string(valb), "\r"), nil
}

View File

@@ -1,93 +0,0 @@
// based on https://code.google.com/p/gopass
// Author: johnsiilver@gmail.com (John Doak)
//
// Original code is based on code by RogerV in the golang-nuts thread:
// https://groups.google.com/group/golang-nuts/browse_thread/thread/40cc41e9d9fc9247
// +build darwin freebsd linux netbsd openbsd solaris
package speakeasy
import (
"fmt"
"os"
"os/signal"
"strings"
"syscall"
)
const sttyArg0 = "/bin/stty"
var (
sttyArgvEOff = []string{"stty", "-echo"}
sttyArgvEOn = []string{"stty", "echo"}
)
// getPassword gets input hidden from the terminal from a user. This is
// accomplished by turning off terminal echo, reading input from the user and
// finally turning on terminal echo.
func getPassword() (password string, err error) {
sig := make(chan os.Signal, 10)
brk := make(chan bool)
// File descriptors for stdin, stdout, and stderr.
fd := []uintptr{os.Stdin.Fd(), os.Stdout.Fd(), os.Stderr.Fd()}
// Setup notifications of termination signals to channel sig, create a process to
// watch for these signals so we can turn back on echo if need be.
signal.Notify(sig, syscall.SIGHUP, syscall.SIGINT, syscall.SIGKILL, syscall.SIGQUIT,
syscall.SIGTERM)
go catchSignal(fd, sig, brk)
// Turn off the terminal echo.
pid, err := echoOff(fd)
if err != nil {
return "", err
}
// Turn on the terminal echo and stop listening for signals.
defer signal.Stop(sig)
defer close(brk)
defer echoOn(fd)
syscall.Wait4(pid, nil, 0, nil)
line, err := readline()
if err == nil {
password = strings.TrimSpace(line)
} else {
err = fmt.Errorf("failed during password entry: %s", err)
}
return password, err
}
// echoOff turns off the terminal echo.
func echoOff(fd []uintptr) (int, error) {
pid, err := syscall.ForkExec(sttyArg0, sttyArgvEOff, &syscall.ProcAttr{Dir: "", Files: fd})
if err != nil {
return 0, fmt.Errorf("failed turning off console echo for password entry:\n\t%s", err)
}
return pid, nil
}
// echoOn turns back on the terminal echo.
func echoOn(fd []uintptr) {
// Turn on the terminal echo.
pid, e := syscall.ForkExec(sttyArg0, sttyArgvEOn, &syscall.ProcAttr{Dir: "", Files: fd})
if e == nil {
syscall.Wait4(pid, nil, 0, nil)
}
}
// catchSignal tries to catch SIGKILL, SIGQUIT and SIGINT so that we can turn
// terminal echo back on before the program ends. Otherwise the user is left
// with echo off on their terminal.
func catchSignal(fd []uintptr, sig chan os.Signal, brk chan bool) {
select {
case <-sig:
echoOn(fd)
os.Exit(-1)
case <-brk:
}
}

View File

@@ -1,43 +0,0 @@
// +build windows
package speakeasy
import (
"os"
"syscall"
)
// SetConsoleMode function can be used to change value of ENABLE_ECHO_INPUT:
// http://msdn.microsoft.com/en-us/library/windows/desktop/ms686033(v=vs.85).aspx
const ENABLE_ECHO_INPUT = 0x0004
func getPassword() (password string, err error) {
hStdin := syscall.Handle(os.Stdin.Fd())
var oldMode uint32
err = syscall.GetConsoleMode(hStdin, &oldMode)
if err != nil {
return
}
var newMode uint32 = (oldMode &^ ENABLE_ECHO_INPUT)
err = setConsoleMode(hStdin, newMode)
defer setConsoleMode(hStdin, oldMode)
if err != nil {
return
}
return readline()
}
func setConsoleMode(console syscall.Handle, mode uint32) (err error) {
dll := syscall.MustLoadDLL("kernel32")
proc := dll.MustFindProc("SetConsoleMode")
r, _, err := proc.Call(uintptr(console), uintptr(mode))
if r == 0 {
return err
}
return nil
}

View File

@@ -1,4 +0,0 @@
*.prof
*.test
*.swp
/bin/

View File

@@ -1,20 +0,0 @@
The MIT License (MIT)
Copyright (c) 2013 Ben Johnson
Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

View File

@@ -1,54 +0,0 @@
TEST=.
BENCH=.
COVERPROFILE=/tmp/c.out
BRANCH=`git rev-parse --abbrev-ref HEAD`
COMMIT=`git rev-parse --short HEAD`
GOLDFLAGS="-X main.branch $(BRANCH) -X main.commit $(COMMIT)"
default: build
bench:
go test -v -test.run=NOTHINCONTAINSTHIS -test.bench=$(BENCH)
# http://cloc.sourceforge.net/
cloc:
@cloc --not-match-f='Makefile|_test.go' .
cover: fmt
go test -coverprofile=$(COVERPROFILE) -test.run=$(TEST) $(COVERFLAG) .
go tool cover -html=$(COVERPROFILE)
rm $(COVERPROFILE)
cpuprofile: fmt
@go test -c
@./bolt.test -test.v -test.run=$(TEST) -test.cpuprofile cpu.prof
# go get github.com/kisielk/errcheck
errcheck:
@echo "=== errcheck ==="
@errcheck github.com/boltdb/bolt
fmt:
@go fmt ./...
get:
@go get -d ./...
build: get
@mkdir -p bin
@go build -ldflags=$(GOLDFLAGS) -a -o bin/bolt ./cmd/bolt
test: fmt
@go get github.com/stretchr/testify/assert
@echo "=== TESTS ==="
@go test -v -cover -test.run=$(TEST)
@echo ""
@echo ""
@echo "=== CLI ==="
@go test -v -test.run=$(TEST) ./cmd/bolt
@echo ""
@echo ""
@echo "=== RACE DETECTOR ==="
@go test -v -race -test.run="TestSimulate_(100op|1000op)"
.PHONY: bench cloc cover cpuprofile fmt memprofile test

View File

@@ -1,621 +0,0 @@
Bolt [![Build Status](https://drone.io/github.com/boltdb/bolt/status.png)](https://drone.io/github.com/boltdb/bolt/latest) [![Coverage Status](https://coveralls.io/repos/boltdb/bolt/badge.png?branch=master)](https://coveralls.io/r/boltdb/bolt?branch=master) [![GoDoc](https://godoc.org/github.com/boltdb/bolt?status.png)](https://godoc.org/github.com/boltdb/bolt) ![Version](http://img.shields.io/badge/version-1.0-green.png)
====
Bolt is a pure Go key/value store inspired by [Howard Chu's][hyc_symas] and
the [LMDB project][lmdb]. The goal of the project is to provide a simple,
fast, and reliable database for projects that don't require a full database
server such as Postgres or MySQL.
Since Bolt is meant to be used as such a low-level piece of functionality,
simplicity is key. The API will be small and only focus on getting values
and setting values. That's it.
[hyc_symas]: https://twitter.com/hyc_symas
[lmdb]: http://symas.com/mdb/
## Project Status
Bolt is stable and the API is fixed. Full unit test coverage and randomized
black box testing are used to ensure database consistency and thread safety.
Bolt is currently in high-load production environments serving databases as
large as 1TB. Many companies such as Shopify and Heroku use Bolt-backed
services every day.
## Getting Started
### Installing
To start using Bolt, install Go and run `go get`:
```sh
$ go get github.com/boltdb/bolt/...
```
This will retrieve the library and install the `bolt` command line utility into
your `$GOBIN` path.
### Opening a database
The top-level object in Bolt is a `DB`. It is represented as a single file on
your disk and represents a consistent snapshot of your data.
To open your database, simply use the `bolt.Open()` function:
```go
package main
import (
"log"
"github.com/boltdb/bolt"
)
func main() {
// Open the my.db data file in your current directory.
// It will be created if it doesn't exist.
db, err := bolt.Open("my.db", 0600, nil)
if err != nil {
log.Fatal(err)
}
defer db.Close()
...
}
```
Please note that Bolt obtains a file lock on the data file so multiple processes
cannot open the same database at the same time. Opening an already open Bolt
database will cause it to hang until the other process closes it. To prevent
an indefinite wait you can pass a timeout option to the `Open()` function:
```go
db, err := bolt.Open("my.db", 0600, &bolt.Options{Timeout: 1 * time.Second})
```
### Transactions
Bolt allows only one read-write transaction at a time but allows as many
read-only transactions as you want at a time. Each transaction has a consistent
view of the data as it existed when the transaction started.
Individual transactions and all objects created from them (e.g. buckets, keys)
are not thread safe. To work with data in multiple goroutines you must start
a transaction for each one or use locking to ensure only one goroutine accesses
a transaction at a time. Creating transaction from the `DB` is thread safe.
Read-only transactions and read-write transactions should not depend on one
another and generally shouldn't be opened simultaneously in the same goroutine.
This can cause a deadlock as the read-write transaction needs to periodically
re-map the data file but it cannot do so while a read-only transaction is open.
#### Read-write transactions
To start a read-write transaction, you can use the `DB.Update()` function:
```go
err := db.Update(func(tx *bolt.Tx) error {
...
return nil
})
```
Inside the closure, you have a consistent view of the database. You commit the
transaction by returning `nil` at the end. You can also rollback the transaction
at any point by returning an error. All database operations are allowed inside
a read-write transaction.
Always check the return error as it will report any disk failures that can cause
your transaction to not complete. If you return an error within your closure
it will be passed through.
#### Read-only transactions
To start a read-only transaction, you can use the `DB.View()` function:
```go
err := db.View(func(tx *bolt.Tx) error {
...
return nil
})
```
You also get a consistent view of the database within this closure, however,
no mutating operations are allowed within a read-only transaction. You can only
retrieve buckets, retrieve values, and copy the database within a read-only
transaction.
#### Batch read-write transactions
Each `DB.Update()` waits for disk to commit the writes. This overhead
can be minimized by combining multiple updates with the `DB.Batch()`
function:
```go
err := db.Batch(func(tx *bolt.Tx) error {
...
return nil
})
```
Concurrent Batch calls are opportunistically combined into larger
transactions. Batch is only useful when there are multiple goroutines
calling it.
The trade-off is that `Batch` can call the given
function multiple times, if parts of the transaction fail. The
function must be idempotent and side effects must take effect only
after a successful return from `DB.Batch()`.
For example: don't display messages from inside the function, instead
set variables in the enclosing scope:
```go
var id uint64
err := db.Batch(func(tx *bolt.Tx) error {
// Find last key in bucket, decode as bigendian uint64, increment
// by one, encode back to []byte, and add new key.
...
id = newValue
return nil
})
if err != nil {
return ...
}
fmt.Println("Allocated ID %d", id)
```
#### Managing transactions manually
The `DB.View()` and `DB.Update()` functions are wrappers around the `DB.Begin()`
function. These helper functions will start the transaction, execute a function,
and then safely close your transaction if an error is returned. This is the
recommended way to use Bolt transactions.
However, sometimes you may want to manually start and end your transactions.
You can use the `Tx.Begin()` function directly but _please_ be sure to close the
transaction.
```go
// Start a writable transaction.
tx, err := db.Begin(true)
if err != nil {
return err
}
defer tx.Rollback()
// Use the transaction...
_, err := tx.CreateBucket([]byte("MyBucket"))
if err != nil {
return err
}
// Commit the transaction and check for error.
if err := tx.Commit(); err != nil {
return err
}
```
The first argument to `DB.Begin()` is a boolean stating if the transaction
should be writable.
### Using buckets
Buckets are collections of key/value pairs within the database. All keys in a
bucket must be unique. You can create a bucket using the `DB.CreateBucket()`
function:
```go
db.Update(func(tx *bolt.Tx) error {
b, err := tx.CreateBucket([]byte("MyBucket"))
if err != nil {
return fmt.Errorf("create bucket: %s", err)
}
return nil
})
```
You can also create a bucket only if it doesn't exist by using the
`Tx.CreateBucketIfNotExists()` function. It's a common pattern to call this
function for all your top-level buckets after you open your database so you can
guarantee that they exist for future transactions.
To delete a bucket, simply call the `Tx.DeleteBucket()` function.
### Using key/value pairs
To save a key/value pair to a bucket, use the `Bucket.Put()` function:
```go
db.Update(func(tx *bolt.Tx) error {
b := tx.Bucket([]byte("MyBucket"))
err := b.Put([]byte("answer"), []byte("42"))
return err
})
```
This will set the value of the `"answer"` key to `"42"` in the `MyBucket`
bucket. To retrieve this value, we can use the `Bucket.Get()` function:
```go
db.View(func(tx *bolt.Tx) error {
b := tx.Bucket([]byte("MyBucket"))
v := b.Get([]byte("answer"))
fmt.Printf("The answer is: %s\n", v)
return nil
})
```
The `Get()` function does not return an error because its operation is
guarenteed to work (unless there is some kind of system failure). If the key
exists then it will return its byte slice value. If it doesn't exist then it
will return `nil`. It's important to note that you can have a zero-length value
set to a key which is different than the key not existing.
Use the `Bucket.Delete()` function to delete a key from the bucket.
Please note that values returned from `Get()` are only valid while the
transaction is open. If you need to use a value outside of the transaction
then you must use `copy()` to copy it to another byte slice.
### Iterating over keys
Bolt stores its keys in byte-sorted order within a bucket. This makes sequential
iteration over these keys extremely fast. To iterate over keys we'll use a
`Cursor`:
```go
db.View(func(tx *bolt.Tx) error {
b := tx.Bucket([]byte("MyBucket"))
c := b.Cursor()
for k, v := c.First(); k != nil; k, v = c.Next() {
fmt.Printf("key=%s, value=%s\n", k, v)
}
return nil
})
```
The cursor allows you to move to a specific point in the list of keys and move
forward or backward through the keys one at a time.
The following functions are available on the cursor:
```
First() Move to the first key.
Last() Move to the last key.
Seek() Move to a specific key.
Next() Move to the next key.
Prev() Move to the previous key.
```
When you have iterated to the end of the cursor then `Next()` will return `nil`.
You must seek to a position using `First()`, `Last()`, or `Seek()` before
calling `Next()` or `Prev()`. If you do not seek to a position then these
functions will return `nil`.
#### Prefix scans
To iterate over a key prefix, you can combine `Seek()` and `bytes.HasPrefix()`:
```go
db.View(func(tx *bolt.Tx) error {
c := tx.Bucket([]byte("MyBucket")).Cursor()
prefix := []byte("1234")
for k, v := c.Seek(prefix); bytes.HasPrefix(k, prefix); k, v = c.Next() {
fmt.Printf("key=%s, value=%s\n", k, v)
}
return nil
})
```
#### Range scans
Another common use case is scanning over a range such as a time range. If you
use a sortable time encoding such as RFC3339 then you can query a specific
date range like this:
```go
db.View(func(tx *bolt.Tx) error {
// Assume our events bucket has RFC3339 encoded time keys.
c := tx.Bucket([]byte("Events")).Cursor()
// Our time range spans the 90's decade.
min := []byte("1990-01-01T00:00:00Z")
max := []byte("2000-01-01T00:00:00Z")
// Iterate over the 90's.
for k, v := c.Seek(min); k != nil && bytes.Compare(k, max) <= 0; k, v = c.Next() {
fmt.Printf("%s: %s\n", k, v)
}
return nil
})
```
#### ForEach()
You can also use the function `ForEach()` if you know you'll be iterating over
all the keys in a bucket:
```go
db.View(func(tx *bolt.Tx) error {
b := tx.Bucket([]byte("MyBucket"))
b.ForEach(func(k, v []byte) error {
fmt.Printf("key=%s, value=%s\n", k, v)
return nil
})
return nil
})
```
### Nested buckets
You can also store a bucket in a key to create nested buckets. The API is the
same as the bucket management API on the `DB` object:
```go
func (*Bucket) CreateBucket(key []byte) (*Bucket, error)
func (*Bucket) CreateBucketIfNotExists(key []byte) (*Bucket, error)
func (*Bucket) DeleteBucket(key []byte) error
```
### Database backups
Bolt is a single file so it's easy to backup. You can use the `Tx.WriteTo()`
function to write a consistent view of the database to a writer. If you call
this from a read-only transaction, it will perform a hot backup and not block
your other database reads and writes. It will also use `O_DIRECT` when available
to prevent page cache trashing.
One common use case is to backup over HTTP so you can use tools like `cURL` to
do database backups:
```go
func BackupHandleFunc(w http.ResponseWriter, req *http.Request) {
err := db.View(func(tx *bolt.Tx) error {
w.Header().Set("Content-Type", "application/octet-stream")
w.Header().Set("Content-Disposition", `attachment; filename="my.db"`)
w.Header().Set("Content-Length", strconv.Itoa(int(tx.Size())))
_, err := tx.WriteTo(w)
return err
})
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
}
```
Then you can backup using this command:
```sh
$ curl http://localhost/backup > my.db
```
Or you can open your browser to `http://localhost/backup` and it will download
automatically.
If you want to backup to another file you can use the `Tx.CopyFile()` helper
function.
### Statistics
The database keeps a running count of many of the internal operations it
performs so you can better understand what's going on. By grabbing a snapshot
of these stats at two points in time we can see what operations were performed
in that time range.
For example, we could start a goroutine to log stats every 10 seconds:
```go
go func() {
// Grab the initial stats.
prev := db.Stats()
for {
// Wait for 10s.
time.Sleep(10 * time.Second)
// Grab the current stats and diff them.
stats := db.Stats()
diff := stats.Sub(&prev)
// Encode stats to JSON and print to STDERR.
json.NewEncoder(os.Stderr).Encode(diff)
// Save stats for the next loop.
prev = stats
}
}()
```
It's also useful to pipe these stats to a service such as statsd for monitoring
or to provide an HTTP endpoint that will perform a fixed-length sample.
### Read-Only Mode
Sometimes it is useful to create a shared, read-only Bolt database. To this,
set the `Options.ReadOnly` flag when opening your database. Read-only mode
uses a shared lock to allow multiple processes to read from the database but
it will block any processes from opening the database in read-write mode.
```go
db, err := bolt.Open("my.db", 0666, &bolt.Options{ReadOnly: true})
if err != nil {
log.Fatal(err)
}
```
## Resources
For more information on getting started with Bolt, check out the following articles:
* [Intro to BoltDB: Painless Performant Persistence](http://npf.io/2014/07/intro-to-boltdb-painless-performant-persistence/) by [Nate Finch](https://github.com/natefinch).
* [Bolt -- an embedded key/value database for Go](https://www.progville.com/go/bolt-embedded-db-golang/) by Progville
## Comparison with other databases
### Postgres, MySQL, & other relational databases
Relational databases structure data into rows and are only accessible through
the use of SQL. This approach provides flexibility in how you store and query
your data but also incurs overhead in parsing and planning SQL statements. Bolt
accesses all data by a byte slice key. This makes Bolt fast to read and write
data by key but provides no built-in support for joining values together.
Most relational databases (with the exception of SQLite) are standalone servers
that run separately from your application. This gives your systems
flexibility to connect multiple application servers to a single database
server but also adds overhead in serializing and transporting data over the
network. Bolt runs as a library included in your application so all data access
has to go through your application's process. This brings data closer to your
application but limits multi-process access to the data.
### LevelDB, RocksDB
LevelDB and its derivatives (RocksDB, HyperLevelDB) are similar to Bolt in that
they are libraries bundled into the application, however, their underlying
structure is a log-structured merge-tree (LSM tree). An LSM tree optimizes
random writes by using a write ahead log and multi-tiered, sorted files called
SSTables. Bolt uses a B+tree internally and only a single file. Both approaches
have trade offs.
If you require a high random write throughput (>10,000 w/sec) or you need to use
spinning disks then LevelDB could be a good choice. If your application is
read-heavy or does a lot of range scans then Bolt could be a good choice.
One other important consideration is that LevelDB does not have transactions.
It supports batch writing of key/values pairs and it supports read snapshots
but it will not give you the ability to do a compare-and-swap operation safely.
Bolt supports fully serializable ACID transactions.
### LMDB
Bolt was originally a port of LMDB so it is architecturally similar. Both use
a B+tree, have ACID semantics with fully serializable transactions, and support
lock-free MVCC using a single writer and multiple readers.
The two projects have somewhat diverged. LMDB heavily focuses on raw performance
while Bolt has focused on simplicity and ease of use. For example, LMDB allows
several unsafe actions such as direct writes for the sake of performance. Bolt
opts to disallow actions which can leave the database in a corrupted state. The
only exception to this in Bolt is `DB.NoSync`.
There are also a few differences in API. LMDB requires a maximum mmap size when
opening an `mdb_env` whereas Bolt will handle incremental mmap resizing
automatically. LMDB overloads the getter and setter functions with multiple
flags whereas Bolt splits these specialized cases into their own functions.
## Caveats & Limitations
It's important to pick the right tool for the job and Bolt is no exception.
Here are a few things to note when evaluating and using Bolt:
* Bolt is good for read intensive workloads. Sequential write performance is
also fast but random writes can be slow. You can add a write-ahead log or
[transaction coalescer](https://github.com/boltdb/coalescer) in front of Bolt
to mitigate this issue.
* Bolt uses a B+tree internally so there can be a lot of random page access.
SSDs provide a significant performance boost over spinning disks.
* Try to avoid long running read transactions. Bolt uses copy-on-write so
old pages cannot be reclaimed while an old transaction is using them.
* Byte slices returned from Bolt are only valid during a transaction. Once the
transaction has been committed or rolled back then the memory they point to
can be reused by a new page or can be unmapped from virtual memory and you'll
see an `unexpected fault address` panic when accessing it.
* Be careful when using `Bucket.FillPercent`. Setting a high fill percent for
buckets that have random inserts will cause your database to have very poor
page utilization.
* Use larger buckets in general. Smaller buckets causes poor page utilization
once they become larger than the page size (typically 4KB).
* Bulk loading a lot of random writes into a new bucket can be slow as the
page will not split until the transaction is committed. Randomly inserting
more than 100,000 key/value pairs into a single new bucket in a single
transaction is not advised.
* Bolt uses a memory-mapped file so the underlying operating system handles the
caching of the data. Typically, the OS will cache as much of the file as it
can in memory and will release memory as needed to other processes. This means
that Bolt can show very high memory usage when working with large databases.
However, this is expected and the OS will release memory as needed. Bolt can
handle databases much larger than the available physical RAM.
* The data structures in the Bolt database are memory mapped so the data file
will be endian specific. This means that you cannot copy a Bolt file from a
little endian machine to a big endian machine and have it work. For most
users this is not a concern since most modern CPUs are little endian.
* Because of the way pages are laid out on disk, Bolt cannot truncate data files
and return free pages back to the disk. Instead, Bolt maintains a free list
of unused pages within its data file. These free pages can be reused by later
transactions. This works well for many use cases as databases generally tend
to grow. However, it's important to note that deleting large chunks of data
will not allow you to reclaim that space on disk.
For more information on page allocation, [see this comment][page-allocation].
[page-allocation]: https://github.com/boltdb/bolt/issues/308#issuecomment-74811638
## Other Projects Using Bolt
Below is a list of public, open source projects that use Bolt:
* [Operation Go: A Routine Mission](http://gocode.io) - An online programming game for Golang using Bolt for user accounts and a leaderboard.
* [Bazil](https://bazil.org/) - A file system that lets your data reside where it is most convenient for it to reside.
* [DVID](https://github.com/janelia-flyem/dvid) - Added Bolt as optional storage engine and testing it against Basho-tuned leveldb.
* [Skybox Analytics](https://github.com/skybox/skybox) - A standalone funnel analysis tool for web analytics.
* [Scuttlebutt](https://github.com/benbjohnson/scuttlebutt) - Uses Bolt to store and process all Twitter mentions of GitHub projects.
* [Wiki](https://github.com/peterhellberg/wiki) - A tiny wiki using Goji, BoltDB and Blackfriday.
* [ChainStore](https://github.com/nulayer/chainstore) - Simple key-value interface to a variety of storage engines organized as a chain of operations.
* [MetricBase](https://github.com/msiebuhr/MetricBase) - Single-binary version of Graphite.
* [Gitchain](https://github.com/gitchain/gitchain) - Decentralized, peer-to-peer Git repositories aka "Git meets Bitcoin".
* [event-shuttle](https://github.com/sclasen/event-shuttle) - A Unix system service to collect and reliably deliver messages to Kafka.
* [ipxed](https://github.com/kelseyhightower/ipxed) - Web interface and api for ipxed.
* [BoltStore](https://github.com/yosssi/boltstore) - Session store using Bolt.
* [photosite/session](http://godoc.org/bitbucket.org/kardianos/photosite/session) - Sessions for a photo viewing site.
* [LedisDB](https://github.com/siddontang/ledisdb) - A high performance NoSQL, using Bolt as optional storage.
* [ipLocator](https://github.com/AndreasBriese/ipLocator) - A fast ip-geo-location-server using bolt with bloom filters.
* [cayley](https://github.com/google/cayley) - Cayley is an open-source graph database using Bolt as optional backend.
* [bleve](http://www.blevesearch.com/) - A pure Go search engine similar to ElasticSearch that uses Bolt as the default storage backend.
* [tentacool](https://github.com/optiflows/tentacool) - REST api server to manage system stuff (IP, DNS, Gateway...) on a linux server.
* [SkyDB](https://github.com/skydb/sky) - Behavioral analytics database.
* [Seaweed File System](https://github.com/chrislusf/weed-fs) - Highly scalable distributed key~file system with O(1) disk read.
* [InfluxDB](http://influxdb.com) - Scalable datastore for metrics, events, and real-time analytics.
* [Freehold](http://tshannon.bitbucket.org/freehold/) - An open, secure, and lightweight platform for your files and data.
* [Prometheus Annotation Server](https://github.com/oliver006/prom_annotation_server) - Annotation server for PromDash & Prometheus service monitoring system.
* [Consul](https://github.com/hashicorp/consul) - Consul is service discovery and configuration made easy. Distributed, highly available, and datacenter-aware.
* [Kala](https://github.com/ajvb/kala) - Kala is a modern job scheduler optimized to run on a single node. It is persistant, JSON over HTTP API, ISO 8601 duration notation, and dependent jobs.
* [drive](https://github.com/odeke-em/drive) - drive is an unofficial Google Drive command line client for \*NIX operating systems.
If you are using Bolt in a project please send a pull request to add it to the list.

View File

@@ -1,138 +0,0 @@
package bolt
import (
"errors"
"fmt"
"sync"
"time"
)
// Batch calls fn as part of a batch. It behaves similar to Update,
// except:
//
// 1. concurrent Batch calls can be combined into a single Bolt
// transaction.
//
// 2. the function passed to Batch may be called multiple times,
// regardless of whether it returns error or not.
//
// This means that Batch function side effects must be idempotent and
// take permanent effect only after a successful return is seen in
// caller.
//
// The maximum batch size and delay can be adjusted with DB.MaxBatchSize
// and DB.MaxBatchDelay, respectively.
//
// Batch is only useful when there are multiple goroutines calling it.
func (db *DB) Batch(fn func(*Tx) error) error {
errCh := make(chan error, 1)
db.batchMu.Lock()
if (db.batch == nil) || (db.batch != nil && len(db.batch.calls) >= db.MaxBatchSize) {
// There is no existing batch, or the existing batch is full; start a new one.
db.batch = &batch{
db: db,
}
db.batch.timer = time.AfterFunc(db.MaxBatchDelay, db.batch.trigger)
}
db.batch.calls = append(db.batch.calls, call{fn: fn, err: errCh})
if len(db.batch.calls) >= db.MaxBatchSize {
// wake up batch, it's ready to run
go db.batch.trigger()
}
db.batchMu.Unlock()
err := <-errCh
if err == trySolo {
err = db.Update(fn)
}
return err
}
type call struct {
fn func(*Tx) error
err chan<- error
}
type batch struct {
db *DB
timer *time.Timer
start sync.Once
calls []call
}
// trigger runs the batch if it hasn't already been run.
func (b *batch) trigger() {
b.start.Do(b.run)
}
// run performs the transactions in the batch and communicates results
// back to DB.Batch.
func (b *batch) run() {
b.db.batchMu.Lock()
b.timer.Stop()
// Make sure no new work is added to this batch, but don't break
// other batches.
if b.db.batch == b {
b.db.batch = nil
}
b.db.batchMu.Unlock()
retry:
for len(b.calls) > 0 {
var failIdx = -1
err := b.db.Update(func(tx *Tx) error {
for i, c := range b.calls {
if err := safelyCall(c.fn, tx); err != nil {
failIdx = i
return err
}
}
return nil
})
if failIdx >= 0 {
// take the failing transaction out of the batch. it's
// safe to shorten b.calls here because db.batch no longer
// points to us, and we hold the mutex anyway.
c := b.calls[failIdx]
b.calls[failIdx], b.calls = b.calls[len(b.calls)-1], b.calls[:len(b.calls)-1]
// tell the submitter re-run it solo, continue with the rest of the batch
c.err <- trySolo
continue retry
}
// pass success, or bolt internal errors, to all callers
for _, c := range b.calls {
if c.err != nil {
c.err <- err
}
}
break retry
}
}
// trySolo is a special sentinel error value used for signaling that a
// transaction function should be re-run. It should never be seen by
// callers.
var trySolo = errors.New("batch function returned an error and should be re-run solo")
type panicked struct {
reason interface{}
}
func (p panicked) Error() string {
if err, ok := p.reason.(error); ok {
return err.Error()
}
return fmt.Sprintf("panic: %v", p.reason)
}
func safelyCall(fn func(*Tx) error, tx *Tx) (err error) {
defer func() {
if p := recover(); p != nil {
err = panicked{p}
}
}()
return fn(tx)
}

View File

@@ -1,170 +0,0 @@
package bolt_test
import (
"bytes"
"encoding/binary"
"errors"
"hash/fnv"
"sync"
"testing"
"github.com/coreos/etcd/Godeps/_workspace/src/github.com/boltdb/bolt"
)
func validateBatchBench(b *testing.B, db *TestDB) {
var rollback = errors.New("sentinel error to cause rollback")
validate := func(tx *bolt.Tx) error {
bucket := tx.Bucket([]byte("bench"))
h := fnv.New32a()
buf := make([]byte, 4)
for id := uint32(0); id < 1000; id++ {
binary.LittleEndian.PutUint32(buf, id)
h.Reset()
h.Write(buf[:])
k := h.Sum(nil)
v := bucket.Get(k)
if v == nil {
b.Errorf("not found id=%d key=%x", id, k)
continue
}
if g, e := v, []byte("filler"); !bytes.Equal(g, e) {
b.Errorf("bad value for id=%d key=%x: %s != %q", id, k, g, e)
}
if err := bucket.Delete(k); err != nil {
return err
}
}
// should be empty now
c := bucket.Cursor()
for k, v := c.First(); k != nil; k, v = c.Next() {
b.Errorf("unexpected key: %x = %q", k, v)
}
return rollback
}
if err := db.Update(validate); err != nil && err != rollback {
b.Error(err)
}
}
func BenchmarkDBBatchAutomatic(b *testing.B) {
db := NewTestDB()
defer db.Close()
db.MustCreateBucket([]byte("bench"))
b.ResetTimer()
for i := 0; i < b.N; i++ {
start := make(chan struct{})
var wg sync.WaitGroup
for round := 0; round < 1000; round++ {
wg.Add(1)
go func(id uint32) {
defer wg.Done()
<-start
h := fnv.New32a()
buf := make([]byte, 4)
binary.LittleEndian.PutUint32(buf, id)
h.Write(buf[:])
k := h.Sum(nil)
insert := func(tx *bolt.Tx) error {
b := tx.Bucket([]byte("bench"))
return b.Put(k, []byte("filler"))
}
if err := db.Batch(insert); err != nil {
b.Error(err)
return
}
}(uint32(round))
}
close(start)
wg.Wait()
}
b.StopTimer()
validateBatchBench(b, db)
}
func BenchmarkDBBatchSingle(b *testing.B) {
db := NewTestDB()
defer db.Close()
db.MustCreateBucket([]byte("bench"))
b.ResetTimer()
for i := 0; i < b.N; i++ {
start := make(chan struct{})
var wg sync.WaitGroup
for round := 0; round < 1000; round++ {
wg.Add(1)
go func(id uint32) {
defer wg.Done()
<-start
h := fnv.New32a()
buf := make([]byte, 4)
binary.LittleEndian.PutUint32(buf, id)
h.Write(buf[:])
k := h.Sum(nil)
insert := func(tx *bolt.Tx) error {
b := tx.Bucket([]byte("bench"))
return b.Put(k, []byte("filler"))
}
if err := db.Update(insert); err != nil {
b.Error(err)
return
}
}(uint32(round))
}
close(start)
wg.Wait()
}
b.StopTimer()
validateBatchBench(b, db)
}
func BenchmarkDBBatchManual10x100(b *testing.B) {
db := NewTestDB()
defer db.Close()
db.MustCreateBucket([]byte("bench"))
b.ResetTimer()
for i := 0; i < b.N; i++ {
start := make(chan struct{})
var wg sync.WaitGroup
for major := 0; major < 10; major++ {
wg.Add(1)
go func(id uint32) {
defer wg.Done()
<-start
insert100 := func(tx *bolt.Tx) error {
h := fnv.New32a()
buf := make([]byte, 4)
for minor := uint32(0); minor < 100; minor++ {
binary.LittleEndian.PutUint32(buf, uint32(id*100+minor))
h.Reset()
h.Write(buf[:])
k := h.Sum(nil)
b := tx.Bucket([]byte("bench"))
if err := b.Put(k, []byte("filler")); err != nil {
return err
}
}
return nil
}
if err := db.Update(insert100); err != nil {
b.Fatal(err)
}
}(uint32(major))
}
close(start)
wg.Wait()
}
b.StopTimer()
validateBatchBench(b, db)
}

View File

@@ -1,148 +0,0 @@
package bolt_test
import (
"encoding/binary"
"fmt"
"io/ioutil"
"log"
"math/rand"
"net/http"
"net/http/httptest"
"os"
"github.com/coreos/etcd/Godeps/_workspace/src/github.com/boltdb/bolt"
)
// Set this to see how the counts are actually updated.
const verbose = false
// Counter updates a counter in Bolt for every URL path requested.
type counter struct {
db *bolt.DB
}
func (c counter) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
// Communicates the new count from a successful database
// transaction.
var result uint64
increment := func(tx *bolt.Tx) error {
b, err := tx.CreateBucketIfNotExists([]byte("hits"))
if err != nil {
return err
}
key := []byte(req.URL.String())
// Decode handles key not found for us.
count := decode(b.Get(key)) + 1
b.Put(key, encode(count))
// All good, communicate new count.
result = count
return nil
}
if err := c.db.Batch(increment); err != nil {
http.Error(rw, err.Error(), 500)
return
}
if verbose {
log.Printf("server: %s: %d", req.URL.String(), result)
}
rw.Header().Set("Content-Type", "application/octet-stream")
fmt.Fprintf(rw, "%d\n", result)
}
func client(id int, base string, paths []string) error {
// Process paths in random order.
rng := rand.New(rand.NewSource(int64(id)))
permutation := rng.Perm(len(paths))
for i := range paths {
path := paths[permutation[i]]
resp, err := http.Get(base + path)
if err != nil {
return err
}
defer resp.Body.Close()
buf, err := ioutil.ReadAll(resp.Body)
if err != nil {
return err
}
if verbose {
log.Printf("client: %s: %s", path, buf)
}
}
return nil
}
func ExampleDB_Batch() {
// Open the database.
db, _ := bolt.Open(tempfile(), 0666, nil)
defer os.Remove(db.Path())
defer db.Close()
// Start our web server
count := counter{db}
srv := httptest.NewServer(count)
defer srv.Close()
// Decrease the batch size to make things more interesting.
db.MaxBatchSize = 3
// Get every path multiple times concurrently.
const clients = 10
paths := []string{
"/foo",
"/bar",
"/baz",
"/quux",
"/thud",
"/xyzzy",
}
errors := make(chan error, clients)
for i := 0; i < clients; i++ {
go func(id int) {
errors <- client(id, srv.URL, paths)
}(i)
}
// Check all responses to make sure there's no error.
for i := 0; i < clients; i++ {
if err := <-errors; err != nil {
fmt.Printf("client error: %v", err)
return
}
}
// Check the final result
db.View(func(tx *bolt.Tx) error {
b := tx.Bucket([]byte("hits"))
c := b.Cursor()
for k, v := c.First(); k != nil; k, v = c.Next() {
fmt.Printf("hits to %s: %d\n", k, decode(v))
}
return nil
})
// Output:
// hits to /bar: 10
// hits to /baz: 10
// hits to /foo: 10
// hits to /quux: 10
// hits to /thud: 10
// hits to /xyzzy: 10
}
// encode marshals a counter.
func encode(n uint64) []byte {
buf := make([]byte, 8)
binary.BigEndian.PutUint64(buf, n)
return buf
}
// decode unmarshals a counter. Nil buffers are decoded as 0.
func decode(buf []byte) uint64 {
if buf == nil {
return 0
}
return binary.BigEndian.Uint64(buf)
}

View File

@@ -1,167 +0,0 @@
package bolt_test
import (
"testing"
"time"
"github.com/coreos/etcd/Godeps/_workspace/src/github.com/boltdb/bolt"
)
// Ensure two functions can perform updates in a single batch.
func TestDB_Batch(t *testing.T) {
db := NewTestDB()
defer db.Close()
db.MustCreateBucket([]byte("widgets"))
// Iterate over multiple updates in separate goroutines.
n := 2
ch := make(chan error)
for i := 0; i < n; i++ {
go func(i int) {
ch <- db.Batch(func(tx *bolt.Tx) error {
return tx.Bucket([]byte("widgets")).Put(u64tob(uint64(i)), []byte{})
})
}(i)
}
// Check all responses to make sure there's no error.
for i := 0; i < n; i++ {
if err := <-ch; err != nil {
t.Fatal(err)
}
}
// Ensure data is correct.
db.MustView(func(tx *bolt.Tx) error {
b := tx.Bucket([]byte("widgets"))
for i := 0; i < n; i++ {
if v := b.Get(u64tob(uint64(i))); v == nil {
t.Errorf("key not found: %d", i)
}
}
return nil
})
}
func TestDB_Batch_Panic(t *testing.T) {
db := NewTestDB()
defer db.Close()
var sentinel int
var bork = &sentinel
var problem interface{}
var err error
// Execute a function inside a batch that panics.
func() {
defer func() {
if p := recover(); p != nil {
problem = p
}
}()
err = db.Batch(func(tx *bolt.Tx) error {
panic(bork)
})
}()
// Verify there is no error.
if g, e := err, error(nil); g != e {
t.Fatalf("wrong error: %v != %v", g, e)
}
// Verify the panic was captured.
if g, e := problem, bork; g != e {
t.Fatalf("wrong error: %v != %v", g, e)
}
}
func TestDB_BatchFull(t *testing.T) {
db := NewTestDB()
defer db.Close()
db.MustCreateBucket([]byte("widgets"))
const size = 3
// buffered so we never leak goroutines
ch := make(chan error, size)
put := func(i int) {
ch <- db.Batch(func(tx *bolt.Tx) error {
return tx.Bucket([]byte("widgets")).Put(u64tob(uint64(i)), []byte{})
})
}
db.MaxBatchSize = size
// high enough to never trigger here
db.MaxBatchDelay = 1 * time.Hour
go put(1)
go put(2)
// Give the batch a chance to exhibit bugs.
time.Sleep(10 * time.Millisecond)
// not triggered yet
select {
case <-ch:
t.Fatalf("batch triggered too early")
default:
}
go put(3)
// Check all responses to make sure there's no error.
for i := 0; i < size; i++ {
if err := <-ch; err != nil {
t.Fatal(err)
}
}
// Ensure data is correct.
db.MustView(func(tx *bolt.Tx) error {
b := tx.Bucket([]byte("widgets"))
for i := 1; i <= size; i++ {
if v := b.Get(u64tob(uint64(i))); v == nil {
t.Errorf("key not found: %d", i)
}
}
return nil
})
}
func TestDB_BatchTime(t *testing.T) {
db := NewTestDB()
defer db.Close()
db.MustCreateBucket([]byte("widgets"))
const size = 1
// buffered so we never leak goroutines
ch := make(chan error, size)
put := func(i int) {
ch <- db.Batch(func(tx *bolt.Tx) error {
return tx.Bucket([]byte("widgets")).Put(u64tob(uint64(i)), []byte{})
})
}
db.MaxBatchSize = 1000
db.MaxBatchDelay = 0
go put(1)
// Batch must trigger by time alone.
// Check all responses to make sure there's no error.
for i := 0; i < size; i++ {
if err := <-ch; err != nil {
t.Fatal(err)
}
}
// Ensure data is correct.
db.MustView(func(tx *bolt.Tx) error {
b := tx.Bucket([]byte("widgets"))
for i := 1; i <= size; i++ {
if v := b.Get(u64tob(uint64(i))); v == nil {
t.Errorf("key not found: %d", i)
}
}
return nil
})
}

View File

@@ -1,7 +0,0 @@
package bolt
// maxMapSize represents the largest mmap size supported by Bolt.
const maxMapSize = 0x7FFFFFFF // 2GB
// maxAllocSize is the size used when creating array pointers.
const maxAllocSize = 0xFFFFFFF

View File

@@ -1,7 +0,0 @@
package bolt
// maxMapSize represents the largest mmap size supported by Bolt.
const maxMapSize = 0xFFFFFFFFFFFF // 256TB
// maxAllocSize is the size used when creating array pointers.
const maxAllocSize = 0x7FFFFFFF

View File

@@ -1,7 +0,0 @@
package bolt
// maxMapSize represents the largest mmap size supported by Bolt.
const maxMapSize = 0x7FFFFFFF // 2GB
// maxAllocSize is the size used when creating array pointers.
const maxAllocSize = 0xFFFFFFF

View File

@@ -1,12 +0,0 @@
package bolt
import (
"syscall"
)
var odirect = syscall.O_DIRECT
// fdatasync flushes written data to a file descriptor.
func fdatasync(db *DB) error {
return syscall.Fdatasync(int(db.file.Fd()))
}

View File

@@ -1,29 +0,0 @@
package bolt
import (
"syscall"
"unsafe"
)
const (
msAsync = 1 << iota // perform asynchronous writes
msSync // perform synchronous writes
msInvalidate // invalidate cached data
)
var odirect int
func msync(db *DB) error {
_, _, errno := syscall.Syscall(syscall.SYS_MSYNC, uintptr(unsafe.Pointer(db.data)), uintptr(db.datasz), msInvalidate)
if errno != 0 {
return errno
}
return nil
}
func fdatasync(db *DB) error {
if db.data != nil {
return msync(db)
}
return db.file.Sync()
}

View File

@@ -1,36 +0,0 @@
package bolt_test
import (
"fmt"
"path/filepath"
"reflect"
"runtime"
"testing"
)
// assert fails the test if the condition is false.
func assert(tb testing.TB, condition bool, msg string, v ...interface{}) {
if !condition {
_, file, line, _ := runtime.Caller(1)
fmt.Printf("\033[31m%s:%d: "+msg+"\033[39m\n\n", append([]interface{}{filepath.Base(file), line}, v...)...)
tb.FailNow()
}
}
// ok fails the test if an err is not nil.
func ok(tb testing.TB, err error) {
if err != nil {
_, file, line, _ := runtime.Caller(1)
fmt.Printf("\033[31m%s:%d: unexpected error: %s\033[39m\n\n", filepath.Base(file), line, err.Error())
tb.FailNow()
}
}
// equals fails the test if exp is not equal to act.
func equals(tb testing.TB, exp, act interface{}) {
if !reflect.DeepEqual(exp, act) {
_, file, line, _ := runtime.Caller(1)
fmt.Printf("\033[31m%s:%d:\n\n\texp: %#v\n\n\tgot: %#v\033[39m\n\n", filepath.Base(file), line, exp, act)
tb.FailNow()
}
}

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@@ -1,100 +0,0 @@
// +build !windows,!plan9,!solaris
package bolt
import (
"fmt"
"os"
"syscall"
"time"
"unsafe"
)
// flock acquires an advisory lock on a file descriptor.
func flock(f *os.File, exclusive bool, timeout time.Duration) error {
var t time.Time
for {
// If we're beyond our timeout then return an error.
// This can only occur after we've attempted a flock once.
if t.IsZero() {
t = time.Now()
} else if timeout > 0 && time.Since(t) > timeout {
return ErrTimeout
}
flag := syscall.LOCK_SH
if exclusive {
flag = syscall.LOCK_EX
}
// Otherwise attempt to obtain an exclusive lock.
err := syscall.Flock(int(f.Fd()), flag|syscall.LOCK_NB)
if err == nil {
return nil
} else if err != syscall.EWOULDBLOCK {
return err
}
// Wait for a bit and try again.
time.Sleep(50 * time.Millisecond)
}
}
// funlock releases an advisory lock on a file descriptor.
func funlock(f *os.File) error {
return syscall.Flock(int(f.Fd()), syscall.LOCK_UN)
}
// mmap memory maps a DB's data file.
func mmap(db *DB, sz int) error {
// Truncate and fsync to ensure file size metadata is flushed.
// https://github.com/boltdb/bolt/issues/284
if !db.NoGrowSync && !db.readOnly {
if err := db.file.Truncate(int64(sz)); err != nil {
return fmt.Errorf("file resize error: %s", err)
}
if err := db.file.Sync(); err != nil {
return fmt.Errorf("file sync error: %s", err)
}
}
// Map the data file to memory.
b, err := syscall.Mmap(int(db.file.Fd()), 0, sz, syscall.PROT_READ, syscall.MAP_SHARED)
if err != nil {
return err
}
// Advise the kernel that the mmap is accessed randomly.
if err := madvise(b, syscall.MADV_RANDOM); err != nil {
return fmt.Errorf("madvise: %s", err)
}
// Save the original byte slice and convert to a byte array pointer.
db.dataref = b
db.data = (*[maxMapSize]byte)(unsafe.Pointer(&b[0]))
db.datasz = sz
return nil
}
// munmap unmaps a DB's data file from memory.
func munmap(db *DB) error {
// Ignore the unmap if we have no mapped data.
if db.dataref == nil {
return nil
}
// Unmap using the original byte slice.
err := syscall.Munmap(db.dataref)
db.dataref = nil
db.data = nil
db.datasz = 0
return err
}
// NOTE: This function is copied from stdlib because it is not available on darwin.
func madvise(b []byte, advice int) (err error) {
_, _, e1 := syscall.Syscall(syscall.SYS_MADVISE, uintptr(unsafe.Pointer(&b[0])), uintptr(len(b)), uintptr(advice))
if e1 != 0 {
err = e1
}
return
}

View File

@@ -1,100 +0,0 @@
package bolt
import (
"fmt"
"github.com/coreos/etcd/Godeps/_workspace/src/golang.org/x/sys/unix"
"os"
"syscall"
"time"
"unsafe"
)
// flock acquires an advisory lock on a file descriptor.
func flock(f *os.File, exclusive bool, timeout time.Duration) error {
var t time.Time
for {
// If we're beyond our timeout then return an error.
// This can only occur after we've attempted a flock once.
if t.IsZero() {
t = time.Now()
} else if timeout > 0 && time.Since(t) > timeout {
return ErrTimeout
}
var lock syscall.Flock_t
lock.Start = 0
lock.Len = 0
lock.Pid = 0
lock.Whence = 0
lock.Pid = 0
if exclusive {
lock.Type = syscall.F_WRLCK
} else {
lock.Type = syscall.F_RDLCK
}
err := syscall.FcntlFlock(f.Fd(), syscall.F_SETLK, &lock)
if err == nil {
return nil
} else if err != syscall.EAGAIN {
return err
}
// Wait for a bit and try again.
time.Sleep(50 * time.Millisecond)
}
}
// funlock releases an advisory lock on a file descriptor.
func funlock(f *os.File) error {
var lock syscall.Flock_t
lock.Start = 0
lock.Len = 0
lock.Type = syscall.F_UNLCK
lock.Whence = 0
return syscall.FcntlFlock(uintptr(f.Fd()), syscall.F_SETLK, &lock)
}
// mmap memory maps a DB's data file.
func mmap(db *DB, sz int) error {
// Truncate and fsync to ensure file size metadata is flushed.
// https://github.com/boltdb/bolt/issues/284
if !db.NoGrowSync && !db.readOnly {
if err := db.file.Truncate(int64(sz)); err != nil {
return fmt.Errorf("file resize error: %s", err)
}
if err := db.file.Sync(); err != nil {
return fmt.Errorf("file sync error: %s", err)
}
}
// Map the data file to memory.
b, err := unix.Mmap(int(db.file.Fd()), 0, sz, syscall.PROT_READ, syscall.MAP_SHARED)
if err != nil {
return err
}
// Advise the kernel that the mmap is accessed randomly.
if err := unix.Madvise(b, syscall.MADV_RANDOM); err != nil {
return fmt.Errorf("madvise: %s", err)
}
// Save the original byte slice and convert to a byte array pointer.
db.dataref = b
db.data = (*[maxMapSize]byte)(unsafe.Pointer(&b[0]))
db.datasz = sz
return nil
}
// munmap unmaps a DB's data file from memory.
func munmap(db *DB) error {
// Ignore the unmap if we have no mapped data.
if db.dataref == nil {
return nil
}
// Unmap using the original byte slice.
err := unix.Munmap(db.dataref)
db.dataref = nil
db.data = nil
db.datasz = 0
return err
}

View File

@@ -1,76 +0,0 @@
package bolt
import (
"fmt"
"os"
"syscall"
"time"
"unsafe"
)
var odirect int
// fdatasync flushes written data to a file descriptor.
func fdatasync(db *DB) error {
return db.file.Sync()
}
// flock acquires an advisory lock on a file descriptor.
func flock(f *os.File, _ bool, _ time.Duration) error {
return nil
}
// funlock releases an advisory lock on a file descriptor.
func funlock(f *os.File) error {
return nil
}
// mmap memory maps a DB's data file.
// Based on: https://github.com/edsrzf/mmap-go
func mmap(db *DB, sz int) error {
if !db.readOnly {
// Truncate the database to the size of the mmap.
if err := db.file.Truncate(int64(sz)); err != nil {
return fmt.Errorf("truncate: %s", err)
}
}
// Open a file mapping handle.
sizelo := uint32(sz >> 32)
sizehi := uint32(sz) & 0xffffffff
h, errno := syscall.CreateFileMapping(syscall.Handle(db.file.Fd()), nil, syscall.PAGE_READONLY, sizelo, sizehi, nil)
if h == 0 {
return os.NewSyscallError("CreateFileMapping", errno)
}
// Create the memory map.
addr, errno := syscall.MapViewOfFile(h, syscall.FILE_MAP_READ, 0, 0, uintptr(sz))
if addr == 0 {
return os.NewSyscallError("MapViewOfFile", errno)
}
// Close mapping handle.
if err := syscall.CloseHandle(syscall.Handle(h)); err != nil {
return os.NewSyscallError("CloseHandle", err)
}
// Convert to a byte array.
db.data = ((*[maxMapSize]byte)(unsafe.Pointer(addr)))
db.datasz = sz
return nil
}
// munmap unmaps a pointer from a file.
// Based on: https://github.com/edsrzf/mmap-go
func munmap(db *DB) error {
if db.data == nil {
return nil
}
addr := (uintptr)(unsafe.Pointer(&db.data[0]))
if err := syscall.UnmapViewOfFile(addr); err != nil {
return os.NewSyscallError("UnmapViewOfFile", err)
}
return nil
}

View File

@@ -1,10 +0,0 @@
// +build !windows,!plan9,!linux,!openbsd
package bolt
var odirect int
// fdatasync flushes written data to a file descriptor.
func fdatasync(db *DB) error {
return db.file.Sync()
}

View File

@@ -1,743 +0,0 @@
package bolt
import (
"bytes"
"fmt"
"unsafe"
)
const (
// MaxKeySize is the maximum length of a key, in bytes.
MaxKeySize = 32768
// MaxValueSize is the maximum length of a value, in bytes.
MaxValueSize = 4294967295
)
const (
maxUint = ^uint(0)
minUint = 0
maxInt = int(^uint(0) >> 1)
minInt = -maxInt - 1
)
const bucketHeaderSize = int(unsafe.Sizeof(bucket{}))
const (
minFillPercent = 0.1
maxFillPercent = 1.0
)
// DefaultFillPercent is the percentage that split pages are filled.
// This value can be changed by setting Bucket.FillPercent.
const DefaultFillPercent = 0.5
// Bucket represents a collection of key/value pairs inside the database.
type Bucket struct {
*bucket
tx *Tx // the associated transaction
buckets map[string]*Bucket // subbucket cache
page *page // inline page reference
rootNode *node // materialized node for the root page.
nodes map[pgid]*node // node cache
// Sets the threshold for filling nodes when they split. By default,
// the bucket will fill to 50% but it can be useful to increase this
// amount if you know that your write workloads are mostly append-only.
//
// This is non-persisted across transactions so it must be set in every Tx.
FillPercent float64
}
// bucket represents the on-file representation of a bucket.
// This is stored as the "value" of a bucket key. If the bucket is small enough,
// then its root page can be stored inline in the "value", after the bucket
// header. In the case of inline buckets, the "root" will be 0.
type bucket struct {
root pgid // page id of the bucket's root-level page
sequence uint64 // monotonically incrementing, used by NextSequence()
}
// newBucket returns a new bucket associated with a transaction.
func newBucket(tx *Tx) Bucket {
var b = Bucket{tx: tx, FillPercent: DefaultFillPercent}
if tx.writable {
b.buckets = make(map[string]*Bucket)
b.nodes = make(map[pgid]*node)
}
return b
}
// Tx returns the tx of the bucket.
func (b *Bucket) Tx() *Tx {
return b.tx
}
// Root returns the root of the bucket.
func (b *Bucket) Root() pgid {
return b.root
}
// Writable returns whether the bucket is writable.
func (b *Bucket) Writable() bool {
return b.tx.writable
}
// Cursor creates a cursor associated with the bucket.
// The cursor is only valid as long as the transaction is open.
// Do not use a cursor after the transaction is closed.
func (b *Bucket) Cursor() *Cursor {
// Update transaction statistics.
b.tx.stats.CursorCount++
// Allocate and return a cursor.
return &Cursor{
bucket: b,
stack: make([]elemRef, 0),
}
}
// Bucket retrieves a nested bucket by name.
// Returns nil if the bucket does not exist.
func (b *Bucket) Bucket(name []byte) *Bucket {
if b.buckets != nil {
if child := b.buckets[string(name)]; child != nil {
return child
}
}
// Move cursor to key.
c := b.Cursor()
k, v, flags := c.seek(name)
// Return nil if the key doesn't exist or it is not a bucket.
if !bytes.Equal(name, k) || (flags&bucketLeafFlag) == 0 {
return nil
}
// Otherwise create a bucket and cache it.
var child = b.openBucket(v)
if b.buckets != nil {
b.buckets[string(name)] = child
}
return child
}
// Helper method that re-interprets a sub-bucket value
// from a parent into a Bucket
func (b *Bucket) openBucket(value []byte) *Bucket {
var child = newBucket(b.tx)
// If this is a writable transaction then we need to copy the bucket entry.
// Read-only transactions can point directly at the mmap entry.
if b.tx.writable {
child.bucket = &bucket{}
*child.bucket = *(*bucket)(unsafe.Pointer(&value[0]))
} else {
child.bucket = (*bucket)(unsafe.Pointer(&value[0]))
}
// Save a reference to the inline page if the bucket is inline.
if child.root == 0 {
child.page = (*page)(unsafe.Pointer(&value[bucketHeaderSize]))
}
return &child
}
// CreateBucket creates a new bucket at the given key and returns the new bucket.
// Returns an error if the key already exists, if the bucket name is blank, or if the bucket name is too long.
func (b *Bucket) CreateBucket(key []byte) (*Bucket, error) {
if b.tx.db == nil {
return nil, ErrTxClosed
} else if !b.tx.writable {
return nil, ErrTxNotWritable
} else if len(key) == 0 {
return nil, ErrBucketNameRequired
}
// Move cursor to correct position.
c := b.Cursor()
k, _, flags := c.seek(key)
// Return an error if there is an existing key.
if bytes.Equal(key, k) {
if (flags & bucketLeafFlag) != 0 {
return nil, ErrBucketExists
} else {
return nil, ErrIncompatibleValue
}
}
// Create empty, inline bucket.
var bucket = Bucket{
bucket: &bucket{},
rootNode: &node{isLeaf: true},
FillPercent: DefaultFillPercent,
}
var value = bucket.write()
// Insert into node.
key = cloneBytes(key)
c.node().put(key, key, value, 0, bucketLeafFlag)
// Since subbuckets are not allowed on inline buckets, we need to
// dereference the inline page, if it exists. This will cause the bucket
// to be treated as a regular, non-inline bucket for the rest of the tx.
b.page = nil
return b.Bucket(key), nil
}
// CreateBucketIfNotExists creates a new bucket if it doesn't already exist and returns a reference to it.
// Returns an error if the bucket name is blank, or if the bucket name is too long.
func (b *Bucket) CreateBucketIfNotExists(key []byte) (*Bucket, error) {
child, err := b.CreateBucket(key)
if err == ErrBucketExists {
return b.Bucket(key), nil
} else if err != nil {
return nil, err
}
return child, nil
}
// DeleteBucket deletes a bucket at the given key.
// Returns an error if the bucket does not exists, or if the key represents a non-bucket value.
func (b *Bucket) DeleteBucket(key []byte) error {
if b.tx.db == nil {
return ErrTxClosed
} else if !b.Writable() {
return ErrTxNotWritable
}
// Move cursor to correct position.
c := b.Cursor()
k, _, flags := c.seek(key)
// Return an error if bucket doesn't exist or is not a bucket.
if !bytes.Equal(key, k) {
return ErrBucketNotFound
} else if (flags & bucketLeafFlag) == 0 {
return ErrIncompatibleValue
}
// Recursively delete all child buckets.
child := b.Bucket(key)
err := child.ForEach(func(k, v []byte) error {
if v == nil {
if err := child.DeleteBucket(k); err != nil {
return fmt.Errorf("delete bucket: %s", err)
}
}
return nil
})
if err != nil {
return err
}
// Remove cached copy.
delete(b.buckets, string(key))
// Release all bucket pages to freelist.
child.nodes = nil
child.rootNode = nil
child.free()
// Delete the node if we have a matching key.
c.node().del(key)
return nil
}
// Get retrieves the value for a key in the bucket.
// Returns a nil value if the key does not exist or if the key is a nested bucket.
// The returned value is only valid for the life of the transaction.
func (b *Bucket) Get(key []byte) []byte {
k, v, flags := b.Cursor().seek(key)
// Return nil if this is a bucket.
if (flags & bucketLeafFlag) != 0 {
return nil
}
// If our target node isn't the same key as what's passed in then return nil.
if !bytes.Equal(key, k) {
return nil
}
return v
}
// Put sets the value for a key in the bucket.
// If the key exist then its previous value will be overwritten.
// Returns an error if the bucket was created from a read-only transaction, if the key is blank, if the key is too large, or if the value is too large.
func (b *Bucket) Put(key []byte, value []byte) error {
if b.tx.db == nil {
return ErrTxClosed
} else if !b.Writable() {
return ErrTxNotWritable
} else if len(key) == 0 {
return ErrKeyRequired
} else if len(key) > MaxKeySize {
return ErrKeyTooLarge
} else if int64(len(value)) > MaxValueSize {
return ErrValueTooLarge
}
// Move cursor to correct position.
c := b.Cursor()
k, _, flags := c.seek(key)
// Return an error if there is an existing key with a bucket value.
if bytes.Equal(key, k) && (flags&bucketLeafFlag) != 0 {
return ErrIncompatibleValue
}
// Insert into node.
key = cloneBytes(key)
c.node().put(key, key, value, 0, 0)
return nil
}
// Delete removes a key from the bucket.
// If the key does not exist then nothing is done and a nil error is returned.
// Returns an error if the bucket was created from a read-only transaction.
func (b *Bucket) Delete(key []byte) error {
if b.tx.db == nil {
return ErrTxClosed
} else if !b.Writable() {
return ErrTxNotWritable
}
// Move cursor to correct position.
c := b.Cursor()
_, _, flags := c.seek(key)
// Return an error if there is already existing bucket value.
if (flags & bucketLeafFlag) != 0 {
return ErrIncompatibleValue
}
// Delete the node if we have a matching key.
c.node().del(key)
return nil
}
// NextSequence returns an autoincrementing integer for the bucket.
func (b *Bucket) NextSequence() (uint64, error) {
if b.tx.db == nil {
return 0, ErrTxClosed
} else if !b.Writable() {
return 0, ErrTxNotWritable
}
// Materialize the root node if it hasn't been already so that the
// bucket will be saved during commit.
if b.rootNode == nil {
_ = b.node(b.root, nil)
}
// Increment and return the sequence.
b.bucket.sequence++
return b.bucket.sequence, nil
}
// ForEach executes a function for each key/value pair in a bucket.
// If the provided function returns an error then the iteration is stopped and
// the error is returned to the caller.
func (b *Bucket) ForEach(fn func(k, v []byte) error) error {
if b.tx.db == nil {
return ErrTxClosed
}
c := b.Cursor()
for k, v := c.First(); k != nil; k, v = c.Next() {
if err := fn(k, v); err != nil {
return err
}
}
return nil
}
// Stat returns stats on a bucket.
func (b *Bucket) Stats() BucketStats {
var s, subStats BucketStats
pageSize := b.tx.db.pageSize
s.BucketN += 1
if b.root == 0 {
s.InlineBucketN += 1
}
b.forEachPage(func(p *page, depth int) {
if (p.flags & leafPageFlag) != 0 {
s.KeyN += int(p.count)
// used totals the used bytes for the page
used := pageHeaderSize
if p.count != 0 {
// If page has any elements, add all element headers.
used += leafPageElementSize * int(p.count-1)
// Add all element key, value sizes.
// The computation takes advantage of the fact that the position
// of the last element's key/value equals to the total of the sizes
// of all previous elements' keys and values.
// It also includes the last element's header.
lastElement := p.leafPageElement(p.count - 1)
used += int(lastElement.pos + lastElement.ksize + lastElement.vsize)
}
if b.root == 0 {
// For inlined bucket just update the inline stats
s.InlineBucketInuse += used
} else {
// For non-inlined bucket update all the leaf stats
s.LeafPageN++
s.LeafInuse += used
s.LeafOverflowN += int(p.overflow)
// Collect stats from sub-buckets.
// Do that by iterating over all element headers
// looking for the ones with the bucketLeafFlag.
for i := uint16(0); i < p.count; i++ {
e := p.leafPageElement(i)
if (e.flags & bucketLeafFlag) != 0 {
// For any bucket element, open the element value
// and recursively call Stats on the contained bucket.
subStats.Add(b.openBucket(e.value()).Stats())
}
}
}
} else if (p.flags & branchPageFlag) != 0 {
s.BranchPageN++
lastElement := p.branchPageElement(p.count - 1)
// used totals the used bytes for the page
// Add header and all element headers.
used := pageHeaderSize + (branchPageElementSize * int(p.count-1))
// Add size of all keys and values.
// Again, use the fact that last element's position equals to
// the total of key, value sizes of all previous elements.
used += int(lastElement.pos + lastElement.ksize)
s.BranchInuse += used
s.BranchOverflowN += int(p.overflow)
}
// Keep track of maximum page depth.
if depth+1 > s.Depth {
s.Depth = (depth + 1)
}
})
// Alloc stats can be computed from page counts and pageSize.
s.BranchAlloc = (s.BranchPageN + s.BranchOverflowN) * pageSize
s.LeafAlloc = (s.LeafPageN + s.LeafOverflowN) * pageSize
// Add the max depth of sub-buckets to get total nested depth.
s.Depth += subStats.Depth
// Add the stats for all sub-buckets
s.Add(subStats)
return s
}
// forEachPage iterates over every page in a bucket, including inline pages.
func (b *Bucket) forEachPage(fn func(*page, int)) {
// If we have an inline page then just use that.
if b.page != nil {
fn(b.page, 0)
return
}
// Otherwise traverse the page hierarchy.
b.tx.forEachPage(b.root, 0, fn)
}
// forEachPageNode iterates over every page (or node) in a bucket.
// This also includes inline pages.
func (b *Bucket) forEachPageNode(fn func(*page, *node, int)) {
// If we have an inline page or root node then just use that.
if b.page != nil {
fn(b.page, nil, 0)
return
}
b._forEachPageNode(b.root, 0, fn)
}
func (b *Bucket) _forEachPageNode(pgid pgid, depth int, fn func(*page, *node, int)) {
var p, n = b.pageNode(pgid)
// Execute function.
fn(p, n, depth)
// Recursively loop over children.
if p != nil {
if (p.flags & branchPageFlag) != 0 {
for i := 0; i < int(p.count); i++ {
elem := p.branchPageElement(uint16(i))
b._forEachPageNode(elem.pgid, depth+1, fn)
}
}
} else {
if !n.isLeaf {
for _, inode := range n.inodes {
b._forEachPageNode(inode.pgid, depth+1, fn)
}
}
}
}
// spill writes all the nodes for this bucket to dirty pages.
func (b *Bucket) spill() error {
// Spill all child buckets first.
for name, child := range b.buckets {
// If the child bucket is small enough and it has no child buckets then
// write it inline into the parent bucket's page. Otherwise spill it
// like a normal bucket and make the parent value a pointer to the page.
var value []byte
if child.inlineable() {
child.free()
value = child.write()
} else {
if err := child.spill(); err != nil {
return err
}
// Update the child bucket header in this bucket.
value = make([]byte, unsafe.Sizeof(bucket{}))
var bucket = (*bucket)(unsafe.Pointer(&value[0]))
*bucket = *child.bucket
}
// Skip writing the bucket if there are no materialized nodes.
if child.rootNode == nil {
continue
}
// Update parent node.
var c = b.Cursor()
k, _, flags := c.seek([]byte(name))
if !bytes.Equal([]byte(name), k) {
panic(fmt.Sprintf("misplaced bucket header: %x -> %x", []byte(name), k))
}
if flags&bucketLeafFlag == 0 {
panic(fmt.Sprintf("unexpected bucket header flag: %x", flags))
}
c.node().put([]byte(name), []byte(name), value, 0, bucketLeafFlag)
}
// Ignore if there's not a materialized root node.
if b.rootNode == nil {
return nil
}
// Spill nodes.
if err := b.rootNode.spill(); err != nil {
return err
}
b.rootNode = b.rootNode.root()
// Update the root node for this bucket.
if b.rootNode.pgid >= b.tx.meta.pgid {
panic(fmt.Sprintf("pgid (%d) above high water mark (%d)", b.rootNode.pgid, b.tx.meta.pgid))
}
b.root = b.rootNode.pgid
return nil
}
// inlineable returns true if a bucket is small enough to be written inline
// and if it contains no subbuckets. Otherwise returns false.
func (b *Bucket) inlineable() bool {
var n = b.rootNode
// Bucket must only contain a single leaf node.
if n == nil || !n.isLeaf {
return false
}
// Bucket is not inlineable if it contains subbuckets or if it goes beyond
// our threshold for inline bucket size.
var size = pageHeaderSize
for _, inode := range n.inodes {
size += leafPageElementSize + len(inode.key) + len(inode.value)
if inode.flags&bucketLeafFlag != 0 {
return false
} else if size > b.maxInlineBucketSize() {
return false
}
}
return true
}
// Returns the maximum total size of a bucket to make it a candidate for inlining.
func (b *Bucket) maxInlineBucketSize() int {
return b.tx.db.pageSize / 4
}
// write allocates and writes a bucket to a byte slice.
func (b *Bucket) write() []byte {
// Allocate the appropriate size.
var n = b.rootNode
var value = make([]byte, bucketHeaderSize+n.size())
// Write a bucket header.
var bucket = (*bucket)(unsafe.Pointer(&value[0]))
*bucket = *b.bucket
// Convert byte slice to a fake page and write the root node.
var p = (*page)(unsafe.Pointer(&value[bucketHeaderSize]))
n.write(p)
return value
}
// rebalance attempts to balance all nodes.
func (b *Bucket) rebalance() {
for _, n := range b.nodes {
n.rebalance()
}
for _, child := range b.buckets {
child.rebalance()
}
}
// node creates a node from a page and associates it with a given parent.
func (b *Bucket) node(pgid pgid, parent *node) *node {
_assert(b.nodes != nil, "nodes map expected")
// Retrieve node if it's already been created.
if n := b.nodes[pgid]; n != nil {
return n
}
// Otherwise create a node and cache it.
n := &node{bucket: b, parent: parent}
if parent == nil {
b.rootNode = n
} else {
parent.children = append(parent.children, n)
}
// Use the inline page if this is an inline bucket.
var p = b.page
if p == nil {
p = b.tx.page(pgid)
}
// Read the page into the node and cache it.
n.read(p)
b.nodes[pgid] = n
// Update statistics.
b.tx.stats.NodeCount++
return n
}
// free recursively frees all pages in the bucket.
func (b *Bucket) free() {
if b.root == 0 {
return
}
var tx = b.tx
b.forEachPageNode(func(p *page, n *node, _ int) {
if p != nil {
tx.db.freelist.free(tx.meta.txid, p)
} else {
n.free()
}
})
b.root = 0
}
// dereference removes all references to the old mmap.
func (b *Bucket) dereference() {
if b.rootNode != nil {
b.rootNode.root().dereference()
}
for _, child := range b.buckets {
child.dereference()
}
}
// pageNode returns the in-memory node, if it exists.
// Otherwise returns the underlying page.
func (b *Bucket) pageNode(id pgid) (*page, *node) {
// Inline buckets have a fake page embedded in their value so treat them
// differently. We'll return the rootNode (if available) or the fake page.
if b.root == 0 {
if id != 0 {
panic(fmt.Sprintf("inline bucket non-zero page access(2): %d != 0", id))
}
if b.rootNode != nil {
return nil, b.rootNode
}
return b.page, nil
}
// Check the node cache for non-inline buckets.
if b.nodes != nil {
if n := b.nodes[id]; n != nil {
return nil, n
}
}
// Finally lookup the page from the transaction if no node is materialized.
return b.tx.page(id), nil
}
// BucketStats records statistics about resources used by a bucket.
type BucketStats struct {
// Page count statistics.
BranchPageN int // number of logical branch pages
BranchOverflowN int // number of physical branch overflow pages
LeafPageN int // number of logical leaf pages
LeafOverflowN int // number of physical leaf overflow pages
// Tree statistics.
KeyN int // number of keys/value pairs
Depth int // number of levels in B+tree
// Page size utilization.
BranchAlloc int // bytes allocated for physical branch pages
BranchInuse int // bytes actually used for branch data
LeafAlloc int // bytes allocated for physical leaf pages
LeafInuse int // bytes actually used for leaf data
// Bucket statistics
BucketN int // total number of buckets including the top bucket
InlineBucketN int // total number on inlined buckets
InlineBucketInuse int // bytes used for inlined buckets (also accounted for in LeafInuse)
}
func (s *BucketStats) Add(other BucketStats) {
s.BranchPageN += other.BranchPageN
s.BranchOverflowN += other.BranchOverflowN
s.LeafPageN += other.LeafPageN
s.LeafOverflowN += other.LeafOverflowN
s.KeyN += other.KeyN
if s.Depth < other.Depth {
s.Depth = other.Depth
}
s.BranchAlloc += other.BranchAlloc
s.BranchInuse += other.BranchInuse
s.LeafAlloc += other.LeafAlloc
s.LeafInuse += other.LeafInuse
s.BucketN += other.BucketN
s.InlineBucketN += other.InlineBucketN
s.InlineBucketInuse += other.InlineBucketInuse
}
// cloneBytes returns a copy of a given slice.
func cloneBytes(v []byte) []byte {
var clone = make([]byte, len(v))
copy(clone, v)
return clone
}

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@@ -1,145 +0,0 @@
package main_test
import (
"bytes"
"io/ioutil"
"os"
"strconv"
"testing"
"github.com/coreos/etcd/Godeps/_workspace/src/github.com/boltdb/bolt"
"github.com/coreos/etcd/Godeps/_workspace/src/github.com/boltdb/bolt/cmd/bolt"
)
// Ensure the "info" command can print information about a database.
func TestInfoCommand_Run(t *testing.T) {
db := MustOpen(0666, nil)
db.DB.Close()
defer db.Close()
// Run the info command.
m := NewMain()
if err := m.Run("info", db.Path); err != nil {
t.Fatal(err)
}
}
// Ensure the "stats" command can execute correctly.
func TestStatsCommand_Run(t *testing.T) {
// Ignore
if os.Getpagesize() != 4096 {
t.Skip("system does not use 4KB page size")
}
db := MustOpen(0666, nil)
defer db.Close()
if err := db.Update(func(tx *bolt.Tx) error {
// Create "foo" bucket.
b, err := tx.CreateBucket([]byte("foo"))
if err != nil {
return err
}
for i := 0; i < 10; i++ {
if err := b.Put([]byte(strconv.Itoa(i)), []byte(strconv.Itoa(i))); err != nil {
return err
}
}
// Create "bar" bucket.
b, err = tx.CreateBucket([]byte("bar"))
if err != nil {
return err
}
for i := 0; i < 100; i++ {
if err := b.Put([]byte(strconv.Itoa(i)), []byte(strconv.Itoa(i))); err != nil {
return err
}
}
// Create "baz" bucket.
b, err = tx.CreateBucket([]byte("baz"))
if err != nil {
return err
}
if err := b.Put([]byte("key"), []byte("value")); err != nil {
return err
}
return nil
}); err != nil {
t.Fatal(err)
}
db.DB.Close()
// Generate expected result.
exp := "Aggregate statistics for 3 buckets\n\n" +
"Page count statistics\n" +
"\tNumber of logical branch pages: 0\n" +
"\tNumber of physical branch overflow pages: 0\n" +
"\tNumber of logical leaf pages: 1\n" +
"\tNumber of physical leaf overflow pages: 0\n" +
"Tree statistics\n" +
"\tNumber of keys/value pairs: 111\n" +
"\tNumber of levels in B+tree: 1\n" +
"Page size utilization\n" +
"\tBytes allocated for physical branch pages: 0\n" +
"\tBytes actually used for branch data: 0 (0%)\n" +
"\tBytes allocated for physical leaf pages: 4096\n" +
"\tBytes actually used for leaf data: 1996 (48%)\n" +
"Bucket statistics\n" +
"\tTotal number of buckets: 3\n" +
"\tTotal number on inlined buckets: 2 (66%)\n" +
"\tBytes used for inlined buckets: 236 (11%)\n"
// Run the command.
m := NewMain()
if err := m.Run("stats", db.Path); err != nil {
t.Fatal(err)
} else if m.Stdout.String() != exp {
t.Fatalf("unexpected stdout:\n\n%s", m.Stdout.String())
}
}
// Main represents a test wrapper for main.Main that records output.
type Main struct {
*main.Main
Stdin bytes.Buffer
Stdout bytes.Buffer
Stderr bytes.Buffer
}
// NewMain returns a new instance of Main.
func NewMain() *Main {
m := &Main{Main: main.NewMain()}
m.Main.Stdin = &m.Stdin
m.Main.Stdout = &m.Stdout
m.Main.Stderr = &m.Stderr
return m
}
// MustOpen creates a Bolt database in a temporary location.
func MustOpen(mode os.FileMode, options *bolt.Options) *DB {
// Create temporary path.
f, _ := ioutil.TempFile("", "bolt-")
f.Close()
os.Remove(f.Name())
db, err := bolt.Open(f.Name(), mode, options)
if err != nil {
panic(err.Error())
}
return &DB{DB: db, Path: f.Name()}
}
// DB is a test wrapper for bolt.DB.
type DB struct {
*bolt.DB
Path string
}
// Close closes and removes the database.
func (db *DB) Close() error {
defer os.Remove(db.Path)
return db.DB.Close()
}

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@@ -1,384 +0,0 @@
package bolt
import (
"bytes"
"fmt"
"sort"
)
// Cursor represents an iterator that can traverse over all key/value pairs in a bucket in sorted order.
// Cursors see nested buckets with value == nil.
// Cursors can be obtained from a transaction and are valid as long as the transaction is open.
//
// Keys and values returned from the cursor are only valid for the life of the transaction.
//
// Changing data while traversing with a cursor may cause it to be invalidated
// and return unexpected keys and/or values. You must reposition your cursor
// after mutating data.
type Cursor struct {
bucket *Bucket
stack []elemRef
}
// Bucket returns the bucket that this cursor was created from.
func (c *Cursor) Bucket() *Bucket {
return c.bucket
}
// First moves the cursor to the first item in the bucket and returns its key and value.
// If the bucket is empty then a nil key and value are returned.
// The returned key and value are only valid for the life of the transaction.
func (c *Cursor) First() (key []byte, value []byte) {
_assert(c.bucket.tx.db != nil, "tx closed")
c.stack = c.stack[:0]
p, n := c.bucket.pageNode(c.bucket.root)
c.stack = append(c.stack, elemRef{page: p, node: n, index: 0})
c.first()
k, v, flags := c.keyValue()
if (flags & uint32(bucketLeafFlag)) != 0 {
return k, nil
}
return k, v
}
// Last moves the cursor to the last item in the bucket and returns its key and value.
// If the bucket is empty then a nil key and value are returned.
// The returned key and value are only valid for the life of the transaction.
func (c *Cursor) Last() (key []byte, value []byte) {
_assert(c.bucket.tx.db != nil, "tx closed")
c.stack = c.stack[:0]
p, n := c.bucket.pageNode(c.bucket.root)
ref := elemRef{page: p, node: n}
ref.index = ref.count() - 1
c.stack = append(c.stack, ref)
c.last()
k, v, flags := c.keyValue()
if (flags & uint32(bucketLeafFlag)) != 0 {
return k, nil
}
return k, v
}
// Next moves the cursor to the next item in the bucket and returns its key and value.
// If the cursor is at the end of the bucket then a nil key and value are returned.
// The returned key and value are only valid for the life of the transaction.
func (c *Cursor) Next() (key []byte, value []byte) {
_assert(c.bucket.tx.db != nil, "tx closed")
k, v, flags := c.next()
if (flags & uint32(bucketLeafFlag)) != 0 {
return k, nil
}
return k, v
}
// Prev moves the cursor to the previous item in the bucket and returns its key and value.
// If the cursor is at the beginning of the bucket then a nil key and value are returned.
// The returned key and value are only valid for the life of the transaction.
func (c *Cursor) Prev() (key []byte, value []byte) {
_assert(c.bucket.tx.db != nil, "tx closed")
// Attempt to move back one element until we're successful.
// Move up the stack as we hit the beginning of each page in our stack.
for i := len(c.stack) - 1; i >= 0; i-- {
elem := &c.stack[i]
if elem.index > 0 {
elem.index--
break
}
c.stack = c.stack[:i]
}
// If we've hit the end then return nil.
if len(c.stack) == 0 {
return nil, nil
}
// Move down the stack to find the last element of the last leaf under this branch.
c.last()
k, v, flags := c.keyValue()
if (flags & uint32(bucketLeafFlag)) != 0 {
return k, nil
}
return k, v
}
// Seek moves the cursor to a given key and returns it.
// If the key does not exist then the next key is used. If no keys
// follow, a nil key is returned.
// The returned key and value are only valid for the life of the transaction.
func (c *Cursor) Seek(seek []byte) (key []byte, value []byte) {
k, v, flags := c.seek(seek)
// If we ended up after the last element of a page then move to the next one.
if ref := &c.stack[len(c.stack)-1]; ref.index >= ref.count() {
k, v, flags = c.next()
}
if k == nil {
return nil, nil
} else if (flags & uint32(bucketLeafFlag)) != 0 {
return k, nil
}
return k, v
}
// Delete removes the current key/value under the cursor from the bucket.
// Delete fails if current key/value is a bucket or if the transaction is not writable.
func (c *Cursor) Delete() error {
if c.bucket.tx.db == nil {
return ErrTxClosed
} else if !c.bucket.Writable() {
return ErrTxNotWritable
}
key, _, flags := c.keyValue()
// Return an error if current value is a bucket.
if (flags & bucketLeafFlag) != 0 {
return ErrIncompatibleValue
}
c.node().del(key)
return nil
}
// seek moves the cursor to a given key and returns it.
// If the key does not exist then the next key is used.
func (c *Cursor) seek(seek []byte) (key []byte, value []byte, flags uint32) {
_assert(c.bucket.tx.db != nil, "tx closed")
// Start from root page/node and traverse to correct page.
c.stack = c.stack[:0]
c.search(seek, c.bucket.root)
ref := &c.stack[len(c.stack)-1]
// If the cursor is pointing to the end of page/node then return nil.
if ref.index >= ref.count() {
return nil, nil, 0
}
// If this is a bucket then return a nil value.
return c.keyValue()
}
// first moves the cursor to the first leaf element under the last page in the stack.
func (c *Cursor) first() {
for {
// Exit when we hit a leaf page.
var ref = &c.stack[len(c.stack)-1]
if ref.isLeaf() {
break
}
// Keep adding pages pointing to the first element to the stack.
var pgid pgid
if ref.node != nil {
pgid = ref.node.inodes[ref.index].pgid
} else {
pgid = ref.page.branchPageElement(uint16(ref.index)).pgid
}
p, n := c.bucket.pageNode(pgid)
c.stack = append(c.stack, elemRef{page: p, node: n, index: 0})
}
}
// last moves the cursor to the last leaf element under the last page in the stack.
func (c *Cursor) last() {
for {
// Exit when we hit a leaf page.
ref := &c.stack[len(c.stack)-1]
if ref.isLeaf() {
break
}
// Keep adding pages pointing to the last element in the stack.
var pgid pgid
if ref.node != nil {
pgid = ref.node.inodes[ref.index].pgid
} else {
pgid = ref.page.branchPageElement(uint16(ref.index)).pgid
}
p, n := c.bucket.pageNode(pgid)
var nextRef = elemRef{page: p, node: n}
nextRef.index = nextRef.count() - 1
c.stack = append(c.stack, nextRef)
}
}
// next moves to the next leaf element and returns the key and value.
// If the cursor is at the last leaf element then it stays there and returns nil.
func (c *Cursor) next() (key []byte, value []byte, flags uint32) {
// Attempt to move over one element until we're successful.
// Move up the stack as we hit the end of each page in our stack.
var i int
for i = len(c.stack) - 1; i >= 0; i-- {
elem := &c.stack[i]
if elem.index < elem.count()-1 {
elem.index++
break
}
}
// If we've hit the root page then stop and return. This will leave the
// cursor on the last element of the last page.
if i == -1 {
return nil, nil, 0
}
// Otherwise start from where we left off in the stack and find the
// first element of the first leaf page.
c.stack = c.stack[:i+1]
c.first()
return c.keyValue()
}
// search recursively performs a binary search against a given page/node until it finds a given key.
func (c *Cursor) search(key []byte, pgid pgid) {
p, n := c.bucket.pageNode(pgid)
if p != nil && (p.flags&(branchPageFlag|leafPageFlag)) == 0 {
panic(fmt.Sprintf("invalid page type: %d: %x", p.id, p.flags))
}
e := elemRef{page: p, node: n}
c.stack = append(c.stack, e)
// If we're on a leaf page/node then find the specific node.
if e.isLeaf() {
c.nsearch(key)
return
}
if n != nil {
c.searchNode(key, n)
return
}
c.searchPage(key, p)
}
func (c *Cursor) searchNode(key []byte, n *node) {
var exact bool
index := sort.Search(len(n.inodes), func(i int) bool {
// TODO(benbjohnson): Optimize this range search. It's a bit hacky right now.
// sort.Search() finds the lowest index where f() != -1 but we need the highest index.
ret := bytes.Compare(n.inodes[i].key, key)
if ret == 0 {
exact = true
}
return ret != -1
})
if !exact && index > 0 {
index--
}
c.stack[len(c.stack)-1].index = index
// Recursively search to the next page.
c.search(key, n.inodes[index].pgid)
}
func (c *Cursor) searchPage(key []byte, p *page) {
// Binary search for the correct range.
inodes := p.branchPageElements()
var exact bool
index := sort.Search(int(p.count), func(i int) bool {
// TODO(benbjohnson): Optimize this range search. It's a bit hacky right now.
// sort.Search() finds the lowest index where f() != -1 but we need the highest index.
ret := bytes.Compare(inodes[i].key(), key)
if ret == 0 {
exact = true
}
return ret != -1
})
if !exact && index > 0 {
index--
}
c.stack[len(c.stack)-1].index = index
// Recursively search to the next page.
c.search(key, inodes[index].pgid)
}
// nsearch searches the leaf node on the top of the stack for a key.
func (c *Cursor) nsearch(key []byte) {
e := &c.stack[len(c.stack)-1]
p, n := e.page, e.node
// If we have a node then search its inodes.
if n != nil {
index := sort.Search(len(n.inodes), func(i int) bool {
return bytes.Compare(n.inodes[i].key, key) != -1
})
e.index = index
return
}
// If we have a page then search its leaf elements.
inodes := p.leafPageElements()
index := sort.Search(int(p.count), func(i int) bool {
return bytes.Compare(inodes[i].key(), key) != -1
})
e.index = index
}
// keyValue returns the key and value of the current leaf element.
func (c *Cursor) keyValue() ([]byte, []byte, uint32) {
ref := &c.stack[len(c.stack)-1]
if ref.count() == 0 || ref.index >= ref.count() {
return nil, nil, 0
}
// Retrieve value from node.
if ref.node != nil {
inode := &ref.node.inodes[ref.index]
return inode.key, inode.value, inode.flags
}
// Or retrieve value from page.
elem := ref.page.leafPageElement(uint16(ref.index))
return elem.key(), elem.value(), elem.flags
}
// node returns the node that the cursor is currently positioned on.
func (c *Cursor) node() *node {
_assert(len(c.stack) > 0, "accessing a node with a zero-length cursor stack")
// If the top of the stack is a leaf node then just return it.
if ref := &c.stack[len(c.stack)-1]; ref.node != nil && ref.isLeaf() {
return ref.node
}
// Start from root and traverse down the hierarchy.
var n = c.stack[0].node
if n == nil {
n = c.bucket.node(c.stack[0].page.id, nil)
}
for _, ref := range c.stack[:len(c.stack)-1] {
_assert(!n.isLeaf, "expected branch node")
n = n.childAt(int(ref.index))
}
_assert(n.isLeaf, "expected leaf node")
return n
}
// elemRef represents a reference to an element on a given page/node.
type elemRef struct {
page *page
node *node
index int
}
// isLeaf returns whether the ref is pointing at a leaf page/node.
func (r *elemRef) isLeaf() bool {
if r.node != nil {
return r.node.isLeaf
}
return (r.page.flags & leafPageFlag) != 0
}
// count returns the number of inodes or page elements.
func (r *elemRef) count() int {
if r.node != nil {
return len(r.node.inodes)
}
return int(r.page.count)
}

View File

@@ -1,511 +0,0 @@
package bolt_test
import (
"bytes"
"encoding/binary"
"fmt"
"os"
"sort"
"testing"
"testing/quick"
"github.com/coreos/etcd/Godeps/_workspace/src/github.com/boltdb/bolt"
)
// Ensure that a cursor can return a reference to the bucket that created it.
func TestCursor_Bucket(t *testing.T) {
db := NewTestDB()
defer db.Close()
db.Update(func(tx *bolt.Tx) error {
b, _ := tx.CreateBucket([]byte("widgets"))
c := b.Cursor()
equals(t, b, c.Bucket())
return nil
})
}
// Ensure that a Tx cursor can seek to the appropriate keys.
func TestCursor_Seek(t *testing.T) {
db := NewTestDB()
defer db.Close()
db.Update(func(tx *bolt.Tx) error {
b, err := tx.CreateBucket([]byte("widgets"))
ok(t, err)
ok(t, b.Put([]byte("foo"), []byte("0001")))
ok(t, b.Put([]byte("bar"), []byte("0002")))
ok(t, b.Put([]byte("baz"), []byte("0003")))
_, err = b.CreateBucket([]byte("bkt"))
ok(t, err)
return nil
})
db.View(func(tx *bolt.Tx) error {
c := tx.Bucket([]byte("widgets")).Cursor()
// Exact match should go to the key.
k, v := c.Seek([]byte("bar"))
equals(t, []byte("bar"), k)
equals(t, []byte("0002"), v)
// Inexact match should go to the next key.
k, v = c.Seek([]byte("bas"))
equals(t, []byte("baz"), k)
equals(t, []byte("0003"), v)
// Low key should go to the first key.
k, v = c.Seek([]byte(""))
equals(t, []byte("bar"), k)
equals(t, []byte("0002"), v)
// High key should return no key.
k, v = c.Seek([]byte("zzz"))
assert(t, k == nil, "")
assert(t, v == nil, "")
// Buckets should return their key but no value.
k, v = c.Seek([]byte("bkt"))
equals(t, []byte("bkt"), k)
assert(t, v == nil, "")
return nil
})
}
func TestCursor_Delete(t *testing.T) {
db := NewTestDB()
defer db.Close()
var count = 1000
// Insert every other key between 0 and $count.
db.Update(func(tx *bolt.Tx) error {
b, _ := tx.CreateBucket([]byte("widgets"))
for i := 0; i < count; i += 1 {
k := make([]byte, 8)
binary.BigEndian.PutUint64(k, uint64(i))
b.Put(k, make([]byte, 100))
}
b.CreateBucket([]byte("sub"))
return nil
})
db.Update(func(tx *bolt.Tx) error {
c := tx.Bucket([]byte("widgets")).Cursor()
bound := make([]byte, 8)
binary.BigEndian.PutUint64(bound, uint64(count/2))
for key, _ := c.First(); bytes.Compare(key, bound) < 0; key, _ = c.Next() {
if err := c.Delete(); err != nil {
return err
}
}
c.Seek([]byte("sub"))
err := c.Delete()
equals(t, err, bolt.ErrIncompatibleValue)
return nil
})
db.View(func(tx *bolt.Tx) error {
b := tx.Bucket([]byte("widgets"))
equals(t, b.Stats().KeyN, count/2+1)
return nil
})
}
// Ensure that a Tx cursor can seek to the appropriate keys when there are a
// large number of keys. This test also checks that seek will always move
// forward to the next key.
//
// Related: https://github.com/boltdb/bolt/pull/187
func TestCursor_Seek_Large(t *testing.T) {
db := NewTestDB()
defer db.Close()
var count = 10000
// Insert every other key between 0 and $count.
db.Update(func(tx *bolt.Tx) error {
b, _ := tx.CreateBucket([]byte("widgets"))
for i := 0; i < count; i += 100 {
for j := i; j < i+100; j += 2 {
k := make([]byte, 8)
binary.BigEndian.PutUint64(k, uint64(j))
b.Put(k, make([]byte, 100))
}
}
return nil
})
db.View(func(tx *bolt.Tx) error {
c := tx.Bucket([]byte("widgets")).Cursor()
for i := 0; i < count; i++ {
seek := make([]byte, 8)
binary.BigEndian.PutUint64(seek, uint64(i))
k, _ := c.Seek(seek)
// The last seek is beyond the end of the the range so
// it should return nil.
if i == count-1 {
assert(t, k == nil, "")
continue
}
// Otherwise we should seek to the exact key or the next key.
num := binary.BigEndian.Uint64(k)
if i%2 == 0 {
equals(t, uint64(i), num)
} else {
equals(t, uint64(i+1), num)
}
}
return nil
})
}
// Ensure that a cursor can iterate over an empty bucket without error.
func TestCursor_EmptyBucket(t *testing.T) {
db := NewTestDB()
defer db.Close()
db.Update(func(tx *bolt.Tx) error {
_, err := tx.CreateBucket([]byte("widgets"))
return err
})
db.View(func(tx *bolt.Tx) error {
c := tx.Bucket([]byte("widgets")).Cursor()
k, v := c.First()
assert(t, k == nil, "")
assert(t, v == nil, "")
return nil
})
}
// Ensure that a Tx cursor can reverse iterate over an empty bucket without error.
func TestCursor_EmptyBucketReverse(t *testing.T) {
db := NewTestDB()
defer db.Close()
db.Update(func(tx *bolt.Tx) error {
_, err := tx.CreateBucket([]byte("widgets"))
return err
})
db.View(func(tx *bolt.Tx) error {
c := tx.Bucket([]byte("widgets")).Cursor()
k, v := c.Last()
assert(t, k == nil, "")
assert(t, v == nil, "")
return nil
})
}
// Ensure that a Tx cursor can iterate over a single root with a couple elements.
func TestCursor_Iterate_Leaf(t *testing.T) {
db := NewTestDB()
defer db.Close()
db.Update(func(tx *bolt.Tx) error {
tx.CreateBucket([]byte("widgets"))
tx.Bucket([]byte("widgets")).Put([]byte("baz"), []byte{})
tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte{0})
tx.Bucket([]byte("widgets")).Put([]byte("bar"), []byte{1})
return nil
})
tx, _ := db.Begin(false)
c := tx.Bucket([]byte("widgets")).Cursor()
k, v := c.First()
equals(t, string(k), "bar")
equals(t, v, []byte{1})
k, v = c.Next()
equals(t, string(k), "baz")
equals(t, v, []byte{})
k, v = c.Next()
equals(t, string(k), "foo")
equals(t, v, []byte{0})
k, v = c.Next()
assert(t, k == nil, "")
assert(t, v == nil, "")
k, v = c.Next()
assert(t, k == nil, "")
assert(t, v == nil, "")
tx.Rollback()
}
// Ensure that a Tx cursor can iterate in reverse over a single root with a couple elements.
func TestCursor_LeafRootReverse(t *testing.T) {
db := NewTestDB()
defer db.Close()
db.Update(func(tx *bolt.Tx) error {
tx.CreateBucket([]byte("widgets"))
tx.Bucket([]byte("widgets")).Put([]byte("baz"), []byte{})
tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte{0})
tx.Bucket([]byte("widgets")).Put([]byte("bar"), []byte{1})
return nil
})
tx, _ := db.Begin(false)
c := tx.Bucket([]byte("widgets")).Cursor()
k, v := c.Last()
equals(t, string(k), "foo")
equals(t, v, []byte{0})
k, v = c.Prev()
equals(t, string(k), "baz")
equals(t, v, []byte{})
k, v = c.Prev()
equals(t, string(k), "bar")
equals(t, v, []byte{1})
k, v = c.Prev()
assert(t, k == nil, "")
assert(t, v == nil, "")
k, v = c.Prev()
assert(t, k == nil, "")
assert(t, v == nil, "")
tx.Rollback()
}
// Ensure that a Tx cursor can restart from the beginning.
func TestCursor_Restart(t *testing.T) {
db := NewTestDB()
defer db.Close()
db.Update(func(tx *bolt.Tx) error {
tx.CreateBucket([]byte("widgets"))
tx.Bucket([]byte("widgets")).Put([]byte("bar"), []byte{})
tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte{})
return nil
})
tx, _ := db.Begin(false)
c := tx.Bucket([]byte("widgets")).Cursor()
k, _ := c.First()
equals(t, string(k), "bar")
k, _ = c.Next()
equals(t, string(k), "foo")
k, _ = c.First()
equals(t, string(k), "bar")
k, _ = c.Next()
equals(t, string(k), "foo")
tx.Rollback()
}
// Ensure that a Tx can iterate over all elements in a bucket.
func TestCursor_QuickCheck(t *testing.T) {
f := func(items testdata) bool {
db := NewTestDB()
defer db.Close()
// Bulk insert all values.
tx, _ := db.Begin(true)
tx.CreateBucket([]byte("widgets"))
b := tx.Bucket([]byte("widgets"))
for _, item := range items {
ok(t, b.Put(item.Key, item.Value))
}
ok(t, tx.Commit())
// Sort test data.
sort.Sort(items)
// Iterate over all items and check consistency.
var index = 0
tx, _ = db.Begin(false)
c := tx.Bucket([]byte("widgets")).Cursor()
for k, v := c.First(); k != nil && index < len(items); k, v = c.Next() {
equals(t, k, items[index].Key)
equals(t, v, items[index].Value)
index++
}
equals(t, len(items), index)
tx.Rollback()
return true
}
if err := quick.Check(f, qconfig()); err != nil {
t.Error(err)
}
}
// Ensure that a transaction can iterate over all elements in a bucket in reverse.
func TestCursor_QuickCheck_Reverse(t *testing.T) {
f := func(items testdata) bool {
db := NewTestDB()
defer db.Close()
// Bulk insert all values.
tx, _ := db.Begin(true)
tx.CreateBucket([]byte("widgets"))
b := tx.Bucket([]byte("widgets"))
for _, item := range items {
ok(t, b.Put(item.Key, item.Value))
}
ok(t, tx.Commit())
// Sort test data.
sort.Sort(revtestdata(items))
// Iterate over all items and check consistency.
var index = 0
tx, _ = db.Begin(false)
c := tx.Bucket([]byte("widgets")).Cursor()
for k, v := c.Last(); k != nil && index < len(items); k, v = c.Prev() {
equals(t, k, items[index].Key)
equals(t, v, items[index].Value)
index++
}
equals(t, len(items), index)
tx.Rollback()
return true
}
if err := quick.Check(f, qconfig()); err != nil {
t.Error(err)
}
}
// Ensure that a Tx cursor can iterate over subbuckets.
func TestCursor_QuickCheck_BucketsOnly(t *testing.T) {
db := NewTestDB()
defer db.Close()
db.Update(func(tx *bolt.Tx) error {
b, err := tx.CreateBucket([]byte("widgets"))
ok(t, err)
_, err = b.CreateBucket([]byte("foo"))
ok(t, err)
_, err = b.CreateBucket([]byte("bar"))
ok(t, err)
_, err = b.CreateBucket([]byte("baz"))
ok(t, err)
return nil
})
db.View(func(tx *bolt.Tx) error {
var names []string
c := tx.Bucket([]byte("widgets")).Cursor()
for k, v := c.First(); k != nil; k, v = c.Next() {
names = append(names, string(k))
assert(t, v == nil, "")
}
equals(t, names, []string{"bar", "baz", "foo"})
return nil
})
}
// Ensure that a Tx cursor can reverse iterate over subbuckets.
func TestCursor_QuickCheck_BucketsOnly_Reverse(t *testing.T) {
db := NewTestDB()
defer db.Close()
db.Update(func(tx *bolt.Tx) error {
b, err := tx.CreateBucket([]byte("widgets"))
ok(t, err)
_, err = b.CreateBucket([]byte("foo"))
ok(t, err)
_, err = b.CreateBucket([]byte("bar"))
ok(t, err)
_, err = b.CreateBucket([]byte("baz"))
ok(t, err)
return nil
})
db.View(func(tx *bolt.Tx) error {
var names []string
c := tx.Bucket([]byte("widgets")).Cursor()
for k, v := c.Last(); k != nil; k, v = c.Prev() {
names = append(names, string(k))
assert(t, v == nil, "")
}
equals(t, names, []string{"foo", "baz", "bar"})
return nil
})
}
func ExampleCursor() {
// Open the database.
db, _ := bolt.Open(tempfile(), 0666, nil)
defer os.Remove(db.Path())
defer db.Close()
// Start a read-write transaction.
db.Update(func(tx *bolt.Tx) error {
// Create a new bucket.
tx.CreateBucket([]byte("animals"))
// Insert data into a bucket.
b := tx.Bucket([]byte("animals"))
b.Put([]byte("dog"), []byte("fun"))
b.Put([]byte("cat"), []byte("lame"))
b.Put([]byte("liger"), []byte("awesome"))
// Create a cursor for iteration.
c := b.Cursor()
// Iterate over items in sorted key order. This starts from the
// first key/value pair and updates the k/v variables to the
// next key/value on each iteration.
//
// The loop finishes at the end of the cursor when a nil key is returned.
for k, v := c.First(); k != nil; k, v = c.Next() {
fmt.Printf("A %s is %s.\n", k, v)
}
return nil
})
// Output:
// A cat is lame.
// A dog is fun.
// A liger is awesome.
}
func ExampleCursor_reverse() {
// Open the database.
db, _ := bolt.Open(tempfile(), 0666, nil)
defer os.Remove(db.Path())
defer db.Close()
// Start a read-write transaction.
db.Update(func(tx *bolt.Tx) error {
// Create a new bucket.
tx.CreateBucket([]byte("animals"))
// Insert data into a bucket.
b := tx.Bucket([]byte("animals"))
b.Put([]byte("dog"), []byte("fun"))
b.Put([]byte("cat"), []byte("lame"))
b.Put([]byte("liger"), []byte("awesome"))
// Create a cursor for iteration.
c := b.Cursor()
// Iterate over items in reverse sorted key order. This starts
// from the last key/value pair and updates the k/v variables to
// the previous key/value on each iteration.
//
// The loop finishes at the beginning of the cursor when a nil key
// is returned.
for k, v := c.Last(); k != nil; k, v = c.Prev() {
fmt.Printf("A %s is %s.\n", k, v)
}
return nil
})
// Output:
// A liger is awesome.
// A dog is fun.
// A cat is lame.
}

View File

@@ -1,792 +0,0 @@
package bolt
import (
"fmt"
"hash/fnv"
"os"
"runtime"
"runtime/debug"
"strings"
"sync"
"time"
"unsafe"
)
// The largest step that can be taken when remapping the mmap.
const maxMmapStep = 1 << 30 // 1GB
// The data file format version.
const version = 2
// Represents a marker value to indicate that a file is a Bolt DB.
const magic uint32 = 0xED0CDAED
// IgnoreNoSync specifies whether the NoSync field of a DB is ignored when
// syncing changes to a file. This is required as some operating systems,
// such as OpenBSD, do not have a unified buffer cache (UBC) and writes
// must be synchronzied using the msync(2) syscall.
const IgnoreNoSync = runtime.GOOS == "openbsd"
// Default values if not set in a DB instance.
const (
DefaultMaxBatchSize int = 1000
DefaultMaxBatchDelay = 10 * time.Millisecond
)
// DB represents a collection of buckets persisted to a file on disk.
// All data access is performed through transactions which can be obtained through the DB.
// All the functions on DB will return a ErrDatabaseNotOpen if accessed before Open() is called.
type DB struct {
// When enabled, the database will perform a Check() after every commit.
// A panic is issued if the database is in an inconsistent state. This
// flag has a large performance impact so it should only be used for
// debugging purposes.
StrictMode bool
// Setting the NoSync flag will cause the database to skip fsync()
// calls after each commit. This can be useful when bulk loading data
// into a database and you can restart the bulk load in the event of
// a system failure or database corruption. Do not set this flag for
// normal use.
//
// If the package global IgnoreNoSync constant is true, this value is
// ignored. See the comment on that constant for more details.
//
// THIS IS UNSAFE. PLEASE USE WITH CAUTION.
NoSync bool
// When true, skips the truncate call when growing the database.
// Setting this to true is only safe on non-ext3/ext4 systems.
// Skipping truncation avoids preallocation of hard drive space and
// bypasses a truncate() and fsync() syscall on remapping.
//
// https://github.com/boltdb/bolt/issues/284
NoGrowSync bool
// MaxBatchSize is the maximum size of a batch. Default value is
// copied from DefaultMaxBatchSize in Open.
//
// If <=0, disables batching.
//
// Do not change concurrently with calls to Batch.
MaxBatchSize int
// MaxBatchDelay is the maximum delay before a batch starts.
// Default value is copied from DefaultMaxBatchDelay in Open.
//
// If <=0, effectively disables batching.
//
// Do not change concurrently with calls to Batch.
MaxBatchDelay time.Duration
path string
file *os.File
dataref []byte // mmap'ed readonly, write throws SEGV
data *[maxMapSize]byte
datasz int
meta0 *meta
meta1 *meta
pageSize int
opened bool
rwtx *Tx
txs []*Tx
freelist *freelist
stats Stats
batchMu sync.Mutex
batch *batch
rwlock sync.Mutex // Allows only one writer at a time.
metalock sync.Mutex // Protects meta page access.
mmaplock sync.RWMutex // Protects mmap access during remapping.
statlock sync.RWMutex // Protects stats access.
ops struct {
writeAt func(b []byte, off int64) (n int, err error)
}
// Read only mode.
// When true, Update() and Begin(true) return ErrDatabaseReadOnly immediately.
readOnly bool
}
// Path returns the path to currently open database file.
func (db *DB) Path() string {
return db.path
}
// GoString returns the Go string representation of the database.
func (db *DB) GoString() string {
return fmt.Sprintf("bolt.DB{path:%q}", db.path)
}
// String returns the string representation of the database.
func (db *DB) String() string {
return fmt.Sprintf("DB<%q>", db.path)
}
// Open creates and opens a database at the given path.
// If the file does not exist then it will be created automatically.
// Passing in nil options will cause Bolt to open the database with the default options.
func Open(path string, mode os.FileMode, options *Options) (*DB, error) {
var db = &DB{opened: true}
// Set default options if no options are provided.
if options == nil {
options = DefaultOptions
}
db.NoGrowSync = options.NoGrowSync
// Set default values for later DB operations.
db.MaxBatchSize = DefaultMaxBatchSize
db.MaxBatchDelay = DefaultMaxBatchDelay
flag := os.O_RDWR
if options.ReadOnly {
flag = os.O_RDONLY
db.readOnly = true
}
// Open data file and separate sync handler for metadata writes.
db.path = path
var err error
if db.file, err = os.OpenFile(db.path, flag|os.O_CREATE, mode); err != nil {
_ = db.close()
return nil, err
}
// Lock file so that other processes using Bolt in read-write mode cannot
// use the database at the same time. This would cause corruption since
// the two processes would write meta pages and free pages separately.
// The database file is locked exclusively (only one process can grab the lock)
// if !options.ReadOnly.
// The database file is locked using the shared lock (more than one process may
// hold a lock at the same time) otherwise (options.ReadOnly is set).
if err := flock(db.file, !db.readOnly, options.Timeout); err != nil {
_ = db.close()
return nil, err
}
// Default values for test hooks
db.ops.writeAt = db.file.WriteAt
// Initialize the database if it doesn't exist.
if info, err := db.file.Stat(); err != nil {
return nil, fmt.Errorf("stat error: %s", err)
} else if info.Size() == 0 {
// Initialize new files with meta pages.
if err := db.init(); err != nil {
return nil, err
}
} else {
// Read the first meta page to determine the page size.
var buf [0x1000]byte
if _, err := db.file.ReadAt(buf[:], 0); err == nil {
m := db.pageInBuffer(buf[:], 0).meta()
if err := m.validate(); err != nil {
return nil, fmt.Errorf("meta0 error: %s", err)
}
db.pageSize = int(m.pageSize)
}
}
// Memory map the data file.
if err := db.mmap(0); err != nil {
_ = db.close()
return nil, err
}
// Read in the freelist.
db.freelist = newFreelist()
db.freelist.read(db.page(db.meta().freelist))
// Mark the database as opened and return.
return db, nil
}
// mmap opens the underlying memory-mapped file and initializes the meta references.
// minsz is the minimum size that the new mmap can be.
func (db *DB) mmap(minsz int) error {
db.mmaplock.Lock()
defer db.mmaplock.Unlock()
info, err := db.file.Stat()
if err != nil {
return fmt.Errorf("mmap stat error: %s", err)
} else if int(info.Size()) < db.pageSize*2 {
return fmt.Errorf("file size too small")
}
// Ensure the size is at least the minimum size.
var size = int(info.Size())
if size < minsz {
size = minsz
}
size, err = db.mmapSize(size)
if err != nil {
return err
}
// Dereference all mmap references before unmapping.
if db.rwtx != nil {
db.rwtx.root.dereference()
}
// Unmap existing data before continuing.
if err := db.munmap(); err != nil {
return err
}
// Memory-map the data file as a byte slice.
if err := mmap(db, size); err != nil {
return err
}
// Save references to the meta pages.
db.meta0 = db.page(0).meta()
db.meta1 = db.page(1).meta()
// Validate the meta pages.
if err := db.meta0.validate(); err != nil {
return fmt.Errorf("meta0 error: %s", err)
}
if err := db.meta1.validate(); err != nil {
return fmt.Errorf("meta1 error: %s", err)
}
return nil
}
// munmap unmaps the data file from memory.
func (db *DB) munmap() error {
if err := munmap(db); err != nil {
return fmt.Errorf("unmap error: " + err.Error())
}
return nil
}
// mmapSize determines the appropriate size for the mmap given the current size
// of the database. The minimum size is 1MB and doubles until it reaches 1GB.
// Returns an error if the new mmap size is greater than the max allowed.
func (db *DB) mmapSize(size int) (int, error) {
// Double the size from 32KB until 1GB.
for i := uint(15); i <= 30; i++ {
if size <= 1<<i {
return 1 << i, nil
}
}
// Verify the requested size is not above the maximum allowed.
if size > maxMapSize {
return 0, fmt.Errorf("mmap too large")
}
// If larger than 1GB then grow by 1GB at a time.
sz := int64(size)
if remainder := sz % int64(maxMmapStep); remainder > 0 {
sz += int64(maxMmapStep) - remainder
}
// Ensure that the mmap size is a multiple of the page size.
// This should always be true since we're incrementing in MBs.
pageSize := int64(db.pageSize)
if (sz % pageSize) != 0 {
sz = ((sz / pageSize) + 1) * pageSize
}
// If we've exceeded the max size then only grow up to the max size.
if sz > maxMapSize {
sz = maxMapSize
}
return int(sz), nil
}
// init creates a new database file and initializes its meta pages.
func (db *DB) init() error {
// Set the page size to the OS page size.
db.pageSize = os.Getpagesize()
// Create two meta pages on a buffer.
buf := make([]byte, db.pageSize*4)
for i := 0; i < 2; i++ {
p := db.pageInBuffer(buf[:], pgid(i))
p.id = pgid(i)
p.flags = metaPageFlag
// Initialize the meta page.
m := p.meta()
m.magic = magic
m.version = version
m.pageSize = uint32(db.pageSize)
m.freelist = 2
m.root = bucket{root: 3}
m.pgid = 4
m.txid = txid(i)
}
// Write an empty freelist at page 3.
p := db.pageInBuffer(buf[:], pgid(2))
p.id = pgid(2)
p.flags = freelistPageFlag
p.count = 0
// Write an empty leaf page at page 4.
p = db.pageInBuffer(buf[:], pgid(3))
p.id = pgid(3)
p.flags = leafPageFlag
p.count = 0
// Write the buffer to our data file.
if _, err := db.ops.writeAt(buf, 0); err != nil {
return err
}
if err := fdatasync(db); err != nil {
return err
}
return nil
}
// Close releases all database resources.
// All transactions must be closed before closing the database.
func (db *DB) Close() error {
db.rwlock.Lock()
defer db.rwlock.Unlock()
db.metalock.Lock()
defer db.metalock.Unlock()
db.mmaplock.RLock()
defer db.mmaplock.RUnlock()
return db.close()
}
func (db *DB) close() error {
db.opened = false
db.freelist = nil
db.path = ""
// Clear ops.
db.ops.writeAt = nil
// Close the mmap.
if err := db.munmap(); err != nil {
return err
}
// Close file handles.
if db.file != nil {
// No need to unlock read-only file.
if !db.readOnly {
// Unlock the file.
_ = funlock(db.file)
}
// Close the file descriptor.
if err := db.file.Close(); err != nil {
return fmt.Errorf("db file close: %s", err)
}
db.file = nil
}
return nil
}
// Begin starts a new transaction.
// Multiple read-only transactions can be used concurrently but only one
// write transaction can be used at a time. Starting multiple write transactions
// will cause the calls to block and be serialized until the current write
// transaction finishes.
//
// Transactions should not be depedent on one another. Opening a read
// transaction and a write transaction in the same goroutine can cause the
// writer to deadlock because the database periodically needs to re-mmap itself
// as it grows and it cannot do that while a read transaction is open.
//
// IMPORTANT: You must close read-only transactions after you are finished or
// else the database will not reclaim old pages.
func (db *DB) Begin(writable bool) (*Tx, error) {
if writable {
return db.beginRWTx()
}
return db.beginTx()
}
func (db *DB) beginTx() (*Tx, error) {
// Lock the meta pages while we initialize the transaction. We obtain
// the meta lock before the mmap lock because that's the order that the
// write transaction will obtain them.
db.metalock.Lock()
// Obtain a read-only lock on the mmap. When the mmap is remapped it will
// obtain a write lock so all transactions must finish before it can be
// remapped.
db.mmaplock.RLock()
// Exit if the database is not open yet.
if !db.opened {
db.mmaplock.RUnlock()
db.metalock.Unlock()
return nil, ErrDatabaseNotOpen
}
// Create a transaction associated with the database.
t := &Tx{}
t.init(db)
// Keep track of transaction until it closes.
db.txs = append(db.txs, t)
n := len(db.txs)
// Unlock the meta pages.
db.metalock.Unlock()
// Update the transaction stats.
db.statlock.Lock()
db.stats.TxN++
db.stats.OpenTxN = n
db.statlock.Unlock()
return t, nil
}
func (db *DB) beginRWTx() (*Tx, error) {
// If the database was opened with Options.ReadOnly, return an error.
if db.readOnly {
return nil, ErrDatabaseReadOnly
}
// Obtain writer lock. This is released by the transaction when it closes.
// This enforces only one writer transaction at a time.
db.rwlock.Lock()
// Once we have the writer lock then we can lock the meta pages so that
// we can set up the transaction.
db.metalock.Lock()
defer db.metalock.Unlock()
// Exit if the database is not open yet.
if !db.opened {
db.rwlock.Unlock()
return nil, ErrDatabaseNotOpen
}
// Create a transaction associated with the database.
t := &Tx{writable: true}
t.init(db)
db.rwtx = t
// Free any pages associated with closed read-only transactions.
var minid txid = 0xFFFFFFFFFFFFFFFF
for _, t := range db.txs {
if t.meta.txid < minid {
minid = t.meta.txid
}
}
if minid > 0 {
db.freelist.release(minid - 1)
}
return t, nil
}
// removeTx removes a transaction from the database.
func (db *DB) removeTx(tx *Tx) {
// Release the read lock on the mmap.
db.mmaplock.RUnlock()
// Use the meta lock to restrict access to the DB object.
db.metalock.Lock()
// Remove the transaction.
for i, t := range db.txs {
if t == tx {
db.txs = append(db.txs[:i], db.txs[i+1:]...)
break
}
}
n := len(db.txs)
// Unlock the meta pages.
db.metalock.Unlock()
// Merge statistics.
db.statlock.Lock()
db.stats.OpenTxN = n
db.stats.TxStats.add(&tx.stats)
db.statlock.Unlock()
}
// Update executes a function within the context of a read-write managed transaction.
// If no error is returned from the function then the transaction is committed.
// If an error is returned then the entire transaction is rolled back.
// Any error that is returned from the function or returned from the commit is
// returned from the Update() method.
//
// Attempting to manually commit or rollback within the function will cause a panic.
func (db *DB) Update(fn func(*Tx) error) error {
t, err := db.Begin(true)
if err != nil {
return err
}
// Make sure the transaction rolls back in the event of a panic.
defer func() {
if t.db != nil {
t.rollback()
}
}()
// Mark as a managed tx so that the inner function cannot manually commit.
t.managed = true
// If an error is returned from the function then rollback and return error.
err = fn(t)
t.managed = false
if err != nil {
_ = t.Rollback()
return err
}
return t.Commit()
}
// View executes a function within the context of a managed read-only transaction.
// Any error that is returned from the function is returned from the View() method.
//
// Attempting to manually rollback within the function will cause a panic.
func (db *DB) View(fn func(*Tx) error) error {
t, err := db.Begin(false)
if err != nil {
return err
}
// Make sure the transaction rolls back in the event of a panic.
defer func() {
if t.db != nil {
t.rollback()
}
}()
// Mark as a managed tx so that the inner function cannot manually rollback.
t.managed = true
// If an error is returned from the function then pass it through.
err = fn(t)
t.managed = false
if err != nil {
_ = t.Rollback()
return err
}
if err := t.Rollback(); err != nil {
return err
}
return nil
}
// Sync executes fdatasync() against the database file handle.
//
// This is not necessary under normal operation, however, if you use NoSync
// then it allows you to force the database file to sync against the disk.
func (db *DB) Sync() error { return fdatasync(db) }
// Stats retrieves ongoing performance stats for the database.
// This is only updated when a transaction closes.
func (db *DB) Stats() Stats {
db.statlock.RLock()
defer db.statlock.RUnlock()
return db.stats
}
// This is for internal access to the raw data bytes from the C cursor, use
// carefully, or not at all.
func (db *DB) Info() *Info {
return &Info{uintptr(unsafe.Pointer(&db.data[0])), db.pageSize}
}
// page retrieves a page reference from the mmap based on the current page size.
func (db *DB) page(id pgid) *page {
pos := id * pgid(db.pageSize)
return (*page)(unsafe.Pointer(&db.data[pos]))
}
// pageInBuffer retrieves a page reference from a given byte array based on the current page size.
func (db *DB) pageInBuffer(b []byte, id pgid) *page {
return (*page)(unsafe.Pointer(&b[id*pgid(db.pageSize)]))
}
// meta retrieves the current meta page reference.
func (db *DB) meta() *meta {
if db.meta0.txid > db.meta1.txid {
return db.meta0
}
return db.meta1
}
// allocate returns a contiguous block of memory starting at a given page.
func (db *DB) allocate(count int) (*page, error) {
// Allocate a temporary buffer for the page.
buf := make([]byte, count*db.pageSize)
p := (*page)(unsafe.Pointer(&buf[0]))
p.overflow = uint32(count - 1)
// Use pages from the freelist if they are available.
if p.id = db.freelist.allocate(count); p.id != 0 {
return p, nil
}
// Resize mmap() if we're at the end.
p.id = db.rwtx.meta.pgid
var minsz = int((p.id+pgid(count))+1) * db.pageSize
if minsz >= db.datasz {
if err := db.mmap(minsz); err != nil {
return nil, fmt.Errorf("mmap allocate error: %s", err)
}
}
// Move the page id high water mark.
db.rwtx.meta.pgid += pgid(count)
return p, nil
}
func (db *DB) IsReadOnly() bool {
return db.readOnly
}
// Options represents the options that can be set when opening a database.
type Options struct {
// Timeout is the amount of time to wait to obtain a file lock.
// When set to zero it will wait indefinitely. This option is only
// available on Darwin and Linux.
Timeout time.Duration
// Sets the DB.NoGrowSync flag before memory mapping the file.
NoGrowSync bool
// Open database in read-only mode. Uses flock(..., LOCK_SH |LOCK_NB) to
// grab a shared lock (UNIX).
ReadOnly bool
}
// DefaultOptions represent the options used if nil options are passed into Open().
// No timeout is used which will cause Bolt to wait indefinitely for a lock.
var DefaultOptions = &Options{
Timeout: 0,
NoGrowSync: false,
}
// Stats represents statistics about the database.
type Stats struct {
// Freelist stats
FreePageN int // total number of free pages on the freelist
PendingPageN int // total number of pending pages on the freelist
FreeAlloc int // total bytes allocated in free pages
FreelistInuse int // total bytes used by the freelist
// Transaction stats
TxN int // total number of started read transactions
OpenTxN int // number of currently open read transactions
TxStats TxStats // global, ongoing stats.
}
// Sub calculates and returns the difference between two sets of database stats.
// This is useful when obtaining stats at two different points and time and
// you need the performance counters that occurred within that time span.
func (s *Stats) Sub(other *Stats) Stats {
if other == nil {
return *s
}
var diff Stats
diff.FreePageN = s.FreePageN
diff.PendingPageN = s.PendingPageN
diff.FreeAlloc = s.FreeAlloc
diff.FreelistInuse = s.FreelistInuse
diff.TxN = other.TxN - s.TxN
diff.TxStats = s.TxStats.Sub(&other.TxStats)
return diff
}
func (s *Stats) add(other *Stats) {
s.TxStats.add(&other.TxStats)
}
type Info struct {
Data uintptr
PageSize int
}
type meta struct {
magic uint32
version uint32
pageSize uint32
flags uint32
root bucket
freelist pgid
pgid pgid
txid txid
checksum uint64
}
// validate checks the marker bytes and version of the meta page to ensure it matches this binary.
func (m *meta) validate() error {
if m.checksum != 0 && m.checksum != m.sum64() {
return ErrChecksum
} else if m.magic != magic {
return ErrInvalid
} else if m.version != version {
return ErrVersionMismatch
}
return nil
}
// copy copies one meta object to another.
func (m *meta) copy(dest *meta) {
*dest = *m
}
// write writes the meta onto a page.
func (m *meta) write(p *page) {
if m.root.root >= m.pgid {
panic(fmt.Sprintf("root bucket pgid (%d) above high water mark (%d)", m.root.root, m.pgid))
} else if m.freelist >= m.pgid {
panic(fmt.Sprintf("freelist pgid (%d) above high water mark (%d)", m.freelist, m.pgid))
}
// Page id is either going to be 0 or 1 which we can determine by the transaction ID.
p.id = pgid(m.txid % 2)
p.flags |= metaPageFlag
// Calculate the checksum.
m.checksum = m.sum64()
m.copy(p.meta())
}
// generates the checksum for the meta.
func (m *meta) sum64() uint64 {
var h = fnv.New64a()
_, _ = h.Write((*[unsafe.Offsetof(meta{}.checksum)]byte)(unsafe.Pointer(m))[:])
return h.Sum64()
}
// _assert will panic with a given formatted message if the given condition is false.
func _assert(condition bool, msg string, v ...interface{}) {
if !condition {
panic(fmt.Sprintf("assertion failed: "+msg, v...))
}
}
func warn(v ...interface{}) { fmt.Fprintln(os.Stderr, v...) }
func warnf(msg string, v ...interface{}) { fmt.Fprintf(os.Stderr, msg+"\n", v...) }
func printstack() {
stack := strings.Join(strings.Split(string(debug.Stack()), "\n")[2:], "\n")
fmt.Fprintln(os.Stderr, stack)
}

View File

@@ -1,913 +0,0 @@
package bolt_test
import (
"encoding/binary"
"errors"
"flag"
"fmt"
"io/ioutil"
"os"
"regexp"
"runtime"
"sort"
"strings"
"testing"
"time"
"github.com/coreos/etcd/Godeps/_workspace/src/github.com/boltdb/bolt"
)
var statsFlag = flag.Bool("stats", false, "show performance stats")
// Ensure that opening a database with a bad path returns an error.
func TestOpen_BadPath(t *testing.T) {
db, err := bolt.Open("", 0666, nil)
assert(t, err != nil, "err: %s", err)
assert(t, db == nil, "")
}
// Ensure that a database can be opened without error.
func TestOpen(t *testing.T) {
path := tempfile()
defer os.Remove(path)
db, err := bolt.Open(path, 0666, nil)
assert(t, db != nil, "")
ok(t, err)
equals(t, db.Path(), path)
ok(t, db.Close())
}
// Ensure that opening an already open database file will timeout.
func TestOpen_Timeout(t *testing.T) {
if runtime.GOOS == "windows" {
t.Skip("timeout not supported on windows")
}
if runtime.GOOS == "solaris" {
t.Skip("solaris fcntl locks don't support intra-process locking")
}
path := tempfile()
defer os.Remove(path)
// Open a data file.
db0, err := bolt.Open(path, 0666, nil)
assert(t, db0 != nil, "")
ok(t, err)
// Attempt to open the database again.
start := time.Now()
db1, err := bolt.Open(path, 0666, &bolt.Options{Timeout: 100 * time.Millisecond})
assert(t, db1 == nil, "")
equals(t, bolt.ErrTimeout, err)
assert(t, time.Since(start) > 100*time.Millisecond, "")
db0.Close()
}
// Ensure that opening an already open database file will wait until its closed.
func TestOpen_Wait(t *testing.T) {
if runtime.GOOS == "windows" {
t.Skip("timeout not supported on windows")
}
if runtime.GOOS == "solaris" {
t.Skip("solaris fcntl locks don't support intra-process locking")
}
path := tempfile()
defer os.Remove(path)
// Open a data file.
db0, err := bolt.Open(path, 0666, nil)
assert(t, db0 != nil, "")
ok(t, err)
// Close it in just a bit.
time.AfterFunc(100*time.Millisecond, func() { db0.Close() })
// Attempt to open the database again.
start := time.Now()
db1, err := bolt.Open(path, 0666, &bolt.Options{Timeout: 200 * time.Millisecond})
assert(t, db1 != nil, "")
ok(t, err)
assert(t, time.Since(start) > 100*time.Millisecond, "")
}
// Ensure that opening a database does not increase its size.
// https://github.com/boltdb/bolt/issues/291
func TestOpen_Size(t *testing.T) {
// Open a data file.
db := NewTestDB()
path := db.Path()
defer db.Close()
// Insert until we get above the minimum 4MB size.
ok(t, db.Update(func(tx *bolt.Tx) error {
b, _ := tx.CreateBucketIfNotExists([]byte("data"))
for i := 0; i < 10000; i++ {
ok(t, b.Put([]byte(fmt.Sprintf("%04d", i)), make([]byte, 1000)))
}
return nil
}))
// Close database and grab the size.
db.DB.Close()
sz := fileSize(path)
if sz == 0 {
t.Fatalf("unexpected new file size: %d", sz)
}
// Reopen database, update, and check size again.
db0, err := bolt.Open(path, 0666, nil)
ok(t, err)
ok(t, db0.Update(func(tx *bolt.Tx) error { return tx.Bucket([]byte("data")).Put([]byte{0}, []byte{0}) }))
ok(t, db0.Close())
newSz := fileSize(path)
if newSz == 0 {
t.Fatalf("unexpected new file size: %d", newSz)
}
// Compare the original size with the new size.
if sz != newSz {
t.Fatalf("unexpected file growth: %d => %d", sz, newSz)
}
}
// Ensure that opening a database beyond the max step size does not increase its size.
// https://github.com/boltdb/bolt/issues/303
func TestOpen_Size_Large(t *testing.T) {
if testing.Short() {
t.Skip("short mode")
}
// Open a data file.
db := NewTestDB()
path := db.Path()
defer db.Close()
// Insert until we get above the minimum 4MB size.
var index uint64
for i := 0; i < 10000; i++ {
ok(t, db.Update(func(tx *bolt.Tx) error {
b, _ := tx.CreateBucketIfNotExists([]byte("data"))
for j := 0; j < 1000; j++ {
ok(t, b.Put(u64tob(index), make([]byte, 50)))
index++
}
return nil
}))
}
// Close database and grab the size.
db.DB.Close()
sz := fileSize(path)
if sz == 0 {
t.Fatalf("unexpected new file size: %d", sz)
} else if sz < (1 << 30) {
t.Fatalf("expected larger initial size: %d", sz)
}
// Reopen database, update, and check size again.
db0, err := bolt.Open(path, 0666, nil)
ok(t, err)
ok(t, db0.Update(func(tx *bolt.Tx) error { return tx.Bucket([]byte("data")).Put([]byte{0}, []byte{0}) }))
ok(t, db0.Close())
newSz := fileSize(path)
if newSz == 0 {
t.Fatalf("unexpected new file size: %d", newSz)
}
// Compare the original size with the new size.
if sz != newSz {
t.Fatalf("unexpected file growth: %d => %d", sz, newSz)
}
}
// Ensure that a re-opened database is consistent.
func TestOpen_Check(t *testing.T) {
path := tempfile()
defer os.Remove(path)
db, err := bolt.Open(path, 0666, nil)
ok(t, err)
ok(t, db.View(func(tx *bolt.Tx) error { return <-tx.Check() }))
db.Close()
db, err = bolt.Open(path, 0666, nil)
ok(t, err)
ok(t, db.View(func(tx *bolt.Tx) error { return <-tx.Check() }))
db.Close()
}
// Ensure that the database returns an error if the file handle cannot be open.
func TestDB_Open_FileError(t *testing.T) {
path := tempfile()
defer os.Remove(path)
_, err := bolt.Open(path+"/youre-not-my-real-parent", 0666, nil)
assert(t, err.(*os.PathError) != nil, "")
equals(t, path+"/youre-not-my-real-parent", err.(*os.PathError).Path)
equals(t, "open", err.(*os.PathError).Op)
}
// Ensure that write errors to the meta file handler during initialization are returned.
func TestDB_Open_MetaInitWriteError(t *testing.T) {
t.Skip("pending")
}
// Ensure that a database that is too small returns an error.
func TestDB_Open_FileTooSmall(t *testing.T) {
path := tempfile()
defer os.Remove(path)
db, err := bolt.Open(path, 0666, nil)
ok(t, err)
db.Close()
// corrupt the database
ok(t, os.Truncate(path, int64(os.Getpagesize())))
db, err = bolt.Open(path, 0666, nil)
equals(t, errors.New("file size too small"), err)
}
// Ensure that a database can be opened in read-only mode by multiple processes
// and that a database can not be opened in read-write mode and in read-only
// mode at the same time.
func TestOpen_ReadOnly(t *testing.T) {
if runtime.GOOS == "solaris" {
t.Skip("solaris fcntl locks don't support intra-process locking")
}
bucket, key, value := []byte(`bucket`), []byte(`key`), []byte(`value`)
path := tempfile()
defer os.Remove(path)
// Open in read-write mode.
db, err := bolt.Open(path, 0666, nil)
ok(t, db.Update(func(tx *bolt.Tx) error {
b, err := tx.CreateBucket(bucket)
if err != nil {
return err
}
return b.Put(key, value)
}))
assert(t, db != nil, "")
assert(t, !db.IsReadOnly(), "")
ok(t, err)
ok(t, db.Close())
// Open in read-only mode.
db0, err := bolt.Open(path, 0666, &bolt.Options{ReadOnly: true})
ok(t, err)
defer db0.Close()
// Opening in read-write mode should return an error.
_, err = bolt.Open(path, 0666, &bolt.Options{Timeout: time.Millisecond * 100})
assert(t, err != nil, "")
// And again (in read-only mode).
db1, err := bolt.Open(path, 0666, &bolt.Options{ReadOnly: true})
ok(t, err)
defer db1.Close()
// Verify both read-only databases are accessible.
for _, db := range []*bolt.DB{db0, db1} {
// Verify is is in read only mode indeed.
assert(t, db.IsReadOnly(), "")
// Read-only databases should not allow updates.
assert(t,
bolt.ErrDatabaseReadOnly == db.Update(func(*bolt.Tx) error {
panic(`should never get here`)
}),
"")
// Read-only databases should not allow beginning writable txns.
_, err = db.Begin(true)
assert(t, bolt.ErrDatabaseReadOnly == err, "")
// Verify the data.
ok(t, db.View(func(tx *bolt.Tx) error {
b := tx.Bucket(bucket)
if b == nil {
return fmt.Errorf("expected bucket `%s`", string(bucket))
}
got := string(b.Get(key))
expected := string(value)
if got != expected {
return fmt.Errorf("expected `%s`, got `%s`", expected, got)
}
return nil
}))
}
}
// TODO(benbjohnson): Test corruption at every byte of the first two pages.
// Ensure that a database cannot open a transaction when it's not open.
func TestDB_Begin_DatabaseNotOpen(t *testing.T) {
var db bolt.DB
tx, err := db.Begin(false)
assert(t, tx == nil, "")
equals(t, err, bolt.ErrDatabaseNotOpen)
}
// Ensure that a read-write transaction can be retrieved.
func TestDB_BeginRW(t *testing.T) {
db := NewTestDB()
defer db.Close()
tx, err := db.Begin(true)
assert(t, tx != nil, "")
ok(t, err)
assert(t, tx.DB() == db.DB, "")
equals(t, tx.Writable(), true)
ok(t, tx.Commit())
}
// Ensure that opening a transaction while the DB is closed returns an error.
func TestDB_BeginRW_Closed(t *testing.T) {
var db bolt.DB
tx, err := db.Begin(true)
equals(t, err, bolt.ErrDatabaseNotOpen)
assert(t, tx == nil, "")
}
func TestDB_Close_PendingTx_RW(t *testing.T) { testDB_Close_PendingTx(t, true) }
func TestDB_Close_PendingTx_RO(t *testing.T) { testDB_Close_PendingTx(t, false) }
// Ensure that a database cannot close while transactions are open.
func testDB_Close_PendingTx(t *testing.T, writable bool) {
db := NewTestDB()
defer db.Close()
// Start transaction.
tx, err := db.Begin(true)
if err != nil {
t.Fatal(err)
}
// Open update in separate goroutine.
done := make(chan struct{})
go func() {
db.Close()
close(done)
}()
// Ensure database hasn't closed.
time.Sleep(100 * time.Millisecond)
select {
case <-done:
t.Fatal("database closed too early")
default:
}
// Commit transaction.
if err := tx.Commit(); err != nil {
t.Fatal(err)
}
// Ensure database closed now.
time.Sleep(100 * time.Millisecond)
select {
case <-done:
default:
t.Fatal("database did not close")
}
}
// Ensure a database can provide a transactional block.
func TestDB_Update(t *testing.T) {
db := NewTestDB()
defer db.Close()
err := db.Update(func(tx *bolt.Tx) error {
tx.CreateBucket([]byte("widgets"))
b := tx.Bucket([]byte("widgets"))
b.Put([]byte("foo"), []byte("bar"))
b.Put([]byte("baz"), []byte("bat"))
b.Delete([]byte("foo"))
return nil
})
ok(t, err)
err = db.View(func(tx *bolt.Tx) error {
assert(t, tx.Bucket([]byte("widgets")).Get([]byte("foo")) == nil, "")
equals(t, []byte("bat"), tx.Bucket([]byte("widgets")).Get([]byte("baz")))
return nil
})
ok(t, err)
}
// Ensure a closed database returns an error while running a transaction block
func TestDB_Update_Closed(t *testing.T) {
var db bolt.DB
err := db.Update(func(tx *bolt.Tx) error {
tx.CreateBucket([]byte("widgets"))
return nil
})
equals(t, err, bolt.ErrDatabaseNotOpen)
}
// Ensure a panic occurs while trying to commit a managed transaction.
func TestDB_Update_ManualCommit(t *testing.T) {
db := NewTestDB()
defer db.Close()
var ok bool
db.Update(func(tx *bolt.Tx) error {
func() {
defer func() {
if r := recover(); r != nil {
ok = true
}
}()
tx.Commit()
}()
return nil
})
assert(t, ok, "expected panic")
}
// Ensure a panic occurs while trying to rollback a managed transaction.
func TestDB_Update_ManualRollback(t *testing.T) {
db := NewTestDB()
defer db.Close()
var ok bool
db.Update(func(tx *bolt.Tx) error {
func() {
defer func() {
if r := recover(); r != nil {
ok = true
}
}()
tx.Rollback()
}()
return nil
})
assert(t, ok, "expected panic")
}
// Ensure a panic occurs while trying to commit a managed transaction.
func TestDB_View_ManualCommit(t *testing.T) {
db := NewTestDB()
defer db.Close()
var ok bool
db.Update(func(tx *bolt.Tx) error {
func() {
defer func() {
if r := recover(); r != nil {
ok = true
}
}()
tx.Commit()
}()
return nil
})
assert(t, ok, "expected panic")
}
// Ensure a panic occurs while trying to rollback a managed transaction.
func TestDB_View_ManualRollback(t *testing.T) {
db := NewTestDB()
defer db.Close()
var ok bool
db.Update(func(tx *bolt.Tx) error {
func() {
defer func() {
if r := recover(); r != nil {
ok = true
}
}()
tx.Rollback()
}()
return nil
})
assert(t, ok, "expected panic")
}
// Ensure a write transaction that panics does not hold open locks.
func TestDB_Update_Panic(t *testing.T) {
db := NewTestDB()
defer db.Close()
func() {
defer func() {
if r := recover(); r != nil {
t.Log("recover: update", r)
}
}()
db.Update(func(tx *bolt.Tx) error {
tx.CreateBucket([]byte("widgets"))
panic("omg")
})
}()
// Verify we can update again.
err := db.Update(func(tx *bolt.Tx) error {
_, err := tx.CreateBucket([]byte("widgets"))
return err
})
ok(t, err)
// Verify that our change persisted.
err = db.Update(func(tx *bolt.Tx) error {
assert(t, tx.Bucket([]byte("widgets")) != nil, "")
return nil
})
}
// Ensure a database can return an error through a read-only transactional block.
func TestDB_View_Error(t *testing.T) {
db := NewTestDB()
defer db.Close()
err := db.View(func(tx *bolt.Tx) error {
return errors.New("xxx")
})
equals(t, errors.New("xxx"), err)
}
// Ensure a read transaction that panics does not hold open locks.
func TestDB_View_Panic(t *testing.T) {
db := NewTestDB()
defer db.Close()
db.Update(func(tx *bolt.Tx) error {
tx.CreateBucket([]byte("widgets"))
return nil
})
func() {
defer func() {
if r := recover(); r != nil {
t.Log("recover: view", r)
}
}()
db.View(func(tx *bolt.Tx) error {
assert(t, tx.Bucket([]byte("widgets")) != nil, "")
panic("omg")
})
}()
// Verify that we can still use read transactions.
db.View(func(tx *bolt.Tx) error {
assert(t, tx.Bucket([]byte("widgets")) != nil, "")
return nil
})
}
// Ensure that an error is returned when a database write fails.
func TestDB_Commit_WriteFail(t *testing.T) {
t.Skip("pending") // TODO(benbjohnson)
}
// Ensure that DB stats can be returned.
func TestDB_Stats(t *testing.T) {
db := NewTestDB()
defer db.Close()
db.Update(func(tx *bolt.Tx) error {
_, err := tx.CreateBucket([]byte("widgets"))
return err
})
stats := db.Stats()
equals(t, 2, stats.TxStats.PageCount)
equals(t, 0, stats.FreePageN)
equals(t, 2, stats.PendingPageN)
}
// Ensure that database pages are in expected order and type.
func TestDB_Consistency(t *testing.T) {
db := NewTestDB()
defer db.Close()
db.Update(func(tx *bolt.Tx) error {
_, err := tx.CreateBucket([]byte("widgets"))
return err
})
for i := 0; i < 10; i++ {
db.Update(func(tx *bolt.Tx) error {
ok(t, tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte("bar")))
return nil
})
}
db.Update(func(tx *bolt.Tx) error {
p, _ := tx.Page(0)
assert(t, p != nil, "")
equals(t, "meta", p.Type)
p, _ = tx.Page(1)
assert(t, p != nil, "")
equals(t, "meta", p.Type)
p, _ = tx.Page(2)
assert(t, p != nil, "")
equals(t, "free", p.Type)
p, _ = tx.Page(3)
assert(t, p != nil, "")
equals(t, "free", p.Type)
p, _ = tx.Page(4)
assert(t, p != nil, "")
equals(t, "leaf", p.Type)
p, _ = tx.Page(5)
assert(t, p != nil, "")
equals(t, "freelist", p.Type)
p, _ = tx.Page(6)
assert(t, p == nil, "")
return nil
})
}
// Ensure that DB stats can be substracted from one another.
func TestDBStats_Sub(t *testing.T) {
var a, b bolt.Stats
a.TxStats.PageCount = 3
a.FreePageN = 4
b.TxStats.PageCount = 10
b.FreePageN = 14
diff := b.Sub(&a)
equals(t, 7, diff.TxStats.PageCount)
// free page stats are copied from the receiver and not subtracted
equals(t, 14, diff.FreePageN)
}
func ExampleDB_Update() {
// Open the database.
db, _ := bolt.Open(tempfile(), 0666, nil)
defer os.Remove(db.Path())
defer db.Close()
// Execute several commands within a write transaction.
err := db.Update(func(tx *bolt.Tx) error {
b, err := tx.CreateBucket([]byte("widgets"))
if err != nil {
return err
}
if err := b.Put([]byte("foo"), []byte("bar")); err != nil {
return err
}
return nil
})
// If our transactional block didn't return an error then our data is saved.
if err == nil {
db.View(func(tx *bolt.Tx) error {
value := tx.Bucket([]byte("widgets")).Get([]byte("foo"))
fmt.Printf("The value of 'foo' is: %s\n", value)
return nil
})
}
// Output:
// The value of 'foo' is: bar
}
func ExampleDB_View() {
// Open the database.
db, _ := bolt.Open(tempfile(), 0666, nil)
defer os.Remove(db.Path())
defer db.Close()
// Insert data into a bucket.
db.Update(func(tx *bolt.Tx) error {
tx.CreateBucket([]byte("people"))
b := tx.Bucket([]byte("people"))
b.Put([]byte("john"), []byte("doe"))
b.Put([]byte("susy"), []byte("que"))
return nil
})
// Access data from within a read-only transactional block.
db.View(func(tx *bolt.Tx) error {
v := tx.Bucket([]byte("people")).Get([]byte("john"))
fmt.Printf("John's last name is %s.\n", v)
return nil
})
// Output:
// John's last name is doe.
}
func ExampleDB_Begin_ReadOnly() {
// Open the database.
db, _ := bolt.Open(tempfile(), 0666, nil)
defer os.Remove(db.Path())
defer db.Close()
// Create a bucket.
db.Update(func(tx *bolt.Tx) error {
_, err := tx.CreateBucket([]byte("widgets"))
return err
})
// Create several keys in a transaction.
tx, _ := db.Begin(true)
b := tx.Bucket([]byte("widgets"))
b.Put([]byte("john"), []byte("blue"))
b.Put([]byte("abby"), []byte("red"))
b.Put([]byte("zephyr"), []byte("purple"))
tx.Commit()
// Iterate over the values in sorted key order.
tx, _ = db.Begin(false)
c := tx.Bucket([]byte("widgets")).Cursor()
for k, v := c.First(); k != nil; k, v = c.Next() {
fmt.Printf("%s likes %s\n", k, v)
}
tx.Rollback()
// Output:
// abby likes red
// john likes blue
// zephyr likes purple
}
// TestDB represents a wrapper around a Bolt DB to handle temporary file
// creation and automatic cleanup on close.
type TestDB struct {
*bolt.DB
}
// NewTestDB returns a new instance of TestDB.
func NewTestDB() *TestDB {
db, err := bolt.Open(tempfile(), 0666, nil)
if err != nil {
panic("cannot open db: " + err.Error())
}
return &TestDB{db}
}
// MustView executes a read-only function. Panic on error.
func (db *TestDB) MustView(fn func(tx *bolt.Tx) error) {
if err := db.DB.View(func(tx *bolt.Tx) error {
return fn(tx)
}); err != nil {
panic(err.Error())
}
}
// MustUpdate executes a read-write function. Panic on error.
func (db *TestDB) MustUpdate(fn func(tx *bolt.Tx) error) {
if err := db.DB.View(func(tx *bolt.Tx) error {
return fn(tx)
}); err != nil {
panic(err.Error())
}
}
// MustCreateBucket creates a new bucket. Panic on error.
func (db *TestDB) MustCreateBucket(name []byte) {
if err := db.Update(func(tx *bolt.Tx) error {
_, err := tx.CreateBucket([]byte(name))
return err
}); err != nil {
panic(err.Error())
}
}
// Close closes the database and deletes the underlying file.
func (db *TestDB) Close() {
// Log statistics.
if *statsFlag {
db.PrintStats()
}
// Check database consistency after every test.
db.MustCheck()
// Close database and remove file.
defer os.Remove(db.Path())
db.DB.Close()
}
// PrintStats prints the database stats
func (db *TestDB) PrintStats() {
var stats = db.Stats()
fmt.Printf("[db] %-20s %-20s %-20s\n",
fmt.Sprintf("pg(%d/%d)", stats.TxStats.PageCount, stats.TxStats.PageAlloc),
fmt.Sprintf("cur(%d)", stats.TxStats.CursorCount),
fmt.Sprintf("node(%d/%d)", stats.TxStats.NodeCount, stats.TxStats.NodeDeref),
)
fmt.Printf(" %-20s %-20s %-20s\n",
fmt.Sprintf("rebal(%d/%v)", stats.TxStats.Rebalance, truncDuration(stats.TxStats.RebalanceTime)),
fmt.Sprintf("spill(%d/%v)", stats.TxStats.Spill, truncDuration(stats.TxStats.SpillTime)),
fmt.Sprintf("w(%d/%v)", stats.TxStats.Write, truncDuration(stats.TxStats.WriteTime)),
)
}
// MustCheck runs a consistency check on the database and panics if any errors are found.
func (db *TestDB) MustCheck() {
db.Update(func(tx *bolt.Tx) error {
// Collect all the errors.
var errors []error
for err := range tx.Check() {
errors = append(errors, err)
if len(errors) > 10 {
break
}
}
// If errors occurred, copy the DB and print the errors.
if len(errors) > 0 {
var path = tempfile()
tx.CopyFile(path, 0600)
// Print errors.
fmt.Print("\n\n")
fmt.Printf("consistency check failed (%d errors)\n", len(errors))
for _, err := range errors {
fmt.Println(err)
}
fmt.Println("")
fmt.Println("db saved to:")
fmt.Println(path)
fmt.Print("\n\n")
os.Exit(-1)
}
return nil
})
}
// CopyTempFile copies a database to a temporary file.
func (db *TestDB) CopyTempFile() {
path := tempfile()
db.View(func(tx *bolt.Tx) error { return tx.CopyFile(path, 0600) })
fmt.Println("db copied to: ", path)
}
// tempfile returns a temporary file path.
func tempfile() string {
f, _ := ioutil.TempFile("", "bolt-")
f.Close()
os.Remove(f.Name())
return f.Name()
}
// mustContainKeys checks that a bucket contains a given set of keys.
func mustContainKeys(b *bolt.Bucket, m map[string]string) {
found := make(map[string]string)
b.ForEach(func(k, _ []byte) error {
found[string(k)] = ""
return nil
})
// Check for keys found in bucket that shouldn't be there.
var keys []string
for k, _ := range found {
if _, ok := m[string(k)]; !ok {
keys = append(keys, k)
}
}
if len(keys) > 0 {
sort.Strings(keys)
panic(fmt.Sprintf("keys found(%d): %s", len(keys), strings.Join(keys, ",")))
}
// Check for keys not found in bucket that should be there.
for k, _ := range m {
if _, ok := found[string(k)]; !ok {
keys = append(keys, k)
}
}
if len(keys) > 0 {
sort.Strings(keys)
panic(fmt.Sprintf("keys not found(%d): %s", len(keys), strings.Join(keys, ",")))
}
}
func trunc(b []byte, length int) []byte {
if length < len(b) {
return b[:length]
}
return b
}
func truncDuration(d time.Duration) string {
return regexp.MustCompile(`^(\d+)(\.\d+)`).ReplaceAllString(d.String(), "$1")
}
func fileSize(path string) int64 {
fi, err := os.Stat(path)
if err != nil {
return 0
}
return fi.Size()
}
func warn(v ...interface{}) { fmt.Fprintln(os.Stderr, v...) }
func warnf(msg string, v ...interface{}) { fmt.Fprintf(os.Stderr, msg+"\n", v...) }
// u64tob converts a uint64 into an 8-byte slice.
func u64tob(v uint64) []byte {
b := make([]byte, 8)
binary.BigEndian.PutUint64(b, v)
return b
}
// btou64 converts an 8-byte slice into an uint64.
func btou64(b []byte) uint64 { return binary.BigEndian.Uint64(b) }

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