-
Notifications
You must be signed in to change notification settings - Fork 164
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
raft: add learner state for rebuildme
- Loading branch information
Showing
9 changed files
with
628 additions
and
8 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,214 @@ | ||
| /* | ||
| * Xenon | ||
| * | ||
| * Copyright 2018 The Xenon Authors. | ||
| * Code is licensed under the GPLv3. | ||
| * | ||
| */ | ||
|
|
||
| package raft | ||
|
|
||
| import ( | ||
| "model" | ||
| ) | ||
|
|
||
| // LEARNER is a special STATE with other FOLLOWER/CANDICATE/LEADER states. | ||
| // It is usually used as READ-ONLY but does not have RAFT features, such as | ||
| // LEADER election | ||
| // FOLLOWER promotion | ||
| // | ||
| // Because of we bring LEARNER state in RaftRPCResponse as vote-request response, | ||
| // the LEARNER vote will be filtered out by other CANDIDATEs. | ||
| // LEARNER is one member of a RAFT cluster but without the rights to vote. | ||
|
|
||
| // Learner tuple. | ||
| type Learner struct { | ||
| *Raft | ||
|
|
||
| // learner process heartbeat request handler | ||
| processHeartbeatRequestHandler func(*model.RaftRPCRequest) *model.RaftRPCResponse | ||
|
|
||
| // learner process voterequest request handler | ||
| processRequestVoteRequestHandler func(*model.RaftRPCRequest) *model.RaftRPCResponse | ||
|
|
||
| // learner process raft ping request handler | ||
| processPingRequestHandler func(*model.RaftRPCRequest) *model.RaftRPCResponse | ||
| } | ||
|
|
||
| // NewLearner creates new learner. | ||
| func NewLearner(r *Raft) *Learner { | ||
| B := &Learner{Raft: r} | ||
| B.initHandlers() | ||
| return B | ||
| } | ||
|
|
||
| // Loop used to start the loop of the state machine. | ||
| //-------------------------------------- | ||
| // State Machine | ||
| //-------------------------------------- | ||
| // in LEARNER state, we never do leader election | ||
| // | ||
| func (r *Learner) Loop() { | ||
| // update begin | ||
| r.updateStateBegin() | ||
| r.stateInit() | ||
|
|
||
| for r.getState() == LEARNER { | ||
| select { | ||
| case <-r.fired: | ||
| r.WARNING("state.machine.loop.got.fired") | ||
| case e := <-r.c: | ||
| switch e.Type { | ||
| // 1) Heartbeat | ||
| case MsgRaftHeartbeat: | ||
| req := e.request.(*model.RaftRPCRequest) | ||
| rsp := r.processHeartbeatRequestHandler(req) | ||
| e.response <- rsp | ||
|
|
||
| // 2) RequestVote | ||
| case MsgRaftRequestVote: | ||
| req := e.request.(*model.RaftRPCRequest) | ||
| rsp := r.processRequestVoteRequest(req) | ||
| e.response <- rsp | ||
|
|
||
| // 3) Ping | ||
| case MsgRaftPing: | ||
| req := e.request.(*model.RaftRPCRequest) | ||
| rsp := r.processPingRequestHandler(req) | ||
| e.response <- rsp | ||
|
|
||
| default: | ||
| r.ERROR("get.unknown.request[%v]", e.Type) | ||
| } | ||
| } | ||
| } | ||
| } | ||
|
|
||
| // processHeartbeatRequest | ||
| // EFFECT | ||
| // handles the heartbeat request from the leader | ||
| // In LEARNER state, we only handle the master changed | ||
| // | ||
| func (r *Learner) processHeartbeatRequest(req *model.RaftRPCRequest) *model.RaftRPCResponse { | ||
| rsp := model.NewRaftRPCResponse(model.OK) | ||
| rsp.Raft.From = r.getID() | ||
| rsp.Raft.ViewID = r.getViewID() | ||
| rsp.Raft.EpochID = r.getEpochID() | ||
| rsp.Raft.State = r.state.String() | ||
| rsp.Relay_Master_Log_File = r.mysql.RelayMasterLogFile() | ||
|
|
||
| if !r.checkRequest(req) { | ||
| rsp.RetCode = model.ErrorInvalidRequest | ||
| return rsp | ||
| } | ||
|
|
||
| viewdiff := (int)(r.getViewID() - req.GetViewID()) | ||
| epochdiff := (int)(r.getEpochID() - req.GetEpochID()) | ||
| switch { | ||
| case viewdiff <= 0: | ||
| // MySQL1: disable master semi-sync because I am a slave | ||
| if err := r.mysql.DisableSemiSyncMaster(); err != nil { | ||
| r.ERROR("mysql.DisableSemiSyncMaster.error[%v]", err) | ||
| } | ||
|
|
||
| // MySQL2: set mysql readonly(mysql maybe down and up then the LEADER changes) | ||
| if err := r.mysql.SetReadOnly(); err != nil { | ||
| r.ERROR("mysql.SetReadOnly.error[%v]", err) | ||
| } | ||
|
|
||
| // MySQL3: start slave | ||
| if err := r.mysql.StartSlave(); err != nil { | ||
| r.ERROR("mysql.StartSlave.error[%v]", err) | ||
| } | ||
|
|
||
| // MySQL4: change master | ||
| if r.getLeader() != req.GetFrom() { | ||
| r.WARNING("get.heartbeat.from[N:%v, V:%v, E:%v].change.mysql.master[%+v]", req.GetFrom(), req.GetViewID(), req.GetEpochID(), req.GetGTID()) | ||
|
|
||
| if err := r.mysql.ChangeMasterTo(&req.Repl); err != nil { | ||
| r.ERROR("change.master.to[FROM:%v, GTID:%v].error[%v]", req.GetFrom(), req.GetRepl(), err) | ||
| rsp.RetCode = model.ErrorChangeMaster | ||
| return rsp | ||
| } | ||
| r.leader = req.GetFrom() | ||
| } | ||
|
|
||
| // view change | ||
| if viewdiff < 0 { | ||
| r.WARNING("get.heartbeat.from[N:%v, V:%v, E:%v].update.view", req.GetFrom(), req.GetViewID(), req.GetEpochID()) | ||
| r.updateView(req.GetViewID(), req.GetFrom()) | ||
| } | ||
|
|
||
| // epoch change | ||
| if epochdiff != 0 { | ||
| r.WARNING("get.heartbeat.from[N:%v, V:%v, E:%v].update.epoch", req.GetFrom(), req.GetViewID(), req.GetEpochID()) | ||
| r.updateEpoch(req.GetEpochID(), req.GetPeers()) | ||
| } | ||
| } | ||
| return rsp | ||
| } | ||
|
|
||
| // processRequestVoteRequest | ||
| // EFFECT | ||
| // handles the requestvote request from other CANDIDATEs | ||
| // LEARNER is special, it returns ErrorVoteNotGranted expect Request Denied | ||
| // | ||
| // RETURN | ||
| // 1. ErrorVoteNotGranted: dont give any vote | ||
| func (r *Learner) processRequestVoteRequest(req *model.RaftRPCRequest) *model.RaftRPCResponse { | ||
| rsp := model.NewRaftRPCResponse(model.ErrorVoteNotGranted) | ||
| rsp.Raft.From = r.getID() | ||
| rsp.Raft.ViewID = r.getViewID() | ||
| rsp.Raft.EpochID = r.getEpochID() | ||
| rsp.Raft.State = r.state.String() | ||
|
|
||
| if !r.checkRequest(req) { | ||
| rsp.RetCode = model.ErrorInvalidRequest | ||
| return rsp | ||
| } | ||
| return rsp | ||
| } | ||
|
|
||
| func (r *Learner) processPingRequest(req *model.RaftRPCRequest) *model.RaftRPCResponse { | ||
| rsp := model.NewRaftRPCResponse(model.OK) | ||
| rsp.Raft.State = r.state.String() | ||
| return rsp | ||
| } | ||
|
|
||
| func (r *Learner) stateInit() { | ||
| // 1. stop vip | ||
| if err := r.leaderStopShellCommand(); err != nil { | ||
| // TODO(array): what todo? | ||
| r.ERROR("stopshell.error[%v]", err) | ||
| } | ||
|
|
||
| // MySQL1: set readonly | ||
| if err := r.mysql.SetReadOnly(); err != nil { | ||
| r.ERROR("mysql.SetReadOnly.error[%v]", err) | ||
| } | ||
|
|
||
| // MySQL2. set mysql slave system variables | ||
| if err := r.mysql.SetSlaveGlobalSysVar(); err != nil { | ||
| r.ERROR("mysql.SetSlaveGlobalSysVar.error[%v]", err) | ||
| } | ||
| } | ||
|
|
||
| // handlers | ||
| func (r *Learner) initHandlers() { | ||
| r.setProcessHeartbeatRequestHandler(r.processHeartbeatRequest) | ||
| r.setProcessRequestVoteRequestHandler(r.processRequestVoteRequest) | ||
| r.setProcessPingRequestHandler(r.processPingRequest) | ||
| } | ||
|
|
||
| // for tests | ||
| func (r *Learner) setProcessHeartbeatRequestHandler(f func(*model.RaftRPCRequest) *model.RaftRPCResponse) { | ||
| r.processHeartbeatRequestHandler = f | ||
| } | ||
|
|
||
| func (r *Learner) setProcessRequestVoteRequestHandler(f func(*model.RaftRPCRequest) *model.RaftRPCResponse) { | ||
| r.processRequestVoteRequestHandler = f | ||
| } | ||
|
|
||
| func (r *Learner) setProcessPingRequestHandler(f func(*model.RaftRPCRequest) *model.RaftRPCResponse) { | ||
| r.processPingRequestHandler = f | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.