void PaxosProposer::OnProposeResponse(PaxosMessage& imsg)
{
PaxosMessage omsg;
Log_Trace("msg.nodeID = %u", imsg.nodeID);
if (!state.proposing || imsg.proposalID != state.proposalID)
return;
if (imsg.type == PAXOS_PROPOSE_REJECTED)
{
Log_Debug("Propose rejected");
vote->RegisterRejected(imsg.nodeID);
}
else
vote->RegisterAccepted(imsg.nodeID);
// see if we have enough positive replies to advance
if (vote->IsAccepted())
{
// a majority have accepted our proposal, we have consensus
StopProposing();
omsg.LearnProposal(context->GetPaxosID(), MY_NODEID, state.proposalID);
BroadcastMessage(omsg);
}
else if (vote->IsComplete())
StartPreparing();
}
void PaxosProposer::OnProposeResponse(PaxosMessage& imsg)
{
PaxosMessage omsg;
Log_Trace("msg.nodeID = %u", imsg.nodeID);
if (!state.proposing || imsg.proposalID != state.proposalID)
return;
if (imsg.type == PAXOS_PROPOSE_REJECTED)
{
Log_Debug("Propose rejected, quorumID: %U", context->GetQuorumID());
vote->RegisterRejected(imsg.nodeID);
}
else
vote->RegisterAccepted(imsg.nodeID);
if (vote->IsRejected())
{
StopProposing();
EventLoop::Add(&restartTimeout);
}
else if (vote->IsAccepted())
{
// a majority have accepted our proposal, we have consensus
StopProposing();
omsg.LearnProposal(context->GetPaxosID(), MY_NODEID, state.proposalID);
BroadcastMessage(omsg);
state.learnSent = true;
}
}
void ReplicatedLog::OnMessage(PaxosMessage& imsg)
{
Log_Trace();
bool processed;
processed = false;
if (imsg.type == PAXOS_PREPARE_REQUEST)
processed = OnPrepareRequest(imsg);
else if (imsg.IsPrepareResponse())
processed = OnPrepareResponse(imsg);
else if (imsg.type == PAXOS_PROPOSE_REQUEST)
processed = OnProposeRequest(imsg);
else if (imsg.IsProposeResponse())
processed = OnProposeResponse(imsg);
else if (imsg.IsLearn())
processed = OnLearnChosen(imsg);
else if (imsg.type == PAXOS_REQUEST_CHOSEN)
processed = OnRequestChosen(imsg);
else if (imsg.type == PAXOS_START_CATCHUP)
processed = OnStartCatchup(imsg);
else
ASSERT_FAIL();
if (processed)
context->OnMessageProcessed();
}
void ReplicatedLog::OnRequestChosen(PaxosMessage& imsg)
{
Buffer value;
PaxosMessage omsg;
#ifdef RLOG_DEBUG_MESSAGES
Log_Debug("ReplicatedLog::OnRequestChosen, imsg.paxosID = %U, mine = %U",
imsg.paxosID, GetPaxosID());
#endif
if (imsg.paxosID >= GetPaxosID())
return;
// the node is lagging and needs to catch-up
context->GetDatabase()->GetAcceptedValue(imsg.paxosID, value);
if (value.GetLength() > 0)
{
Log_Trace("Sending paxosID %d to node %d", imsg.paxosID, imsg.nodeID);
omsg.LearnValue(imsg.paxosID, MY_NODEID, 0, value);
}
else
{
Log_Trace("Node requested a paxosID I no longer have");
omsg.StartCatchup(paxosID, MY_NODEID);
}
context->GetTransport()->SendMessage(imsg.nodeID, omsg);
}
void PaxosProposer::OnMessage(PaxosMessage& imsg)
{
if (imsg.IsPrepareResponse())
OnPrepareResponse(imsg);
else if (imsg.IsProposeResponse())
OnProposeResponse(imsg);
else
ASSERT_FAIL();
}
void ReplicatedLog::RequestChosen(uint64_t nodeID)
{
PaxosMessage omsg;
if (context->IsLeaseOwner() || EventLoop::Now() - lastRequestChosenTime < REQUEST_CHOSEN_TIMEOUT)
return;
lastRequestChosenTime = EventLoop::Now();
omsg.RequestChosen(GetPaxosID(), MY_NODEID);
context->GetTransport()->SendMessage(nodeID, omsg);
#ifdef RLOG_DEBUG_MESSAGES
Log_Debug("ReplicatedLog::RequestChosen, paxosID = %U, to = %U", GetPaxosID(), nodeID);
#endif
}
void PaxosProposer::StartProposing()
{
PaxosMessage omsg;
Log_Trace();
StopPreparing();
NewVote();
state.proposing = true;
ASSERT(state.proposedValue.GetLength() > 0);
omsg.ProposeRequest(context->GetPaxosID(), MY_NODEID, state.proposalID,
state.proposedRunID, state.proposedValue);
BroadcastMessage(omsg);
EventLoop::Reset(&proposeTimeout);
}
void PaxosProposer::StartPreparing()
{
PaxosMessage omsg;
Log_Trace();
StopProposing();
NewVote();
state.preparing = true;
state.numProposals++;
state.proposalID = REPLICATION_CONFIG->NextProposalID(MAX(state.proposalID, state.highestPromisedProposalID));
state.highestReceivedProposalID = 0;
omsg.PrepareRequest(context->GetPaxosID(), MY_NODEID, state.proposalID);
BroadcastMessage(omsg);
EventLoop::Reset(&prepareTimeout);
}
void ReplicatedLog::OnRequest(PaxosMessage& imsg)
{
Buffer value;
PaxosMessage omsg;
Log_Trace();
if (imsg.paxosID < GetPaxosID())
{
context->GetDatabase()->GetAcceptedValue(imsg.paxosID, value);
if (value.GetLength() == 0)
return;
omsg.LearnValue(imsg.paxosID, MY_NODEID, 0, value);
context->GetTransport()->SendMessage(imsg.nodeID, omsg);
}
else if (GetPaxosID() < imsg.paxosID)
{
// I am lagging and need to catch-up
RequestChosen(imsg.nodeID);
}
}
void ReplicatedLog::OnMessage(PaxosMessage& imsg)
{
Log_Trace();
if (imsg.type == PAXOS_PREPARE_REQUEST)
OnPrepareRequest(imsg);
else if (imsg.IsPrepareResponse())
OnPrepareResponse(imsg);
else if (imsg.type == PAXOS_PROPOSE_REQUEST)
OnProposeRequest(imsg);
else if (imsg.IsProposeResponse())
OnProposeResponse(imsg);
else if (imsg.IsLearn())
OnLearnChosen(imsg);
else if (imsg.type == PAXOS_REQUEST_CHOSEN)
OnRequestChosen(imsg);
else if (imsg.type == PAXOS_START_CATCHUP)
OnStartCatchup(imsg);
else
ASSERT_FAIL();
}
void ConfigQuorumContext::OnPaxosMessage(ReadBuffer buffer)
{
PaxosMessage msg;
if (!isReplicationActive)
return;
msg.Read(buffer);
if (msg.IsPaxosRequest() || msg.IsPaxosResponse() || msg.IsLearn())
{
if (!quorum.IsMember(msg.nodeID))
{
Log_Message("Dropping paxos msg from %U because that node is not a quourm member", msg.nodeID);
OnMessageProcessed();
return;
}
}
RegisterPaxosID(msg.paxosID);
replicatedLog.RegisterPaxosID(msg.paxosID, msg.nodeID);
replicatedLog.OnMessage(msg);
}