Golang Message.Snapshot方法代码示例

// createMergedSnapshotMessage creates a snapshot message that contains: raft status (term, conf),
// a snapshot of v2 store inside raft.Snapshot as []byte, a snapshot of v3 KV in the top level message
// as ReadCloser.
func (s *EtcdServer) createMergedSnapshotMessage(m raftpb.Message, snapi uint64, confState raftpb.ConfState) snap.Message {
	snapt, err := s.r.raftStorage.Term(snapi)
	if err != nil {
		log.Panicf("get term should never fail: %v", err)
	}

	// get a snapshot of v2 store as []byte
	clone := s.store.Clone()
	d, err := clone.SaveNoCopy()
	if err != nil {
		plog.Panicf("store save should never fail: %v", err)
	}

	// get a snapshot of v3 KV as readCloser
	rc := newSnapshotReaderCloser(s.kv.Snapshot())

	// put the []byte snapshot of store into raft snapshot and return the merged snapshot with
	// KV readCloser snapshot.
	snapshot := raftpb.Snapshot{
		Metadata: raftpb.SnapshotMetadata{
			Index:     snapi,
			Term:      snapt,
			ConfState: confState,
		},
		Data: d,
	}
	m.Snapshot = snapshot

	return snap.Message{
		Message:    m,
		ReadCloser: rc,
	}
}

// sendAppend sends RRPC, with entries to the given peer.
func (r *raft) sendAppend(to uint64) {
	pr := r.prs[to]
	m := pb.Message{}
	m.To = to
	if r.needSnapshot(pr.next) {
		m.Type = pb.MsgSnap
		snapshot, err := r.raftLog.snapshot()
		if err != nil {
			panic(err) // TODO(bdarnell)
		}
		if IsEmptySnap(snapshot) {
			panic("need non-empty snapshot")
		}
		m.Snapshot = snapshot
		sindex, sterm := snapshot.Metadata.Index, snapshot.Metadata.Term
		log.Printf("raft: %x [firstindex: %d, commit: %d] sent snapshot[index: %d, term: %d] to %x [%s]",
			r.id, r.raftLog.firstIndex(), r.Commit, sindex, sterm, to, pr)
	} else {
		m.Type = pb.MsgApp
		m.Index = pr.next - 1
		m.LogTerm = r.raftLog.term(pr.next - 1)
		m.Entries = r.raftLog.entries(pr.next)
		m.Commit = r.raftLog.committed
		// optimistically increase the next if the follower
		// has been matched.
		if n := len(m.Entries); pr.match != 0 && n != 0 {
			pr.optimisticUpdate(m.Entries[n-1].Index)
		}
	}
	r.send(m)
}

// sendAppend sends RRPC, with entries to the given peer.
func (r *raft) sendAppend(to uint64) {
	pr := r.prs[to]
	m := pb.Message{}
	m.To = to
	if r.needSnapshot(pr.next) {
		m.Type = pb.MsgSnap
		snapshot, err := r.raftLog.snapshot()
		if err != nil {
			panic(err) // TODO(bdarnell)
		}
		if IsEmptySnap(snapshot) {
			panic("need non-empty snapshot")
		}
		m.Snapshot = snapshot
	} else {
		m.Type = pb.MsgApp
		m.Index = pr.next - 1
		m.LogTerm = r.raftLog.term(pr.next - 1)
		m.Entries = r.raftLog.entries(pr.next)
		m.Commit = r.raftLog.committed
		// optimistically increase the next if the follower
		// has been matched.
		if n := len(m.Entries); pr.match != 0 && n != 0 {
			pr.optimisticUpdate(m.Entries[n-1].Index)
		}
	}
	r.send(m)
}

// createMergedSnapshotMessage creates a snapshot message that contains: raft status (term, conf),
// a snapshot of v2 store inside raft.Snapshot as []byte, a snapshot of v3 KV in the top level message
// as ReadCloser.
func (s *EtcdServer) createMergedSnapshotMessage(m raftpb.Message, snapi uint64, confState raftpb.ConfState) snap.Message {
	snapt, err := s.r.raftStorage.Term(snapi)
	if err != nil {
		log.Panicf("get term should never fail: %v", err)
	}

	// get a snapshot of v2 store as []byte
	clone := s.store.Clone()
	d, err := clone.SaveNoCopy()
	if err != nil {
		plog.Panicf("store save should never fail: %v", err)
	}

	// commit kv to write metadata(for example: consistent index).
	s.KV().Commit()
	dbsnap := s.be.Snapshot()
	// get a snapshot of v3 KV as readCloser
	rc := newSnapshotReaderCloser(dbsnap)

	// put the []byte snapshot of store into raft snapshot and return the merged snapshot with
	// KV readCloser snapshot.
	snapshot := raftpb.Snapshot{
		Metadata: raftpb.SnapshotMetadata{
			Index:     snapi,
			Term:      snapt,
			ConfState: confState,
		},
		Data: d,
	}
	m.Snapshot = snapshot

	return *snap.NewMessage(m, rc, dbsnap.Size())
}

// sendAppend sends RPC, with entries to the given peer.
func (r *raft) sendAppend(to uint64) {
	pr := r.prs[to]
	if pr.isPaused() {
		return
	}
	m := pb.Message{}
	m.To = to

	term, errt := r.raftLog.term(pr.Next - 1)
	ents, erre := r.raftLog.entries(pr.Next, r.maxMsgSize)

	if errt != nil || erre != nil { // send snapshot if we failed to get term or entries
		if !pr.RecentActive {
			r.logger.Debugf("ignore sending snapshot to %x since it is not recently active", to)
			return
		}

		m.Type = pb.MsgSnap
		snapshot, err := r.raftLog.snapshot()
		if err != nil {
			if err == ErrSnapshotTemporarilyUnavailable {
				r.logger.Debugf("%x failed to send snapshot to %x because snapshot is temporarily unavailable", r.id, to)
				return
			}
			panic(err) // TODO(bdarnell)
		}
		if IsEmptySnap(snapshot) {
			panic("need non-empty snapshot")
		}
		m.Snapshot = snapshot
		sindex, sterm := snapshot.Metadata.Index, snapshot.Metadata.Term
		r.logger.Debugf("%x [firstindex: %d, commit: %d] sent snapshot[index: %d, term: %d] to %x [%s]",
			r.id, r.raftLog.firstIndex(), r.raftLog.committed, sindex, sterm, to, pr)
		pr.becomeSnapshot(sindex)
		r.logger.Debugf("%x paused sending replication messages to %x [%s]", r.id, to, pr)
	} else {
		m.Type = pb.MsgApp
		m.Index = pr.Next - 1
		m.LogTerm = term
		m.Entries = ents
		m.Commit = r.raftLog.committed
		if n := len(m.Entries); n != 0 {
			switch pr.State {
			// optimistically increase the next when in ProgressStateReplicate
			case ProgressStateReplicate:
				last := m.Entries[n-1].Index
				pr.optimisticUpdate(last)
				pr.ins.add(last)
			case ProgressStateProbe:
				pr.pause()
			default:
				r.logger.Panicf("%x is sending append in unhandled state %s", r.id, pr.State)
			}
		}
	}
	r.send(m)
}

// sendAppend sends RRPC, with entries to the given peer.
func (r *raft) sendAppend(to int64) {
	pr := r.prs[to]
	m := pb.Message{}
	m.To = to
	m.Index = pr.next - 1
	if r.needSnapshot(m.Index) {
		m.Type = msgSnap
		m.Snapshot = r.raftLog.snapshot
	} else {
		m.Type = msgApp
		m.LogTerm = r.raftLog.term(pr.next - 1)
		m.Entries = r.raftLog.entries(pr.next)
		m.Commit = r.raftLog.committed
	}
	r.send(m)
}

// sendAppend sends RRPC, with entries to the given peer.
func (r *raft) sendAppend(to uint64) {
	pr := r.prs[to]
	if pr.isPaused() {
		return
	}
	m := pb.Message{}
	m.To = to
	if r.needSnapshot(pr.Next) {
		m.Type = pb.MsgSnap
		snapshot, err := r.raftLog.snapshot()
		if err != nil {
			panic(err) // TODO(bdarnell)
		}
		if IsEmptySnap(snapshot) {
			panic("need non-empty snapshot")
		}
		m.Snapshot = snapshot
		sindex, sterm := snapshot.Metadata.Index, snapshot.Metadata.Term
		raftLogger.Infof("%x [firstindex: %d, commit: %d] sent snapshot[index: %d, term: %d] to %x [%s]",
			r.id, r.raftLog.firstIndex(), r.Commit, sindex, sterm, to, pr)
		pr.becomeSnapshot(sindex)
		raftLogger.Infof("%x paused sending replication messages to %x [%s]", r.id, to, pr)
	} else {
		m.Type = pb.MsgApp
		m.Index = pr.Next - 1
		m.LogTerm = r.raftLog.term(pr.Next - 1)
		m.Entries = r.raftLog.entries(pr.Next, r.maxMsgSize)
		m.Commit = r.raftLog.committed
		if n := len(m.Entries); n != 0 {
			switch pr.State {
			// optimistically increase the next when in ProgressStateReplicate
			case ProgressStateReplicate:
				last := m.Entries[n-1].Index
				pr.optimisticUpdate(last)
				pr.ins.add(last)
			case ProgressStateProbe:
				pr.pause()
			default:
				raftLogger.Panicf("%x is sending append in unhandled state %s", r.id, pr.State)
			}
		}
	}
	r.send(m)
}

// sendAppend sends RRPC, with entries to the given peer.
func (r *raft) sendAppend(to uint64) {
	pr := r.prs[to]
	if pr.shouldWait() {
		log.Printf("raft: %x ignored sending %s to %x [%s]", r.id, pb.MsgApp, to, pr)
		return
	}
	m := pb.Message{}
	m.To = to
	if r.needSnapshot(pr.next) {
		m.Type = pb.MsgSnap
		snapshot, err := r.raftLog.snapshot()
		if err != nil {
			panic(err) // TODO(bdarnell)
		}
		if IsEmptySnap(snapshot) {
			panic("need non-empty snapshot")
		}
		m.Snapshot = snapshot
		sindex, sterm := snapshot.Metadata.Index, snapshot.Metadata.Term
		log.Printf("raft: %x [firstindex: %d, commit: %d] sent snapshot[index: %d, term: %d] to %x [%s]",
			r.id, r.raftLog.firstIndex(), r.Commit, sindex, sterm, to, pr)
		pr.waitSet(r.electionTimeout)
	} else {
		m.Type = pb.MsgApp
		m.Index = pr.next - 1
		m.LogTerm = r.raftLog.term(pr.next - 1)
		m.Entries = r.raftLog.entries(pr.next)
		m.Commit = r.raftLog.committed
		// optimistically increase the next if the follower
		// has been matched.
		if n := len(m.Entries); pr.match != 0 && n != 0 {
			pr.optimisticUpdate(m.Entries[n-1].Index)
		} else if pr.match == 0 {
			// TODO (xiangli): better way to find out if the follower is in good path or not
			// a follower might be in bad path even if match != 0, since we optimistically
			// increase the next.
			pr.waitSet(r.heartbeatTimeout)
		}
	}
	r.send(m)
}