Fix#2841.
From Prometheus developer:
```
the recommended way for etcd as an open source project and under
consideration of its size would be etcd_<subsystem>_<name>.
```
We made the naming change accordingly.
This reverts commit f8ce5996b0.
etcd no longer resolves TCP addresses passed in through flags,
so there is no need to compare hostname and IP slices anymore.
(for more details: a3892221ee)
Conflicts:
etcdserver/cluster.go
etcdserver/config.go
pkg/netutil/netutil.go
pkg/netutil/netutil_test.go
etcdhttp will check the cluster version and update its
capability version periodically.
Any new handler's after 2.0 needs to wrap by capability handler
to ensure it is not accessable until rolling upgrade finished.
After this PR, only cluster's interface Cluster is exposed, which makes
code much cleaner. And it avoids external packages to rely on cluster
struct in the future.
The PR extracts types.Cluster from etcdserver.Cluster. types.Cluster
is used for flag parsing and etcdserver config.
There is no need to expose etcdserver.Cluster public, which contains
lots of etcdserver internal details and methods. This is the first step
for it.
1. Persist the cluster version change through raft. When the member is restarted, it can recover
the previous known decided cluster version.
2. When there is a new leader, it is forced to do a version checking immediately. This helps to
update the first cluster version fast.
We store cluster related key in StoreAdminPrefix for some
historical reason. The previous API is called admin. But now,
the admin name is gone and `cluster` is a more clear and correct
name.
Cluster version is the min major.minor of all members in
the etcd cluster. Cluster version is set to the min version
that a etcd member is compatible with when first bootstrapp.
During a rolling upgrades, the cluster version will be updated
automatically.
For example:
```
Cluster [a:1, b:1 ,c:1] -> clusterVersion 1
update a -> 2, b -> 2
after a detection
Cluster [a:2, b:2 ,c:1] -> clusterVersion 1, since c is still 1
update c -> 2
after a detection
Cluster [a:2, b:2 ,c:2] -> clusterVersion 2
```
The API/raft component can utilize clusterVersion to determine if
it can accept a client request or a raft RPC.
We choose polling rather than pushing since we want to use the same
logic for cluster version detection and (TODO) cluster version checking.
Before a member actually joins a etcd cluster, it should check the version
of the cluster. Push does not work since the other members cannot push
version info to it before it actually joins. Moreover, we do not want our
raft RPC system (which is doing the heartbeat pushing) to coordinate cluster version.
The original process is stopping etcd only when pipeline message finds itself
has been removed. After this PR, stream dial has this functionality too.
It helps fast etcd stop, which doesn't need to wait for stream break to
fall back to pipeline, and wait for election timeout to send out message
to detect self removal.
Add remotes to rafthttp, who help newly joined members catch up the
progress of the cluster. It supports basic message sending to remote, and
has no stream connection for simplicity. remotes will not be used
after the latest peers have been added into rafthttp.
Subcommits:
decouple root and security enable/disable
create root role
prefix matching
godep: bump go-etcd to include credentials
add godep for speakeasy and auth entry parsing
appropriate errors for security enable/disable
WIP adding to etcd/client all the security client methods
add guest access
minor ui return tweaks
revert client changes
respond to comments, log more security operations
fix major ensure() bug, add better UX
block recursive access
fix some boneheaded mistakes
fix integration test
last comments
fix up security_api.md
philips nits
fix docs
It is more reasonable to init the variable before passing it as an
argument.
It fixes a bug that etcdserver may panic on server stats when processing
a message from rafthttp streamReader before server stats is initialized
in server.Start().
It exposes the metrics of file descriptor limit and file descriptor used.
Moreover, it prints out warning when more than 80% of fd limit has been used.
```
2015/04/08 01:26:19 etcdserver: 80% of the file descriptor limit is open
[open = 969, limit = 1024]
```
Stop raftNode goroutine before stopping server goroutine, so
server.Stop does stop all underlying stuffs elegantly now. This fixes
the problem that previous-round lock on WAL may not be released when
etcd is restarted.
It is safe to repair the unexpectedEOF error in the last wal. raft
will not send out message before the entry successfully comitted
into wal. Thus we can safely truncate the last entry in the wal
to repair.
Xiang Li