// Start implements replication.LogReplicator
func (l *raftLog) Start(lo uint64) error {
inited, err := l.config.Storage.(*raftStorage).IsInitialized()
if err != nil {
return err
}
if inited {
l.config.Applied = lo
l.node = raft.RestartNode(&l.config)
} else {
if lo != 0 {
log.Panicf("storage uninitialized but state machine not fresh: lo = %d", lo)
}
// Add a dummy first entry
hardState, confState, err := l.config.Storage.InitialState()
if err != nil {
return err
}
confNodes := make([]raft.Peer, 0, len(confState.Nodes))
for _, id := range confState.Nodes {
confNodes = append(confNodes, raft.Peer{ID: id})
}
l.config.Storage.(*raftStorage).save(hardState, make([]raftpb.Entry, 1))
l.node = raft.StartNode(&l.config, confNodes)
}
l.leaderHintSet = make(chan bool, COMMITTED_BUFFER)
l.waitCommitted = make(chan replication.LogEntry, COMMITTED_BUFFER)
l.stop = make(chan struct{})
l.stopped = make(chan struct{})
l.grpcDropClient = make(chan uint64)
l.grpcClientCache = make(map[uint64]proto.RaftClient)
go l.run()
return nil
}
// restart restarts the node. restart a started node
// blocks and might affect the future stop operation.
func (n *node) restart() {
// wait for the shutdown
<-n.stopc
n.Node = raft.RestartNode(n.id, 10, 1, n.storage, 0)
n.start()
n.iface.connect()
}
func restartNode(cfg *ServerConfig, snapshot *raftpb.Snapshot) (types.ID, *cluster, raft.Node, *raftStorage, *wal.WAL) {
var walsnap walpb.Snapshot
if snapshot != nil {
walsnap.Index, walsnap.Term = snapshot.Metadata.Index, snapshot.Metadata.Term
}
w, id, cid, st, ents := readWAL(cfg.WALDir(), walsnap)
plog.Infof("restarting member %s in cluster %s at commit index %d", id, cid, st.Commit)
cl := newCluster("")
cl.SetID(cid)
s := newRaftStorage()
if snapshot != nil {
s.ApplySnapshot(*snapshot)
}
s.SetHardState(st)
s.Append(ents)
c := &raft.Config{
ID: uint64(id),
ElectionTick: cfg.ElectionTicks,
HeartbeatTick: 1,
Storage: s,
MaxSizePerMsg: maxSizePerMsg,
MaxInflightMsgs: maxInflightMsgs,
}
n := raft.RestartNode(c)
raftStatus = n.Status
advanceTicksForElection(n, c.ElectionTick)
return id, cl, n, s, w
}
// InitAndStartNode gets called after having at least one membership sync with the cluster.
func (n *node) InitAndStartNode(wal *raftwal.Wal) {
restart, err := n.initFromWal(wal)
x.Check(err)
if restart {
fmt.Printf("RESTARTING\n")
n.raft = raft.RestartNode(n.cfg)
} else {
if groups().HasPeer(n.gid) {
n.joinPeers()
n.raft = raft.StartNode(n.cfg, nil)
} else {
peers := []raft.Peer{{ID: n.id}}
n.raft = raft.StartNode(n.cfg, peers)
// Trigger election, so this node can become the leader of this single-node cluster.
n.canCampaign = true
}
}
go n.processCommitCh()
go n.Run()
// TODO: Find a better way to snapshot, so we don't lose the membership
// state information, which isn't persisted.
// go n.snapshotPeriodically()
go n.batchAndSendMessages()
}
func (rc *raftNode) startRaft() {
if !fileutil.Exist(rc.snapdir) {
if err := os.Mkdir(rc.snapdir, 0750); err != nil {
log.Fatalf("raftexample: cannot create dir for snapshot (%v)", err)
}
}
rc.snapshotter = snap.New(rc.snapdir)
rc.snapshotterReady <- rc.snapshotter
oldwal := wal.Exist(rc.waldir)
rc.wal = rc.replayWAL()
rpeers := make([]raft.Peer, len(rc.peers))
for i := range rpeers {
rpeers[i] = raft.Peer{ID: uint64(i + 1)}
}
c := &raft.Config{
ID: uint64(rc.id),
ElectionTick: 10,
HeartbeatTick: 1,
Storage: rc.raftStorage,
MaxSizePerMsg: 1024 * 1024,
MaxInflightMsgs: 256,
}
if oldwal {
rc.node = raft.RestartNode(c)
} else {
startPeers := rpeers
if rc.join {
startPeers = nil
}
rc.node = raft.StartNode(c, startPeers)
}
ss := &stats.ServerStats{}
ss.Initialize()
rc.transport = &rafthttp.Transport{
ID: types.ID(rc.id),
ClusterID: 0x1000,
Raft: rc,
ServerStats: ss,
LeaderStats: stats.NewLeaderStats(strconv.Itoa(rc.id)),
ErrorC: make(chan error),
}
rc.transport.Start()
for i := range rc.peers {
if i+1 != rc.id {
rc.transport.AddPeer(types.ID(i+1), []string{rc.peers[i]})
}
}
go rc.serveRaft()
go rc.serveChannels()
}
func (n *Node) loadAndStart(ctx context.Context, forceNewCluster bool) error {
walDir := n.walDir()
snapDir := n.snapDir()
if err := os.MkdirAll(snapDir, 0700); err != nil {
return fmt.Errorf("create snapshot directory error: %v", err)
}
// Create a snapshotter
n.snapshotter = snap.New(snapDir)
if !wal.Exist(walDir) {
raftNode := &api.RaftMember{
RaftID: n.Config.ID,
Addr: n.Address,
}
metadata, err := raftNode.Marshal()
if err != nil {
return fmt.Errorf("error marshalling raft node: %v", err)
}
n.wal, err = wal.Create(walDir, metadata)
if err != nil {
return fmt.Errorf("create wal error: %v", err)
}
n.cluster.AddMember(&membership.Member{RaftMember: raftNode})
n.startNodePeers = []raft.Peer{{ID: n.Config.ID, Context: metadata}}
return nil
}
// Load snapshot data
snapshot, err := n.snapshotter.Load()
if err != nil && err != snap.ErrNoSnapshot {
return err
}
if snapshot != nil {
// Load the snapshot data into the store
if err := n.restoreFromSnapshot(snapshot.Data, forceNewCluster); err != nil {
return err
}
}
// Read logs to fully catch up store
if err := n.readWAL(ctx, snapshot, forceNewCluster); err != nil {
return err
}
n.Node = raft.RestartNode(n.Config)
return nil
}
func restartNode(cfg *ServerConfig, index uint64, snapshot *raftpb.Snapshot) (types.ID, raft.Node, *raft.MemoryStorage, *wal.WAL) {
w, id, cid, st, ents := readWAL(cfg.WALDir(), index)
cfg.Cluster.SetID(cid)
log.Printf("etcdserver: restart member %s in cluster %s at commit index %d", id, cfg.Cluster.ID(), st.Commit)
s := raft.NewMemoryStorage()
if snapshot != nil {
s.ApplySnapshot(*snapshot)
}
s.SetHardState(st)
s.Append(ents)
n := raft.RestartNode(uint64(id), 10, 1, s)
return id, n, s, w
}
func restartAsStandaloneNode(cfg *ServerConfig, snapshot *raftpb.Snapshot) (types.ID, *cluster, raft.Node, *raftStorage, *wal.WAL) {
var walsnap walpb.Snapshot
if snapshot != nil {
walsnap.Index, walsnap.Term = snapshot.Metadata.Index, snapshot.Metadata.Term
}
w, id, cid, st, ents := readWAL(cfg.WALDir(), walsnap)
// discard the previously uncommitted entries
for i, ent := range ents {
if ent.Index > st.Commit {
plog.Infof("discarding %d uncommitted WAL entries ", len(ents)-i)
ents = ents[:i]
break
}
}
// force append the configuration change entries
toAppEnts := createConfigChangeEnts(getIDs(snapshot, ents), uint64(id), st.Term, st.Commit)
ents = append(ents, toAppEnts...)
// force commit newly appended entries
err := w.Save(raftpb.HardState{}, toAppEnts)
if err != nil {
plog.Fatalf("%v", err)
}
if len(ents) != 0 {
st.Commit = ents[len(ents)-1].Index
}
plog.Printf("forcing restart of member %s in cluster %s at commit index %d", id, cid, st.Commit)
cl := newCluster("")
cl.SetID(cid)
s := newRaftStorage()
if snapshot != nil {
s.ApplySnapshot(*snapshot)
}
s.SetHardState(st)
s.Append(ents)
c := &raft.Config{
ID: uint64(id),
ElectionTick: cfg.ElectionTicks,
HeartbeatTick: 1,
Storage: s,
MaxSizePerMsg: maxSizePerMsg,
MaxInflightMsgs: maxInflightMsgs,
}
n := raft.RestartNode(c)
raftStatus = n.Status
return id, cl, n, s, w
}
// restart restarts the node. restart a started node
// blocks and might affect the future stop operation.
func (n *node) restart() {
// wait for the shutdown
<-n.stopc
c := &raft.Config{
ID: n.id,
ElectionTick: 10,
HeartbeatTick: 1,
Storage: n.storage,
MaxSizePerMsg: 1024 * 1024,
MaxInflightMsgs: 256,
}
n.Node = raft.RestartNode(c)
n.start()
n.iface.connect()
}
func (rc *raftNode) startRaft() {
oldwal := wal.Exist(rc.waldir)
rc.wal = rc.replayWAL()
rpeers := make([]raft.Peer, len(rc.peers))
for i := range rpeers {
rpeers[i] = raft.Peer{ID: uint64(i + 1)}
}
c := &raft.Config{
ID: uint64(rc.id),
ElectionTick: 10,
HeartbeatTick: 1,
Storage: rc.raftStorage,
MaxSizePerMsg: 1024 * 1024,
MaxInflightMsgs: 256,
}
if oldwal {
rc.node = raft.RestartNode(c)
} else {
rc.node = raft.StartNode(c, rpeers)
}
ss := &stats.ServerStats{}
ss.Initialize()
rc.transport = &rafthttp.Transport{
ID: types.ID(rc.id),
ClusterID: 0x1000,
Raft: rc,
ServerStats: ss,
LeaderStats: stats.NewLeaderStats(strconv.Itoa(rc.id)),
ErrorC: make(chan error),
}
rc.transport.Start()
for i := range rc.peers {
if i+1 != rc.id {
rc.transport.AddPeer(types.ID(i+1), []string{rc.peers[i]})
}
}
go rc.serveRaft()
go rc.serveChannels()
}
func restartNode(cfg *ServerConfig, snapshot *raftpb.Snapshot) (types.ID, raft.Node, *raft.MemoryStorage, *wal.WAL) {
var walsnap walpb.Snapshot
if snapshot != nil {
walsnap.Index, walsnap.Term = snapshot.Metadata.Index, snapshot.Metadata.Term
}
w, id, cid, st, ents := readWAL(cfg.WALDir(), walsnap)
cfg.Cluster.SetID(cid)
log.Printf("etcdserver: restart member %s in cluster %s at commit index %d", id, cfg.Cluster.ID(), st.Commit)
s := raft.NewMemoryStorage()
if snapshot != nil {
s.ApplySnapshot(*snapshot)
}
s.SetHardState(st)
s.Append(ents)
n := raft.RestartNode(uint64(id), cfg.ElectionTicks, 1, s, 0)
return id, n, s, w
}
func restartNode(cfg *ServerConfig, index uint64, snapshot *raftpb.Snapshot) (id uint64, n raft.Node, w *wal.WAL) {
var err error
// restart a node from previous wal
if w, err = wal.OpenAtIndex(cfg.WALDir(), index); err != nil {
log.Fatal(err)
}
wmetadata, st, ents, err := w.ReadAll()
if err != nil {
log.Fatal(err)
}
var metadata pb.Metadata
pbutil.MustUnmarshal(&metadata, wmetadata)
id = metadata.NodeID
cfg.Cluster.SetID(metadata.ClusterID)
log.Printf("etcdserver: restart member %x in cluster %x at commit index %d", id, cfg.Cluster.ID(), st.Commit)
n = raft.RestartNode(id, 10, 1, snapshot, st, ents)
return
}
func restartAsStandaloneNode(cfg *ServerConfig, snapshot *raftpb.Snapshot) (types.ID, raft.Node, *raft.MemoryStorage, *wal.WAL) {
var walsnap walpb.Snapshot
if snapshot != nil {
walsnap.Index, walsnap.Term = snapshot.Metadata.Index, snapshot.Metadata.Term
}
w, id, cid, st, ents := readWAL(cfg.WALDir(), walsnap)
cfg.Cluster.SetID(cid)
// discard the previously uncommitted entries
for i, ent := range ents {
if ent.Index > st.Commit {
log.Printf("etcdserver: discarding %d uncommitted WAL entries ", len(ents)-i)
ents = ents[:i]
break
}
}
// force append the configuration change entries
toAppEnts := createConfigChangeEnts(getIDs(snapshot, ents), uint64(id), st.Term, st.Commit)
ents = append(ents, toAppEnts...)
// force commit newly appended entries
for _, e := range toAppEnts {
err := w.SaveEntry(&e)
if err != nil {
log.Fatalf("etcdserver: %v", err)
}
}
if len(ents) != 0 {
st.Commit = ents[len(ents)-1].Index
}
log.Printf("etcdserver: forcing restart of member %s in cluster %s at commit index %d", id, cfg.Cluster.ID(), st.Commit)
s := raft.NewMemoryStorage()
if snapshot != nil {
s.ApplySnapshot(*snapshot)
}
s.SetHardState(st)
s.Append(ents)
n := raft.RestartNode(uint64(id), 10, 1, s)
return id, n, s, w
}
func (n *Node) loadAndStart(ctx context.Context, forceNewCluster bool) error {
walDir := n.walDir()
snapDir := n.snapDir()
if err := os.MkdirAll(snapDir, 0700); err != nil {
return fmt.Errorf("create snapshot directory error: %v", err)
}
// Create a snapshotter
n.snapshotter = snap.New(snapDir)
if !wal.Exist(walDir) {
return errNoWAL
}
// Load snapshot data
snapshot, err := n.snapshotter.Load()
if err != nil && err != snap.ErrNoSnapshot {
return err
}
if snapshot != nil {
// Load the snapshot data into the store
if err := n.restoreFromSnapshot(snapshot.Data, forceNewCluster); err != nil {
return err
}
}
// Read logs to fully catch up store
if err := n.readWAL(ctx, snapshot, forceNewCluster); err != nil {
return err
}
n.Node = raft.RestartNode(n.Config)
return nil
}
// NewNode generates a new Raft node
func NewNode(ctx context.Context, opts NewNodeOptions) (*Node, error) {
cfg := opts.Config
if cfg == nil {
cfg = DefaultNodeConfig()
}
if opts.TickInterval == 0 {
opts.TickInterval = time.Second
}
raftID, err := identity.ParseNodeID(opts.ID)
if err != nil {
return nil, err
}
raftStore := raft.NewMemoryStorage()
ctx, cancel := context.WithCancel(ctx)
n := &Node{
Ctx: ctx,
cancel: cancel,
cluster: membership.NewCluster(),
tlsCredentials: opts.TLSCredentials,
raftStore: raftStore,
Address: opts.Addr,
Config: &raft.Config{
ElectionTick: cfg.ElectionTick,
HeartbeatTick: cfg.HeartbeatTick,
Storage: raftStore,
MaxSizePerMsg: cfg.MaxSizePerMsg,
MaxInflightMsgs: cfg.MaxInflightMsgs,
Logger: cfg.Logger,
ID: raftID,
},
forceNewCluster: opts.ForceNewCluster,
stopCh: make(chan struct{}),
doneCh: make(chan struct{}),
StateDir: opts.StateDir,
joinAddr: opts.JoinAddr,
sendTimeout: 2 * time.Second,
leadershipBroadcast: events.NewBroadcaster(),
}
n.memoryStore = store.NewMemoryStore(n)
if opts.ClockSource == nil {
n.ticker = clock.NewClock().NewTicker(opts.TickInterval)
} else {
n.ticker = opts.ClockSource.NewTicker(opts.TickInterval)
}
if opts.SendTimeout != 0 {
n.sendTimeout = opts.SendTimeout
}
if err := n.loadAndStart(ctx, opts.ForceNewCluster); err != nil {
n.ticker.Stop()
return nil, err
}
snapshot, err := raftStore.Snapshot()
// Snapshot never returns an error
if err != nil {
panic("could not get snapshot of raft store")
}
n.confState = snapshot.Metadata.ConfState
n.appliedIndex = snapshot.Metadata.Index
n.snapshotIndex = snapshot.Metadata.Index
n.reqIDGen = idutil.NewGenerator(uint16(n.Config.ID), time.Now())
n.wait = newWait()
if n.startNodePeers != nil {
if n.joinAddr != "" {
c, err := n.ConnectToMember(n.joinAddr, 10*time.Second)
if err != nil {
return nil, err
}
defer func() {
_ = c.Conn.Close()
}()
ctx, cancel := context.WithTimeout(n.Ctx, 10*time.Second)
defer cancel()
resp, err := c.Join(ctx, &api.JoinRequest{
Addr: n.Address,
})
if err != nil {
return nil, err
}
n.Node = raft.StartNode(n.Config, []raft.Peer{})
if err := n.registerNodes(resp.Members); err != nil {
return nil, err
}
} else {
n.Node = raft.StartNode(n.Config, n.startNodePeers)
if err := n.Campaign(n.Ctx); err != nil {
return nil, err
}
}
return n, nil
}
if n.joinAddr != "" {
n.Config.Logger.Warning("ignoring request to join cluster, because raft state already exists")
}
n.Node = raft.RestartNode(n.Config)
return n, nil
}
// JoinAndStart joins and starts the raft server
func (n *Node) JoinAndStart(ctx context.Context) (err error) {
ctx, cancel := n.WithContext(ctx)
defer func() {
cancel()
if err != nil {
n.done()
}
}()
loadAndStartErr := n.loadAndStart(ctx, n.opts.ForceNewCluster)
if loadAndStartErr != nil && loadAndStartErr != errNoWAL {
return loadAndStartErr
}
snapshot, err := n.raftStore.Snapshot()
// Snapshot never returns an error
if err != nil {
panic("could not get snapshot of raft store")
}
n.confState = snapshot.Metadata.ConfState
n.appliedIndex = snapshot.Metadata.Index
n.snapshotIndex = snapshot.Metadata.Index
if loadAndStartErr == errNoWAL {
if n.opts.JoinAddr != "" {
c, err := n.ConnectToMember(n.opts.JoinAddr, 10*time.Second)
if err != nil {
return err
}
client := api.NewRaftMembershipClient(c.Conn)
defer func() {
_ = c.Conn.Close()
}()
joinCtx, joinCancel := context.WithTimeout(ctx, 10*time.Second)
defer joinCancel()
resp, err := client.Join(joinCtx, &api.JoinRequest{
Addr: n.opts.Addr,
})
if err != nil {
return err
}
n.Config.ID = resp.RaftID
if _, err := n.createWAL(n.opts.ID); err != nil {
return err
}
n.raftNode = raft.StartNode(n.Config, []raft.Peer{})
if err := n.registerNodes(resp.Members); err != nil {
if walErr := n.wal.Close(); err != nil {
log.G(ctx).WithError(walErr).Error("raft: error closing WAL")
}
return err
}
} else {
// First member in the cluster, self-assign ID
n.Config.ID = uint64(rand.Int63()) + 1
peer, err := n.createWAL(n.opts.ID)
if err != nil {
return err
}
n.raftNode = raft.StartNode(n.Config, []raft.Peer{peer})
n.campaignWhenAble = true
}
atomic.StoreUint32(&n.isMember, 1)
return nil
}
if n.opts.JoinAddr != "" {
log.G(ctx).Warning("ignoring request to join cluster, because raft state already exists")
}
n.campaignWhenAble = true
n.raftNode = raft.RestartNode(n.Config)
atomic.StoreUint32(&n.isMember, 1)
return nil
}
// JoinAndStart joins and starts the raft server
func (n *Node) JoinAndStart() error {
loadAndStartErr := n.loadAndStart(n.Ctx, n.opts.ForceNewCluster)
if loadAndStartErr != nil && loadAndStartErr != errNoWAL {
n.ticker.Stop()
return loadAndStartErr
}
snapshot, err := n.raftStore.Snapshot()
// Snapshot never returns an error
if err != nil {
panic("could not get snapshot of raft store")
}
n.confState = snapshot.Metadata.ConfState
n.appliedIndex = snapshot.Metadata.Index
n.snapshotIndex = snapshot.Metadata.Index
if loadAndStartErr == errNoWAL {
if n.joinAddr != "" {
c, err := n.ConnectToMember(n.joinAddr, 10*time.Second)
if err != nil {
return err
}
client := api.NewRaftMembershipClient(c.Conn)
defer func() {
_ = c.Conn.Close()
}()
ctx, cancel := context.WithTimeout(n.Ctx, 10*time.Second)
defer cancel()
resp, err := client.Join(ctx, &api.JoinRequest{
Addr: n.Address,
})
if err != nil {
return err
}
n.Config.ID = resp.RaftID
if _, err := n.createWAL(n.opts.ID); err != nil {
return err
}
n.Node = raft.StartNode(n.Config, []raft.Peer{})
if err := n.registerNodes(resp.Members); err != nil {
return err
}
} else {
// First member in the cluster, self-assign ID
n.Config.ID = uint64(rand.Int63()) + 1
peer, err := n.createWAL(n.opts.ID)
if err != nil {
return err
}
n.Node = raft.StartNode(n.Config, []raft.Peer{peer})
if err := n.Campaign(n.Ctx); err != nil {
return err
}
}
atomic.StoreUint32(&n.isMember, 1)
return nil
}
if n.joinAddr != "" {
n.Config.Logger.Warning("ignoring request to join cluster, because raft state already exists")
}
n.Node = raft.RestartNode(n.Config)
atomic.StoreUint32(&n.isMember, 1)
return 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) *EtcdServer {
m := cfg.Cluster.FindName(cfg.Name)
if m == nil {
// Should never happen
log.Fatalf("could not find name %v in cluster!", cfg.Name)
}
snapdir := path.Join(cfg.DataDir, "snap")
if err := os.MkdirAll(snapdir, privateDirMode); err != nil {
log.Fatalf("etcdserver: cannot create snapshot directory: %v", err)
}
ss := snap.New(snapdir)
st := store.New()
var w *wal.WAL
var n raft.Node
var err error
waldir := path.Join(cfg.DataDir, "wal")
if !wal.Exist(waldir) {
if w, err = wal.Create(waldir); err != nil {
log.Fatal(err)
}
n = raft.StartNode(m.ID, cfg.Cluster.IDs(), 10, 1)
} else {
var index int64
snapshot, err := ss.Load()
if err != nil && err != snap.ErrNoSnapshot {
log.Fatal(err)
}
if snapshot != nil {
log.Printf("etcdserver: restart from snapshot at index %d", snapshot.Index)
st.Recovery(snapshot.Data)
index = snapshot.Index
}
// restart a node from previous wal
if w, err = wal.OpenAtIndex(waldir, index); err != nil {
log.Fatal(err)
}
wid, st, ents, err := w.ReadAll()
if err != nil {
log.Fatal(err)
}
// TODO(xiangli): save/recovery nodeID?
if wid != 0 {
log.Fatalf("unexpected nodeid %d: nodeid should always be zero until we save nodeid into wal", wid)
}
n = raft.RestartNode(m.ID, cfg.Cluster.IDs(), 10, 1, snapshot, st, ents)
}
cls := NewClusterStore(st, *cfg.Cluster)
s := &EtcdServer{
store: st,
node: n,
name: cfg.Name,
storage: struct {
*wal.WAL
*snap.Snapshotter
}{w, ss},
send: Sender(cfg.Transport, cls),
clientURLs: cfg.ClientURLs,
ticker: time.Tick(100 * time.Millisecond),
syncTicker: time.Tick(500 * time.Millisecond),
snapCount: cfg.SnapCount,
ClusterStore: cls,
}
return s
}
