import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;
+import javax.annotation.Nullable;
import org.opendaylight.controller.cluster.raft.base.messages.LeaderTransitioning;
import org.opendaylight.controller.cluster.raft.behaviors.Leader;
import org.opendaylight.controller.cluster.raft.behaviors.RaftActorBehavior;
/**
* A raft actor support class that participates in leadership transfer. An instance is created upon
* initialization of leadership transfer.
+ *
* <p>
* The transfer process is as follows:
* <ol>
* their local RoleChangeNotifiers.</li>
* <li>Call {@link RaftActor#pauseLeader} passing this RaftActorLeadershipTransferCohort
* instance. This allows derived classes to perform work prior to transferring leadership.</li>
- * <li>When the pause is complete, the {@link #run} method is called which in turn calls
- * {@link Leader#transferLeadership}.</li>
+ * <li>When the pause is complete, the run method is called which in turn calls
+ * {@link Leader#transferLeadership(RaftActorLeadershipTransferCohort)}.</li>
* <li>The Leader calls {@link #transferComplete} on successful completion.</li>
* <li>Wait a short period of time for the new leader to be elected to give the derived class a chance to
* possibly complete work that was suspended while we were transferring.</li>
* <li>On notification of the new leader from the RaftActor or on time out, notify {@link OnComplete} callbacks.</li>
* </ol>
+ *
* <p>
* NOTE: All methods on this class must be called on the actor's thread dispatcher as they may access/modify
* internal state.
public class RaftActorLeadershipTransferCohort {
private static final Logger LOG = LoggerFactory.getLogger(RaftActorLeadershipTransferCohort.class);
- private final RaftActor raftActor;
- private Cancellable newLeaderTimer;
+ static final long USE_DEFAULT_LEADER_TIMEOUT = -1;
+
private final List<OnComplete> onCompleteCallbacks = new ArrayList<>();
- private long newLeaderTimeoutInMillis = 2000;
private final Stopwatch transferTimer = Stopwatch.createUnstarted();
+ private final RaftActor raftActor;
+ private final String requestedFollowerId;
+
+ private long newLeaderTimeoutInMillis = 2000;
+ private Cancellable newLeaderTimer;
private boolean isTransferring;
- RaftActorLeadershipTransferCohort(RaftActor raftActor) {
+ RaftActorLeadershipTransferCohort(final RaftActor raftActor) {
+ this(raftActor, null);
+ }
+
+ RaftActorLeadershipTransferCohort(final RaftActor raftActor, @Nullable final String requestedFollowerId) {
this.raftActor = raftActor;
+ this.requestedFollowerId = requestedFollowerId;
+
+ // We'll wait an election timeout period for a new leader to be elected plus some cushion to take into
+ // account the variance.
+ final long electionTimeout = raftActor.getRaftActorContext().getConfigParams()
+ .getElectionTimeOutInterval().toMillis();
+ final int variance = raftActor.getRaftActorContext().getConfigParams().getElectionTimeVariance();
+ newLeaderTimeoutInMillis = 2 * (electionTimeout + variance);
}
void init() {
transferTimer.start();
Optional<ActorRef> roleChangeNotifier = raftActor.getRoleChangeNotifier();
- if(roleChangeNotifier.isPresent()) {
+ if (roleChangeNotifier.isPresent()) {
roleChangeNotifier.get().tell(raftActor.newLeaderStateChanged(context.getId(), null,
currentBehavior.getLeaderPayloadVersion()), raftActor.self());
}
- for(String peerId: context.getPeerIds()) {
+ for (String peerId: context.getPeerIds()) {
ActorSelection followerActor = context.getPeerActorSelection(peerId);
- if(followerActor != null) {
- followerActor.tell(LeaderTransitioning.INSTANCE, context.getActor());
+ if (followerActor != null) {
+ followerActor.tell(new LeaderTransitioning(context.getId()), context.getActor());
}
}
raftActor.pauseLeader(new TimedRunnable(context.getConfigParams().getElectionTimeOutInterval(), raftActor) {
@Override
protected void doRun() {
+ LOG.debug("{}: pauseLeader successfully completed - doing transfer", raftActor.persistenceId());
doTransfer();
}
@Override
protected void doCancel() {
- LOG.debug("{}: pauseLeader timed out - aborting transfer", raftActor.persistenceId());
- abortTransfer();
+ LOG.debug("{}: pauseLeader timed out - continuing with transfer", raftActor.persistenceId());
+ doTransfer();
}
});
}
void doTransfer() {
RaftActorBehavior behavior = raftActor.getCurrentBehavior();
// Sanity check...
- if(behavior instanceof Leader) {
+ if (behavior instanceof Leader) {
isTransferring = true;
((Leader)behavior).transferLeadership(this);
} else {
// and convert to follower due to higher term. We should then get an AppendEntries heart
// beat with the new leader id.
- // Add a timer in case we don't get a leader change - 2 sec should be plenty of time if a new
- // leader is elected. Note: the Runnable is sent as a message to the raftActor which executes it
- // safely run on the actor's thread dispatcher.
+ // Add a timer in case we don't get a leader change. Note: the Runnable is sent as a message to the raftActor
+ // which executes it safely run on the actor's thread dispatcher.
FiniteDuration timeout = FiniteDuration.create(newLeaderTimeoutInMillis, TimeUnit.MILLISECONDS);
newLeaderTimer = raftActor.getContext().system().scheduler().scheduleOnce(timeout, raftActor.self(),
- new Runnable() {
- @Override
- public void run() {
- LOG.debug("{}: leader not elected in time", raftActor.persistenceId());
- finish(true);
- }
- }, raftActor.getContext().system().dispatcher(), raftActor.self());
+ (Runnable) () -> {
+ LOG.debug("{}: leader not elected in time", raftActor.persistenceId());
+ finish(true);
+ }, raftActor.getContext().system().dispatcher(), raftActor.self());
}
- void onNewLeader(String newLeader) {
- if(newLeader != null && newLeaderTimer != null) {
+ void onNewLeader(final String newLeader) {
+ if (newLeader != null && newLeaderTimer != null) {
LOG.debug("{}: leader changed to {}", raftActor.persistenceId(), newLeader);
newLeaderTimer.cancel();
finish(true);
}
}
- private void finish(boolean success) {
+ private void finish(final boolean success) {
isTransferring = false;
- if(transferTimer.isRunning()) {
+ if (transferTimer.isRunning()) {
transferTimer.stop();
- if(success) {
+ if (success) {
LOG.info("{}: Successfully transferred leadership to {} in {}", raftActor.persistenceId(),
raftActor.getLeaderId(), transferTimer);
} else {
LOG.warn("{}: Failed to transfer leadership in {}", raftActor.persistenceId(), transferTimer);
+ raftActor.unpauseLeader();
}
}
- for(OnComplete onComplete: onCompleteCallbacks) {
- if(success) {
+ for (OnComplete onComplete: onCompleteCallbacks) {
+ if (success) {
onComplete.onSuccess(raftActor.self());
} else {
onComplete.onFailure(raftActor.self());
}
}
- void addOnComplete(OnComplete onComplete) {
+ void addOnComplete(final OnComplete onComplete) {
onCompleteCallbacks.add(onComplete);
}
return isTransferring;
}
- @VisibleForTesting
- void setNewLeaderTimeoutInMillis(long newLeaderTimeoutInMillis) {
- this.newLeaderTimeoutInMillis = newLeaderTimeoutInMillis;
+ void setNewLeaderTimeoutInMillis(final long newLeaderTimeoutInMillis) {
+ if (newLeaderTimeoutInMillis != USE_DEFAULT_LEADER_TIMEOUT) {
+ this.newLeaderTimeoutInMillis = newLeaderTimeoutInMillis;
+ }
+ }
+
+ public Optional<String> getRequestedFollowerId() {
+ return Optional.fromNullable(requestedFollowerId);
}
interface OnComplete {
void onSuccess(ActorRef raftActorRef);
+
void onFailure(ActorRef raftActorRef);
}
}
Code Review / controller.git / blobdiff