*: bump to v2.0.10

extended wasn't documented in the help as one of the output formats, fix
this!

Conflicts:
	etcdctl/main.go

Documentation/allow_legacy_mode.md

@@ -1,120 +0,0 @@
-## Allow-legacy mode
-
-Allow-legacy is a special mode in etcd that contains logic to enable a running etcd cluster to smoothly transition between major versions of etcd. For example, the internal API versions between etcd 0.4 (internal v1) and etcd 2.0 (internal v2) aren't compatible and the cluster needs to be updated all at once to make the switch. To minimize downtime, allow-legacy coordinates with all of the members of the cluster to shutdown, migration of data and restart onto the new version.
-
-Allow-legacy helps users upgrade v0.4 etcd clusters easily, and allows your etcd cluster to have a minimal amount of downtime -- less than 1 minute for clusters storing less than 50 MB.
-
-It supports upgrading from internal v1 to internal v2 now.
-
-### Setup
-
-This mode is enabled if `ETCD_ALLOW_LEGACY_MODE` is set to true, or etcd is running in CoreOS system.
-
-It treats `ETCD_BINARY_DIR` as the directory for etcd binaries, which is organized in this way:
-
-```
-ETCD_BINARY_DIR
-  |
-  -- 1
-  |
-  -- 2
-```
-
-`1` is etcd with internal v1 protocol. You should use etcd v0.4.7 here. `2` is etcd with internal v2 protocol, which is etcd v2.x.
-
-The default value for `ETCD_BINARY_DIR` is `/usr/libexec/etcd/internal_versions/`.
-
-### Upgrading a Cluster
-
-When starting etcd with a v1 data directory and v1 flags, etcd executes the v0.4.7 binary and runs exactly the same as before. To start the migration, follow the steps below:
-
-![Migration Steps](etcd-migration-steps.png)
-
-#### 1. Check the Cluster Health
-
-Before upgrading, you should check the health of the cluster to double check that everything working perfectly. Check the health by running:
-
-```
-$ etcdctl cluster-health
-cluster is healthy
-member 6e3bd23ae5f1eae0 is healthy
-member 924e2e83e93f2560 is healthy
-member a8266ecf031671f3 is healthy
-```
-
-If the cluster and all members are healthy, you can start the upgrading process. If not, check the unhealthy machines and repair them using [admin guide](./admin_guide.md).
-
-#### 2. Trigger the Upgrade
-
-When you're ready, use the `etcdctl upgrade` command to start the upgrade the etcd cluster to 2.0:
-
-```
-# Defaults work on a CoreOS machine running etcd
-$ etcdctl upgrade
-```
-
-```
-# Advanced example specifying a peer url
-$ etcdctl upgrade --old-version=1 --new-version=2 --peer-url=$PEER_URL
-```
-
-`PEER_URL` can be any accessible peer url of the cluster.
-
-Once triggered, all peer-mode members will print out:
-
-```
-detected next internal version 2, exit after 10 seconds.
-```
-
-#### Parallel Coordinated Upgrade
-
-As part of the upgrade, etcd does internal coordination within the cluster for a brief period and then exits. Clusters storing 50 MB should be unavailable for less than 1 minute.
-
-#### Restart etcd Processes
-
-After the etcd processes exit, they need to be restarted. You can do this manually or configure your unit system to do this automatically. On CoreOS, etcd is already configured to start automatically with systemd.
-
-When restarted, the data directory of each member is upgraded, and afterwards etcd v2.0 will be running and servicing requests. The upgrade is now complete!
-
-Standby-mode members are a special case — they will be upgraded into proxy mode (a new feature in etcd 2.0) upon restarting. When the upgrade is triggered, any standbys will exit with the message:
-
-```
-Detect the cluster has been upgraded to internal API v2. Exit now.
-```
-
-Once restarted, standbys run in v2.0 proxy mode, which proxy user requests to the etcd cluster.
-
-#### 3. Check the Cluster Health
-
-After the upgrade process, you can run the health check again to verify the upgrade. If the cluster is unhealthy or there is an unhealthy member, please refer to start [failure recovery](#failure-recovery).
-
-### Downgrade
-
-If the upgrading fails due to disk/network issues, you still can restart the upgrading process manually. However, once you upgrade etcd to internal v2 protocol, you CANNOT downgrade it back to internal v1 protocol. If you want to downgrade etcd in the future, please backup your v1 data dir beforehand.
-
-### Upgrade Process on CoreOS
-
-When running on a CoreOS system, allow-legacy mode is enabled by default and an automatic update will set up everything needed to execute the upgrade. The `etcd.service` on CoreOS is already configured to restart automatically. All you need to do is run `etcdctl upgrade` when you're ready, as described
-
-### Internal Details
-
-etcd v0.4.7 registers versions of available etcd binaries in its local machine into the key space at bootstrap stage. When the upgrade command is executed, etcdctl checks whether each member has internal-version-v2 etcd binary around. If that is true, each member is asked to record the fact that it needs to be upgraded the next time it reboots, and exits after 10 seconds.
-
-Once restarted, etcd v2.0 sees the upgrade flag recorded. It upgrades the data directory, and executes etcd v2.0.
-
-### Failure Recovery
-
-If `etcdctl cluster-health` says that the cluster is unhealthy, the upgrade process fails, which may happen if the network is broken, or the disk cannot work.
-
-The way to recover it is to manually upgrade the whole cluster to v2.0:
-
-- Log into machines that ran v0.4 peer-mode etcd
-- Stop all etcd services
-- Remove the `member` directory under the etcd data-dir
-- Start etcd service using [2.0 flags](configuration.md). An example for this is:
-```
-$ etcd --data-dir=$DATA_DIR --listen-peer-urls http://$LISTEN_PEER_ADDR \
-    --advertise-client-urls http://$ADVERTISE_CLIENT_ADDR \
-    --listen-client-urls http://$LISTEN_CLIENT_ADDR
-```
-- When this is done, v2.0 etcd cluster should work now.

Documentation/api.md

@@ -287,7 +287,7 @@ curl 'http://127.0.0.1:2379/v2/keys/foo?wait=true&waitIndex=7'
 
 The watch command returns immediately with the same response as previously.
 
-**Note**: etcd only keeps the responses of the most recent 1000 events. 
+**Note**: etcd only keeps the responses of the most recent 1000 events across all etcd keys. 
 It is recommended to send the response to another thread to process immediately
 instead of blocking the watch while processing the result. 
 

Documentation/proxy.md

@@ -4,6 +4,8 @@ etcd can now run as a transparent proxy. Running etcd as a proxy allows for easi
 
 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.
+
 ### 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`). 
 

build

@@ -14,5 +14,3 @@ eval $(go env)
 # Static compilation is useful when etcd is run in a container
 CGO_ENABLED=0 go build -a -installsuffix cgo -ldflags '-s' -o bin/etcd ${REPO_PATH}
 CGO_ENABLED=0 go build -a -installsuffix cgo -ldflags '-s' -o bin/etcdctl ${REPO_PATH}/etcdctl
-go build -o bin/etcd-migrate ${REPO_PATH}/tools/etcd-migrate
-go build -o bin/etcd-dump-logs ${REPO_PATH}/tools/etcd-dump-logs

discovery/srv.go

@@ -25,7 +25,8 @@ import (
 
 var (
 	// indirection for testing
-	lookupSRV = net.LookupSRV
+	lookupSRV      = net.LookupSRV
+	resolveTCPAddr = net.ResolveTCPAddr
 )
 
 // TODO(barakmich): Currently ignores priority and weight (as they don't make as much sense for a bootstrap)
@@ -38,7 +39,7 @@ func SRVGetCluster(name, dns string, defaultToken string, apurls types.URLs) (st
 
 	// First, resolve the apurls
 	for _, url := range apurls {
-		tcpAddr, err := net.ResolveTCPAddr("tcp", url.Host)
+		tcpAddr, err := resolveTCPAddr("tcp", url.Host)
 		if err != nil {
 			log.Printf("discovery: Couldn't resolve host %s during SRV discovery", url.Host)
 			return "", "", err
@@ -52,8 +53,9 @@ func SRVGetCluster(name, dns string, defaultToken string, apurls types.URLs) (st
 			return err
 		}
 		for _, srv := range addrs {
-			host := net.JoinHostPort(srv.Target, fmt.Sprintf("%d", srv.Port))
-			tcpAddr, err := net.ResolveTCPAddr("tcp", host)
+			target := strings.TrimSuffix(srv.Target, ".")
+			host := net.JoinHostPort(target, fmt.Sprintf("%d", srv.Port))
+			tcpAddr, err := resolveTCPAddr("tcp", host)
 			if err != nil {
 				log.Printf("discovery: Couldn't resolve host %s during SRV discovery", host)
 				continue
@@ -68,8 +70,8 @@ func SRVGetCluster(name, dns string, defaultToken string, apurls types.URLs) (st
 				n = fmt.Sprintf("%d", tempName)
 				tempName += 1
 			}
-			stringParts = append(stringParts, fmt.Sprintf("%s=%s%s", n, prefix, tcpAddr.String()))
-			log.Printf("discovery: Got bootstrap from DNS for %s at host %s to %s%s", service, host, prefix, tcpAddr.String())
+			stringParts = append(stringParts, fmt.Sprintf("%s=%s%s", n, prefix, host))
+			log.Printf("discovery: Got bootstrap from DNS for %s at %s%s", service, prefix, host)
 		}
 		return nil
 	}

discovery/srv_test.go

@@ -23,19 +23,26 @@ import (
 )
 
 func TestSRVGetCluster(t *testing.T) {
-	defer func() { lookupSRV = net.LookupSRV }()
+	defer func() {
+		lookupSRV = net.LookupSRV
+		resolveTCPAddr = net.ResolveTCPAddr
+	}()
 
 	name := "dnsClusterTest"
 	tests := []struct {
 		withSSL    []*net.SRV
 		withoutSSL []*net.SRV
 		urls       []string
-		expected   string
+		dns        map[string]string
+
+		expected string
 	}{
 		{
 			[]*net.SRV{},
 			[]*net.SRV{},
 			nil,
+			nil,
+
 			"",
 		},
 		{
@@ -46,6 +53,8 @@ func TestSRVGetCluster(t *testing.T) {
 			},
 			[]*net.SRV{},
 			nil,
+			nil,
+
 			"0=https://10.0.0.1:2480,1=https://10.0.0.2:2480,2=https://10.0.0.3:2480",
 		},
 		{
@@ -58,6 +67,7 @@ func TestSRVGetCluster(t *testing.T) {
 				&net.SRV{Target: "10.0.0.1", Port: 7001},
 			},
 			nil,
+			nil,
 			"0=https://10.0.0.1:2480,1=https://10.0.0.2:2480,2=https://10.0.0.3:2480,3=http://10.0.0.1:7001",
 		},
 		{
@@ -70,8 +80,22 @@ func TestSRVGetCluster(t *testing.T) {
 				&net.SRV{Target: "10.0.0.1", Port: 7001},
 			},
 			[]string{"https://10.0.0.1:2480"},
+			nil,
 			"dnsClusterTest=https://10.0.0.1:2480,0=https://10.0.0.2:2480,1=https://10.0.0.3:2480,2=http://10.0.0.1:7001",
 		},
+		// matching local member with resolved addr and return unresolved hostnames
+		{
+			[]*net.SRV{
+				&net.SRV{Target: "1.example.com.", Port: 2480},
+				&net.SRV{Target: "2.example.com.", Port: 2480},
+				&net.SRV{Target: "3.example.com.", Port: 2480},
+			},
+			nil,
+			[]string{"https://10.0.0.1:2480"},
+			map[string]string{"1.example.com:2480": "10.0.0.1:2480", "2.example.com:2480": "10.0.0.2:2480", "3.example.com:2480": "10.0.0.3:2480"},
+
+			"dnsClusterTest=https://1.example.com:2480,0=https://2.example.com:2480,1=https://3.example.com:2480",
+		},
 	}
 
 	for i, tt := range tests {
@@ -84,6 +108,12 @@ func TestSRVGetCluster(t *testing.T) {
 			}
 			return "", nil, errors.New("Unkown service in mock")
 		}
+		resolveTCPAddr = func(network, addr string) (*net.TCPAddr, error) {
+			if tt.dns == nil || tt.dns[addr] == "" {
+				return net.ResolveTCPAddr(network, addr)
+			}
+			return net.ResolveTCPAddr(network, tt.dns[addr])
+		}
 		urls := testutil.MustNewURLs(t, tt.urls)
 		str, token, err := SRVGetCluster(name, "example.com", "token", urls)
 		if err != nil {

etcdctl/command/backup_command.go

@@ -44,10 +44,10 @@ func NewBackupCommand() cli.Command {
 
 // handleBackup handles a request that intends to do a backup.
 func handleBackup(c *cli.Context) {
-	srcSnap := path.Join(c.String("data-dir"), "snap")
-	destSnap := path.Join(c.String("backup-dir"), "snap")
-	srcWAL := path.Join(c.String("data-dir"), "wal")
-	destWAL := path.Join(c.String("backup-dir"), "wal")
+	srcSnap := path.Join(c.String("data-dir"), "member", "snap")
+	destSnap := path.Join(c.String("backup-dir"), "member", "snap")
+	srcWAL := path.Join(c.String("data-dir"), "member", "wal")
+	destWAL := path.Join(c.String("backup-dir"), "member", "wal")
 
 	if err := os.MkdirAll(destSnap, 0700); err != nil {
 		log.Fatalf("failed creating backup snapshot dir %v: %v", destSnap, err)

etcdctl/command/import_snap_command.go

@@ -0,0 +1,128 @@
+package command
+
+import (
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+	"strings"
+	"sync"
+
+	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/codegangsta/cli"
+	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/coreos/go-etcd/etcd"
+	"github.com/coreos/etcd/store"
+)
+
+type set struct {
+	key   string
+	value string
+	ttl   int64
+}
+
+func NewImportSnapCommand() cli.Command {
+	return cli.Command{
+		Name:  "import",
+		Usage: "import a snapshot to a cluster",
+		Flags: []cli.Flag{
+			cli.StringFlag{Name: "snap", Value: "", Usage: "Path to the vaild etcd 0.4.x snapshot."},
+			cli.StringSliceFlag{Name: "hidden", Value: new(cli.StringSlice), Usage: "Hidden key spaces to import from snapshot"},
+			cli.IntFlag{Name: "c", Value: 10, Usage: "Number of concurrent clients to import the data"},
+		},
+		Action: handleImportSnap,
+	}
+}
+
+func handleImportSnap(c *cli.Context) {
+	d, err := ioutil.ReadFile(c.String("snap"))
+	if err != nil {
+		if c.String("snap") == "" {
+			fmt.Printf("no snapshot file provided (use --snap)\n")
+		} else {
+			fmt.Printf("cannot read snapshot file %s\n", c.String("snap"))
+		}
+		os.Exit(1)
+	}
+
+	st := store.New()
+	err = st.Recovery(d)
+	if err != nil {
+		fmt.Printf("cannot recover the snapshot file: %v\n", err)
+		os.Exit(1)
+	}
+
+	endpoints, err := getEndpoints(c)
+	if err != nil {
+		handleError(ErrorFromEtcd, err)
+	}
+	tr, err := getTransport(c)
+	if err != nil {
+		handleError(ErrorFromEtcd, err)
+	}
+
+	wg := &sync.WaitGroup{}
+	setc := make(chan set)
+	concurrent := c.Int("c")
+	fmt.Printf("starting to import snapshot %s with %d clients\n", c.String("snap"), concurrent)
+	for i := 0; i < concurrent; i++ {
+		client := etcd.NewClient(endpoints)
+		client.SetTransport(tr)
+
+		if c.GlobalBool("debug") {
+			go dumpCURL(client)
+		}
+
+		if ok := client.SyncCluster(); !ok {
+			handleError(FailedToConnectToHost, errors.New("cannot sync with the cluster using endpoints "+strings.Join(endpoints, ", ")))
+		}
+		wg.Add(1)
+		go runSet(client, setc, wg)
+	}
+
+	all, err := st.Get("/", true, true)
+	if err != nil {
+		handleError(ErrorFromEtcd, err)
+	}
+	n := copyKeys(all.Node, setc)
+
+	hiddens := c.StringSlice("hidden")
+	for _, h := range hiddens {
+		allh, err := st.Get(h, true, true)
+		if err != nil {
+			handleError(ErrorFromEtcd, err)
+		}
+		n += copyKeys(allh.Node, setc)
+	}
+	close(setc)
+	wg.Wait()
+	fmt.Printf("finished importing %d keys\n", n)
+}
+
+func copyKeys(n *store.NodeExtern, setc chan set) int {
+	num := 0
+	if !n.Dir {
+		setc <- set{n.Key, *n.Value, n.TTL}
+		return 1
+	}
+	log.Println("entering dir:", n.Key)
+	for _, nn := range n.Nodes {
+		sub := copyKeys(nn, setc)
+		num += sub
+	}
+	return num
+}
+
+func runSet(c *etcd.Client, setc chan set, wg *sync.WaitGroup) {
+	for s := range setc {
+		log.Println("copying key:", s.key)
+		if s.ttl != 0 && s.ttl < 300 {
+			log.Printf("extending key %s's ttl to 300 seconds", s.key)
+			s.ttl = 5 * 60
+		}
+		_, err := c.Set(s.key, s.value, uint64(s.ttl))
+		if err != nil {
+			log.Fatalf("failed to copy key: %v\n", err)
+		}
+	}
+	wg.Done()
+}

etcdctl/command/upgrade.go

@@ -1,78 +0,0 @@
-/*
-   Copyright 2015 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 command
-
-import (
-	"fmt"
-	"log"
-	"net/http"
-	"os"
-
-	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/codegangsta/cli"
-	"github.com/coreos/etcd/pkg/transport"
-)
-
-func UpgradeCommand() cli.Command {
-	return cli.Command{
-		Name:  "upgrade",
-		Usage: "upgrade an old version etcd cluster to a new version",
-		Flags: []cli.Flag{
-			cli.StringFlag{Name: "old-version", Value: "1", Usage: "Old internal version"},
-			cli.StringFlag{Name: "new-version", Value: "2", Usage: "New internal version"},
-			cli.StringFlag{Name: "peer-url", Value: "http://localhost:7001", Usage: "An etcd peer url string"},
-			cli.StringFlag{Name: "peer-cert-file", Value: "", Usage: "identify HTTPS peer using this SSL certificate file"},
-			cli.StringFlag{Name: "peer-key-file", Value: "", Usage: "identify HTTPS peer using this SSL key file"},
-			cli.StringFlag{Name: "peer-ca-file", Value: "", Usage: "verify certificates of HTTPS-enabled peers using this CA bundle"},
-		},
-		Action: handleUpgrade,
-	}
-}
-
-func handleUpgrade(c *cli.Context) {
-	if c.String("old-version") != "1" {
-		fmt.Printf("Do not support upgrade from version %s\n", c.String("old-version"))
-		os.Exit(1)
-	}
-	if c.String("new-version") != "2" {
-		fmt.Printf("Do not support upgrade to version %s\n", c.String("new-version"))
-		os.Exit(1)
-	}
-	tls := transport.TLSInfo{
-		CAFile:   c.String("peer-ca-file"),
-		CertFile: c.String("peer-cert-file"),
-		KeyFile:  c.String("peer-key-file"),
-	}
-	t, err := transport.NewTransport(tls)
-	if err != nil {
-		log.Fatal(err)
-	}
-	client := http.Client{Transport: t}
-	resp, err := client.Get(c.String("peer-url") + "/v2/admin/next-internal-version")
-	if err != nil {
-		fmt.Printf("Failed to send upgrade request to %s: %v\n", c.String("peer-url"), err)
-		return
-	}
-	if resp.StatusCode == http.StatusOK {
-		fmt.Println("Cluster will start upgrading from internal version 1 to 2 in 10 seconds.")
-		return
-	}
-	if resp.StatusCode == http.StatusNotFound {
-		fmt.Println("Cluster cannot upgrade to 2: version is not 0.4.7")
-		return
-	}
-	fmt.Printf("Faild to send upgrade request to %s: bad status code %d\n", c.String("cluster-url"), resp.StatusCode)
-}

etcdctl/command/util.go

@@ -65,7 +65,7 @@ func getPeersFlagValue(c *cli.Context) []string {
 
 	// If we still don't have peers, use a default
 	if peerstr == "" {
-		peerstr = "127.0.0.1:4001"
+		peerstr = "127.0.0.1:4001,127.0.0.1:2379"
 	}
 
 	return strings.Split(peerstr, ",")

etcdctl/main.go

@@ -31,7 +31,7 @@ func main() {
 	app.Flags = []cli.Flag{
 		cli.BoolFlag{Name: "debug", Usage: "output cURL commands which can be used to reproduce the request"},
 		cli.BoolFlag{Name: "no-sync", Usage: "don't synchronize cluster information before sending request"},
-		cli.StringFlag{Name: "output, o", Value: "simple", Usage: "output response in the given format (`simple` or `json`)"},
+		cli.StringFlag{Name: "output, o", Value: "simple", Usage: "output response in the given format (`simple`, `extended` or `json`)"},
 		cli.StringFlag{Name: "peers, C", Value: "", Usage: "a comma-delimited list of machine addresses in the cluster (default: \"127.0.0.1:4001\")"},
 		cli.StringFlag{Name: "cert-file", Value: "", Usage: "identify HTTPS client using this SSL certificate file"},
 		cli.StringFlag{Name: "key-file", Value: "", Usage: "identify HTTPS client using this SSL key file"},
@@ -53,7 +53,7 @@ func main() {
 		command.NewWatchCommand(),
 		command.NewExecWatchCommand(),
 		command.NewMemberCommand(),
-		command.UpgradeCommand(),
+		command.NewImportSnapCommand(),
 	}
 
 	app.Run(os.Args)

etcdmain/config.go

@@ -15,7 +15,6 @@
 package etcdmain
 
 import (
-	"errors"
 	"flag"
 	"fmt"
 	"log"
@@ -26,7 +25,6 @@ import (
 	"github.com/coreos/etcd/etcdserver"
 	"github.com/coreos/etcd/pkg/cors"
 	"github.com/coreos/etcd/pkg/flags"
-	"github.com/coreos/etcd/pkg/netutil"
 	"github.com/coreos/etcd/pkg/transport"
 	"github.com/coreos/etcd/version"
 )
@@ -208,6 +206,9 @@ func (cfg *config) Parse(arguments []string) error {
 	default:
 		os.Exit(2)
 	}
+	if len(cfg.FlagSet.Args()) != 0 {
+		return fmt.Errorf("'%s' is not a valid flag", cfg.FlagSet.Arg(0))
+	}
 
 	if cfg.printVersion {
 		fmt.Println("etcd version", version.Version)
@@ -253,10 +254,6 @@ func (cfg *config) Parse(arguments []string) error {
 		return err
 	}
 
-	if err := cfg.resolveUrls(); err != nil {
-		return errors.New("cannot resolve DNS hostnames.")
-	}
-
 	if 5*cfg.TickMs > cfg.ElectionMs {
 		return fmt.Errorf("-election-timeout[%vms] should be at least as 5 times as -heartbeat-interval[%vms]", cfg.ElectionMs, cfg.TickMs)
 	}
@@ -272,10 +269,6 @@ func initialClusterFromName(name string) string {
 	return fmt.Sprintf("%s=http://localhost:2380,%s=http://localhost:7001", n, n)
 }
 
-func (cfg *config) resolveUrls() error {
-	return netutil.ResolveTCPAddrs(cfg.lpurls, cfg.apurls, cfg.lcurls, cfg.acurls)
-}
-
 func (cfg config) isNewCluster() bool          { return cfg.clusterState.String() == clusterStateFlagNew }
 func (cfg config) isProxy() bool               { return cfg.proxy.String() != proxyFlagOff }
 func (cfg config) isReadonlyProxy() bool       { return cfg.proxy.String() == proxyFlagReadonly }

etcdmain/etcd.go

@@ -56,7 +56,7 @@ func Main() {
 	cfg := NewConfig()
 	err := cfg.Parse(os.Args[1:])
 	if err != nil {
-		log.Printf("etcd: error verifying flags, %v", err)
+		log.Printf("etcd: error verifying flags, %v. See 'etcd -help'.", err)
 		os.Exit(2)
 	}
 

etcdserver/config.go

@@ -46,9 +46,43 @@ type ServerConfig struct {
 	ElectionTicks int
 }
 
-// VerifyBootstrapConfig sanity-checks the initial config and returns an error
-// for things that should never happen.
-func (c *ServerConfig) VerifyBootstrapConfig() error {
+// VerifyBootstrapConfig sanity-checks the initial config for bootstrap case
+// and returns an error for things that should never happen.
+func (c *ServerConfig) VerifyBootstrap() error {
+	if err := c.verifyLocalMember(true); err != nil {
+		return err
+	}
+	if err := c.Cluster.Validate(); err != nil {
+		return err
+	}
+	if c.Cluster.String() == "" && c.DiscoveryURL == "" {
+		return fmt.Errorf("initial cluster unset and no discovery URL found")
+	}
+	return nil
+}
+
+// VerifyJoinExisting sanity-checks the initial config for join existing cluster
+// case and returns an error for things that should never happen.
+func (c *ServerConfig) VerifyJoinExisting() error {
+	// no need for strict checking since the member have announced its
+	// peer urls to the cluster before starting and do not have to set
+	// it in the configuration again.
+	if err := c.verifyLocalMember(false); err != nil {
+		return err
+	}
+	if err := c.Cluster.Validate(); err != nil {
+		return err
+	}
+	if c.DiscoveryURL != "" {
+		return fmt.Errorf("discovery URL should not be set when joining existing initial cluster")
+	}
+	return nil
+}
+
+// verifyLocalMember verifies the configured member is in configured
+// cluster. If strict is set, it also verifies the configured member
+// has the same peer urls as configured advertised peer urls.
+func (c *ServerConfig) verifyLocalMember(strict bool) error {
 	m := c.Cluster.MemberByName(c.Name)
 	// Make sure the cluster at least contains the local server.
 	if m == nil {
@@ -58,20 +92,14 @@ func (c *ServerConfig) VerifyBootstrapConfig() error {
 		return fmt.Errorf("cannot use %x as member id", raft.None)
 	}
 
-	if c.DiscoveryURL == "" && !c.NewCluster {
-		return fmt.Errorf("initial cluster state unset and no wal or discovery URL found")
-	}
-
-	if err := c.Cluster.Validate(); err != nil {
-		return err
-	}
-
 	// Advertised peer URLs must match those in the cluster peer list
 	// TODO: Remove URLStringsEqual after improvement of using hostnames #2150 #2123
 	apurls := c.PeerURLs.StringSlice()
 	sort.Strings(apurls)
-	if !netutil.URLStringsEqual(apurls, m.PeerURLs) {
-		return fmt.Errorf("%s has different advertised URLs in the cluster and advertised peer URLs list", c.Name)
+	if strict {
+		if !netutil.URLStringsEqual(apurls, m.PeerURLs) {
+			return fmt.Errorf("%s has different advertised URLs in the cluster and advertised peer URLs list", c.Name)
+		}
 	}
 	return nil
 }

etcdserver/config_test.go

@@ -22,6 +22,9 @@ import (
 )
 
 func mustNewURLs(t *testing.T, urls []string) []url.URL {
+	if len(urls) == 0 {
+		return nil
+	}
 	u, err := types.NewURLs(urls)
 	if err != nil {
 		t.Fatalf("error creating new URLs from %q: %v", urls, err)
@@ -29,77 +32,101 @@ func mustNewURLs(t *testing.T, urls []string) []url.URL {
 	return u
 }
 
-func TestBootstrapConfigVerify(t *testing.T) {
+func TestConfigVerifyBootstrapWithoutClusterAndDiscoveryURLFail(t *testing.T) {
+	cluster, err := NewClusterFromString("", "")
+	if err != nil {
+		t.Fatalf("NewClusterFromString error: %v", err)
+	}
+	c := &ServerConfig{
+		Name:         "node1",
+		DiscoveryURL: "",
+		Cluster:      cluster,
+	}
+	if err := c.VerifyBootstrap(); err == nil {
+		t.Errorf("err = nil, want not nil")
+	}
+}
+
+func TestConfigVerifyExistingWithDiscoveryURLFail(t *testing.T) {
+	cluster, err := NewClusterFromString("", "node1=http://127.0.0.1:2380")
+	if err != nil {
+		t.Fatalf("NewClusterFromString error: %v", err)
+	}
+	c := &ServerConfig{
+		Name:         "node1",
+		DiscoveryURL: "http://127.0.0.1:4001/abcdefg",
+		PeerURLs:     mustNewURLs(t, []string{"http://127.0.0.1:2380"}),
+		Cluster:      cluster,
+		NewCluster:   false,
+	}
+	if err := c.VerifyJoinExisting(); err == nil {
+		t.Errorf("err = nil, want not nil")
+	}
+}
+
+func TestConfigVerifyLocalMember(t *testing.T) {
 	tests := []struct {
 		clusterSetting string
-		newclst        bool
 		apurls         []string
-		disc           string
+		strict         bool
 		shouldError    bool
 	}{
 		{
 			// Node must exist in cluster
 			"",
-			true,
 			nil,
-			"",
+			true,
 
 			true,
 		},
 		{
-			// Cannot have duplicate URLs in cluster config
-			"node1=http://localhost:7001,node2=http://localhost:7001,node2=http://localhost:7002",
-			true,
-			nil,
-			"",
-
-			true,
-		},
-		{
-			// Node defined, ClusterState OK
+			// Initial cluster set
 			"node1=http://localhost:7001,node2=http://localhost:7002",
-			true,
 			[]string{"http://localhost:7001"},
-			"",
+			true,
 
 			false,
 		},
 		{
-			// Node defined, discovery OK
-			"node1=http://localhost:7001",
-			false,
-			[]string{"http://localhost:7001"},
-			"http://discovery",
-
-			false,
-		},
-		{
-			// Cannot have ClusterState!=new && !discovery
-			"node1=http://localhost:7001",
-			false,
-			nil,
-			"",
-
+			// Default initial cluster
+			"node1=http://localhost:2380,node1=http://localhost:7001",
+			[]string{"http://localhost:2380", "http://localhost:7001"},
 			true,
+
+			false,
 		},
 		{
 			// Advertised peer URLs must match those in cluster-state
 			"node1=http://localhost:7001",
-			true,
 			[]string{"http://localhost:12345"},
-			"",
+			true,
 
 			true,
 		},
 		{
 			// Advertised peer URLs must match those in cluster-state
 			"node1=http://localhost:7001,node1=http://localhost:12345",
-			true,
 			[]string{"http://localhost:12345"},
-			"",
+			true,
 
 			true,
 		},
+		{
+			// Advertised peer URLs must match those in cluster-state
+			"node1=http://localhost:7001",
+			[]string{},
+			true,
+
+			true,
+		},
+		{
+			// do not care about the urls if strict is not set
+			"node1=http://localhost:7001",
+			[]string{},
+			false,
+
+			false,
+		},
 	}
 
 	for i, tt := range tests {
@@ -108,15 +135,13 @@ func TestBootstrapConfigVerify(t *testing.T) {
 			t.Fatalf("#%d: Got unexpected error: %v", i, err)
 		}
 		cfg := ServerConfig{
-			Name:         "node1",
-			DiscoveryURL: tt.disc,
-			Cluster:      cluster,
-			NewCluster:   tt.newclst,
+			Name:    "node1",
+			Cluster: cluster,
 		}
 		if tt.apurls != nil {
 			cfg.PeerURLs = mustNewURLs(t, tt.apurls)
 		}
-		err = cfg.VerifyBootstrapConfig()
+		err = cfg.verifyLocalMember(tt.strict)
 		if (err == nil) && tt.shouldError {
 			t.Errorf("%#v", *cluster)
 			t.Errorf("#%d: Got no error where one was expected", i)

etcdserver/etcdhttp/client.go

@@ -119,7 +119,6 @@ func (h *keysHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		writeError(w, err)
 		return
 	}
-
 	switch {
 	case resp.Event != nil:
 		if err := writeKeyEvent(w, resp.Event, h.timer); err != nil {
@@ -334,7 +333,7 @@ func serveVersion(w http.ResponseWriter, r *http.Request) {
 	if !allowMethod(w, r.Method, "GET") {
 		return
 	}
-	fmt.Fprintf(w, `{"releaseVersion":"%s","internalVersion":"%s"}`, version.Version, version.InternalVersion)
+	w.Write([]byte("etcd " + version.Version))
 }
 
 // parseKeyRequest converts a received http.Request on keysPrefix to

etcdserver/etcdhttp/client_test.go

@@ -1327,7 +1327,7 @@ func TestServeVersion(t *testing.T) {
 	if rw.Code != http.StatusOK {
 		t.Errorf("code=%d, want %d", rw.Code, http.StatusOK)
 	}
-	w := fmt.Sprintf(`{"releaseVersion":"%s","internalVersion":"%s"}`, version.Version, version.InternalVersion)
+	w := fmt.Sprintf("etcd %s", version.Version)
 	if g := rw.Body.String(); g != w {
 		t.Fatalf("body = %q, want %q", g, w)
 	}

etcdserver/server.go

@@ -42,6 +42,7 @@ import (
 	"github.com/coreos/etcd/rafthttp"
 	"github.com/coreos/etcd/snap"
 	"github.com/coreos/etcd/store"
+	"github.com/coreos/etcd/version"
 	"github.com/coreos/etcd/wal"
 
 	"github.com/coreos/etcd/Godeps/_workspace/src/golang.org/x/net/context"
@@ -145,18 +146,23 @@ func NewServer(cfg *ServerConfig) (*EtcdServer, error) {
 	var s *raft.MemoryStorage
 	var id types.ID
 
-	walVersion, err := wal.DetectVersion(cfg.DataDir)
+	// Run the migrations.
+	dataVer, err := version.DetectDataDir(cfg.DataDir)
 	if err != nil {
 		return nil, err
 	}
-	if walVersion == wal.WALUnknown {
-		return nil, fmt.Errorf("unknown wal version in data dir %s", cfg.DataDir)
+	if err := upgradeDataDir(cfg.DataDir, cfg.Name, dataVer); err != nil {
+		return nil, err
 	}
-	haveWAL := walVersion != wal.WALNotExist
+
+	haveWAL := wal.Exist(cfg.WALDir())
 	ss := snap.New(cfg.SnapDir())
 
 	switch {
 	case !haveWAL && !cfg.NewCluster:
+		if err := cfg.VerifyJoinExisting(); err != nil {
+			return nil, err
+		}
 		existingCluster, err := GetClusterFromRemotePeers(getRemotePeerURLs(cfg.Cluster, cfg.Name), cfg.Transport)
 		if err != nil {
 			return nil, fmt.Errorf("cannot fetch cluster info from peer urls: %v", err)
@@ -170,7 +176,7 @@ func NewServer(cfg *ServerConfig) (*EtcdServer, error) {
 		cfg.Print()
 		id, n, s, w = startNode(cfg, nil)
 	case !haveWAL && cfg.NewCluster:
-		if err := cfg.VerifyBootstrapConfig(); err != nil {
+		if err := cfg.VerifyBootstrap(); err != nil {
 			return nil, err
 		}
 		m := cfg.Cluster.MemberByName(cfg.Name)
@@ -193,11 +199,6 @@ func NewServer(cfg *ServerConfig) (*EtcdServer, error) {
 		cfg.PrintWithInitial()
 		id, n, s, w = startNode(cfg, cfg.Cluster.MemberIDs())
 	case haveWAL:
-		// Run the migrations.
-		if err := upgradeWAL(cfg.DataDir, cfg.Name, walVersion); err != nil {
-			return nil, err
-		}
-
 		if err := fileutil.IsDirWriteable(cfg.DataDir); err != nil {
 			return nil, fmt.Errorf("cannot write to data directory: %v", err)
 		}
@@ -670,9 +671,9 @@ func (s *EtcdServer) publish(retryInterval time.Duration) {
 }
 
 func (s *EtcdServer) send(ms []raftpb.Message) {
-	for _, m := range ms {
-		if !s.Cluster.IsIDRemoved(types.ID(m.To)) {
-			m.To = 0
+	for i, _ := range ms {
+		if s.Cluster.IsIDRemoved(types.ID(ms[i].To)) {
+			ms[i].To = 0
 		}
 	}
 	s.r.transport.Send(ms)
@@ -722,7 +723,11 @@ func (s *EtcdServer) applyRequest(r pb.Request) Response {
 		switch {
 		case existsSet:
 			if exists {
-				return f(s.store.Update(r.Path, r.Val, expr))
+				if r.PrevIndex == 0 && r.PrevValue == "" {
+					return f(s.store.Update(r.Path, r.Val, expr))
+				} else {
+					return f(s.store.CompareAndSwap(r.Path, r.PrevValue, r.PrevIndex, r.Val, expr))
+				}
 			}
 			return f(s.store.Create(r.Path, r.Dir, r.Val, false, expr))
 		case r.PrevIndex > 0 || r.PrevValue != "":

etcdserver/server_test.go

@@ -235,20 +235,18 @@ func TestApplyRequest(t *testing.T) {
 				},
 			},
 		},
-		// PUT with PrevExist=true *and* PrevIndex set ==> Update
-		// TODO(jonboulle): is this expected?!
+		// PUT with PrevExist=true *and* PrevIndex set ==> CompareAndSwap
 		{
 			pb.Request{Method: "PUT", ID: 1, PrevExist: pbutil.Boolp(true), PrevIndex: 1},
 			Response{Event: &store.Event{}},
 			[]testutil.Action{
 				{
-					Name:   "Update",
-					Params: []interface{}{"", "", time.Time{}},
+					Name:   "CompareAndSwap",
+					Params: []interface{}{"", "", uint64(1), "", time.Time{}},
 				},
 			},
 		},
 		// PUT with PrevExist=false *and* PrevIndex set ==> Create
-		// TODO(jonboulle): is this expected?!
 		{
 			pb.Request{Method: "PUT", ID: 1, PrevExist: pbutil.Boolp(false), PrevIndex: 1},
 			Response{Event: &store.Event{}},

etcdserver/storage.go

@@ -25,6 +25,7 @@ import (
 	"github.com/coreos/etcd/pkg/types"
 	"github.com/coreos/etcd/raft/raftpb"
 	"github.com/coreos/etcd/snap"
+	"github.com/coreos/etcd/version"
 	"github.com/coreos/etcd/wal"
 	"github.com/coreos/etcd/wal/walpb"
 )
@@ -93,9 +94,9 @@ func readWAL(waldir string, snap walpb.Snapshot) (w *wal.WAL, id, cid types.ID,
 
 // upgradeWAL converts an older version of the etcdServer data to the newest version.
 // It must ensure that, after upgrading, the most recent version is present.
-func upgradeWAL(baseDataDir string, name string, ver wal.WalVersion) error {
+func upgradeDataDir(baseDataDir string, name string, ver version.DataDirVersion) error {
 	switch ver {
-	case wal.WALv0_4:
+	case version.DataDir0_4:
 		log.Print("etcdserver: converting v0.4 log to v2.0")
 		err := migrate.Migrate4To2(baseDataDir, name)
 		if err != nil {
@@ -103,16 +104,16 @@ func upgradeWAL(baseDataDir string, name string, ver wal.WalVersion) error {
 			return err
 		}
 		fallthrough
-	case wal.WALv2_0:
+	case version.DataDir2_0:
 		err := makeMemberDir(baseDataDir)
 		if err != nil {
 			return err
 		}
 		fallthrough
-	case wal.WALv2_0_1:
+	case version.DataDir2_0_1:
 		fallthrough
 	default:
-		log.Printf("datadir is valid for the 2.0.1 format")
+		log.Printf("etcdserver: datadir is valid for the 2.0.1 format")
 	}
 	return nil
 }

proxy/director.go

@@ -16,6 +16,7 @@ package proxy
 
 import (
 	"log"
+	"math/rand"
 	"net/url"
 	"sync"
 	"time"
@@ -65,6 +66,13 @@ func (d *director) refresh() {
 		}
 		endpoints = append(endpoints, newEndpoint(*uu))
 	}
+
+	// shuffle array to avoid connections being "stuck" to a single endpoint
+	for i := range endpoints {
+		j := rand.Intn(i + 1)
+		endpoints[i], endpoints[j] = endpoints[j], endpoints[i]
+	}
+
 	d.ep = endpoints
 }
 

snap/snapshotter.go

@@ -82,7 +82,10 @@ func (s *Snapshotter) Load() (*raftpb.Snapshot, error) {
 			break
 		}
 	}
-	return snap, err
+	if err != nil {
+		return nil, ErrNoSnapshot
+	}
+	return snap, nil
 }
 
 func loadSnap(dir, name string) (*raftpb.Snapshot, error) {

snap/snapshotter_test.go

@@ -76,7 +76,7 @@ func TestBadCRC(t *testing.T) {
 	// fake a crc mismatch
 	crcTable = crc32.MakeTable(crc32.Koopman)
 
-	_, err = ss.Load()
+	_, err = Read(path.Join(dir, fmt.Sprintf("%016x-%016x.snap", 1, 1)))
 	if err == nil || err != ErrCRCMismatch {
 		t.Errorf("err = %v, want %v", err, ErrCRCMismatch)
 	}
@@ -182,7 +182,7 @@ func TestNoSnapshot(t *testing.T) {
 	defer os.RemoveAll(dir)
 	ss := New(dir)
 	_, err = ss.Load()
-	if err == nil || err != ErrNoSnapshot {
+	if err != ErrNoSnapshot {
 		t.Errorf("err = %v, want %v", err, ErrNoSnapshot)
 	}
 }
@@ -195,14 +195,35 @@ func TestEmptySnapshot(t *testing.T) {
 	}
 	defer os.RemoveAll(dir)
 
-	err = ioutil.WriteFile(path.Join(dir, "1.snap"), []byte("shit"), 0x700)
+	err = ioutil.WriteFile(path.Join(dir, "1.snap"), []byte(""), 0x700)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, err = Read(path.Join(dir, "1.snap"))
+	if err != ErrEmptySnapshot {
+		t.Errorf("err = %v, want %v", err, ErrEmptySnapshot)
+	}
+}
+
+// TestAllSnapshotBroken ensures snapshotter returens
+// ErrNoSnapshot if all the snapshots are broken.
+func TestAllSnapshotBroken(t *testing.T) {
+	dir := path.Join(os.TempDir(), "snapshot")
+	err := os.Mkdir(dir, 0700)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(dir)
+
+	err = ioutil.WriteFile(path.Join(dir, "1.snap"), []byte("bad"), 0x700)
 	if err != nil {
 		t.Fatal(err)
 	}
 
 	ss := New(dir)
 	_, err = ss.Load()
-	if err == nil || err != ErrEmptySnapshot {
-		t.Errorf("err = %v, want %v", err, ErrEmptySnapshot)
+	if err != ErrNoSnapshot {
+		t.Errorf("err = %v, want %v", err, ErrNoSnapshot)
 	}
 }

store/watcher_hub.go

@@ -84,7 +84,6 @@ func (wh *watcherHub) watch(key string, recursive, stream bool, index, storeInde
 
 	if ok { // add the new watcher to the back of the list
 		elem = l.PushBack(w)
-
 	} else { // create a new list and add the new watcher
 		l = list.New()
 		elem = l.PushBack(w)
@@ -146,6 +145,7 @@ func (wh *watcherHub) notifyWatchers(e *Event, nodePath string, deleted bool) {
 					// if we successfully notify a watcher
 					// we need to remove the watcher from the list
 					// and decrease the counter
+					w.removed = true
 					l.Remove(curr)
 					atomic.AddInt64(&wh.count, -1)
 				}

test

@@ -15,7 +15,7 @@ COVER=${COVER:-"-cover"}
 source ./build
 
 # Hack: gofmt ./ will recursively check the .git directory. So use *.go for gofmt.
-TESTABLE_AND_FORMATTABLE="client discovery error etcdctl/command etcdmain etcdserver etcdserver/etcdhttp etcdserver/etcdhttp/httptypes migrate pkg/fileutil pkg/flags pkg/idutil pkg/ioutil pkg/netutil pkg/osutil pkg/pbutil pkg/types pkg/transport pkg/wait proxy raft rafthttp snap store wal"
+TESTABLE_AND_FORMATTABLE="client discovery error etcdctl/command etcdmain etcdserver etcdserver/etcdhttp etcdserver/etcdhttp/httptypes migrate pkg/fileutil pkg/flags pkg/idutil pkg/ioutil pkg/netutil pkg/osutil pkg/pbutil pkg/types pkg/transport pkg/wait proxy raft rafthttp snap store version wal"
 FORMATTABLE="$TESTABLE_AND_FORMATTABLE *.go etcdctl/ integration"
 
 # user has not provided PKG override

tools/etcd-migrate/README.md

@@ -15,7 +15,8 @@ etcd will detect 0.4.x data dir and update the data automatically (while leaving
 
 The tool can be run via:
 ```sh
-./bin/etcd-migrate --data-dir=<PATH TO YOUR DATA>
+./go build
+./etcd-migrate --data-dir=<PATH TO YOUR DATA>
 ```
 
 It should autodetect everything and convert the data-dir to be 2.0 compatible. It does not remove the 0.4.x data, and is safe to convert multiple times; the 2.0 data will be overwritten. Recovering the disk space once everything is settled is covered later in the document.
@@ -44,4 +45,4 @@ If the conversion has completed, the entire cluster is running on something 2.0-
 rm -ri snapshot conf log
 ```
 
-It will ask before every deletion, but these are the 0.4.x files and will not affect the working 2.0 data.
+It will ask before every deletion, but these are the 0.4.x files and will not affect the working 2.0 data.

version/version.go

@@ -14,7 +14,65 @@
 
 package version
 
-var (
-	Version         = "2.0.6"
-	InternalVersion = "2"
+import (
+	"os"
+	"path"
+
+	"github.com/coreos/etcd/pkg/fileutil"
+	"github.com/coreos/etcd/pkg/types"
 )
+
+var (
+	Version = "2.0.10"
+)
+
+// WalVersion is an enum for versions of etcd logs.
+type DataDirVersion string
+
+const (
+	DataDirUnknown  DataDirVersion = "Unknown WAL"
+	DataDir0_4      DataDirVersion = "0.4.x"
+	DataDir2_0      DataDirVersion = "2.0.0"
+	DataDir2_0Proxy DataDirVersion = "2.0 proxy"
+	DataDir2_0_1    DataDirVersion = "2.0.1"
+)
+
+func DetectDataDir(dirpath string) (DataDirVersion, error) {
+	names, err := fileutil.ReadDir(dirpath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			err = nil
+		}
+		// Error reading the directory
+		return DataDirUnknown, err
+	}
+	nameSet := types.NewUnsafeSet(names...)
+	if nameSet.Contains("member") {
+		ver, err := DetectDataDir(path.Join(dirpath, "member"))
+		if ver == DataDir2_0 {
+			return DataDir2_0_1, nil
+		} else if ver == DataDir0_4 {
+			// How in the blazes did it get there?
+			return DataDirUnknown, nil
+		}
+		return ver, err
+	}
+	if nameSet.ContainsAll([]string{"snap", "wal"}) {
+		// .../wal cannot be empty to exist.
+		walnames, err := fileutil.ReadDir(path.Join(dirpath, "wal"))
+		if err == nil && len(walnames) > 0 {
+			return DataDir2_0, nil
+		}
+	}
+	if nameSet.ContainsAll([]string{"proxy"}) {
+		return DataDir2_0Proxy, nil
+	}
+	if nameSet.ContainsAll([]string{"snapshot", "conf", "log"}) {
+		return DataDir0_4, nil
+	}
+	if nameSet.ContainsAll([]string{"standby_info"}) {
+		return DataDir0_4, nil
+	}
+
+	return DataDirUnknown, nil
+}

version/version_test.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package wal
+package version
 
 import (
 	"io/ioutil"
@@ -22,21 +22,20 @@ import (
 	"testing"
 )
 
-func TestDetectVersion(t *testing.T) {
+func TestDetectDataDir(t *testing.T) {
 	tests := []struct {
 		names []string
-		wver  WalVersion
+		wver  DataDirVersion
 	}{
-		{[]string{}, WALNotExist},
-		{[]string{"member/", "member/wal/", "member/wal/1", "member/snap/"}, WALv2_0_1},
-		{[]string{"snap/", "wal/", "wal/1"}, WALv2_0},
-		{[]string{"snapshot/", "conf", "log"}, WALv0_4},
-		{[]string{"weird"}, WALUnknown},
-		{[]string{"snap/", "wal/"}, WALUnknown},
+		{[]string{"member/", "member/wal/", "member/wal/1", "member/snap/"}, DataDir2_0_1},
+		{[]string{"snap/", "wal/", "wal/1"}, DataDir2_0},
+		{[]string{"snapshot/", "conf", "log"}, DataDir0_4},
+		{[]string{"weird"}, DataDirUnknown},
+		{[]string{"snap/", "wal/"}, DataDirUnknown},
 	}
 	for i, tt := range tests {
 		p := mustMakeDir(t, tt.names...)
-		ver, err := DetectVersion(p)
+		ver, err := DetectDataDir(p)
 		if ver != tt.wver {
 			t.Errorf("#%d: version = %s, want %s", i, ver, tt.wver)
 		}
@@ -45,15 +44,6 @@ func TestDetectVersion(t *testing.T) {
 		}
 		os.RemoveAll(p)
 	}
-
-	// detect on non-exist directory
-	v, err := DetectVersion(path.Join(os.TempDir(), "waltest", "not-exist"))
-	if v != WALNotExist {
-		t.Errorf("#non-exist: version = %s, want %s", v, WALNotExist)
-	}
-	if err != nil {
-		t.Errorf("#non-exist: err = %s, want %s", v, WALNotExist)
-	}
 }
 
 // mustMakeDir builds the directory that contains files with the given

wal/util.go

@@ -17,68 +17,10 @@ package wal
 import (
 	"fmt"
 	"log"
-	"os"
-	"path"
 
 	"github.com/coreos/etcd/pkg/fileutil"
-	"github.com/coreos/etcd/pkg/types"
 )
 
-// WalVersion is an enum for versions of etcd logs.
-type WalVersion string
-
-const (
-	WALUnknown   WalVersion = "Unknown WAL"
-	WALNotExist  WalVersion = "No WAL"
-	WALv0_4      WalVersion = "0.4.x"
-	WALv2_0      WalVersion = "2.0.0"
-	WALv2_0Proxy WalVersion = "2.0 proxy"
-	WALv2_0_1    WalVersion = "2.0.1"
-)
-
-func DetectVersion(dirpath string) (WalVersion, error) {
-	names, err := fileutil.ReadDir(dirpath)
-	if err != nil {
-		if os.IsNotExist(err) {
-			err = nil
-		}
-		// Error reading the directory
-		return WALNotExist, err
-	}
-	if len(names) == 0 {
-		// Empty WAL directory
-		return WALNotExist, nil
-	}
-	nameSet := types.NewUnsafeSet(names...)
-	if nameSet.Contains("member") {
-		ver, err := DetectVersion(path.Join(dirpath, "member"))
-		if ver == WALv2_0 {
-			return WALv2_0_1, nil
-		} else if ver == WALv0_4 {
-			// How in the blazes did it get there?
-			return WALUnknown, nil
-		}
-		return ver, err
-	}
-	if nameSet.ContainsAll([]string{"snap", "wal"}) {
-		// .../wal cannot be empty to exist.
-		if Exist(path.Join(dirpath, "wal")) {
-			return WALv2_0, nil
-		}
-	}
-	if nameSet.ContainsAll([]string{"proxy"}) {
-		return WALv2_0Proxy, nil
-	}
-	if nameSet.ContainsAll([]string{"snapshot", "conf", "log"}) {
-		return WALv0_4, nil
-	}
-	if nameSet.ContainsAll([]string{"standby_info"}) {
-		return WALv0_4, nil
-	}
-
-	return WALUnknown, nil
-}
-
 func Exist(dirpath string) bool {
 	names, err := fileutil.ReadDir(dirpath)
 	if err != nil {
@@ -125,7 +67,7 @@ func checkWalNames(names []string) []string {
 	wnames := make([]string, 0)
 	for _, name := range names {
 		if _, _, err := parseWalName(name); err != nil {
-			log.Printf("wal: parse %s error: %v", name, err)
+			log.Printf("wal: ignored file %v in wal", name)
 			continue
 		}
 		wnames = append(wnames, name)

wal/wal.go

@@ -273,30 +273,28 @@ func (w *WAL) ReadAll() (metadata []byte, state raftpb.HardState, ents []raftpb.
 }
 
 // Cut closes current file written and creates a new one ready to append.
+// cut first creates a temp wal file and writes necessary headers into it.
+// Then cut atomtically rename temp wal file to a wal file.
 func (w *WAL) Cut() error {
-	// create a new wal file with name sequence + 1
+	// close old wal file
+	if err := w.sync(); err != nil {
+		return err
+	}
+	if err := w.f.Close(); err != nil {
+		return err
+	}
+
 	fpath := path.Join(w.dir, walName(w.seq+1, w.enti+1))
-	f, err := os.OpenFile(fpath, os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0600)
+	ftpath := fpath + ".tmp"
+
+	// create a temp wal file with name sequence + 1, or tuncate the existing one
+	ft, err := os.OpenFile(ftpath, os.O_WRONLY|os.O_APPEND|os.O_CREATE|os.O_TRUNC, 0600)
 	if err != nil {
 		return err
 	}
-	l, err := fileutil.NewLock(f.Name())
-	if err != nil {
-		return err
-	}
-	err = l.Lock()
-	if err != nil {
-		return err
-	}
-	w.locks = append(w.locks, l)
-	if err = w.sync(); err != nil {
-		return err
-	}
-	w.f.Close()
 
 	// update writer and save the previous crc
-	w.f = f
-	w.seq++
+	w.f = ft
 	prevCrc := w.encoder.crc.Sum32()
 	w.encoder = newEncoder(w.f, prevCrc)
 	if err := w.saveCrc(prevCrc); err != nil {
@@ -308,7 +306,45 @@ func (w *WAL) Cut() error {
 	if err := w.saveState(&w.state); err != nil {
 		return err
 	}
-	return w.sync()
+	// close temp wal file
+	if err := w.sync(); err != nil {
+		return err
+	}
+	if err := w.f.Close(); err != nil {
+		return err
+	}
+
+	// atomically move temp wal file to wal file
+	if err := os.Rename(ftpath, fpath); err != nil {
+		return err
+	}
+
+	// open the wal file and update writer again
+	f, err := os.OpenFile(fpath, os.O_WRONLY|os.O_APPEND, 0600)
+	if err != nil {
+		return err
+	}
+	w.f = f
+	prevCrc = w.encoder.crc.Sum32()
+	w.encoder = newEncoder(w.f, prevCrc)
+
+	// lock the new wal file
+	l, err := fileutil.NewLock(f.Name())
+	if err != nil {
+		return err
+	}
+	err = l.Lock()
+	if err != nil {
+		return err
+	}
+	w.locks = append(w.locks, l)
+
+	// increase the wal seq
+	w.seq++
+
+	log.Printf("wal: segmented wal file %v is created", fpath)
+
+	return nil
 }
 
 func (w *WAL) sync() error {
@@ -326,6 +362,7 @@ func (w *WAL) sync() error {
 // lock 1,2 but keep 3. ReleaseLockTo(5) will release 1,2,3 but keep 4.
 func (w *WAL) ReleaseLockTo(index uint64) error {
 	var smaller int
+	found := false
 
 	for i, l := range w.locks {
 		_, lockIndex, err := parseWalName(path.Base(l.Name()))
@@ -334,10 +371,17 @@ func (w *WAL) ReleaseLockTo(index uint64) error {
 		}
 		if lockIndex >= index {
 			smaller = i - 1
+			found = true
 			break
 		}
 	}
 
+	// if no lock index is greater than the release index, we can
+	// release lock upto the last one(excluding).
+	if !found && len(w.locks) != 0 {
+		smaller = len(w.locks) - 1
+	}
+
 	if smaller <= 0 {
 		return nil
 	}

wal/wal_test.go

@@ -504,4 +504,21 @@ func TestReleaseLockTo(t *testing.T) {
 			t.Errorf("#%d: lockindex = %d, want %d", i, lockIndex, uint64(i+4))
 		}
 	}
+
+	// release the lock to 15
+	unlockIndex = uint64(15)
+	w.ReleaseLockTo(unlockIndex)
+
+	// expected remaining is 10
+	if len(w.locks) != 1 {
+		t.Errorf("len(w.locks) = %d, want %d", len(w.locks), 1)
+	}
+	_, lockIndex, err := parseWalName(path.Base(w.locks[0].Name()))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if lockIndex != uint64(10) {
+		t.Errorf("lockindex = %d, want %d", lockIndex, 10)
+	}
 }