X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?a=blobdiff_plain;f=opendaylight%2Fmd-sal%2Fsal-akka-raft%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fcontroller%2Fcluster%2Fraft%2Fbehaviors%2FCandidate.java;h=74bede171f1f6e6ad6b33feef6806d3c77321581;hb=a681e6bec3bbd7b536302ee9e083ae04b7f5ebdd;hp=774691154a8ee4782e02532916ebb9c7f29734a5;hpb=26cd54f2cbe0737db6e82aa96cd31671c6f6bf7e;p=controller.git
diff --git a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/Candidate.java b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/Candidate.java
index 774691154a..74bede171f 100644
--- a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/Candidate.java
+++ b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/Candidate.java
@@ -9,18 +9,20 @@
package org.opendaylight.controller.cluster.raft.behaviors;
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.AppendEntries;
import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply;
+import org.opendaylight.controller.cluster.raft.messages.RaftRPC;
import org.opendaylight.controller.cluster.raft.messages.RequestVote;
import org.opendaylight.controller.cluster.raft.messages.RequestVoteReply;
-import java.util.List;
-
/**
* The behavior of a RaftActor when it is in the CandidateState
- *
+ *
* Candidates (§5.2):
*
* - On conversion to candidate, start election:
@@ -37,39 +39,146 @@ import java.util.List;
*
*/
public class Candidate extends AbstractRaftActorBehavior {
- private final List peers;
- public Candidate(RaftActorContext context, List peers) {
- super(context);
- this.peers = peers;
- }
+ private int voteCount;
+
+ private final int votesRequired;
+
+ private final Set peers;
+
+ public Candidate(RaftActorContext context) {
+ super(context, RaftState.Candidate);
+
+ peers = context.getPeerAddresses().keySet();
+
+ if(LOG.isDebugEnabled()) {
+ LOG.debug("{}: Election: Candidate has following peers: {}", logName(), peers);
+ }
+
+ votesRequired = getMajorityVoteCount(peers.size());
+
+ startNewTerm();
+
+ if(context.getPeerAddresses().isEmpty()){
+ actor().tell(ELECTION_TIMEOUT, actor());
+ } else {
+ scheduleElection(electionDuration());
+ }
- @Override protected RaftState handleAppendEntries(ActorRef sender,
- AppendEntries appendEntries, RaftState suggestedState) {
- return suggestedState;
- }
- @Override protected RaftState handleAppendEntriesReply(ActorRef sender,
- AppendEntriesReply appendEntriesReply, RaftState suggestedState) {
- return suggestedState;
}
- @Override protected RaftState handleRequestVote(ActorRef sender,
- RequestVote requestVote, RaftState suggestedState) {
- return suggestedState;
+ @Override protected RaftActorBehavior handleAppendEntries(ActorRef sender,
+ AppendEntries appendEntries) {
+
+ if(LOG.isDebugEnabled()) {
+ LOG.debug("{}: handleAppendEntries: {}", logName(), appendEntries);
+ }
+
+ return this;
}
- @Override protected RaftState handleRequestVoteReply(ActorRef sender,
- RequestVoteReply requestVoteReply, RaftState suggestedState) {
- return suggestedState;
+ @Override protected RaftActorBehavior handleAppendEntriesReply(ActorRef sender,
+ AppendEntriesReply appendEntriesReply) {
+
+ return this;
}
- @Override protected RaftState state() {
- return RaftState.Candidate;
+ @Override protected RaftActorBehavior handleRequestVoteReply(ActorRef sender,
+ RequestVoteReply requestVoteReply) {
+
+ LOG.debug("{}: handleRequestVoteReply: {}, current voteCount: {}", logName(), requestVoteReply,
+ voteCount);
+
+ if (requestVoteReply.isVoteGranted()) {
+ voteCount++;
+ }
+
+ if (voteCount >= votesRequired) {
+ return switchBehavior(new Leader(context));
+ }
+
+ return this;
}
@Override
- public RaftState handleMessage(ActorRef sender, Object message) {
+ public RaftActorBehavior handleMessage(ActorRef sender, Object originalMessage) {
+
+ Object message = fromSerializableMessage(originalMessage);
+
+ if (message instanceof RaftRPC) {
+
+ RaftRPC rpc = (RaftRPC) message;
+
+ if(LOG.isDebugEnabled()) {
+ LOG.debug("{}: RaftRPC message received {}, my term is {}", logName(), rpc,
+ context.getTermInformation().getCurrentTerm());
+ }
+
+ // If RPC request or response contains term T > currentTerm:
+ // set currentTerm = T, convert to follower (§5.1)
+ // This applies to all RPC messages and responses
+ if (rpc.getTerm() > context.getTermInformation().getCurrentTerm()) {
+ context.getTermInformation().updateAndPersist(rpc.getTerm(), null);
+
+ return switchBehavior(new Follower(context));
+ }
+ }
+
+ 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
+ // ourselves the leader. This gives enough time for a leader
+ // who we do not know about (as a peer)
+ // to send a message to the candidate
+
+ return switchBehavior(new Leader(context));
+ }
+ startNewTerm();
+ scheduleElection(electionDuration());
+ return this;
+ }
+
return super.handleMessage(sender, message);
}
+
+
+ private void startNewTerm() {
+
+
+ // set voteCount back to 1 (that is voting for self)
+ voteCount = 1;
+
+ // Increment the election term and vote for self
+ long currentTerm = context.getTermInformation().getCurrentTerm();
+ long newTerm = currentTerm + 1;
+ context.getTermInformation().updateAndPersist(newTerm, context.getId());
+
+ LOG.debug("{}: Starting new term {}", logName(), newTerm);
+
+ // Request for a vote
+ // TODO: Retry request for vote if replies do not arrive in a reasonable
+ // amount of time TBD
+ for (String peerId : peers) {
+ ActorSelection peerActor = context.getPeerActorSelection(peerId);
+ if(peerActor != null) {
+ RequestVote requestVote = new RequestVote(
+ context.getTermInformation().getCurrentTerm(),
+ context.getId(),
+ context.getReplicatedLog().lastIndex(),
+ context.getReplicatedLog().lastTerm());
+
+ LOG.debug("{}: Sending {} to peer {}", logName(), requestVote, peerId);
+
+ peerActor.tell(requestVote, context.getActor());
+ }
+ }
+ }
+
+ @Override public void close() throws Exception {
+ stopElection();
+ }
}