// getRemotePeerURLs returns peer urls of remote members in the cluster. The
// returned list is sorted in ascending lexicographical order.
func getRemotePeerURLs(cl *membership.RaftCluster, local string) []string {
us := make([]string, 0)
for _, m := range cl.Members() {
if m.Name == local {
continue
}
us = append(us, m.PeerURLs...)
}
sort.Strings(us)
return us
}
// isMemberBootstrapped tries to check if the given member has been bootstrapped
// in the given cluster.
func isMemberBootstrapped(cl *membership.RaftCluster, member string, rt http.RoundTripper, timeout time.Duration) bool {
rcl, err := getClusterFromRemotePeers(getRemotePeerURLs(cl, member), timeout, false, rt)
if err != nil {
return false
}
id := cl.MemberByName(member).ID
m := rcl.Member(id)
if m == nil {
return false
}
if len(m.ClientURLs) > 0 {
return true
}
return false
}
// makeWAL creates a WAL for the initial cluster
func makeWAL(waldir string, cl *membership.RaftCluster) {
if err := os.MkdirAll(waldir, 0755); err != nil {
ExitWithError(ExitIO, err)
}
m := cl.MemberByName(restoreName)
md := &etcdserverpb.Metadata{NodeID: uint64(m.ID), ClusterID: uint64(cl.ID())}
metadata, merr := md.Marshal()
if merr != nil {
ExitWithError(ExitInvalidInput, merr)
}
w, walerr := wal.Create(waldir, metadata)
if walerr != nil {
ExitWithError(ExitIO, walerr)
}
defer w.Close()
peers := make([]raft.Peer, len(cl.MemberIDs()))
for i, id := range cl.MemberIDs() {
ctx, err := json.Marshal((*cl).Member(id))
if err != nil {
ExitWithError(ExitInvalidInput, err)
}
peers[i] = raft.Peer{ID: uint64(id), Context: ctx}
}
ents := make([]raftpb.Entry, len(peers))
for i, p := range peers {
cc := raftpb.ConfChange{
Type: raftpb.ConfChangeAddNode,
NodeID: p.ID,
Context: p.Context}
d, err := cc.Marshal()
if err != nil {
ExitWithError(ExitInvalidInput, err)
}
e := raftpb.Entry{
Type: raftpb.EntryConfChange,
Term: 1,
Index: uint64(i + 1),
Data: d,
}
ents[i] = e
}
w.Save(raftpb.HardState{
Term: 1,
Vote: peers[0].ID,
Commit: uint64(len(ents))}, ents)
}
func applyConf(cc raftpb.ConfChange, cl *membership.RaftCluster) {
if err := cl.ValidateConfigurationChange(cc); err != nil {
return
}
switch cc.Type {
case raftpb.ConfChangeAddNode:
m := new(membership.Member)
if err := json.Unmarshal(cc.Context, m); err != nil {
panic(err)
}
cl.AddMember(m)
case raftpb.ConfChangeRemoveNode:
cl.RemoveMember(types.ID(cc.NodeID))
case raftpb.ConfChangeUpdateNode:
m := new(membership.Member)
if err := json.Unmarshal(cc.Context, m); err != nil {
panic(err)
}
cl.UpdateRaftAttributes(m.ID, m.RaftAttributes)
}
}
func startNode(cfg *ServerConfig, cl *membership.RaftCluster, ids []types.ID) (id types.ID, n raft.Node, s *raft.MemoryStorage, w *wal.WAL) {
var err error
member := cl.MemberByName(cfg.Name)
metadata := pbutil.MustMarshal(
&pb.Metadata{
NodeID: uint64(member.ID),
ClusterID: uint64(cl.ID()),
},
)
if err = os.MkdirAll(cfg.SnapDir(), privateDirMode); err != nil {
plog.Fatalf("create snapshot directory error: %v", err)
}
if w, err = wal.Create(cfg.WALDir(), metadata); err != nil {
plog.Fatalf("create wal error: %v", err)
}
peers := make([]raft.Peer, len(ids))
for i, id := range ids {
ctx, err := json.Marshal((*cl).Member(id))
if err != nil {
plog.Panicf("marshal member should never fail: %v", err)
}
peers[i] = raft.Peer{ID: uint64(id), Context: ctx}
}
id = member.ID
plog.Infof("starting member %s in cluster %s", id, cl.ID())
s = raft.NewMemoryStorage()
c := &raft.Config{
ID: uint64(id),
ElectionTick: cfg.ElectionTicks,
HeartbeatTick: 1,
Storage: s,
MaxSizePerMsg: maxSizePerMsg,
MaxInflightMsgs: maxInflightMsgs,
CheckQuorum: true,
}
n = raft.StartNode(c, peers)
raftStatusMu.Lock()
raftStatus = n.Status
raftStatusMu.Unlock()
advanceTicksForElection(n, c.ElectionTick)
return
}
// getVersions returns the versions of the members in the given cluster.
// The key of the returned map is the member's ID. The value of the returned map
// is the semver versions string, including server and cluster.
// If it fails to get the version of a member, the key will be nil.
func getVersions(cl *membership.RaftCluster, local types.ID, rt http.RoundTripper) map[string]*version.Versions {
members := cl.Members()
vers := make(map[string]*version.Versions)
for _, m := range members {
if m.ID == local {
cv := "not_decided"
if cl.Version() != nil {
cv = cl.Version().String()
}
vers[m.ID.String()] = &version.Versions{Server: version.Version, Cluster: cv}
continue
}
ver, err := getVersion(m, rt)
if err != nil {
plog.Warningf("cannot get the version of member %s (%v)", m.ID, err)
vers[m.ID.String()] = nil
} else {
vers[m.ID.String()] = ver
}
}
return vers
}
// NewServer creates a new EtcdServer from the supplied configuration. The
// configuration is considered static for the lifetime of the EtcdServer.
func NewServer(cfg *ServerConfig) (srv *EtcdServer, err error) {
st := store.New(StoreClusterPrefix, StoreKeysPrefix)
var (
w *wal.WAL
n raft.Node
s *raft.MemoryStorage
id types.ID
cl *membership.RaftCluster
)
if terr := fileutil.TouchDirAll(cfg.DataDir); terr != nil {
return nil, fmt.Errorf("cannot access data directory: %v", terr)
}
// Run the migrations.
dataVer, err := version.DetectDataDir(cfg.DataDir)
if err != nil {
return nil, err
}
if err = upgradeDataDir(cfg.DataDir, cfg.Name, dataVer); err != nil {
return nil, err
}
haveWAL := wal.Exist(cfg.WALDir())
if err = os.MkdirAll(cfg.SnapDir(), privateDirMode); err != nil && !os.IsExist(err) {
plog.Fatalf("create snapshot directory error: %v", err)
}
ss := snap.New(cfg.SnapDir())
be := backend.NewDefaultBackend(path.Join(cfg.SnapDir(), databaseFilename))
defer func() {
if err != nil {
be.Close()
}
}()
prt, err := rafthttp.NewRoundTripper(cfg.PeerTLSInfo, cfg.peerDialTimeout())
if err != nil {
return nil, err
}
var remotes []*membership.Member
switch {
case !haveWAL && !cfg.NewCluster:
if err = cfg.VerifyJoinExisting(); err != nil {
return nil, err
}
cl, err = membership.NewClusterFromURLsMap(cfg.InitialClusterToken, cfg.InitialPeerURLsMap)
if err != nil {
return nil, err
}
existingCluster, gerr := GetClusterFromRemotePeers(getRemotePeerURLs(cl, cfg.Name), prt)
if gerr != nil {
return nil, fmt.Errorf("cannot fetch cluster info from peer urls: %v", gerr)
}
if err = membership.ValidateClusterAndAssignIDs(cl, existingCluster); err != nil {
return nil, fmt.Errorf("error validating peerURLs %s: %v", existingCluster, err)
}
if !isCompatibleWithCluster(cl, cl.MemberByName(cfg.Name).ID, prt) {
return nil, fmt.Errorf("incomptible with current running cluster")
}
remotes = existingCluster.Members()
cl.SetID(existingCluster.ID())
cl.SetStore(st)
cl.SetBackend(be)
cfg.Print()
id, n, s, w = startNode(cfg, cl, nil)
case !haveWAL && cfg.NewCluster:
if err = cfg.VerifyBootstrap(); err != nil {
return nil, err
}
cl, err = membership.NewClusterFromURLsMap(cfg.InitialClusterToken, cfg.InitialPeerURLsMap)
if err != nil {
return nil, err
}
m := cl.MemberByName(cfg.Name)
if isMemberBootstrapped(cl, cfg.Name, prt, cfg.bootstrapTimeout()) {
return nil, fmt.Errorf("member %s has already been bootstrapped", m.ID)
}
if cfg.ShouldDiscover() {
var str string
str, err = discovery.JoinCluster(cfg.DiscoveryURL, cfg.DiscoveryProxy, m.ID, cfg.InitialPeerURLsMap.String())
if err != nil {
return nil, &DiscoveryError{Op: "join", Err: err}
}
var urlsmap types.URLsMap
urlsmap, err = types.NewURLsMap(str)
if err != nil {
return nil, err
}
if checkDuplicateURL(urlsmap) {
return nil, fmt.Errorf("discovery cluster %s has duplicate url", urlsmap)
}
if cl, err = membership.NewClusterFromURLsMap(cfg.InitialClusterToken, urlsmap); err != nil {
return nil, err
}
}
cl.SetStore(st)
cl.SetBackend(be)
cfg.PrintWithInitial()
id, n, s, w = startNode(cfg, cl, cl.MemberIDs())
case haveWAL:
if err = fileutil.IsDirWriteable(cfg.MemberDir()); err != nil {
return nil, fmt.Errorf("cannot write to member directory: %v", err)
}
if err = fileutil.IsDirWriteable(cfg.WALDir()); err != nil {
return nil, fmt.Errorf("cannot write to WAL directory: %v", err)
}
if cfg.ShouldDiscover() {
plog.Warningf("discovery token ignored since a cluster has already been initialized. Valid log found at %q", cfg.WALDir())
}
var snapshot *raftpb.Snapshot
snapshot, err = ss.Load()
if err != nil && err != snap.ErrNoSnapshot {
return nil, err
}
if snapshot != nil {
if err = st.Recovery(snapshot.Data); err != nil {
plog.Panicf("recovered store from snapshot error: %v", err)
}
plog.Infof("recovered store from snapshot at index %d", snapshot.Metadata.Index)
}
cfg.Print()
if !cfg.ForceNewCluster {
id, cl, n, s, w = restartNode(cfg, snapshot)
} else {
id, cl, n, s, w = restartAsStandaloneNode(cfg, snapshot)
}
cl.SetStore(st)
cl.SetBackend(be)
cl.Recover()
default:
return nil, fmt.Errorf("unsupported bootstrap config")
}
if terr := fileutil.TouchDirAll(cfg.MemberDir()); terr != nil {
return nil, fmt.Errorf("cannot access member directory: %v", terr)
}
sstats := &stats.ServerStats{
Name: cfg.Name,
ID: id.String(),
}
sstats.Initialize()
lstats := stats.NewLeaderStats(id.String())
srv = &EtcdServer{
readych: make(chan struct{}),
Cfg: cfg,
snapCount: cfg.SnapCount,
errorc: make(chan error, 1),
store: st,
r: raftNode{
Node: n,
ticker: time.Tick(time.Duration(cfg.TickMs) * time.Millisecond),
raftStorage: s,
storage: NewStorage(w, ss),
},
id: id,
attributes: membership.Attributes{Name: cfg.Name, ClientURLs: cfg.ClientURLs.StringSlice()},
cluster: cl,
stats: sstats,
lstats: lstats,
SyncTicker: time.Tick(500 * time.Millisecond),
peerRt: prt,
reqIDGen: idutil.NewGenerator(uint16(id), time.Now()),
forceVersionC: make(chan struct{}),
msgSnapC: make(chan raftpb.Message, maxInFlightMsgSnap),
}
srv.applyV2 = &applierV2store{store: srv.store, cluster: srv.cluster}
srv.be = be
srv.lessor = lease.NewLessor(srv.be)
srv.kv = mvcc.New(srv.be, srv.lessor, &srv.consistIndex)
srv.consistIndex.setConsistentIndex(srv.kv.ConsistentIndex())
srv.authStore = auth.NewAuthStore(srv.be)
if h := cfg.AutoCompactionRetention; h != 0 {
srv.compactor = compactor.NewPeriodic(h, srv.kv, srv)
srv.compactor.Run()
}
if err = srv.restoreAlarms(); err != nil {
return nil, err
}
// TODO: move transport initialization near the definition of remote
tr := &rafthttp.Transport{
TLSInfo: cfg.PeerTLSInfo,
DialTimeout: cfg.peerDialTimeout(),
ID: id,
URLs: cfg.PeerURLs,
ClusterID: cl.ID(),
Raft: srv,
Snapshotter: ss,
ServerStats: sstats,
LeaderStats: lstats,
ErrorC: srv.errorc,
}
if err = tr.Start(); err != nil {
return nil, err
}
// add all remotes into transport
for _, m := range remotes {
if m.ID != id {
tr.AddRemote(m.ID, m.PeerURLs)
}
}
for _, m := range cl.Members() {
if m.ID != id {
tr.AddPeer(m.ID, m.PeerURLs)
}
}
srv.r.transport = tr
return srv, nil
}
// NewServer creates a new EtcdServer from the supplied configuration. The
// configuration is considered static for the lifetime of the EtcdServer.
func NewServer(cfg *ServerConfig) (srv *EtcdServer, err error) {
st := store.New(StoreClusterPrefix, StoreKeysPrefix)
var (
w *wal.WAL
n raft.Node
s *raft.MemoryStorage
id types.ID
cl *membership.RaftCluster
)
if terr := fileutil.TouchDirAll(cfg.DataDir); terr != nil {
return nil, fmt.Errorf("cannot access data directory: %v", terr)
}
haveWAL := wal.Exist(cfg.WALDir())
if err = fileutil.TouchDirAll(cfg.SnapDir()); err != nil {
plog.Fatalf("create snapshot directory error: %v", err)
}
ss := snap.New(cfg.SnapDir())
bepath := path.Join(cfg.SnapDir(), databaseFilename)
beExist := fileutil.Exist(bepath)
var be backend.Backend
beOpened := make(chan struct{})
go func() {
be = backend.NewDefaultBackend(bepath)
beOpened <- struct{}{}
}()
select {
case <-beOpened:
case <-time.After(time.Second):
plog.Warningf("another etcd process is running with the same data dir and holding the file lock.")
plog.Warningf("waiting for it to exit before starting...")
<-beOpened
}
defer func() {
if err != nil {
be.Close()
}
}()
prt, err := rafthttp.NewRoundTripper(cfg.PeerTLSInfo, cfg.peerDialTimeout())
if err != nil {
return nil, err
}
var (
remotes []*membership.Member
snapshot *raftpb.Snapshot
)
switch {
case !haveWAL && !cfg.NewCluster:
if err = cfg.VerifyJoinExisting(); err != nil {
return nil, err
}
cl, err = membership.NewClusterFromURLsMap(cfg.InitialClusterToken, cfg.InitialPeerURLsMap)
if err != nil {
return nil, err
}
existingCluster, gerr := GetClusterFromRemotePeers(getRemotePeerURLs(cl, cfg.Name), prt)
if gerr != nil {
return nil, fmt.Errorf("cannot fetch cluster info from peer urls: %v", gerr)
}
if err = membership.ValidateClusterAndAssignIDs(cl, existingCluster); err != nil {
return nil, fmt.Errorf("error validating peerURLs %s: %v", existingCluster, err)
}
if !isCompatibleWithCluster(cl, cl.MemberByName(cfg.Name).ID, prt) {
return nil, fmt.Errorf("incompatible with current running cluster")
}
remotes = existingCluster.Members()
cl.SetID(existingCluster.ID())
cl.SetStore(st)
cl.SetBackend(be)
cfg.Print()
id, n, s, w = startNode(cfg, cl, nil)
case !haveWAL && cfg.NewCluster:
if err = cfg.VerifyBootstrap(); err != nil {
return nil, err
}
cl, err = membership.NewClusterFromURLsMap(cfg.InitialClusterToken, cfg.InitialPeerURLsMap)
if err != nil {
return nil, err
}
m := cl.MemberByName(cfg.Name)
if isMemberBootstrapped(cl, cfg.Name, prt, cfg.bootstrapTimeout()) {
return nil, fmt.Errorf("member %s has already been bootstrapped", m.ID)
}
if cfg.ShouldDiscover() {
var str string
str, err = discovery.JoinCluster(cfg.DiscoveryURL, cfg.DiscoveryProxy, m.ID, cfg.InitialPeerURLsMap.String())
if err != nil {
return nil, &DiscoveryError{Op: "join", Err: err}
}
var urlsmap types.URLsMap
urlsmap, err = types.NewURLsMap(str)
if err != nil {
return nil, err
}
if checkDuplicateURL(urlsmap) {
return nil, fmt.Errorf("discovery cluster %s has duplicate url", urlsmap)
}
if cl, err = membership.NewClusterFromURLsMap(cfg.InitialClusterToken, urlsmap); err != nil {
return nil, err
}
}
cl.SetStore(st)
cl.SetBackend(be)
cfg.PrintWithInitial()
id, n, s, w = startNode(cfg, cl, cl.MemberIDs())
case haveWAL:
if err = fileutil.IsDirWriteable(cfg.MemberDir()); err != nil {
return nil, fmt.Errorf("cannot write to member directory: %v", err)
}
if err = fileutil.IsDirWriteable(cfg.WALDir()); err != nil {
return nil, fmt.Errorf("cannot write to WAL directory: %v", err)
}
if cfg.ShouldDiscover() {
plog.Warningf("discovery token ignored since a cluster has already been initialized. Valid log found at %q", cfg.WALDir())
}
snapshot, err = ss.Load()
if err != nil && err != snap.ErrNoSnapshot {
return nil, err
}
if snapshot != nil {
if err = st.Recovery(snapshot.Data); err != nil {
plog.Panicf("recovered store from snapshot error: %v", err)
}
plog.Infof("recovered store from snapshot at index %d", snapshot.Metadata.Index)
}
cfg.Print()
if !cfg.ForceNewCluster {
id, cl, n, s, w = restartNode(cfg, snapshot)
} else {
id, cl, n, s, w = restartAsStandaloneNode(cfg, snapshot)
}
cl.SetStore(st)
cl.SetBackend(be)
cl.Recover(api.UpdateCapability)
if cl.Version() != nil && !cl.Version().LessThan(semver.Version{Major: 3}) && !beExist {
os.RemoveAll(bepath)
return nil, fmt.Errorf("database file (%v) of the backend is missing", bepath)
}
default:
return nil, fmt.Errorf("unsupported bootstrap config")
}
if terr := fileutil.TouchDirAll(cfg.MemberDir()); terr != nil {
return nil, fmt.Errorf("cannot access member directory: %v", terr)
}
sstats := &stats.ServerStats{
Name: cfg.Name,
ID: id.String(),
}
sstats.Initialize()
lstats := stats.NewLeaderStats(id.String())
heartbeat := time.Duration(cfg.TickMs) * time.Millisecond
srv = &EtcdServer{
readych: make(chan struct{}),
Cfg: cfg,
snapCount: cfg.SnapCount,
errorc: make(chan error, 1),
store: st,
r: raftNode{
isIDRemoved: func(id uint64) bool { return cl.IsIDRemoved(types.ID(id)) },
Node: n,
ticker: time.Tick(heartbeat),
// set up contention detectors for raft heartbeat message.
// expect to send a heartbeat within 2 heartbeat intervals.
td: contention.NewTimeoutDetector(2 * heartbeat),
heartbeat: heartbeat,
raftStorage: s,
storage: NewStorage(w, ss),
msgSnapC: make(chan raftpb.Message, maxInFlightMsgSnap),
readStateC: make(chan raft.ReadState, 1),
},
id: id,
attributes: membership.Attributes{Name: cfg.Name, ClientURLs: cfg.ClientURLs.StringSlice()},
cluster: cl,
stats: sstats,
lstats: lstats,
SyncTicker: time.Tick(500 * time.Millisecond),
peerRt: prt,
reqIDGen: idutil.NewGenerator(uint16(id), time.Now()),
forceVersionC: make(chan struct{}),
}
srv.applyV2 = &applierV2store{store: srv.store, cluster: srv.cluster}
srv.be = be
minTTL := time.Duration((3*cfg.ElectionTicks)/2) * heartbeat
// always recover lessor before kv. When we recover the mvcc.KV it will reattach keys to its leases.
// If we recover mvcc.KV first, it will attach the keys to the wrong lessor before it recovers.
srv.lessor = lease.NewLessor(srv.be, int64(math.Ceil(minTTL.Seconds())))
srv.kv = mvcc.New(srv.be, srv.lessor, &srv.consistIndex)
if beExist {
kvindex := srv.kv.ConsistentIndex()
// TODO: remove kvindex != 0 checking when we do not expect users to upgrade
// etcd from pre-3.0 release.
if snapshot != nil && kvindex < snapshot.Metadata.Index {
if kvindex != 0 {
return nil, fmt.Errorf("database file (%v index %d) does not match with snapshot (index %d).", bepath, kvindex, snapshot.Metadata.Index)
}
plog.Warningf("consistent index never saved (snapshot index=%d)", snapshot.Metadata.Index)
}
}
srv.consistIndex.setConsistentIndex(srv.kv.ConsistentIndex())
srv.authStore = auth.NewAuthStore(srv.be)
if h := cfg.AutoCompactionRetention; h != 0 {
srv.compactor = compactor.NewPeriodic(h, srv.kv, srv)
srv.compactor.Run()
}
srv.applyV3Base = &applierV3backend{srv}
if err = srv.restoreAlarms(); err != nil {
return nil, err
}
// TODO: move transport initialization near the definition of remote
tr := &rafthttp.Transport{
TLSInfo: cfg.PeerTLSInfo,
DialTimeout: cfg.peerDialTimeout(),
ID: id,
URLs: cfg.PeerURLs,
ClusterID: cl.ID(),
Raft: srv,
Snapshotter: ss,
ServerStats: sstats,
LeaderStats: lstats,
ErrorC: srv.errorc,
}
if err = tr.Start(); err != nil {
return nil, err
}
// add all remotes into transport
for _, m := range remotes {
if m.ID != id {
tr.AddRemote(m.ID, m.PeerURLs)
}
}
for _, m := range cl.Members() {
if m.ID != id {
tr.AddPeer(m.ID, m.PeerURLs)
}
}
srv.r.transport = tr
return srv, nil
}
// makeWAL creates a WAL for the initial cluster
func makeWALAndSnap(waldir, snapdir string, cl *membership.RaftCluster) {
if err := fileutil.CreateDirAll(waldir); err != nil {
ExitWithError(ExitIO, err)
}
// add members again to persist them to the store we create.
st := store.New(etcdserver.StoreClusterPrefix, etcdserver.StoreKeysPrefix)
cl.SetStore(st)
for _, m := range cl.Members() {
cl.AddMember(m)
}
m := cl.MemberByName(restoreName)
md := &etcdserverpb.Metadata{NodeID: uint64(m.ID), ClusterID: uint64(cl.ID())}
metadata, merr := md.Marshal()
if merr != nil {
ExitWithError(ExitInvalidInput, merr)
}
w, walerr := wal.Create(waldir, metadata)
if walerr != nil {
ExitWithError(ExitIO, walerr)
}
defer w.Close()
peers := make([]raft.Peer, len(cl.MemberIDs()))
for i, id := range cl.MemberIDs() {
ctx, err := json.Marshal((*cl).Member(id))
if err != nil {
ExitWithError(ExitInvalidInput, err)
}
peers[i] = raft.Peer{ID: uint64(id), Context: ctx}
}
ents := make([]raftpb.Entry, len(peers))
nodeIDs := make([]uint64, len(peers))
for i, p := range peers {
nodeIDs[i] = p.ID
cc := raftpb.ConfChange{
Type: raftpb.ConfChangeAddNode,
NodeID: p.ID,
Context: p.Context}
d, err := cc.Marshal()
if err != nil {
ExitWithError(ExitInvalidInput, err)
}
e := raftpb.Entry{
Type: raftpb.EntryConfChange,
Term: 1,
Index: uint64(i + 1),
Data: d,
}
ents[i] = e
}
commit, term := uint64(len(ents)), uint64(1)
if err := w.Save(raftpb.HardState{
Term: term,
Vote: peers[0].ID,
Commit: commit}, ents); err != nil {
ExitWithError(ExitIO, err)
}
b, berr := st.Save()
if berr != nil {
ExitWithError(ExitError, berr)
}
raftSnap := raftpb.Snapshot{
Data: b,
Metadata: raftpb.SnapshotMetadata{
Index: commit,
Term: term,
ConfState: raftpb.ConfState{
Nodes: nodeIDs,
},
},
}
snapshotter := snap.New(snapdir)
if err := snapshotter.SaveSnap(raftSnap); err != nil {
panic(err)
}
if err := w.SaveSnapshot(walpb.Snapshot{Index: commit, Term: term}); err != nil {
ExitWithError(ExitIO, err)
}
}