import akka.actor.ActorRef;
import akka.actor.ActorSelection;
+import akka.actor.PoisonPill;
import akka.japi.Procedure;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Objects;
import org.opendaylight.controller.cluster.raft.base.messages.ApplyJournalEntries;
import org.opendaylight.controller.cluster.raft.base.messages.ApplyState;
import org.opendaylight.controller.cluster.raft.base.messages.InitiateCaptureSnapshot;
+import org.opendaylight.controller.cluster.raft.base.messages.LeaderTransitioning;
import org.opendaylight.controller.cluster.raft.base.messages.Replicate;
import org.opendaylight.controller.cluster.raft.base.messages.SwitchBehavior;
import org.opendaylight.controller.cluster.raft.behaviors.AbstractLeader;
-import org.opendaylight.controller.cluster.raft.behaviors.DelegatingRaftActorBehavior;
+import org.opendaylight.controller.cluster.raft.behaviors.AbstractRaftActorBehavior;
import org.opendaylight.controller.cluster.raft.behaviors.Follower;
import org.opendaylight.controller.cluster.raft.behaviors.RaftActorBehavior;
import org.opendaylight.controller.cluster.raft.client.messages.FindLeader;
import org.opendaylight.controller.cluster.raft.client.messages.FollowerInfo;
import org.opendaylight.controller.cluster.raft.client.messages.GetOnDemandRaftState;
import org.opendaylight.controller.cluster.raft.client.messages.OnDemandRaftState;
+import org.opendaylight.controller.cluster.raft.client.messages.Shutdown;
import org.opendaylight.controller.cluster.raft.protobuff.client.messages.Payload;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
protected final Logger LOG = LoggerFactory.getLogger(getClass());
- /**
- * The current state determines the current behavior of a RaftActor
- * A Raft Actor always starts off in the Follower State
- */
- private final DelegatingRaftActorBehavior currentBehavior = new DelegatingRaftActorBehavior();
-
/**
* This context should NOT be passed directly to any other actor it is
* only to be consumed by the RaftActorBehaviors
private RaftActorServerConfigurationSupport serverConfigurationSupport;
+ private RaftActorLeadershipTransferCohort leadershipTransferInProgress;
+
+ private boolean shuttingDown;
+
public RaftActor(String id, Map<String, String> peerAddresses,
Optional<ConfigParams> configParams, short payloadVersion) {
delegatingPersistenceProvider, LOG);
context.setPayloadVersion(payloadVersion);
- context.setReplicatedLog(ReplicatedLogImpl.newInstance(context, currentBehavior));
+ context.setReplicatedLog(ReplicatedLogImpl.newInstance(context));
}
@Override
super.preStart();
snapshotSupport = newRaftActorSnapshotMessageSupport();
- serverConfigurationSupport = new RaftActorServerConfigurationSupport(getRaftActorContext());
+ serverConfigurationSupport = new RaftActorServerConfigurationSupport(this);
}
@Override
public void postStop() {
- if(currentBehavior.getDelegate() != null) {
- try {
- currentBehavior.close();
- } catch (Exception e) {
- LOG.debug("{}: Error closing behavior {}", persistenceId(), currentBehavior.state());
- }
- }
-
+ context.close();
super.postStop();
}
@Override
- public void handleRecover(Object message) {
+ protected void handleRecover(Object message) {
if(raftRecovery == null) {
raftRecovery = newRaftActorRecoverySupport();
}
if (context.getReplicatedLog().size() > 0) {
self().tell(new InitiateCaptureSnapshot(), self());
- LOG.info("Snapshot capture initiated after recovery");
+ LOG.info("{}: Snapshot capture initiated after recovery", persistenceId());
} else {
- LOG.info("Snapshot capture NOT initiated after recovery, journal empty");
+ LOG.info("{}: Snapshot capture NOT initiated after recovery, journal empty", persistenceId());
}
}
}
protected RaftActorRecoverySupport newRaftActorRecoverySupport() {
- return new RaftActorRecoverySupport(context, currentBehavior, getRaftActorRecoveryCohort());
+ return new RaftActorRecoverySupport(context, getRaftActorRecoveryCohort());
}
- protected void initializeBehavior(){
+ @VisibleForTesting
+ void initializeBehavior(){
changeCurrentBehavior(new Follower(context));
}
+ @VisibleForTesting
protected void changeCurrentBehavior(RaftActorBehavior newBehavior){
+ if(getCurrentBehavior() != null) {
+ try {
+ getCurrentBehavior().close();
+ } catch(Exception e) {
+ LOG.warn("{}: Error closing behavior {}", persistence(), getCurrentBehavior(), e);
+ }
+ }
+
reusableBehaviorStateHolder.init(getCurrentBehavior());
setCurrentBehavior(newBehavior);
handleBehaviorChange(reusableBehaviorStateHolder, getCurrentBehavior());
}
@Override
- public void handleCommand(final Object message) {
- if(serverConfigurationSupport.handleMessage(message, this, getSender())) {
+ protected void handleCommand(final Object message) {
+ if (serverConfigurationSupport.handleMessage(message, getSender())) {
+ return;
+ }
+ if (snapshotSupport.handleSnapshotMessage(message, getSender())) {
return;
- } else if (message instanceof ApplyState){
+ }
+
+ if (message instanceof ApplyState) {
ApplyState applyState = (ApplyState) message;
long elapsedTime = (System.nanoTime() - applyState.getStartTime());
// and recovery shows data missing
context.getReplicatedLog().captureSnapshotIfReady(applyState.getReplicatedLogEntry());
- context.getSnapshotManager().trimLog(context.getLastApplied(), currentBehavior);
+ context.getSnapshotManager().trimLog(context.getLastApplied());
}
- } else if (message instanceof ApplyJournalEntries){
+ } else if (message instanceof ApplyJournalEntries) {
ApplyJournalEntries applyEntries = (ApplyJournalEntries) message;
if(LOG.isDebugEnabled()) {
- LOG.debug("{}: Persisting ApplyLogEntries with index={}", persistenceId(), applyEntries.getToIndex());
+ LOG.debug("{}: Persisting ApplyJournalEntries with index={}", persistenceId(), applyEntries.getToIndex());
}
persistence().persist(applyEntries, NoopProcedure.instance());
onGetOnDemandRaftStats();
} else if(message instanceof InitiateCaptureSnapshot) {
captureSnapshot();
- } else if(message instanceof SwitchBehavior){
+ } else if(message instanceof SwitchBehavior) {
switchBehavior(((SwitchBehavior) message));
- } else if(!snapshotSupport.handleSnapshotMessage(message, getSender())) {
+ } else if(message instanceof LeaderTransitioning) {
+ onLeaderTransitioning();
+ } else if(message instanceof Shutdown) {
+ onShutDown();
+ } else if(message instanceof Runnable) {
+ ((Runnable)message).run();
+ } else {
switchBehavior(reusableSwitchBehaviorSupplier.handleMessage(getSender(), message));
}
}
+ private void initiateLeadershipTransfer(final RaftActorLeadershipTransferCohort.OnComplete onComplete) {
+ LOG.debug("{}: Initiating leader transfer", persistenceId());
+
+ if(leadershipTransferInProgress == null) {
+ leadershipTransferInProgress = new RaftActorLeadershipTransferCohort(this, getSender());
+ leadershipTransferInProgress.addOnComplete(new RaftActorLeadershipTransferCohort.OnComplete() {
+ @Override
+ public void onSuccess(ActorRef raftActorRef, ActorRef replyTo) {
+ leadershipTransferInProgress = null;
+ }
+
+ @Override
+ public void onFailure(ActorRef raftActorRef, ActorRef replyTo) {
+ leadershipTransferInProgress = null;
+ }
+ });
+
+ leadershipTransferInProgress.addOnComplete(onComplete);
+ leadershipTransferInProgress.init();
+ } else {
+ LOG.debug("{}: prior leader transfer in progress - adding callback", persistenceId());
+ leadershipTransferInProgress.addOnComplete(onComplete);
+ }
+ }
+
+ private void onShutDown() {
+ LOG.debug("{}: onShutDown", persistenceId());
+
+ if(shuttingDown) {
+ return;
+ }
+
+ shuttingDown = true;
+
+ final RaftActorBehavior currentBehavior = context.getCurrentBehavior();
+ if(currentBehavior.state() == RaftState.Leader && context.hasFollowers()) {
+ initiateLeadershipTransfer(new RaftActorLeadershipTransferCohort.OnComplete() {
+ @Override
+ public void onSuccess(ActorRef raftActorRef, ActorRef replyTo) {
+ LOG.debug("{}: leader transfer succeeded - sending PoisonPill", persistenceId());
+ raftActorRef.tell(PoisonPill.getInstance(), raftActorRef);
+ }
+
+ @Override
+ public void onFailure(ActorRef raftActorRef, ActorRef replyTo) {
+ LOG.debug("{}: leader transfer failed - sending PoisonPill", persistenceId());
+ raftActorRef.tell(PoisonPill.getInstance(), raftActorRef);
+ }
+ });
+ } else if(currentBehavior.state() == RaftState.Leader) {
+ pauseLeader(new TimedRunnable(context.getConfigParams().getElectionTimeOutInterval(), this) {
+ @Override
+ protected void doRun() {
+ self().tell(PoisonPill.getInstance(), self());
+ }
+
+ @Override
+ protected void doCancel() {
+ self().tell(PoisonPill.getInstance(), self());
+ }
+ });
+ } else {
+ self().tell(PoisonPill.getInstance(), self());
+ }
+ }
+
+ private void onLeaderTransitioning() {
+ LOG.debug("{}: onLeaderTransitioning", persistenceId());
+ Optional<ActorRef> roleChangeNotifier = getRoleChangeNotifier();
+ if(getRaftState() == RaftState.Follower && roleChangeNotifier.isPresent()) {
+ roleChangeNotifier.get().tell(newLeaderStateChanged(getId(), null,
+ getCurrentBehavior().getLeaderPayloadVersion()), getSelf());
+ }
+ }
+
private void switchBehavior(SwitchBehavior message) {
if(!getRaftActorContext().getRaftPolicy().automaticElectionsEnabled()) {
RaftState newState = message.getNewState();
handleBehaviorChange(reusableBehaviorStateHolder, getCurrentBehavior());
}
- protected RaftActorSnapshotMessageSupport newRaftActorSnapshotMessageSupport() {
- return new RaftActorSnapshotMessageSupport(context, currentBehavior,
- getRaftActorSnapshotCohort());
+ @VisibleForTesting
+ RaftActorSnapshotMessageSupport newRaftActorSnapshotMessageSupport() {
+ return new RaftActorSnapshotMessageSupport(context, getRaftActorSnapshotCohort());
}
private void onGetOnDemandRaftStats() {
peerAddresses.put(peerId, context.getPeerAddress(peerId));
}
+ final RaftActorBehavior currentBehavior = context.getCurrentBehavior();
OnDemandRaftState.Builder builder = OnDemandRaftState.builder()
.commitIndex(context.getCommitIndex())
.currentTerm(context.getTermInformation().getCurrentTerm())
.snapshotIndex(replicatedLog().getSnapshotIndex())
.snapshotTerm(replicatedLog().getSnapshotTerm())
.votedFor(context.getTermInformation().getVotedFor())
- .peerAddresses(peerAddresses);
+ .peerAddresses(peerAddresses)
+ .customRaftPolicyClassName(context.getConfigParams().getCustomRaftPolicyImplementationClass());
- ReplicatedLogEntry lastLogEntry = getLastLogEntry();
+ ReplicatedLogEntry lastLogEntry = replicatedLog().last();
if (lastLogEntry != null) {
builder.lastLogIndex(lastLogEntry.getIndex());
builder.lastLogTerm(lastLogEntry.getTerm());
}
onLeaderChanged(lastValidLeaderId, currentBehavior.getLeaderId());
+
+ if(leadershipTransferInProgress != null) {
+ leadershipTransferInProgress.onNewLeader(currentBehavior.getLeaderId());
+ }
+
+ serverConfigurationSupport.onNewLeader(currentBehavior.getLeaderId());
}
if (roleChangeNotifier.isPresent() &&
context.getReplicatedLog().captureSnapshotIfReady(replicatedLogEntry);
// Send message for replication
- currentBehavior.handleMessage(getSelf(),
+ getCurrentBehavior().handleMessage(getSelf(),
new Replicate(clientActor, identifier, replicatedLogEntry));
}
}
@VisibleForTesting
void setCurrentBehavior(RaftActorBehavior behavior) {
- currentBehavior.setDelegate(behavior);
+ context.setCurrentBehavior(behavior);
}
protected RaftActorBehavior getCurrentBehavior() {
- return currentBehavior.getDelegate();
+ return context.getCurrentBehavior();
}
/**
* @return true it this RaftActor is a Leader false otherwise
*/
protected boolean isLeader() {
- return context.getId().equals(currentBehavior.getLeaderId());
+ return context.getId().equals(getCurrentBehavior().getLeaderId());
+ }
+
+ protected final boolean isLeaderActive() {
+ return getRaftState() != RaftState.IsolatedLeader && !shuttingDown &&
+ !isLeadershipTransferInProgress();
+ }
+
+ private boolean isLeadershipTransferInProgress() {
+ return leadershipTransferInProgress != null && leadershipTransferInProgress.isTransferring();
}
/**
*
* @return the current leader's id
*/
- protected String getLeaderId(){
- return currentBehavior.getLeaderId();
- }
-
- protected RaftState getRaftState() {
- return currentBehavior.state();
+ protected final String getLeaderId(){
+ return getCurrentBehavior().getLeaderId();
}
- protected ReplicatedLogEntry getLastLogEntry() {
- return replicatedLog().last();
+ @VisibleForTesting
+ protected final RaftState getRaftState() {
+ return getCurrentBehavior().state();
}
protected Long getCurrentTerm(){
return context.getTermInformation().getCurrentTerm();
}
- protected Long getCommitIndex(){
- return context.getCommitIndex();
- }
-
- protected Long getLastApplied(){
- return context.getLastApplied();
- }
-
protected RaftActorContext getRaftActorContext() {
return context;
}
String newRaftPolicy = configParams.
getCustomRaftPolicyImplementationClass();
- LOG.debug ("RaftPolicy used with prev.config {}, RaftPolicy used with newConfig {}",
+ LOG.debug("{}: RaftPolicy used with prev.config {}, RaftPolicy used with newConfig {}", persistenceId(),
oldRaftPolicy, newRaftPolicy);
context.setConfigParams(configParams);
if (!Objects.equal(oldRaftPolicy, newRaftPolicy)) {
- //RaftPolicy is modifed for the Actor. Re-initialize its current behaviour
- initializeBehavior();
+ // The RaftPolicy was modified. If the current behavior is Follower then re-initialize to Follower
+ // but transfer the previous leaderId so it doesn't immediately try to schedule an election. This
+ // avoids potential disruption. Otherwise, switch to Follower normally.
+ RaftActorBehavior behavior = getCurrentBehavior();
+ if(behavior instanceof Follower) {
+ String previousLeaderId = ((Follower)behavior).getLeaderId();
+ short previousLeaderPayloadVersion = behavior.getLeaderPayloadVersion();
+
+ LOG.debug("{}: Re-initializing to Follower with previous leaderId {}", persistenceId(), previousLeaderId);
+
+ changeCurrentBehavior(new Follower(context, previousLeaderId, previousLeaderPayloadVersion));
+ } else {
+ initializeBehavior();
+ }
}
}
*/
protected abstract Optional<ActorRef> getRoleChangeNotifier();
- protected void onLeaderChanged(String oldLeader, String newLeader){};
+ /**
+ * This method is called prior to operations such as leadership transfer and actor shutdown when the leader
+ * must pause or stop its duties. This method allows derived classes to gracefully pause or finish current
+ * work prior to performing the operation. On completion of any work, the run method must be called on the
+ * given Runnable to proceed with the given operation. <b>Important:</b> the run method must be called on
+ * this actor's thread dispatcher as as it modifies internal state.
+ * <p>
+ * The default implementation immediately runs the operation.
+ *
+ * @param operation the operation to run
+ */
+ protected void pauseLeader(Runnable operation) {
+ operation.run();
+ }
+
+ protected void onLeaderChanged(String oldLeader, String newLeader) {
+
+ };
private String getLeaderAddress(){
if(isLeader()){
return getSelf().path().toString();
}
- String leaderId = currentBehavior.getLeaderId();
+ String leaderId = getLeaderId();
if (leaderId == null) {
return null;
}
private void captureSnapshot() {
SnapshotManager snapshotManager = context.getSnapshotManager();
- if(!snapshotManager.isCapturing()) {
+ if (!snapshotManager.isCapturing()) {
+ final long idx = getCurrentBehavior().getReplicatedToAllIndex();
LOG.debug("Take a snapshot of current state. lastReplicatedLog is {} and replicatedToAllIndex is {}",
- replicatedLog().last(), currentBehavior.getReplicatedToAllIndex());
+ replicatedLog().last(), idx);
+
+ snapshotManager.capture(replicatedLog().last(), idx);
+ }
+ }
+
+ /**
+ * Switch this member to non-voting status. This is a no-op for all behaviors except when we are the leader,
+ * in which case we need to step down.
+ */
+ void becomeNonVoting() {
+ if (isLeader()) {
+ initiateLeadershipTransfer(new RaftActorLeadershipTransferCohort.OnComplete() {
+ @Override
+ public void onSuccess(ActorRef raftActorRef, ActorRef replyTo) {
+ LOG.debug("{}: leader transfer succeeded after change to non-voting", persistenceId());
+ ensureFollowerState();
+ }
+
+ @Override
+ public void onFailure(ActorRef raftActorRef, ActorRef replyTo) {
+ LOG.debug("{}: leader transfer failed after change to non-voting", persistenceId());
+ ensureFollowerState();
+ }
- snapshotManager.capture(replicatedLog().last(), currentBehavior.getReplicatedToAllIndex());
+ private void ensureFollowerState() {
+ // Whether or not leadership transfer succeeded, we have to step down as leader and
+ // switch to Follower so ensure that.
+ if (getRaftState() != RaftState.Follower) {
+ initializeBehavior();
+ }
+ }
+ });
}
}
@Override
public RaftActorBehavior get() {
if(this.message instanceof SwitchBehavior){
- return ((SwitchBehavior) message).getNewState().createBehavior(getRaftActorContext());
+ return AbstractRaftActorBehavior.createBehavior(context, ((SwitchBehavior) message).getNewState());
}
- return currentBehavior.handleMessage(sender, message);
+ return getCurrentBehavior().handleMessage(sender, message);
}
}
}
Code Review / controller.git / blobdiff