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Fix bug in leader election (missing HB)

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Reviewers: msantl

Reviewed By: msantl

Subscribers: pullbot

Differential Revision: https://phabricator.memgraph.io/D1767
This commit is contained in:
Ivan Paljak 2018-12-11 14:12:24 +01:00
parent 8e35d8afdc
commit 00506b9962
1 changed files with 15 additions and 9 deletions
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24
src/raft/raft_server.cpp
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@ -272,17 +272,19 @@ void RaftServer::Transition(const Mode &new_mode) {
if (mode_ == Mode::LEADER) {
reset_callback_();
}
LOG(INFO) << "Server " << server_id_ << ": Transition to FOLLOWER";
LOG(INFO) << "Server " << server_id_
<< ": Transition to FOLLOWER (Term: " << CurrentTerm() << ")";
mode_ = Mode::FOLLOWER;
// log_entry_buffer_.Disable();
log_entry_buffer_.Disable();
SetNextElectionTimePoint();
election_change_.notify_all();
break;
}
case Mode::CANDIDATE: {
LOG(INFO) << "Server " << server_id_ << ": Transition to CANDIDATE";
// log_entry_buffer_.Disable();
LOG(INFO) << "Server " << server_id_
<< ": Transition to CANDIDATE (Term: " << CurrentTerm() << ")";
log_entry_buffer_.Disable();
// [Raft thesis, section 3.4]
// "Each candidate restarts its randomized election timeout at the start
@ -315,8 +317,9 @@ void RaftServer::Transition(const Mode &new_mode) {
}
case Mode::LEADER: {
LOG(INFO) << "Server " << server_id_ << ": Transition to LEADER";
// log_entry_buffer_.Enable();
LOG(INFO) << "Server " << server_id_
<< ": Transition to LEADER (Term: " << CurrentTerm() << ")";
log_entry_buffer_.Enable();
// Freeze election timer
next_election_ = TimePoint::max();
@ -349,7 +352,9 @@ void RaftServer::ElectionThreadMain() {
std::unique_lock<std::mutex> lock(lock_);
while (!exiting_) {
if (Clock::now() >= next_election_) {
LOG(INFO) << "Server " << server_id_ << ": Election timeout exceeded";
LOG(INFO) << "Server " << server_id_
<< ": Election timeout exceeded (Term: " << CurrentTerm()
<< ")";
Transition(Mode::CANDIDATE);
state_changed_.notify_all();
}
@ -439,7 +444,7 @@ void RaftServer::PeerThreadMain(int peer_id) {
case Mode::LEADER: {
if (now >= next_heartbeat_[peer_id]) {
LOG(INFO) << "Server " << server_id_ << ": Send HB to server "
<< peer_id;
<< peer_id << " (Term: " << CurrentTerm() << ")";
auto peer_future = coordination_->ExecuteOnWorker<AppendEntriesRes>(
peer_id, [&](int worker_id, auto &client) {
auto last_entry_data = LastEntryData();
@ -480,7 +485,8 @@ void RaftServer::SetNextElectionTimePoint() {
bool RaftServer::HasMajortyVote() {
if (2 * granted_votes_ > coordination_->WorkerCount()) {
LOG(INFO) << "Server " << server_id_ << ": Obtained majority vote";
LOG(INFO) << "Server " << server_id_
<< ": Obtained majority vote (Term: " << CurrentTerm() << ")";
return true;
}
return false;