// This is a fork of raft.DescribeMessage with a tweak to avoid logging
// snapshot data.
func raftDescribeMessage(m raftpb.Message, f raft.EntryFormatter) string {
var buf bytes.Buffer
fmt.Fprintf(&buf, "%x->%x %v Term:%d Log:%d/%d", m.From, m.To, m.Type, m.Term, m.LogTerm, m.Index)
if m.Reject {
fmt.Fprintf(&buf, " Rejected")
if m.RejectHint != 0 {
fmt.Fprintf(&buf, "(Hint:%d)", m.RejectHint)
}
}
if m.Commit != 0 {
fmt.Fprintf(&buf, " Commit:%d", m.Commit)
}
if len(m.Entries) > 0 {
fmt.Fprintf(&buf, " Entries:[")
for i, e := range m.Entries {
if i != 0 {
buf.WriteString(", ")
}
buf.WriteString(raft.DescribeEntry(e, f))
}
fmt.Fprintf(&buf, "]")
}
if !raft.IsEmptySnap(m.Snapshot) {
snap := m.Snapshot
snap.Data = nil
fmt.Fprintf(&buf, " Snapshot:%v", snap)
}
return buf.String()
}
func (n *Node) start() {
tk := time.Tick(5 * time.Millisecond)
for {
select {
case <-tk:
n.Tick()
case rd := <-n.Ready():
if !raft.IsEmptyHardState(rd.HardState) {
n.state = rd.HardState
n.storage.SetHardState(n.state)
}
n.storage.Append(rd.Entries)
n.send(rd.Messages)
if !raft.IsEmptySnap(rd.Snapshot) {
n.storage.ApplySnapshot(rd.Snapshot)
}
time.Sleep(time.Millisecond)
for _, entry := range rd.CommittedEntries {
n.process(entry)
// if entry.Type == raftpb.EntryConfChange {
// }
// var cc raftpb.ConfChange
// cc.Unmarshal(entry.Data)
// n.ApplyConfChange(cc)
}
n.Advance()
case m := <-n.receive():
n.Step(context.TODO(), m)
}
}
}
func logRaftReady(storeID roachpb.StoreID, groupID roachpb.RangeID, ready raft.Ready) {
if log.V(5) {
// Globally synchronize to avoid interleaving different sets of logs in tests.
logRaftReadyMu.Lock()
defer logRaftReadyMu.Unlock()
log.Infof("store %s: group %s raft ready", storeID, groupID)
if ready.SoftState != nil {
log.Infof("SoftState updated: %+v", *ready.SoftState)
}
if !raft.IsEmptyHardState(ready.HardState) {
log.Infof("HardState updated: %+v", ready.HardState)
}
for i, e := range ready.Entries {
log.Infof("New Entry[%d]: %.200s", i, raft.DescribeEntry(e, raftEntryFormatter))
}
for i, e := range ready.CommittedEntries {
log.Infof("Committed Entry[%d]: %.200s", i, raft.DescribeEntry(e, raftEntryFormatter))
}
if !raft.IsEmptySnap(ready.Snapshot) {
log.Infof("Snapshot updated: %.200s", ready.Snapshot.String())
}
for i, m := range ready.Messages {
log.Infof("Outgoing Message[%d]: %.200s", i, raft.DescribeMessage(m, raftEntryFormatter))
}
}
}
func logRaftReady(ctx context.Context, prefix fmt.Stringer, ready raft.Ready) {
if log.V(5) {
var buf bytes.Buffer
if ready.SoftState != nil {
fmt.Fprintf(&buf, " SoftState updated: %+v\n", *ready.SoftState)
}
if !raft.IsEmptyHardState(ready.HardState) {
fmt.Fprintf(&buf, " HardState updated: %+v\n", ready.HardState)
}
for i, e := range ready.Entries {
fmt.Fprintf(&buf, " New Entry[%d]: %.200s\n",
i, raft.DescribeEntry(e, raftEntryFormatter))
}
for i, e := range ready.CommittedEntries {
fmt.Fprintf(&buf, " Committed Entry[%d]: %.200s\n",
i, raft.DescribeEntry(e, raftEntryFormatter))
}
if !raft.IsEmptySnap(ready.Snapshot) {
fmt.Fprintf(&buf, " Snapshot updated: %.200s\n", ready.Snapshot.String())
}
for i, m := range ready.Messages {
fmt.Fprintf(&buf, " Outgoing Message[%d]: %.200s\n",
i, raft.DescribeMessage(m, raftEntryFormatter))
}
log.Infof(ctx, "%s raft ready\n%s", prefix, buf.String())
}
}
func (s *state) logRaftReady(readyGroups map[uint64]raft.Ready) {
for groupID, ready := range readyGroups {
if log.V(5) {
log.Infof("node %v: group %v raft ready", s.nodeID, groupID)
if ready.SoftState != nil {
log.Infof("SoftState updated: %+v", *ready.SoftState)
}
if !raft.IsEmptyHardState(ready.HardState) {
log.Infof("HardState updated: %+v", ready.HardState)
}
for i, e := range ready.Entries {
log.Infof("New Entry[%d]: %.200s", i, raft.DescribeEntry(e, s.EntryFormatter))
}
for i, e := range ready.CommittedEntries {
log.Infof("Committed Entry[%d]: %.200s", i, raft.DescribeEntry(e, s.EntryFormatter))
}
if !raft.IsEmptySnap(ready.Snapshot) {
log.Infof("Snapshot updated: %.200s", ready.Snapshot.String())
}
for i, m := range ready.Messages {
log.Infof("Outgoing Message[%d]: %.200s", i, raft.DescribeMessage(m, s.EntryFormatter))
}
}
}
}
func (n *node) run() {
for {
select {
case <-n.ticker:
n.raft.Tick()
case rd := <-n.raft.Ready():
n.saveToStorage(rd.HardState, rd.Entries, rd.Snapshot)
n.send(rd.Messages)
if !raft.IsEmptySnap(rd.Snapshot) {
n.processSnapshot(rd.Snapshot)
}
for _, entry := range rd.CommittedEntries {
n.process(entry)
if entry.Type == raftpb.EntryConfChange {
var cc raftpb.ConfChange
cc.Unmarshal(entry.Data)
n.raft.ApplyConfChange(cc)
}
}
n.raft.Advance()
case <-n.done:
return
}
}
}
// HardState contains term, vote and commit.
// Snapshot contains data and snapshot metadata.
func (n *node) saveToStorage(hardState raftpb.HardState,
entries []raftpb.Entry, snapshot raftpb.Snapshot) {
if !raft.IsEmptySnap(snapshot) {
fmt.Printf("saveToStorage snapshot: %v\n", snapshot.String())
le, err := n.store.LastIndex()
if err != nil {
log.Fatalf("While retrieving last index: %v\n", err)
}
te, err := n.store.Term(le)
if err != nil {
log.Fatalf("While retrieving term: %v\n", err)
}
fmt.Printf("%d node Term for le: %v is %v\n", n.id, le, te)
if snapshot.Metadata.Index <= le {
fmt.Printf("%d node ignoring snapshot. Last index: %v\n", n.id, le)
return
}
if err := n.store.ApplySnapshot(snapshot); err != nil {
log.Fatalf("Applying snapshot: %v", err)
}
}
if !raft.IsEmptyHardState(hardState) {
n.store.SetHardState(hardState)
}
n.store.Append(entries)
}
// handleWriteReady converts a set of raft.Ready structs into a writeRequest
// to be persisted, marks the group as writing and sends it to the writeTask.
func (s *state) handleWriteReady(readyGroups map[uint64]raft.Ready) {
if log.V(6) {
log.Infof("node %v write ready, preparing request", s.nodeID)
}
writeRequest := newWriteRequest()
for groupID, ready := range readyGroups {
raftGroupID := proto.RaftID(groupID)
g, ok := s.groups[raftGroupID]
if !ok {
if log.V(6) {
log.Infof("dropping write request to group %d", groupID)
}
continue
}
g.writing = true
gwr := &groupWriteRequest{}
if !raft.IsEmptyHardState(ready.HardState) {
gwr.state = ready.HardState
}
if !raft.IsEmptySnap(ready.Snapshot) {
gwr.snapshot = ready.Snapshot
}
if len(ready.Entries) > 0 {
gwr.entries = ready.Entries
}
writeRequest.groups[raftGroupID] = gwr
}
s.writeTask.in <- writeRequest
}
// Saves a log entry to our Store
func (n *Node) saveToStorage(
ctx context.Context,
raftConfig *api.RaftConfig,
hardState raftpb.HardState,
entries []raftpb.Entry,
snapshot raftpb.Snapshot,
) (err error) {
if !raft.IsEmptySnap(snapshot) {
if err := n.raftLogger.SaveSnapshot(snapshot); err != nil {
return ErrApplySnapshot
}
if err := n.raftLogger.GC(snapshot.Metadata.Index, snapshot.Metadata.Term, raftConfig.KeepOldSnapshots); err != nil {
log.G(ctx).WithError(err).Error("unable to clean old snapshots and WALs")
}
if err = n.raftStore.ApplySnapshot(snapshot); err != nil {
return ErrApplySnapshot
}
}
if err := n.raftLogger.SaveEntries(hardState, entries); err != nil {
// TODO(aaronl): These error types should really wrap more
// detailed errors.
return ErrApplySnapshot
}
if err = n.raftStore.Append(entries); err != nil {
return ErrAppendEntry
}
return nil
}
func (s *EtcdServer) applySnapshot(ep *etcdProgress, apply *apply) {
if raft.IsEmptySnap(apply.snapshot) {
return
}
if apply.snapshot.Metadata.Index <= ep.appliedi {
plog.Panicf("snapshot index [%d] should > appliedi[%d] + 1",
apply.snapshot.Metadata.Index, ep.appliedi)
}
if s.cfg.V3demo {
snapfn, err := s.r.storage.DBFilePath(apply.snapshot.Metadata.Index)
if err != nil {
plog.Panicf("get database snapshot file path error: %v", err)
}
fn := path.Join(s.cfg.SnapDir(), databaseFilename)
if err := os.Rename(snapfn, fn); err != nil {
plog.Panicf("rename snapshot file error: %v", err)
}
// TODO: recover lessor
newbe := backend.NewDefaultBackend(fn)
if err := s.kv.Restore(newbe); err != nil {
plog.Panicf("restore KV error: %v", err)
}
// Closing old backend might block until all the txns
// on the backend are finished.
// We do not want to wait on closing the old backend.
oldbe := s.be
go func() {
if err := oldbe.Close(); err != nil {
plog.Panicf("close backend error: %v", err)
}
}()
s.be = newbe
}
if err := s.store.Recovery(apply.snapshot.Data); err != nil {
plog.Panicf("recovery store error: %v", err)
}
s.cluster.Recover()
// recover raft transport
s.r.transport.RemoveAllPeers()
for _, m := range s.cluster.Members() {
if m.ID == s.ID() {
continue
}
s.r.transport.AddPeer(m.ID, m.PeerURLs)
}
ep.appliedi = apply.snapshot.Metadata.Index
ep.snapi = ep.appliedi
ep.confState = apply.snapshot.Metadata.ConfState
plog.Infof("recovered from incoming snapshot at index %d", ep.snapi)
}
// Start is the main loop for a Raft node, it
// goes along the state machine, acting on the
// messages received from other Raft nodes in
// the cluster
func (n *Node) Start() {
for {
select {
case <-n.ticker.C:
n.Tick()
case rd := <-n.Ready():
n.saveToStorage(rd.HardState, rd.Entries, rd.Snapshot)
n.send(rd.Messages)
if !raft.IsEmptySnap(rd.Snapshot) {
n.processSnapshot(rd.Snapshot)
}
for _, entry := range rd.CommittedEntries {
n.process(entry)
if entry.Type == raftpb.EntryConfChange {
var cc raftpb.ConfChange
err := cc.Unmarshal(entry.Data)
if err != nil {
log.Fatal("raft: Can't unmarshal configuration change")
}
switch cc.Type {
case raftpb.ConfChangeAddNode:
n.applyAddNode(cc)
case raftpb.ConfChangeRemoveNode:
n.applyRemoveNode(cc)
}
n.ApplyConfChange(cc)
}
}
n.Advance()
case <-n.stopChan:
n.Stop()
n.Node = nil
close(n.stopChan)
return
case pause := <-n.pauseChan:
// FIXME lock hell
n.SetPaused(pause)
for n.pause {
select {
case pause = <-n.pauseChan:
n.SetPaused(pause)
}
}
n.pauseLock.Lock()
// process pending messages
for _, m := range n.rcvmsg {
err := n.Step(n.Ctx, m)
if err != nil {
log.Fatal("Something went wrong when unpausing the node")
}
}
n.rcvmsg = nil
n.pauseLock.Unlock()
}
}
}
func (s *state) handleRaftReady(readyGroups map[uint64]raft.Ready) {
// Soft state is updated immediately; everything else waits for handleWriteReady.
for groupID, ready := range readyGroups {
if log.V(5) {
log.Infof("node %v: group %v raft ready", s.nodeID, groupID)
if ready.SoftState != nil {
log.Infof("SoftState updated: %+v", *ready.SoftState)
}
if !raft.IsEmptyHardState(ready.HardState) {
log.Infof("HardState updated: %+v", ready.HardState)
}
for i, e := range ready.Entries {
log.Infof("New Entry[%d]: %.200s", i, raft.DescribeEntry(e, s.EntryFormatter))
}
for i, e := range ready.CommittedEntries {
log.Infof("Committed Entry[%d]: %.200s", i, raft.DescribeEntry(e, s.EntryFormatter))
}
if !raft.IsEmptySnap(ready.Snapshot) {
log.Infof("Snapshot updated: %.200s", ready.Snapshot.String())
}
for i, m := range ready.Messages {
log.Infof("Outgoing Message[%d]: %.200s", i, raft.DescribeMessage(m, s.EntryFormatter))
}
}
g, ok := s.groups[groupID]
if !ok {
// This is a stale message for a removed group
log.V(4).Infof("node %v: dropping stale ready message for group %v", s.nodeID, groupID)
continue
}
term := g.committedTerm
if ready.SoftState != nil {
// Always save the leader whenever we get a SoftState.
g.leader = NodeID(ready.SoftState.Lead)
}
if len(ready.CommittedEntries) > 0 {
term = ready.CommittedEntries[len(ready.CommittedEntries)-1].Term
}
if term != g.committedTerm && g.leader != 0 {
// Whenever the committed term has advanced and we know our leader,
// emit an event.
g.committedTerm = term
s.sendEvent(&EventLeaderElection{
GroupID: groupID,
NodeID: NodeID(g.leader),
Term: g.committedTerm,
})
// Re-submit all pending proposals
for _, prop := range g.pending {
s.proposalChan <- prop
}
}
}
}
// Saves a log entry to our Store
func (n *Node) saveToStorage(hardState raftpb.HardState, entries []raftpb.Entry, snapshot raftpb.Snapshot) {
n.Store.Append(entries)
if !raft.IsEmptyHardState(hardState) {
n.Store.SetHardState(hardState)
}
if !raft.IsEmptySnap(snapshot) {
n.Store.ApplySnapshot(snapshot)
}
}
// start runs the storage loop in a goroutine.
func (w *writeTask) start(stopper *stop.Stopper) {
stopper.RunWorker(func() {
for {
var request *writeRequest
select {
case <-w.ready:
continue
case <-stopper.ShouldStop():
return
case request = <-w.in:
}
if log.V(6) {
log.Infof("writeTask got request %#v", *request)
}
response := &writeResponse{make(map[roachpb.RangeID]*groupWriteResponse)}
for groupID, groupReq := range request.groups {
group, err := w.storage.GroupStorage(groupID, groupReq.replicaID)
if err == ErrGroupDeleted {
if log.V(4) {
log.Infof("dropping write to deleted group %v", groupID)
}
continue
} else if err != nil {
log.Fatalf("GroupStorage(group %s, replica %s) failed: %s", groupID,
groupReq.replicaID, err)
}
groupResp := &groupWriteResponse{raftpb.HardState{}, -1, -1, groupReq.entries}
response.groups[groupID] = groupResp
if !raft.IsEmptyHardState(groupReq.state) {
err := group.SetHardState(groupReq.state)
if err != nil {
panic(err) // TODO(bdarnell): mark this node dead on storage errors
}
groupResp.state = groupReq.state
}
if !raft.IsEmptySnap(groupReq.snapshot) {
err := group.ApplySnapshot(groupReq.snapshot)
if err != nil {
panic(err) // TODO(bdarnell)
}
}
if len(groupReq.entries) > 0 {
err := group.Append(groupReq.entries)
if err != nil {
panic(err) // TODO(bdarnell)
}
}
}
w.out <- response
}
})
}
// handleWriteReady converts a set of raft.Ready structs into a writeRequest
// to be persisted, marks the group as writing and sends it to the writeTask.
// It will only do this for groups which are tagged via the map.
func (s *state) handleWriteReady(checkReadyGroupIDs map[roachpb.RangeID]struct{}) map[roachpb.RangeID]raft.Ready {
if log.V(6) {
log.Infof("node %v write ready, preparing request", s.nodeID)
}
s.lockStorage()
defer s.unlockStorage()
writeRequest := newWriteRequest()
readys := make(map[roachpb.RangeID]raft.Ready)
for groupID := range checkReadyGroupIDs {
g, ok := s.groups[groupID]
if !ok {
if log.V(6) {
log.Infof("dropping write request to group %d", groupID)
}
continue
}
if !g.raftGroup.HasReady() {
continue
}
ready := g.raftGroup.Ready()
readys[groupID] = ready
g.writing = true
gwr := &groupWriteRequest{}
var err error
gwr.replicaID, err = s.Storage().ReplicaIDForStore(groupID, s.storeID)
if err != nil {
if log.V(1) {
log.Warningf("failed to look up replica ID for range %v (disabling replica ID check): %s",
groupID, err)
}
gwr.replicaID = 0
}
if !raft.IsEmptyHardState(ready.HardState) {
gwr.state = ready.HardState
}
if !raft.IsEmptySnap(ready.Snapshot) {
gwr.snapshot = ready.Snapshot
}
if len(ready.Entries) > 0 {
gwr.entries = ready.Entries
}
writeRequest.groups[groupID] = gwr
}
// If no ready, don't write to writeTask as caller will
// not wait on s.writeTask.out when len(readys) == 0.
if len(readys) > 0 {
s.writeTask.in <- writeRequest
}
return readys
}
// Store stores the snapshot, hardstate and entries for a given RAFT group.
func (w *Wal) Store(gid uint32, s raftpb.Snapshot, h raftpb.HardState, es []raftpb.Entry) error {
b := w.wals.NewWriteBatch()
defer b.Destroy()
if !raft.IsEmptySnap(s) {
data, err := s.Marshal()
if err != nil {
return x.Wrapf(err, "wal.Store: While marshal snapshot")
}
b.Put(w.snapshotKey(gid), data)
}
if !raft.IsEmptyHardState(h) {
data, err := h.Marshal()
if err != nil {
return x.Wrapf(err, "wal.Store: While marshal hardstate")
}
b.Put(w.hardStateKey(gid), data)
}
var t, i uint64
for _, e := range es {
t, i = e.Term, e.Index
data, err := e.Marshal()
if err != nil {
return x.Wrapf(err, "wal.Store: While marshal entry")
}
k := w.entryKey(gid, e.Term, e.Index)
b.Put(k, data)
}
// If we get no entries, then the default value of t and i would be zero. That would
// end up deleting all the previous valid raft entry logs. This check avoids that.
if t > 0 || i > 0 {
// Delete all keys above this index.
start := w.entryKey(gid, t, i+1)
prefix := w.prefix(gid)
itr := w.wals.NewIterator()
defer itr.Close()
for itr.Seek(start); itr.ValidForPrefix(prefix); itr.Next() {
b.Delete(itr.Key().Data())
}
}
err := w.wals.WriteBatch(b)
return x.Wrapf(err, "wal.Store: While WriteBatch")
}
func (rc *raftNode) publishSnapshot(snapshotToSave raftpb.Snapshot) {
if raft.IsEmptySnap(snapshotToSave) {
return
}
log.Printf("publishing snapshot at index %d", rc.snapshotIndex)
defer log.Printf("finished publishing snapshot at index %d", rc.snapshotIndex)
if snapshotToSave.Metadata.Index <= rc.appliedIndex {
log.Fatalf("snapshot index [%d] should > progress.appliedIndex [%d] + 1", snapshotToSave.Metadata.Index, rc.appliedIndex)
}
rc.commitC <- nil // trigger kvstore to load snapshot
rc.confState = snapshotToSave.Metadata.ConfState
rc.snapshotIndex = snapshotToSave.Metadata.Index
rc.appliedIndex = snapshotToSave.Metadata.Index
}
// start runs the storage loop. Blocks until stopped, so should be run in a goroutine.
func (w *writeTask) start() {
for {
var request *writeRequest
select {
case <-w.ready:
continue
case <-w.stopper.ShouldStop():
w.stopper.SetStopped()
return
case request = <-w.in:
}
log.V(6).Infof("writeTask got request %#v", *request)
response := &writeResponse{make(map[uint64]*groupWriteResponse)}
for groupID, groupReq := range request.groups {
group := w.storage.GroupStorage(groupID)
if group == nil {
log.V(4).Infof("dropping write to group %v", groupID)
continue
}
groupResp := &groupWriteResponse{raftpb.HardState{}, -1, -1, groupReq.entries}
response.groups[groupID] = groupResp
if !raft.IsEmptyHardState(groupReq.state) {
err := group.SetHardState(groupReq.state)
if err != nil {
panic(err) // TODO(bdarnell): mark this node dead on storage errors
}
groupResp.state = groupReq.state
}
if !raft.IsEmptySnap(groupReq.snapshot) {
err := group.ApplySnapshot(groupReq.snapshot)
if err != nil {
panic(err) // TODO(bdarnell)
}
}
if len(groupReq.entries) > 0 {
err := group.Append(groupReq.entries)
if err != nil {
panic(err) // TODO(bdarnell)
}
}
}
w.out <- response
}
}
func (s *state) handleWriteReady(readyGroups map[uint64]raft.Ready) {
log.V(6).Infof("node %v write ready, preparing request", s.nodeID)
writeRequest := newWriteRequest()
for groupID, ready := range readyGroups {
gwr := &groupWriteRequest{}
if !raft.IsEmptyHardState(ready.HardState) {
gwr.state = ready.HardState
}
if !raft.IsEmptySnap(ready.Snapshot) {
gwr.snapshot = ready.Snapshot
}
if len(ready.Entries) > 0 {
gwr.entries = ready.Entries
}
writeRequest.groups[groupID] = gwr
}
s.writeTask.in <- writeRequest
}
func (n *node) initFromWal(wal *raftwal.Wal) (restart bool, rerr error) {
n.wal = wal
var sp raftpb.Snapshot
sp, rerr = wal.Snapshot(n.gid)
if rerr != nil {
return
}
var term, idx uint64
if !raft.IsEmptySnap(sp) {
fmt.Printf("Found Snapshot: %+v\n", sp)
restart = true
if rerr = n.store.ApplySnapshot(sp); rerr != nil {
return
}
term = sp.Metadata.Term
idx = sp.Metadata.Index
}
var hd raftpb.HardState
hd, rerr = wal.HardState(n.gid)
if rerr != nil {
return
}
if !raft.IsEmptyHardState(hd) {
fmt.Printf("Found hardstate: %+v\n", sp)
restart = true
if rerr = n.store.SetHardState(hd); rerr != nil {
return
}
}
var es []raftpb.Entry
es, rerr = wal.Entries(n.gid, term, idx)
if rerr != nil {
return
}
fmt.Printf("Found %d entries\n", len(es))
if len(es) > 0 {
restart = true
}
rerr = n.store.Append(es)
return
}
func save(rd raft.Ready, st *raft.MemoryStorage) error {
if !raft.IsEmptyHardState(rd.HardState) {
if err := st.SetHardState(rd.HardState); err != nil {
return err
}
}
if len(rd.Entries) > 0 {
if err := st.Append(rd.Entries); err != nil {
return err
}
}
if !raft.IsEmptySnap(rd.Snapshot) {
if err := st.ApplySnapshot(rd.Snapshot); err != nil {
return err
}
}
return nil
}
func (c *ctrl) readySave(snapshot raftpb.Snapshot, hardState raftpb.HardState, entries []raftpb.Entry) error {
// For the moment, none of these steps persist to disk. That violates some Raft
// invariants. But we are ephemeral, and will always boot empty, willingly
// paying the snapshot cost. I trust that that the etcd Raft implementation
// permits this.
if !raft.IsEmptySnap(snapshot) {
if err := c.storage.ApplySnapshot(snapshot); err != nil {
return fmt.Errorf("apply snapshot: %v", err)
}
}
if !raft.IsEmptyHardState(hardState) {
if err := c.storage.SetHardState(hardState); err != nil {
return fmt.Errorf("set hard state: %v", err)
}
}
if err := c.storage.Append(entries); err != nil {
return fmt.Errorf("append: %v", err)
}
return nil
}
func (n *node) Run() {
firstRun := true
ticker := time.NewTicker(time.Second)
for {
select {
case <-ticker.C:
n.raft.Tick()
case rd := <-n.raft.Ready():
x.Check(n.wal.Store(n.gid, rd.Snapshot, rd.HardState, rd.Entries))
n.saveToStorage(rd.Snapshot, rd.HardState, rd.Entries)
rcBytes, err := n.raftContext.Marshal()
for _, msg := range rd.Messages {
// NOTE: We can do some optimizations here to drop messages.
x.Check(err)
msg.Context = rcBytes
n.send(msg)
}
if !raft.IsEmptySnap(rd.Snapshot) {
n.processSnapshot(rd.Snapshot)
}
if len(rd.CommittedEntries) > 0 {
x.Trace(n.ctx, "Found %d committed entries", len(rd.CommittedEntries))
}
for _, entry := range rd.CommittedEntries {
// Just queue up to be processed. Don't wait on them.
n.commitCh <- entry
}
n.raft.Advance()
if firstRun && n.canCampaign {
go n.raft.Campaign(n.ctx)
firstRun = false
}
case <-n.done:
return
}
}
}
// handleWriteReady converts a set of raft.Ready structs into a writeRequest
// to be persisted, marks the group as writing and sends it to the writeTask.
func (s *state) handleWriteReady() {
if log.V(6) {
log.Infof("node %v write ready, preparing request", s.nodeID)
}
s.lockStorage()
defer s.unlockStorage()
writeRequest := newWriteRequest()
for groupID, ready := range s.readyGroups {
raftGroupID := roachpb.RangeID(groupID)
g, ok := s.groups[raftGroupID]
if !ok {
if log.V(6) {
log.Infof("dropping write request to group %d", groupID)
}
continue
}
g.writing = true
gwr := &groupWriteRequest{}
var err error
gwr.replicaID, err = s.Storage().ReplicaIDForStore(roachpb.RangeID(groupID), s.storeID)
if err != nil {
if log.V(1) {
log.Warningf("failed to look up replica ID for range %v (disabling replica ID check): %s",
groupID, err)
}
gwr.replicaID = 0
}
if !raft.IsEmptyHardState(ready.HardState) {
gwr.state = ready.HardState
}
if !raft.IsEmptySnap(ready.Snapshot) {
gwr.snapshot = ready.Snapshot
}
if len(ready.Entries) > 0 {
gwr.entries = ready.Entries
}
writeRequest.groups[raftGroupID] = gwr
}
s.writeTask.in <- writeRequest
}
func (n *node) saveToStorage(s raftpb.Snapshot, h raftpb.HardState,
es []raftpb.Entry) {
if !raft.IsEmptySnap(s) {
le, err := n.store.LastIndex()
if err != nil {
log.Fatalf("While retrieving last index: %v\n", err)
}
if s.Metadata.Index <= le {
return
}
if err := n.store.ApplySnapshot(s); err != nil {
log.Fatalf("Applying snapshot: %v", err)
}
}
if !raft.IsEmptyHardState(h) {
n.store.SetHardState(h)
}
n.store.Append(es)
}
// Saves a log entry to our Store
func (n *Node) saveToStorage(raftConfig *api.RaftConfig, hardState raftpb.HardState, entries []raftpb.Entry, snapshot raftpb.Snapshot) (err error) {
if !raft.IsEmptySnap(snapshot) {
if err := n.saveSnapshot(snapshot, raftConfig.KeepOldSnapshots); err != nil {
return ErrApplySnapshot
}
if err = n.raftStore.ApplySnapshot(snapshot); err != nil {
return ErrApplySnapshot
}
}
if err := n.wal.Save(hardState, entries); err != nil {
// TODO(aaronl): These error types should really wrap more
// detailed errors.
return ErrApplySnapshot
}
if err = n.raftStore.Append(entries); err != nil {
return ErrAppendEntry
}
return nil
}
func (n *node) run() {
for {
select {
case <-time.Tick(time.Second):
n.raft.Tick()
case rd := <-n.raft.Ready():
n.saveToStorage(rd.HardState, rd.Entries, rd.Snapshot)
n.send(rd.Messages)
if !raft.IsEmptySnap(rd.Snapshot) {
fmt.Println("Applying snapshot to state machine")
n.applyToStateMachine(rd.Snapshot)
}
if len(rd.CommittedEntries) > 0 {
fmt.Printf("Node: %v. Got %d committed entries\n", n.id, len(rd.CommittedEntries))
}
for _, entry := range rd.CommittedEntries {
n.process(entry)
}
n.raft.Advance()
case <-n.done:
return
}
}
}
func (s *EtcdServer) applySnapshot(ep *etcdProgress, apply *apply) {
if raft.IsEmptySnap(apply.snapshot) {
return
}
plog.Infof("applying snapshot at index %d...", ep.snapi)
defer plog.Infof("finished applying incoming snapshot at index %d", ep.snapi)
if apply.snapshot.Metadata.Index <= ep.appliedi {
plog.Panicf("snapshot index [%d] should > appliedi[%d] + 1",
apply.snapshot.Metadata.Index, ep.appliedi)
}
snapfn, err := s.r.storage.DBFilePath(apply.snapshot.Metadata.Index)
if err != nil {
plog.Panicf("get database snapshot file path error: %v", err)
}
fn := path.Join(s.Cfg.SnapDir(), databaseFilename)
if err := os.Rename(snapfn, fn); err != nil {
plog.Panicf("rename snapshot file error: %v", err)
}
newbe := backend.NewDefaultBackend(fn)
// 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.
if s.lessor != nil {
plog.Info("recovering lessor...")
s.lessor.Recover(newbe, s.kv)
plog.Info("finished recovering lessor")
}
plog.Info("restoring mvcc store...")
if err := s.kv.Restore(newbe); err != nil {
plog.Panicf("restore KV error: %v", err)
}
s.consistIndex.setConsistentIndex(s.kv.ConsistentIndex())
plog.Info("finished restoring mvcc store")
// Closing old backend might block until all the txns
// on the backend are finished.
// We do not want to wait on closing the old backend.
s.bemu.Lock()
oldbe := s.be
go func() {
plog.Info("closing old backend...")
defer plog.Info("finished closing old backend")
if err := oldbe.Close(); err != nil {
plog.Panicf("close backend error: %v", err)
}
}()
s.be = newbe
s.bemu.Unlock()
plog.Info("recovering alarms...")
if err := s.restoreAlarms(); err != nil {
plog.Panicf("restore alarms error: %v", err)
}
plog.Info("finished recovering alarms")
if s.authStore != nil {
plog.Info("recovering auth store...")
s.authStore.Recover(newbe)
plog.Info("finished recovering auth store")
}
plog.Info("recovering store v2...")
if err := s.store.Recovery(apply.snapshot.Data); err != nil {
plog.Panicf("recovery store error: %v", err)
}
plog.Info("finished recovering store v2")
s.cluster.SetBackend(s.be)
plog.Info("recovering cluster configuration...")
s.cluster.Recover(api.UpdateCapability)
plog.Info("finished recovering cluster configuration")
plog.Info("removing old peers from network...")
// recover raft transport
s.r.transport.RemoveAllPeers()
plog.Info("finished removing old peers from network")
plog.Info("adding peers from new cluster configuration into network...")
for _, m := range s.cluster.Members() {
if m.ID == s.ID() {
continue
}
s.r.transport.AddPeer(m.ID, m.PeerURLs)
}
plog.Info("finished adding peers from new cluster configuration into network...")
ep.appliedi = apply.snapshot.Metadata.Index
ep.snapi = ep.appliedi
ep.confState = apply.snapshot.Metadata.ConfState
}
// handleWriteResponse updates the state machine and sends messages for a raft Ready batch.
func (s *state) handleWriteResponse(response *writeResponse, readyGroups map[uint64]raft.Ready) {
if log.V(6) {
log.Infof("node %v got write response: %#v", s.nodeID, *response)
}
// Everything has been written to disk; now we can apply updates to the state machine
// and send outgoing messages.
for groupID, ready := range readyGroups {
raftGroupID := proto.RaftID(groupID)
g, ok := s.groups[raftGroupID]
if !ok {
if log.V(4) {
log.Infof("dropping stale write to group %v", groupID)
}
continue
} else if !g.writing {
if log.V(4) {
log.Infof("dropping stale write to reincarnation of group %v", groupID)
}
delete(readyGroups, groupID) // they must not make it to Advance.
continue
}
g.writing = false
// Process committed entries.
for _, entry := range ready.CommittedEntries {
commandID := s.processCommittedEntry(raftGroupID, g, entry)
// TODO(bdarnell): the command is now committed, but not applied until the
// application consumes EventCommandCommitted. Is returning via the channel
// at this point useful or do we need to wait for the command to be
// applied too?
// This could be done with a Callback as in EventMembershipChangeCommitted
// or perhaps we should move away from a channel to a callback-based system.
s.removePending(g, g.pending[commandID], nil /* err */)
}
if !raft.IsEmptySnap(ready.Snapshot) {
// Sync the group/node mapping with the information contained in the snapshot.
for _, nodeID := range ready.Snapshot.Metadata.ConfState.Nodes {
// TODO(bdarnell): if we had any information that predated this snapshot
// we must remove those nodes.
if err := s.addNode(proto.RaftNodeID(nodeID), raftGroupID); err != nil {
log.Errorf("node %v: error adding node %v", s.nodeID, nodeID)
}
}
}
// Process SoftState and leader changes.
s.maybeSendLeaderEvent(raftGroupID, g, &ready)
// Send all messages.
for _, msg := range ready.Messages {
switch msg.Type {
case raftpb.MsgHeartbeat:
if log.V(8) {
log.Infof("node %v dropped individual heartbeat to node %v",
s.nodeID, msg.To)
}
case raftpb.MsgHeartbeatResp:
if log.V(8) {
log.Infof("node %v dropped individual heartbeat response to node %v",
s.nodeID, msg.To)
}
default:
s.sendMessage(raftGroupID, msg)
}
}
}
}
func (s *EtcdServer) run() {
var syncC <-chan time.Time
var shouldstop bool
shouldstopC := s.sendhub.ShouldStopNotify()
// load initial state from raft storage
snap, err := s.raftStorage.Snapshot()
if err != nil {
log.Panicf("etcdserver: get snapshot from raft storage error: %v", err)
}
// snapi indicates the index of the last submitted snapshot request
snapi := snap.Metadata.Index
appliedi := snap.Metadata.Index
confState := snap.Metadata.ConfState
defer func() {
s.node.Stop()
s.sendhub.Stop()
if err := s.storage.Close(); err != nil {
log.Panicf("etcdserver: close storage error: %v", err)
}
close(s.done)
}()
for {
select {
case <-s.Ticker:
s.node.Tick()
case rd := <-s.node.Ready():
if rd.SoftState != nil {
atomic.StoreUint64(&s.raftLead, rd.SoftState.Lead)
if rd.RaftState == raft.StateLeader {
syncC = s.SyncTicker
// TODO: remove the nil checking
// current test utility does not provide the stats
if s.stats != nil {
s.stats.BecomeLeader()
}
} else {
syncC = nil
}
}
// apply snapshot to storage if it is more updated than current snapi
if !raft.IsEmptySnap(rd.Snapshot) && rd.Snapshot.Metadata.Index > snapi {
if err := s.storage.SaveSnap(rd.Snapshot); err != nil {
log.Fatalf("etcdserver: save snapshot error: %v", err)
}
s.raftStorage.ApplySnapshot(rd.Snapshot)
snapi = rd.Snapshot.Metadata.Index
log.Printf("etcdserver: saved incoming snapshot at index %d", snapi)
}
if err := s.storage.Save(rd.HardState, rd.Entries); err != nil {
log.Fatalf("etcdserver: save state and entries error: %v", err)
}
s.raftStorage.Append(rd.Entries)
s.sendhub.Send(rd.Messages)
// recover from snapshot if it is more updated than current applied
if !raft.IsEmptySnap(rd.Snapshot) && rd.Snapshot.Metadata.Index > appliedi {
if err := s.store.Recovery(rd.Snapshot.Data); err != nil {
log.Panicf("recovery store error: %v", err)
}
s.Cluster.Recover()
appliedi = rd.Snapshot.Metadata.Index
log.Printf("etcdserver: recovered from incoming snapshot at index %d", snapi)
}
// TODO(bmizerany): do this in the background, but take
// care to apply entries in a single goroutine, and not
// race them.
if len(rd.CommittedEntries) != 0 {
firsti := rd.CommittedEntries[0].Index
if firsti > appliedi+1 {
log.Panicf("etcdserver: first index of committed entry[%d] should <= appliedi[%d] + 1", firsti, appliedi)
}
var ents []raftpb.Entry
if appliedi+1-firsti < uint64(len(rd.CommittedEntries)) {
ents = rd.CommittedEntries[appliedi+1-firsti:]
}
if len(ents) > 0 {
if appliedi, shouldstop = s.apply(ents, &confState); shouldstop {
return
}
}
}
s.node.Advance()
if appliedi-snapi > s.snapCount {
log.Printf("etcdserver: start to snapshot (applied: %d, lastsnap: %d)", appliedi, snapi)
s.snapshot(appliedi, &confState)
snapi = appliedi
}
case <-syncC:
s.sync(defaultSyncTimeout)
case <-shouldstopC:
return
case <-s.stop:
return
}
}
}
