import akka.actor.Cancellable;
import org.opendaylight.controller.cluster.raft.RaftActorContext;
import org.opendaylight.controller.cluster.raft.RaftState;
+import org.opendaylight.controller.cluster.raft.ReplicatedLogEntry;
import org.opendaylight.controller.cluster.raft.internal.messages.ElectionTimeout;
import org.opendaylight.controller.cluster.raft.messages.AppendEntries;
import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply;
*/
private static final int ELECTION_TIME_MAX_VARIANCE = 100;
+ /**
+ * The interval at which a heart beat message will be sent to the remote
+ * RaftActor
+ * <p/>
+ * Since this is set to 100 milliseconds the Election timeout should be
+ * at least 200 milliseconds
+ */
+ protected static final FiniteDuration HEART_BEAT_INTERVAL =
+ new FiniteDuration(100, TimeUnit.MILLISECONDS);
+
/**
* The interval in which a new election would get triggered if no leader is found
*/
- private static final long ELECTION_TIME_INTERVAL = Leader.HEART_BEAT_INTERVAL.toMillis() * 2;
+ private static final long ELECTION_TIME_INTERVAL =
+ HEART_BEAT_INTERVAL.toMillis() * 2;
/**
*
protected abstract RaftState handleAppendEntries(ActorRef sender,
AppendEntries appendEntries, RaftState suggestedState);
+
+ protected RaftState appendEntries(ActorRef sender,
+ AppendEntries appendEntries, RaftState raftState){
+
+ // 1. Reply false if term < currentTerm (§5.1)
+ if(appendEntries.getTerm() < currentTerm()){
+ sender.tell(new AppendEntriesReply(currentTerm(), false), actor());
+ return state();
+ }
+
+ // 2. Reply false if log doesn’t contain an entry at prevLogIndex
+ // whose term matches prevLogTerm (§5.3)
+ ReplicatedLogEntry previousEntry = context.getReplicatedLog()
+ .get(appendEntries.getPrevLogIndex());
+
+ if(previousEntry == null || previousEntry.getTerm() != appendEntries.getPrevLogTerm()){
+ sender.tell(new AppendEntriesReply(currentTerm(), false), actor());
+ return state();
+ }
+
+ if(appendEntries.getEntries() != null) {
+ // 3. If an existing entry conflicts with a new one (same index
+ // but different terms), delete the existing entry and all that
+ // follow it (§5.3)
+ int addEntriesFrom = 0;
+ for (int i = 0;
+ i < appendEntries.getEntries().size(); i++, addEntriesFrom++) {
+ ReplicatedLogEntry newEntry = context.getReplicatedLog()
+ .get(i + 1);
+
+ if (newEntry != null && newEntry.getTerm() == appendEntries.getEntries().get(i).getTerm()){
+ break;
+ }
+ if (newEntry != null && newEntry.getTerm() != appendEntries
+ .getEntries().get(i).getTerm()) {
+ context.getReplicatedLog().removeFrom(i + 1);
+ break;
+ }
+ }
+
+ // 4. Append any new entries not already in the log
+ for (int i = addEntriesFrom;
+ i < appendEntries.getEntries().size(); i++) {
+ context.getReplicatedLog()
+ .append(appendEntries.getEntries().get(i));
+ }
+ }
+
+
+ // 5. If leaderCommit > commitIndex, set commitIndex =
+ // min(leaderCommit, index of last new entry)
+ context.setCommitIndex(Math.min(appendEntries.getLeaderCommit(),
+ context.getReplicatedLog().last().getIndex()));
+
+ // If commitIndex > lastApplied: increment lastApplied, apply
+ // log[lastApplied] to state machine (§5.3)
+ if (appendEntries.getLeaderCommit() > context.getLastApplied()) {
+ applyLogToStateMachine(appendEntries.getLeaderCommit());
+ }
+
+ sender.tell(new AppendEntriesReply(currentTerm(), true), actor());
+
+ return handleAppendEntries(sender, appendEntries, raftState);
+ }
+
/**
* Derived classes should not directly handle AppendEntriesReply messages it
* should let the base class handle it first. Once the base class handles
protected abstract RaftState handleAppendEntriesReply(ActorRef sender,
AppendEntriesReply appendEntriesReply, RaftState suggestedState);
- protected RaftState handleRequestVote(ActorRef sender,
- RequestVote requestVote, RaftState suggestedState){
+ protected RaftState requestVote(ActorRef sender,
+ RequestVote requestVote, RaftState suggestedState) {
boolean grantVote = false;
// Reply false if term < currentTerm (§5.1)
- if(requestVote.getTerm() < currentTerm()){
+ if (requestVote.getTerm() < currentTerm()) {
grantVote = false;
- // If votedFor is null or candidateId, and candidate’s log is at
- // least as up-to-date as receiver’s log, grant vote (§5.2, §5.4)
- } else if (votedFor() == null || votedFor().equals(requestVote.getCandidateId())) {
+ // If votedFor is null or candidateId, and candidate’s log is at
+ // least as up-to-date as receiver’s log, grant vote (§5.2, §5.4)
+ } else if (votedFor() == null || votedFor()
+ .equals(requestVote.getCandidateId())) {
boolean candidateLatest = false;
// the log with the later term is more up-to-date. If the logs
// end with the same term, then whichever log is longer is
// more up-to-date.
- if(requestVote.getLastLogTerm() > lastTerm()){
+ if (requestVote.getLastLogTerm() > lastTerm()) {
candidateLatest = true;
- } else if((requestVote.getLastLogTerm() == lastTerm()) && requestVote.getLastLogIndex() >= lastTerm()){
+ } else if ((requestVote.getLastLogTerm() == lastTerm())
+ && requestVote.getLastLogIndex() >= lastTerm()) {
candidateLatest = true;
}
- if(candidateLatest) {
+ if (candidateLatest) {
grantVote = true;
context.getTermInformation().update(requestVote.getTerm(),
requestVote.getCandidateId());
*/
protected abstract RaftState state();
- protected FiniteDuration electionDuration(){
+ protected FiniteDuration electionDuration() {
long variance = new Random().nextInt(ELECTION_TIME_MAX_VARIANCE);
- return new FiniteDuration(ELECTION_TIME_INTERVAL + variance, TimeUnit.MILLISECONDS);
+ return new FiniteDuration(ELECTION_TIME_INTERVAL + variance,
+ TimeUnit.MILLISECONDS);
}
protected void scheduleElection(FiniteDuration interval) {
context.getActorSystem().dispatcher(), context.getActor());
}
- protected long currentTerm(){
+ protected long currentTerm() {
return context.getTermInformation().getCurrentTerm();
}
- protected String votedFor(){
+ protected String votedFor() {
return context.getTermInformation().getVotedFor();
}
- protected ActorRef actor(){
+ protected ActorRef actor() {
return context.getActor();
}
raftState = applyTerm((RaftRPC) message);
}
if (message instanceof AppendEntries) {
- AppendEntries appendEntries = (AppendEntries) message;
- if (appendEntries.getLeaderCommit() > context.getLastApplied()) {
- applyLogToStateMachine(appendEntries.getLeaderCommit());
- }
- raftState = handleAppendEntries(sender, appendEntries, raftState);
+ raftState = appendEntries(sender, (AppendEntries) message,
+ raftState);
} else if (message instanceof AppendEntriesReply) {
raftState =
handleAppendEntriesReply(sender, (AppendEntriesReply) message,
raftState);
} else if (message instanceof RequestVote) {
raftState =
- handleRequestVote(sender, (RequestVote) message, raftState);
+ requestVote(sender, (RequestVote) message, raftState);
} else if (message instanceof RequestVoteReply) {
raftState =
handleRequestVoteReply(sender, (RequestVoteReply) message,
Code Review / controller.git / blobdiff