Golang raft.IsEmptySnap函数代码示例

// 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
}