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=09ffe056c3e94fcd4592f8f44f4e29123967f918;hb=664fc9940569ebfd54dcfc3db87bab66fad9300e;hp=3e6b50263122a83bc8252807d65bd25700b1e5f7;hpb=7be62e955c32ff7fa10753c4307199b287b1904c;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 3e6b502631..09ffe056c3 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
@@ -10,21 +10,19 @@ 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.internal.messages.ElectionTimeout;
+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.HashMap;
-import java.util.List;
-import java.util.Map;
-
/**
* The behavior of a RaftActor when it is in the CandidateState
- *
+ *
* Candidates (§5.2):
*
* - On conversion to candidate, start election:
@@ -42,123 +40,139 @@ import java.util.Map;
*/
public class Candidate extends AbstractRaftActorBehavior {
- private final Map peerToActor = new HashMap<>();
-
private int voteCount;
private final int votesRequired;
- public Candidate(RaftActorContext context, List peerPaths) {
+ private final Set peers;
+
+ public Candidate(RaftActorContext context) {
super(context);
- for (String peerPath : peerPaths) {
- peerToActor.put(peerPath,
- context.actorSelection(peerPath));
- }
+ peers = context.getPeerAddresses().keySet();
- if(peerPaths.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 = peerPaths.size();
- int self = 1;
- votesRequired = (noOfPeers + self) / 2 + 1;
- } else {
- votesRequired = 0;
+ if(LOG.isDebugEnabled()) {
+ LOG.debug("{}: Election: Candidate has following peers: {}", context.getId(), peers);
}
+ votesRequired = getMajorityVoteCount(peers.size());
+
startNewTerm();
scheduleElection(electionDuration());
}
- @Override protected RaftState handleAppendEntries(ActorRef sender,
- AppendEntries appendEntries, RaftState suggestedState) {
+ @Override protected RaftActorBehavior handleAppendEntries(ActorRef sender,
+ AppendEntries appendEntries) {
- // There is some peer who thinks it's a leader but is not
- // I will not accept this append entries
- sender.tell(new AppendEntriesReply(
- context.getTermInformation().getCurrentTerm(), false),
- context.getActor());
+ if(LOG.isDebugEnabled()) {
+ LOG.debug("{}: handleAppendEntries: {}", context.getId(), appendEntries);
+ }
- return suggestedState;
+ return this;
}
- @Override protected RaftState handleAppendEntriesReply(ActorRef sender,
- AppendEntriesReply appendEntriesReply, RaftState suggestedState) {
-
- // Some peer thinks I was a leader and sent me a reply
+ @Override protected RaftActorBehavior handleAppendEntriesReply(ActorRef sender,
+ AppendEntriesReply appendEntriesReply) {
- return suggestedState;
+ return this;
}
- @Override protected RaftState handleRequestVoteReply(ActorRef sender,
- RequestVoteReply requestVoteReply, RaftState suggestedState) {
- if(suggestedState == RaftState.Follower) {
- // If base class thinks I should be follower then I am
- return suggestedState;
- }
+ @Override protected RaftActorBehavior handleRequestVoteReply(ActorRef sender,
+ RequestVoteReply requestVoteReply) {
- if(requestVoteReply.isVoteGranted()){
+ if (requestVoteReply.isVoteGranted()) {
voteCount++;
}
- if(voteCount >= votesRequired){
- return RaftState.Leader;
+ if (voteCount >= votesRequired) {
+ return switchBehavior(new Leader(context));
}
- return state();
+ return this;
}
- @Override protected RaftState state() {
+ @Override public RaftState state() {
return RaftState.Candidate;
}
@Override
- public RaftState handleMessage(ActorRef sender, Object message) {
- if(message instanceof ElectionTimeout){
- if(votesRequired == 0){
+ 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 {}", context.getId(), 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) {
+ 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 RaftState.Leader;
+
+ return switchBehavior(new Leader(context));
}
startNewTerm();
scheduleElection(electionDuration());
- return state();
+ return this;
}
+
return super.handleMessage(sender, message);
}
- private void startNewTerm(){
+ 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();
- context.getTermInformation().update(currentTerm+1, context.getId());
+ context.getTermInformation().updateAndPersist(currentTerm + 1,
+ context.getId());
+
+ if(LOG.isDebugEnabled()) {
+ LOG.debug("{}: Starting new term {}", context.getId(), (currentTerm + 1));
+ }
// Request for a vote
- for(ActorSelection peerActor : peerToActor.values()){
- peerActor.tell(new RequestVote(
- context.getTermInformation().getCurrentTerm(),
- context.getId(), context.getReplicatedLog().last().getIndex(),
- context.getReplicatedLog().last().getTerm()),
- context.getActor());
+ // 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) {
+ peerActor.tell(new RequestVote(
+ context.getTermInformation().getCurrentTerm(),
+ context.getId(),
+ context.getReplicatedLog().lastIndex(),
+ context.getReplicatedLog().lastTerm()),
+ context.getActor()
+ );
+ }
}
}
+ @Override public void close() throws Exception {
+ stopElection();
+ }
}