import akka.actor.ActorRef;
import akka.actor.ActorSelection;
+import java.util.Set;
import org.opendaylight.controller.cluster.raft.RaftActorContext;
import org.opendaylight.controller.cluster.raft.RaftState;
import org.opendaylight.controller.cluster.raft.base.messages.ElectionTimeout;
import org.opendaylight.controller.cluster.raft.messages.RequestVote;
import org.opendaylight.controller.cluster.raft.messages.RequestVoteReply;
-import java.util.Set;
-
/**
* The behavior of a RaftActor when it is in the CandidateState
* <p/>
private final Set<String> peers;
public Candidate(RaftActorContext context) {
- super(context);
+ super(context, RaftState.Candidate);
peers = context.getPeerAddresses().keySet();
if(LOG.isDebugEnabled()) {
- LOG.debug("Election:Candidate has following peers: {}", peers);
+ LOG.debug("{}: Election: Candidate has following peers: {}", logName(), peers);
}
- if(peers.size() > 0) {
- // Votes are required from a majority of the peers including self.
- // The votesRequired field therefore stores a calculated value
- // of the number of votes required for this candidate to win an
- // election based on it's known peers.
- // If a peer was added during normal operation and raft replicas
- // came to know about them then the new peer would also need to be
- // taken into consideration when calculating this value.
- // Here are some examples for what the votesRequired would be for n
- // peers
- // 0 peers = 1 votesRequired (0 + 1) / 2 + 1 = 1
- // 2 peers = 2 votesRequired (2 + 1) / 2 + 1 = 2
- // 4 peers = 3 votesRequired (4 + 1) / 2 + 1 = 3
- int noOfPeers = peers.size();
- int self = 1;
- votesRequired = (noOfPeers + self) / 2 + 1;
+ votesRequired = getMajorityVoteCount(peers.size());
+
+ startNewTerm();
+
+ if(context.getPeerAddresses().isEmpty()){
+ actor().tell(ELECTION_TIMEOUT, actor());
} else {
- votesRequired = 0;
+ scheduleElection(electionDuration());
}
- startNewTerm();
- scheduleElection(electionDuration());
+
}
@Override protected RaftActorBehavior handleAppendEntries(ActorRef sender,
AppendEntries appendEntries) {
if(LOG.isDebugEnabled()) {
- LOG.debug(appendEntries.toString());
+ LOG.debug("{}: handleAppendEntries: {}", logName(), appendEntries);
}
return this;
}
@Override protected RaftActorBehavior handleRequestVoteReply(ActorRef sender,
- RequestVoteReply requestVoteReply) {
+ RequestVoteReply requestVoteReply) {
+
+ LOG.debug("{}: handleRequestVoteReply: {}, current voteCount: {}", logName(), requestVoteReply,
+ voteCount);
if (requestVoteReply.isVoteGranted()) {
voteCount++;
return this;
}
- @Override public RaftState state() {
- return RaftState.Candidate;
- }
-
@Override
public RaftActorBehavior handleMessage(ActorRef sender, Object originalMessage) {
RaftRPC rpc = (RaftRPC) message;
if(LOG.isDebugEnabled()) {
- LOG.debug("RaftRPC message received {} my term is {}", rpc, context.getTermInformation().getCurrentTerm());
+ LOG.debug("{}: RaftRPC message received {}, my term is {}", logName(), rpc,
+ context.getTermInformation().getCurrentTerm());
}
// If RPC request or response contains term T > currentTerm:
}
if (message instanceof ElectionTimeout) {
+ LOG.debug("{}: Received ElectionTimeout", logName());
+
if (votesRequired == 0) {
// If there are no peers then we should be a Leader
// We wait for the election timeout to occur before declare
// Increment the election term and vote for self
long currentTerm = context.getTermInformation().getCurrentTerm();
- context.getTermInformation().updateAndPersist(currentTerm + 1,
- context.getId());
+ long newTerm = currentTerm + 1;
+ context.getTermInformation().updateAndPersist(newTerm, context.getId());
- if(LOG.isDebugEnabled()) {
- LOG.debug("Starting new term {}", (currentTerm + 1));
- }
+ LOG.debug("{}: Starting new term {}", logName(), newTerm);
// Request for a vote
// TODO: Retry request for vote if replies do not arrive in a reasonable
for (String peerId : peers) {
ActorSelection peerActor = context.getPeerActorSelection(peerId);
if(peerActor != null) {
- peerActor.tell(new RequestVote(
+ RequestVote requestVote = new RequestVote(
context.getTermInformation().getCurrentTerm(),
context.getId(),
context.getReplicatedLog().lastIndex(),
- context.getReplicatedLog().lastTerm()),
- context.getActor()
- );
- }
- }
+ context.getReplicatedLog().lastTerm());
+ LOG.debug("{}: Sending {} to peer {}", logName(), requestVote, peerId);
+ peerActor.tell(requestVote, context.getActor());
+ }
+ }
}
@Override public void close() throws Exception {