Add timeout and tick() implementation
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cd00bd097f
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c9ef1cc43b
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@ -119,6 +119,10 @@ type
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debugLogs: seq[string]
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stateChange: bool
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RaftConfig* = object
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currentSet*: seq[RaftNodeId]
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RaftStateMachine* = object
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myId*: RaftNodeId
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term: RaftNodeTerm
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@ -126,17 +130,22 @@ type
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toCommit: RaftLogIndex
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log: RaftLog
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output: RaftStateMachineOutput
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electionTimeout: times.Duration
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lastUpdate: Time
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votedFor: RaftNodeId
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currentLeader: RaftNodeId
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pingLeader: bool
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config: RaftConfig
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lastElectionTime: times.Duration
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randomizedElectionTime: times.Duration
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timeNow: times.Duration
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electionTimeout: times.Duration
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case state: RaftNodeState
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of rnsFollower: follower : FollowerState
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of rnsCandidate: candidate: CandidateState
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of rnsLeader: leader: LeaderState
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RaftStateMachineConfig* = object
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RaftFollowerProgressTracker* = object
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id: RaftNodeId
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@ -277,12 +286,20 @@ func termForIndex*(rf: RaftLog, index: RaftLogIndex): RaftNodeTerm =
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func debug*(sm: var RaftStateMachine, log: string) =
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sm.output.debugLogs.add(log)
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func initRaftStateMachine*(config: RaftStateMachineConfig): RaftStateMachine =
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var st = RaftStateMachine()
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st.term = 0
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st.commitIndex = 0
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st.state = RaftNodeState.rnsFollower
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return st
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func resetElectionTimeout*(sm: var RaftStateMachine) =
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# TODO actually pick random time
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sm.randomizedElectionTime = sm.electionTimeout + times.initDuration(milliseconds = 42)
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func initRaftStateMachine*(id: RaftnodeId, currentTerm: RaftNodeTerm, log: RaftLog, commitIndex: RaftLogIndex, config: RaftConfig): RaftStateMachine =
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var sm = RaftStateMachine()
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sm.term = currentTerm
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sm.log = log
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sm.commitIndex = commitIndex
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sm.state = RaftNodeState.rnsFollower
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sm.config = config
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sm.resetElectionTimeout()
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return sm
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func sendTo*(sm: var RaftStateMachine, id: RaftNodeId, request: RaftRpcAppendRequest) =
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sm.output.messages.add(RaftRpcMessage(currentTerm: sm.term, receiver: id, sender: sm.myId, kind: RaftRpcMessageType.Append, appendRequest: request))
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@ -355,107 +372,6 @@ func addEntry*(sm: var RaftStateMachine, config: Config) =
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func addEmptyEntry*(sm: var RaftStateMachine) =
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sm.addEntry(LogEntry(term: sm.term, index: sm.log.nextIndex, kind: rletEmpty, empty: true))
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func tick* (sm: var RaftStateMachine) =
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sm.debug "TODO:implement tick"
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# TODO: here we should keep track of the replications progress
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func poll*(sm: var RaftStateMachine): RaftStateMachineOutput =
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# Should initiate replication if we have new entries
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if sm.state == RaftNodeState.rnsLeader:
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sm.replicate()
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let output = sm.output
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sm.output = RaftStateMachineOutput()
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return output
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func commit*(sm: var RaftStateMachine) =
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if sm.state != RaftNodeState.rnsLeader:
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return
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var new_index = sm.commitIndex
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var next_index = sm.commitIndex + 1
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while next_index < sm.log.lastIndex:
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var replicationCnt = 0
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for p in sm.leader.followersProgress:
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if p.matchIndex > new_index:
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replicationCnt += 1
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if replicationCnt > len(sm.leader.followersProgress):
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sm.output.committed.add(sm.log.getEntryByIndex(next_index))
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sm.commitIndex += next_index;
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next_index += 1
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func find_follower_proggress_by_id(sm: var RaftStateMachine, id: RaftNodeId): Option[RaftFollowerProgressTracker] =
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for follower in sm.leader.followersProgress:
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if follower.id == id:
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return some(follower)
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return none(RaftFollowerProgressTracker)
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func append_entry_reply*(sm: var RaftStateMachine, from_id: RaftNodeId, replay: RaftRpcAppendReplay) =
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if sm.state != RaftNodeState.rnsLeader:
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sm.debug "You can't append append replay to the follower"
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return
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var follower = sm.find_follower_proggress_by_id(from_id)
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if not follower.isSome:
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sm.debug "Can't find the follower"
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return
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follower.get().commitIndex = max(follower.get().commitIndex, replay.commitIndex)
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case replay.result:
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of RaftRpcCode.Accepted:
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let lestIndex = replay.accepted.lastNewIndex
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follower.get().accepted(lestIndex)
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# TODO: add leader stepping down logic here
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sm.commit()
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if sm.state != RaftNodeState.rnsLeader:
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return
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of RaftRpcCode.Rejected:
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if replay.rejected.nonMatchingIndex == 0 and replay.rejected.lastIdx == 0:
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sm.replicateTo(follower.get())
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follower.get().next_index = min(replay.rejected.nonMatchingIndex, replay.rejected.lastIdx + 1)
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# if commit apply configuration that removes current follower
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# we should take it again
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var follower2 = sm.find_follower_proggress_by_id(from_id)
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if follower2.isSome:
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sm.replicate_to(follower2.get())
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func advance_commit_idx(sm: var RaftStateMachine, leaderIdx: RaftLogIndex) =
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let new_idx = min(leaderIdx, sm.log.lastIndex)
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if new_idx > sm.commitIndex:
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sm.commitIndex = new_idx
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# TODO: signal the output for the update
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func append_entry*(sm: var RaftStateMachine, from_id: RaftNodeId, request: RaftRpcAppendRequest) =
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if sm.state != RaftNodeState.rnsFollower:
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sm.debug "You can't append append request to the non follower"
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return
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let (match, term) = sm.log.matchTerm(request.previousLogIndex, request.previousTerm)
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if not match:
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let rejected = RaftRpcAppendReplayRejected(nonMatchingIndex: request.previousLogIndex, lastIdx: sm.log.lastIndex)
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let responce = RaftRpcAppendReplay(term: sm.term, commitIndex: sm.commitIndex, result: RaftRpcCode.Rejected, rejected: rejected)
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sm.send_to(sm.myId, responce)
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sm.debug "Reject to apply the entry"
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# reject to apply
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#send_to()
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sm.log.appendAsFollower(request.entry)
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sm.advance_commit_idx(request.commitIndex)
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let accepted = RaftRpcAppendReplayAccepted(lastNewIndex: sm.log.lastIndex)
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let responce = RaftRpcAppendReplay(term: sm.term, commitIndex: sm.commitIndex, result: RaftRpcCode.Accepted, accepted: accepted)
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sm.send_to(sm.myId, responce)
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func request_vote*(sm: var RaftStateMachine, from_id: RaftNodeId, request: RaftRpcVoteRequest, ) =
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let canVote = sm.votedFor == from_id or (sm.votedFor == RaftNodeId() and sm.currentLeader == RaftNodeId()) or (request.isPrevote and request.currentTerm > sm.term)
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if canVote and sm.log.isUpToDate(request.lastLogIndex, request.lastLogTerm):
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if not request.is_prevote:
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# TODO: Update election time
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sm.votedFor = from_id
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let responce = RaftRpcVoteReplay(currentTerm: sm.term, voteGranted: true, isPrevote: request.is_prevote)
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sm.send_to(sm.myId, responce)
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else:
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let responce = RaftRpcVoteReplay(currentTerm: sm.term, voteGranted: false, isPrevote: request.is_prevote)
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sm.send_to(sm.myId, responce)
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func becomeFollower*(sm: var RaftStateMachine, leaderId: RaftNodeId) =
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if sm.myId == leaderId:
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sm.debug "Can't be follower of itself"
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@ -486,7 +402,128 @@ func becomeCandidate*(sm: var RaftStateMachine, isPrevote: bool) =
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#TODO: implement
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return
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func request_vote_reply*(sm: var RaftStateMachine, from_id: RaftNodeId, request: RaftRpcVoteReplay) =
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func tickLeader*(sm: var RaftStateMachine, now: times.Duration) =
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sm.timeNow = now
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if sm.lastElectionTime - sm.timeNow > sm.electionTimeout:
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sm.becomeFollower(RaftnodeId())
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return
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if sm.state != RaftNodeState.rnsLeader:
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sm.debug "tick_leader can be called only on the leader"
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return
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for followerIndex in 0..sm.leader.followersProgress.len:
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var follower = sm.leader.followersProgress[followerIndex]
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if sm.myId != follower.id:
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if follower.matchIndex < sm.log.lastIndex or follower.commitIndex < sm.commitIndex:
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sm.replicateTo(follower)
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# TODO: implement step down logic
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func tick*(sm: var RaftStateMachine, now: times.Duration) =
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sm.timeNow = now
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if sm.state != RaftNodeState.rnsLeader:
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sm.tickLeader(now);
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elif sm.lastElectionTime - sm.timeNow > sm.randomizedElectionTime:
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sm.becomeCandidate(false)
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func poll*(sm: var RaftStateMachine): RaftStateMachineOutput =
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# Should initiate replication if we have new entries
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if sm.state == RaftNodeState.rnsLeader:
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sm.replicate()
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let output = sm.output
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sm.output = RaftStateMachineOutput()
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return output
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func commit*(sm: var RaftStateMachine) =
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if sm.state != RaftNodeState.rnsLeader:
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return
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var new_index = sm.commitIndex
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var next_index = sm.commitIndex + 1
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while next_index < sm.log.lastIndex:
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var replicationCnt = 0
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for p in sm.leader.followersProgress:
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if p.matchIndex > new_index:
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replicationCnt += 1
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if replicationCnt > len(sm.leader.followersProgress):
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sm.output.committed.add(sm.log.getEntryByIndex(next_index))
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sm.commitIndex += next_index;
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next_index += 1
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func findFollowerProggressById(sm: var RaftStateMachine, id: RaftNodeId): Option[RaftFollowerProgressTracker] =
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for follower in sm.leader.followersProgress:
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if follower.id == id:
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return some(follower)
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return none(RaftFollowerProgressTracker)
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func appendEntryReply*(sm: var RaftStateMachine, from_id: RaftNodeId, replay: RaftRpcAppendReplay) =
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if sm.state != RaftNodeState.rnsLeader:
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sm.debug "You can't append append replay to the follower"
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return
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var follower = sm.findFollowerProggressById(from_id)
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if not follower.isSome:
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sm.debug "Can't find the follower"
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return
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follower.get().commitIndex = max(follower.get().commitIndex, replay.commitIndex)
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case replay.result:
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of RaftRpcCode.Accepted:
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let lestIndex = replay.accepted.lastNewIndex
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follower.get().accepted(lestIndex)
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# TODO: add leader stepping down logic here
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sm.commit()
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if sm.state != RaftNodeState.rnsLeader:
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return
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of RaftRpcCode.Rejected:
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if replay.rejected.nonMatchingIndex == 0 and replay.rejected.lastIdx == 0:
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sm.replicateTo(follower.get())
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follower.get().next_index = min(replay.rejected.nonMatchingIndex, replay.rejected.lastIdx + 1)
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# if commit apply configuration that removes current follower
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# we should take it again
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var follower2 = sm.findFollowerProggressById(from_id)
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if follower2.isSome:
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sm.replicateTo(follower2.get())
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func advanceCommitIdx(sm: var RaftStateMachine, leaderIdx: RaftLogIndex) =
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let new_idx = min(leaderIdx, sm.log.lastIndex)
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if new_idx > sm.commitIndex:
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sm.commitIndex = new_idx
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# TODO: signal the output for the update
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func appendEntry*(sm: var RaftStateMachine, from_id: RaftNodeId, request: RaftRpcAppendRequest) =
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if sm.state != RaftNodeState.rnsFollower:
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sm.debug "You can't append append request to the non follower"
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return
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let (match, term) = sm.log.matchTerm(request.previousLogIndex, request.previousTerm)
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if not match:
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let rejected = RaftRpcAppendReplayRejected(nonMatchingIndex: request.previousLogIndex, lastIdx: sm.log.lastIndex)
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let responce = RaftRpcAppendReplay(term: sm.term, commitIndex: sm.commitIndex, result: RaftRpcCode.Rejected, rejected: rejected)
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sm.sendTo(sm.myId, responce)
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sm.debug "Reject to apply the entry"
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# reject to apply
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#sentTo()
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sm.log.appendAsFollower(request.entry)
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sm.advanceCommitIdx(request.commitIndex)
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let accepted = RaftRpcAppendReplayAccepted(lastNewIndex: sm.log.lastIndex)
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let responce = RaftRpcAppendReplay(term: sm.term, commitIndex: sm.commitIndex, result: RaftRpcCode.Accepted, accepted: accepted)
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sm.sendTo(sm.myId, responce)
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func requestVote*(sm: var RaftStateMachine, from_id: RaftNodeId, request: RaftRpcVoteRequest, ) =
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let canVote = sm.votedFor == from_id or (sm.votedFor == RaftNodeId() and sm.currentLeader == RaftNodeId()) or (request.isPrevote and request.currentTerm > sm.term)
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if canVote and sm.log.isUpToDate(request.lastLogIndex, request.lastLogTerm):
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if not request.is_prevote:
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# TODO: Update election time
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sm.votedFor = from_id
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let responce = RaftRpcVoteReplay(currentTerm: sm.term, voteGranted: true, isPrevote: request.is_prevote)
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sm.sendTo(sm.myId, responce)
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else:
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let responce = RaftRpcVoteReplay(currentTerm: sm.term, voteGranted: false, isPrevote: request.is_prevote)
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sm.sendTo(sm.myId, responce)
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func requestVoteReply*(sm: var RaftStateMachine, from_id: RaftNodeId, request: RaftRpcVoteReplay) =
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if sm.state != RaftNodeState.rnsCandidate:
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sm.debug "Non candidate can't handle votes"
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return
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@ -11,14 +11,23 @@ import unittest2
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import ../raft/types
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import ../raft/consensus_state_machine
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import std/[times, sequtils]
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import uuids
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func configWith3Nodes(): RaftConfig =
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var config = RaftConfig()
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config.currentSet.add(RaftnodeId(parseUUID("a8409b39-f17b-4682-aaef-a19cc9f356fb")))
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config.currentSet.add(RaftnodeId(parseUUID("2a98fc33-6559-44c0-b130-fc3e9df80a69")))
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config.currentSet.add(RaftnodeId(parseUUID("9156756d-697f-4ffa-9b82-0c86720344bd")))
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return config
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proc consensusstatemachineMain*() =
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suite "Basic state machine tests":
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test "create state machine":
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let config = RaftStateMachineConfig()
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let sm = initRaftStateMachine(config)
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var config = configWith3Nodes()
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var log = initRaftLog()
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let sm = initRaftStateMachine(config.currentSet[0], 0, log, 0, config)
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echo sm
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test "advance empty state machine":
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@ -70,5 +79,6 @@ proc consensusstatemachineMain*() =
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check log.entriesCount == 1
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if isMainModule:
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consensusstatemachineMain()
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