func stepFollower(r *raft, m pb.Message) { switch m.Type { case pb.MsgProp: if r.lead == None { raftLogger.Infof("%x no leader at term %d; dropping proposal", r.id, r.Term) return } m.To = r.lead r.send(m) case pb.MsgApp: r.elapsed = 0 r.lead = m.From r.handleAppendEntries(m) case pb.MsgHeartbeat: r.elapsed = 0 r.lead = m.From r.handleHeartbeat(m) case pb.MsgSnap: r.elapsed = 0 r.handleSnapshot(m) case pb.MsgVote: if (r.Vote == None || r.Vote == m.From) && r.raftLog.isUpToDate(m.Index, m.LogTerm) { r.elapsed = 0 raftLogger.Infof("%x [logterm: %d, index: %d, vote: %x] voted for %x [logterm: %d, index: %d] at term %d", r.id, r.raftLog.lastTerm(), r.raftLog.lastIndex(), r.Vote, m.From, m.LogTerm, m.Index, r.Term) r.Vote = m.From r.send(pb.Message{To: m.From, Type: pb.MsgVoteResp}) } else { raftLogger.Infof("%x [logterm: %d, index: %d, vote: %x] rejected vote from %x [logterm: %d, index: %d] at term %d", r.id, r.raftLog.lastTerm(), r.raftLog.lastIndex(), r.Vote, m.From, m.LogTerm, m.Index, r.Term) r.send(pb.Message{To: m.From, Type: pb.MsgVoteResp, Reject: true}) } } }
// 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 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 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.Debugf("%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.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: 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() { 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) }