*: bump to v2.0.11

Conflicts:
	etcdmain/etcd.go

Documentation/admin_guide.md

@@ -61,7 +61,7 @@ After your cluster is up and running, adding or removing members is done via [ru
 
 ### 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. 
+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:
 
@@ -102,7 +102,7 @@ $ sudo systemctl stop etcd
 #### Copy the data directory of the now-idle member to the new machine
 
 ```
-$ tar -cvzf node1.etcd.tar.gz /var/lib/etcd/node1.etcd 
+$ tar -cvzf node1.etcd.tar.gz /var/lib/etcd/node1.etcd
 ```
 
 ```
@@ -181,7 +181,9 @@ Once you have verified that etcd has started successfully, shut it down and move
 
 #### Restoring the cluster
 
-Now that the node is running successfully, you can add more nodes to the cluster and restore resiliency. See the [runtime configuration](runtime-configuration.md) guide for more details.
+Now that the node is running successfully, you should [change its advertised peer URLs](other_apis.md#change-the-peer-urls-of-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 [runtime configuration](runtime-configuration.md) guide for more details.
 
 ### Client Request Timeout
 

Documentation/proxy.md

@@ -4,6 +4,10 @@ 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.
+
+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. 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`). 
 

build

@@ -11,6 +11,8 @@ ln -s ${PWD} $GOPATH/src/${REPO_PATH}
 
 eval $(go env)
 
+GIT_SHA=`git rev-parse --short HEAD`
+
 # 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 -X ${REPO_PATH}/version.GitSHA ${GIT_SHA}" -o bin/etcd ${REPO_PATH}
-CGO_ENABLED=0 go build -a -installsuffix cgo -ldflags '-s' -o bin/etcdctl ${REPO_PATH}/etcdctl
+CGO_ENABLED=0 go build -a -installsuffix cgo -ldflags "-s" -o bin/etcdctl ${REPO_PATH}/etcdctl

client/members.go

@@ -105,7 +105,7 @@ func (m *httpMembersAPI) Remove(ctx context.Context, memberID string) error {
 		return err
 	}
 
-	return assertStatusCode(resp.StatusCode, http.StatusNoContent)
+	return assertStatusCode(resp.StatusCode, http.StatusNoContent, http.StatusGone)
 }
 
 type membersAPIActionList struct{}

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))
+			target := strings.TrimSuffix(srv.Target, ".")
-			tcpAddr, err := net.ResolveTCPAddr("tcp", host)
+			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()))
+			stringParts = append(stringParts, fmt.Sprintf("%s=%s%s", n, prefix, host))
-			log.Printf("discovery: Got bootstrap from DNS for %s at host %s to %s%s", service, host, prefix, tcpAddr.String())
+			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")
+	srcSnap := path.Join(c.String("data-dir"), "member", "snap")
-	destSnap := path.Join(c.String("backup-dir"), "snap")
+	destSnap := path.Join(c.String("backup-dir"), "member", "snap")
-	srcWAL := path.Join(c.String("data-dir"), "wal")
+	srcWAL := path.Join(c.String("data-dir"), "member", "wal")
-	destWAL := path.Join(c.String("backup-dir"), "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

@@ -26,6 +26,7 @@ func NewImportSnapCommand() cli.Command {
 		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,
@@ -36,7 +37,7 @@ 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)")
+			fmt.Printf("no snapshot file provided (use --snap)\n")
 		} else {
 			fmt.Printf("cannot read snapshot file %s\n", c.String("snap"))
 		}
@@ -83,6 +84,15 @@ func handleImportSnap(c *cli.Context) {
 		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)

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"},

etcdmain/config.go

@@ -15,18 +15,17 @@
 package etcdmain
 
 import (
-	"errors"
 	"flag"
 	"fmt"
 	"log"
 	"net/url"
 	"os"
+	"runtime"
 	"strings"
 
 	"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"
 )
@@ -64,6 +63,7 @@ var (
 
 	ErrConflictBootstrapFlags = fmt.Errorf("multiple discovery or bootstrap flags are set" +
 		"Choose one of \"initial-cluster\", \"discovery\" or \"discovery-srv\"")
+	errUnsetAdvertiseClientURLsFlag = fmt.Errorf("-advertise-client-urls is required when -listen-client-urls is set explicitly")
 )
 
 type config struct {
@@ -213,7 +213,10 @@ func (cfg *config) Parse(arguments []string) error {
 	}
 
 	if cfg.printVersion {
-		fmt.Println("etcd version", version.Version)
+		fmt.Printf("etcd Version: %s\n", version.Version)
+		fmt.Printf("Git SHA: %s\n", version.GitSHA)
+		fmt.Printf("Go Version: %s\n", runtime.Version())
+		fmt.Printf("Go OS/Arch: %s/%s\n", runtime.GOOS, runtime.GOARCH)
 		os.Exit(0)
 	}
 
@@ -255,9 +258,8 @@ func (cfg *config) Parse(arguments []string) error {
 	if err != nil {
 		return err
 	}
-
+	if flags.IsSet(cfg.FlagSet, "listen-client-urls") && !flags.IsSet(cfg.FlagSet, "advertise-client-urls") {
-	if err := cfg.resolveUrls(); err != nil {
+		return errUnsetAdvertiseClientURLsFlag
-		return errors.New("cannot resolve DNS hostnames.")
 	}
 
 	if 5*cfg.TickMs > cfg.ElectionMs {
@@ -275,10 +277,6 @@ 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/config_test.go

@@ -29,6 +29,8 @@ func TestConfigParsingMemberFlags(t *testing.T) {
 		"-snapshot-count=10",
 		"-listen-peer-urls=http://localhost:8000,https://localhost:8001",
 		"-listen-client-urls=http://localhost:7000,https://localhost:7001",
+		// it should be set if -listen-client-urls is set
+		"-advertise-client-urls=http://localhost:7000,https://localhost:7001",
 	}
 	wcfg := &config{
 		dir:          "testdir",

etcdmain/etcd.go

@@ -56,8 +56,12 @@ func Main() {
 	cfg := NewConfig()
 	err := cfg.Parse(os.Args[1:])
 	if err != nil {
-		log.Printf("etcd: error verifying flags, %v. See 'etcd -help'.", err)
+		log.Printf("error verifying flags, %v. See 'etcd -help'.", err)
-		os.Exit(2)
+		switch err {
+		case errUnsetAdvertiseClientURLsFlag:
+			log.Printf("When listening on specific address(es), this etcd process must advertise accessible url(s) to each connected client.")
+		}
+		os.Exit(1)
 	}
 
 	var stopped <-chan struct{}
@@ -90,8 +94,10 @@ func Main() {
 	if err != nil {
 		switch err {
 		case discovery.ErrDuplicateID:
-			log.Fatalf("etcd: member %s has previously registered with discovery service (%s), but the data-dir (%s) on disk cannot be found.",
+			log.Printf("member %q has previously registered with discovery service token (%s).", cfg.name, cfg.durl)
-				cfg.name, cfg.durl, cfg.dir)
+			log.Printf("But etcd could not find vaild cluster configuration in the given data dir (%s).", cfg.dir)
+			log.Printf("Please check the given data dir path if the previous bootstrap succeeded")
+			log.Printf("or use a new discovery token if the previous bootstrap failed.")
 		default:
 			log.Fatalf("etcd: %v", err)
 		}
@@ -191,7 +197,7 @@ func startEtcd(cfg *config) (<-chan struct{}, error) {
 		Handler: etcdhttp.NewClientHandler(s),
 		Info:    cfg.corsInfo,
 	}
-	ph := etcdhttp.NewPeerHandler(s.Cluster, etcdserver.RaftTimer(s), s.RaftHandler())
+	ph := etcdhttp.NewPeerHandler(s.Cluster, s.RaftHandler())
 	// Start the peer server in a goroutine
 	for _, l := range plns {
 		go func(l net.Listener) {

etcdmain/help.go

@@ -56,7 +56,8 @@ clustering flags:
 	--initial-cluster-token 'etcd-cluster'
 		initial cluster token for the etcd cluster during bootstrap.
 	--advertise-client-urls 'http://localhost:2379,http://localhost:4001'
-		list of this member's client URLs to advertise to the rest of the cluster.
+		list of this member's client URLs to advertise to the public.
+		The client URLs advertised should be accessible to machines that talk to etcd cluster. etcd client libraries parse these URLs to connect to the cluster.
 	--discovery ''
 		discovery URL used to bootstrap the cluster.
 	--discovery-fallback 'proxy'

etcdserver/cluster.go

@@ -59,12 +59,6 @@ type Cluster struct {
 	id    types.ID
 	token string
 	store store.Store
-	// index is the raft index that cluster is updated at bootstrap
-	// from remote cluster info.
-	// It may have a higher value than local raft index, because it
-	// displays a further view of the cluster.
-	// TODO: upgrade it as last modified index
-	index uint64
 
 	sync.Mutex // guards members and removed map
 	members    map[types.ID]*Member
@@ -236,8 +230,6 @@ func (c *Cluster) SetID(id types.ID) { c.id = id }
 
 func (c *Cluster) SetStore(st store.Store) { c.store = st }
 
-func (c *Cluster) UpdateIndex(index uint64) { c.index = index }
-
 func (c *Cluster) Recover() {
 	c.members, c.removed = membersFromStore(c.store)
 }

etcdserver/cluster_util.go

@@ -21,7 +21,6 @@ import (
 	"log"
 	"net/http"
 	"sort"
-	"strconv"
 	"time"
 
 	"github.com/coreos/etcd/pkg/types"
@@ -89,21 +88,7 @@ func getClusterFromRemotePeers(urls []string, logerr bool, tr *http.Transport) (
 			}
 			continue
 		}
-		var index uint64
+		return NewClusterFromMembers("", id, membs), nil
-		// The header at or before v2.0.3 doesn't have this field. For backward
-		// compatibility, it checks whether the field exists.
-		if indexStr := resp.Header.Get("X-Raft-Index"); indexStr != "" {
-			index, err = strconv.ParseUint(indexStr, 10, 64)
-			if err != nil {
-				if logerr {
-					log.Printf("etcdserver: could not parse raft index: %v", err)
-				}
-				continue
-			}
-		}
-		cl := NewClusterFromMembers("", id, membs)
-		cl.UpdateIndex(index)
-		return cl, nil
 	}
 	return nil, fmt.Errorf("etcdserver: could not retrieve cluster information from the given urls")
 }

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 {

etcdserver/etcdhttp/peer.go

@@ -18,7 +18,6 @@ import (
 	"encoding/json"
 	"log"
 	"net/http"
-	"strconv"
 
 	"github.com/coreos/etcd/etcdserver"
 	"github.com/coreos/etcd/rafthttp"
@@ -29,10 +28,9 @@ const (
 )
 
 // NewPeerHandler generates an http.Handler to handle etcd peer (raft) requests.
-func NewPeerHandler(clusterInfo etcdserver.ClusterInfo, timer etcdserver.RaftTimer, raftHandler http.Handler) http.Handler {
+func NewPeerHandler(clusterInfo etcdserver.ClusterInfo, raftHandler http.Handler) http.Handler {
 	mh := &peerMembersHandler{
 		clusterInfo: clusterInfo,
-		timer:       timer,
 	}
 
 	mux := http.NewServeMux()
@@ -45,7 +43,6 @@ func NewPeerHandler(clusterInfo etcdserver.ClusterInfo, timer etcdserver.RaftTim
 
 type peerMembersHandler struct {
 	clusterInfo etcdserver.ClusterInfo
-	timer       etcdserver.RaftTimer
 }
 
 func (h *peerMembersHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
@@ -53,7 +50,6 @@ func (h *peerMembersHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	w.Header().Set("X-Etcd-Cluster-ID", h.clusterInfo.ID().String())
-	w.Header().Set("X-Raft-Index", strconv.FormatUint(h.timer.Index(), 10))
 
 	if r.URL.Path != peerMembersPrefix {
 		http.Error(w, "bad path", http.StatusBadRequest)

etcdserver/etcdhttp/peer_test.go

@@ -33,7 +33,7 @@ func TestNewPeerHandlerOnRaftPrefix(t *testing.T) {
 	h := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Write([]byte("test data"))
 	})
-	ph := NewPeerHandler(&fakeCluster{}, &dummyRaftTimer{}, h)
+	ph := NewPeerHandler(&fakeCluster{}, h)
 	srv := httptest.NewServer(ph)
 	defer srv.Close()
 
@@ -91,7 +91,7 @@ func TestServeMembersGet(t *testing.T) {
 		id:      1,
 		members: map[uint64]*etcdserver.Member{1: &memb1, 2: &memb2},
 	}
-	h := &peerMembersHandler{clusterInfo: cluster, timer: &dummyRaftTimer{}}
+	h := &peerMembersHandler{clusterInfo: cluster}
 	msb, err := json.Marshal([]etcdserver.Member{memb1, memb2})
 	if err != nil {
 		t.Fatal(err)

etcdserver/server.go

@@ -158,6 +158,7 @@ func NewServer(cfg *ServerConfig) (*EtcdServer, error) {
 	haveWAL := wal.Exist(cfg.WALDir())
 	ss := snap.New(cfg.SnapDir())
 
+	var remotes []*Member
 	switch {
 	case !haveWAL && !cfg.NewCluster:
 		if err := cfg.VerifyJoinExisting(); err != nil {
@@ -170,7 +171,7 @@ func NewServer(cfg *ServerConfig) (*EtcdServer, error) {
 		if err := ValidateClusterAndAssignIDs(cfg.Cluster, existingCluster); err != nil {
 			return nil, fmt.Errorf("error validating peerURLs %s: %v", existingCluster, err)
 		}
-		cfg.Cluster.UpdateIndex(existingCluster.index)
+		remotes = existingCluster.Members()
 		cfg.Cluster.SetID(existingCluster.id)
 		cfg.Cluster.SetStore(st)
 		cfg.Print()
@@ -238,6 +239,7 @@ func NewServer(cfg *ServerConfig) (*EtcdServer, error) {
 		Name: cfg.Name,
 		ID:   id.String(),
 	}
+	sstats.Initialize()
 	lstats := stats.NewLeaderStats(id.String())
 
 	srv := &EtcdServer{
@@ -260,8 +262,14 @@ func NewServer(cfg *ServerConfig) (*EtcdServer, error) {
 		reqIDGen:   idutil.NewGenerator(uint8(id), time.Now()),
 	}
 
+	// TODO: move transport initialization near the definition of remote
 	tr := rafthttp.NewTransporter(cfg.Transport, id, cfg.Cluster.ID(), srv, srv.errorc, sstats, lstats)
-	// add all the remote members into sendhub
+	// add all remotes into transport
+	for _, m := range remotes {
+		if m.ID != id {
+			tr.AddRemote(m.ID, m.PeerURLs)
+		}
+	}
 	for _, m := range cfg.Cluster.Members() {
 		if m.ID != id {
 			tr.AddPeer(m.ID, m.PeerURLs)
@@ -292,7 +300,6 @@ func (s *EtcdServer) start() {
 	s.w = wait.New()
 	s.done = make(chan struct{})
 	s.stop = make(chan struct{})
-	s.stats.Initialize()
 	// TODO: if this is an empty log, writes all peer infos
 	// into the first entry
 	go s.run()
@@ -395,19 +402,15 @@ func (s *EtcdServer) run() {
 				if err := s.store.Recovery(rd.Snapshot.Data); err != nil {
 					log.Panicf("recovery store error: %v", err)
 				}
+				s.Cluster.Recover()
 
-				// It avoids snapshot recovery overwriting newer cluster and
+				// recover raft transport
-				// transport setting, which may block the communication.
+				s.r.transport.RemoveAllPeers()
-				if s.Cluster.index < rd.Snapshot.Metadata.Index {
+				for _, m := range s.Cluster.Members() {
-					s.Cluster.Recover()
+					if m.ID == s.ID() {
-					// recover raft transport
+						continue
-					s.r.transport.RemoveAllPeers()
-					for _, m := range s.Cluster.Members() {
-						if m.ID == s.ID() {
-							continue
-						}
-						s.r.transport.AddPeer(m.ID, m.PeerURLs)
 					}
+					s.r.transport.AddPeer(m.ID, m.PeerURLs)
 				}
 
 				appliedi = rd.Snapshot.Metadata.Index
@@ -671,9 +674,9 @@ func (s *EtcdServer) publish(retryInterval time.Duration) {
 }
 
 func (s *EtcdServer) send(ms []raftpb.Message) {
-	for _, m := range ms {
+	for i, _ := range ms {
-		if !s.Cluster.IsIDRemoved(types.ID(m.To)) {
+		if s.Cluster.IsIDRemoved(types.ID(ms[i].To)) {
-			m.To = 0
+			ms[i].To = 0
 		}
 	}
 	s.r.transport.Send(ms)
@@ -723,7 +726,11 @@ 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
+		// PUT with PrevExist=true *and* PrevIndex set ==> CompareAndSwap
-		// TODO(jonboulle): is this expected?!
 		{
 			pb.Request{Method: "PUT", ID: 1, PrevExist: pbutil.Boolp(true), PrevIndex: 1},
 			Response{Event: &store.Event{}},
 			[]testutil.Action{
 				{
-					Name:   "Update",
+					Name:   "CompareAndSwap",
-					Params: []interface{}{"", "", time.Time{}},
+					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{}},
@@ -1391,6 +1389,7 @@ type nopTransporter struct{}
 
 func (s *nopTransporter) Handler() http.Handler               { return nil }
 func (s *nopTransporter) Send(m []raftpb.Message)             {}
+func (s *nopTransporter) AddRemote(id types.ID, us []string)  {}
 func (s *nopTransporter) AddPeer(id types.ID, us []string)    {}
 func (s *nopTransporter) RemovePeer(id types.ID)              {}
 func (s *nopTransporter) RemoveAllPeers()                     {}

integration/cluster_test.go

@@ -170,6 +170,46 @@ func TestForceNewCluster(t *testing.T) {
 	clusterMustProgress(t, c.Members[:1])
 }
 
+// Ensure we can remove a member then add a new one back immediately.
+func TestIssue2681(t *testing.T) {
+	defer afterTest(t)
+	c := NewCluster(t, 5)
+	c.Launch(t)
+	defer c.Terminate(t)
+
+	c.RemoveMember(t, uint64(c.Members[4].s.ID()))
+	c.waitLeader(t, c.Members)
+
+	c.AddMember(t)
+	c.waitLeader(t, c.Members)
+	clusterMustProgress(t, c.Members)
+}
+
+// Ensure we can remove a member after a snapshot then add a new one back.
+func TestIssue2746(t *testing.T) {
+	defer afterTest(t)
+	c := NewCluster(t, 5)
+
+	for _, m := range c.Members {
+		m.SnapCount = 10
+	}
+
+	c.Launch(t)
+	defer c.Terminate(t)
+
+	// force a snapshot
+	for i := 0; i < 20; i++ {
+		clusterMustProgress(t, c.Members)
+	}
+
+	c.RemoveMember(t, uint64(c.Members[4].s.ID()))
+	c.waitLeader(t, c.Members)
+
+	c.AddMember(t)
+	c.waitLeader(t, c.Members)
+	clusterMustProgress(t, c.Members)
+}
+
 // clusterMustProgress ensures that cluster can make progress. It creates
 // a random key first, and check the new key could be got from all client urls
 // of the cluster.
@@ -526,7 +566,7 @@ func (m *member) Launch() error {
 	m.s.SyncTicker = time.Tick(500 * time.Millisecond)
 	m.s.Start()
 
-	m.raftHandler = &testutil.PauseableHandler{Next: etcdhttp.NewPeerHandler(m.s.Cluster, m.s, m.s.RaftHandler())}
+	m.raftHandler = &testutil.PauseableHandler{Next: etcdhttp.NewPeerHandler(m.s.Cluster, m.s.RaftHandler())}
 
 	for _, ln := range m.PeerListeners {
 		hs := &httptest.Server{

pkg/fileutil/lock_plan9.go

@@ -0,0 +1,90 @@
+// 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 fileutil
+
+import (
+	"errors"
+	"os"
+	"syscall"
+	"time"
+)
+
+var (
+	ErrLocked = errors.New("file already locked")
+)
+
+type Lock interface {
+	Name() string
+	TryLock() error
+	Lock() error
+	Unlock() error
+	Destroy() error
+}
+
+type lock struct {
+	fname string
+	file  *os.File
+}
+
+func (l *lock) Name() string {
+	return l.fname
+}
+
+// TryLock acquires exclusivity on the lock without blocking
+func (l *lock) TryLock() error {
+	err := os.Chmod(l.fname, syscall.DMEXCL|0600)
+	if err != nil {
+		return err
+	}
+
+	f, err := os.Open(l.fname)
+	if err != nil {
+		return ErrLocked
+	}
+
+	l.file = f
+	return nil
+}
+
+// Lock acquires exclusivity on the lock with blocking
+func (l *lock) Lock() error {
+	err := os.Chmod(l.fname, syscall.DMEXCL|0600)
+	if err != nil {
+		return err
+	}
+
+	for {
+		f, err := os.Open(l.fname)
+		if err == nil {
+			l.file = f
+			return nil
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+}
+
+// Unlock unlocks the lock
+func (l *lock) Unlock() error {
+	return l.file.Close()
+}
+
+func (l *lock) Destroy() error {
+	return nil
+}
+
+func NewLock(file string) (Lock, error) {
+	l := &lock{fname: file}
+	return l, nil
+}

pkg/fileutil/lock_solaris.go

@@ -0,0 +1,98 @@
+// 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.
+
+// +build solaris
+
+package fileutil
+
+import (
+	"errors"
+	"os"
+	"syscall"
+)
+
+var (
+	ErrLocked = errors.New("file already locked")
+)
+
+type Lock interface {
+	Name() string
+	TryLock() error
+	Lock() error
+	Unlock() error
+	Destroy() error
+}
+
+type lock struct {
+	fd   int
+	file *os.File
+}
+
+func (l *lock) Name() string {
+	return l.file.Name()
+}
+
+// TryLock acquires exclusivity on the lock without blocking
+func (l *lock) TryLock() error {
+	var lock syscall.Flock_t
+	lock.Start = 0
+	lock.Len = 0
+	lock.Pid = 0
+	lock.Type = syscall.F_WRLCK
+	lock.Whence = 0
+	lock.Pid = 0
+	err := syscall.FcntlFlock(uintptr(l.fd), syscall.F_SETLK, &lock)
+	if err != nil && err == syscall.EAGAIN {
+		return ErrLocked
+	}
+	return err
+}
+
+// Lock acquires exclusivity on the lock without blocking
+func (l *lock) Lock() error {
+	var lock syscall.Flock_t
+	lock.Start = 0
+	lock.Len = 0
+	lock.Type = syscall.F_WRLCK
+	lock.Whence = 0
+	lock.Pid = 0
+	return syscall.FcntlFlock(uintptr(l.fd), syscall.F_SETLK, &lock)
+}
+
+// Unlock unlocks the lock
+func (l *lock) Unlock() error {
+	var lock syscall.Flock_t
+	lock.Start = 0
+	lock.Len = 0
+	lock.Type = syscall.F_UNLCK
+	lock.Whence = 0
+	err := syscall.FcntlFlock(uintptr(l.fd), syscall.F_SETLK, &lock)
+	if err != nil && err == syscall.EAGAIN {
+		return ErrLocked
+	}
+	return err
+}
+
+func (l *lock) Destroy() error {
+	return l.file.Close()
+}
+
+func NewLock(file string) (Lock, error) {
+	f, err := os.OpenFile(file, os.O_WRONLY, 0600)
+	if err != nil {
+		return nil, err
+	}
+	l := &lock{int(f.Fd()), f}
+	return l, nil
+}

pkg/fileutil/lock_unix.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// +build !windows,!plan9
+// +build !windows,!plan9,!solaris
 
 package fileutil
 

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
 }
 

proxy/reverse.go

@@ -73,6 +73,25 @@ func (p *reverseProxy) ServeHTTP(rw http.ResponseWriter, clientreq *http.Request
 		return
 	}
 
+	completeCh := make(chan bool, 1)
+	closeNotifier, ok := rw.(http.CloseNotifier)
+	if ok {
+		go func() {
+			select {
+			case <-closeNotifier.CloseNotify():
+				tp, ok := p.transport.(*http.Transport)
+				if ok {
+					tp.CancelRequest(proxyreq)
+				}
+			case <-completeCh:
+			}
+		}()
+
+		defer func() {
+			completeCh <- true
+		}()
+	}
+
 	var res *http.Response
 	var err error
 

raft/log.go

@@ -65,7 +65,7 @@ func newLog(storage Storage) *raftLog {
 }
 
 func (l *raftLog) String() string {
-	return fmt.Sprintf("committed=%d, applied=%d, unstable.offset=%d, len(unstable.Entries)=%d", l.unstable.offset, l.committed, l.applied, len(l.unstable.entries))
+	return fmt.Sprintf("committed=%d, applied=%d, unstable.offset=%d, len(unstable.Entries)=%d", l.committed, l.applied, l.unstable.offset, len(l.unstable.entries))
 }
 
 // maybeAppend returns (0, false) if the entries cannot be appended. Otherwise,

rafthttp/peer.go

@@ -199,7 +199,7 @@ func (p *peer) handle() {
 				log.Printf("sender: the connection with %s became inactive", p.id)
 				p.active = false
 			}
-			if m.Type == raftpb.MsgApp {
+			if m.Type == raftpb.MsgApp && p.fs != nil {
 				p.fs.Fail()
 			}
 		} else {
@@ -208,7 +208,7 @@ func (p *peer) handle() {
 				p.active = true
 				p.errored = nil
 			}
-			if m.Type == raftpb.MsgApp {
+			if m.Type == raftpb.MsgApp && p.fs != nil {
 				p.fs.Succ(end.Sub(start))
 			}
 		}

rafthttp/remote.go

@@ -0,0 +1,42 @@
+// 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 rafthttp
+
+import (
+	"net/http"
+
+	"github.com/coreos/etcd/pkg/types"
+	"github.com/coreos/etcd/raft/raftpb"
+)
+
+type remote struct {
+	id   types.ID
+	peer *peer
+}
+
+func startRemote(tr http.RoundTripper, u string, local, to, cid types.ID, r Raft, errorc chan error) *remote {
+	return &remote{
+		id:   to,
+		peer: NewPeer(tr, u, to, cid, r, nil, errorc),
+	}
+}
+
+func (g *remote) Send(m raftpb.Message) {
+	g.peer.send(m)
+}
+
+func (g *remote) Stop() {
+	g.peer.Stop()
+}

rafthttp/transport.go

@@ -35,6 +35,12 @@ type Raft interface {
 type Transporter interface {
 	Handler() http.Handler
 	Send(m []raftpb.Message)
+	// AddRemote adds a remote with given peer urls into the transport.
+	// A remote helps newly joined member to catch up the progress of cluster,
+	// and will not be used after that.
+	// It is the caller's responsibility to ensure the urls are all vaild,
+	// or it panics.
+	AddRemote(id types.ID, urls []string)
 	AddPeer(id types.ID, urls []string)
 	RemovePeer(id types.ID)
 	RemoveAllPeers()
@@ -50,9 +56,10 @@ type transport struct {
 	serverStats  *stats.ServerStats
 	leaderStats  *stats.LeaderStats
 
-	mu     sync.RWMutex       // protect the peer map
+	mu      sync.RWMutex         // protect the remote and peer map
-	peers  map[types.ID]*peer // remote peers
+	remotes map[types.ID]*remote // remotes map that helps newly joined member to catch up
-	errorc chan error
+	peers   map[types.ID]*peer   // peers map
+	errorc  chan error
 }
 
 func NewTransporter(rt http.RoundTripper, id, cid types.ID, r Raft, errorc chan error, ss *stats.ServerStats, ls *stats.LeaderStats) Transporter {
@@ -63,6 +70,7 @@ func NewTransporter(rt http.RoundTripper, id, cid types.ID, r Raft, errorc chan
 		raft:         r,
 		serverStats:  ss,
 		leaderStats:  ls,
+		remotes:      make(map[types.ID]*remote),
 		peers:        make(map[types.ID]*peer),
 		errorc:       errorc,
 	}
@@ -90,21 +98,30 @@ func (t *transport) Send(msgs []raftpb.Message) {
 			continue
 		}
 		to := types.ID(m.To)
+
 		p, ok := t.peers[to]
-		if !ok {
+		if ok {
-			log.Printf("etcdserver: send message to unknown receiver %s", to)
+			if m.Type == raftpb.MsgApp {
+				t.serverStats.SendAppendReq(m.Size())
+			}
+			p.Send(m)
 			continue
 		}
 
-		if m.Type == raftpb.MsgApp {
+		g, ok := t.remotes[to]
-			t.serverStats.SendAppendReq(m.Size())
+		if ok {
+			g.Send(m)
+			continue
 		}
 
-		p.Send(m)
+		log.Printf("etcdserver: send message to unknown receiver %s", to)
 	}
 }
 
 func (t *transport) Stop() {
+	for _, r := range t.remotes {
+		r.Stop()
+	}
 	for _, p := range t.peers {
 		p.Stop()
 	}
@@ -113,6 +130,21 @@ func (t *transport) Stop() {
 	}
 }
 
+func (t *transport) AddRemote(id types.ID, us []string) {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	if _, ok := t.remotes[id]; ok {
+		return
+	}
+	peerURL := us[0]
+	u, err := url.Parse(peerURL)
+	if err != nil {
+		log.Panicf("unexpect peer url %s", peerURL)
+	}
+	u.Path = path.Join(u.Path, RaftPrefix)
+	t.remotes[id] = startRemote(t.roundTripper, u.String(), t.id, id, t.clusterID, t.raft, t.errorc)
+}
+
 func (t *transport) AddPeer(id types.ID, urls []string) {
 	t.mu.Lock()
 	defer t.mu.Unlock()

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 {
+	if err != ErrNoSnapshot {
-		t.Errorf("err = %v, want %v", err, ErrEmptySnapshot)
+		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)
 				}

version/version.go

@@ -23,7 +23,10 @@ import (
 )
 
 var (
-	Version = "2.0.8"
+	Version = "2.0.11"
+
+	// Git SHA Value will be set during build
+	GitSHA = "Not provided (use ./build instead of go build)"
 )
 
 // WalVersion is an enum for versions of etcd logs.

wal/util.go

@@ -67,7 +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.f = ft
-	w.seq++
 	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 {