import akka.actor.ActorRef;
import akka.actor.ActorSelection;
-import akka.japi.Procedure;
-import akka.persistence.SnapshotSelectionCriteria;
+import akka.actor.PoisonPill;
import com.google.common.annotations.VisibleForTesting;
-import com.google.common.base.Objects;
import com.google.common.base.Optional;
+import com.google.common.base.Preconditions;
+import com.google.common.base.Verify;
import com.google.common.collect.Lists;
-import java.io.Serializable;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
+import java.util.Objects;
import java.util.concurrent.TimeUnit;
import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
import org.apache.commons.lang3.time.DurationFormatUtils;
import org.opendaylight.controller.cluster.DataPersistenceProvider;
import org.opendaylight.controller.cluster.DelegatingPersistentDataProvider;
import org.opendaylight.controller.cluster.common.actor.AbstractUntypedPersistentActor;
import org.opendaylight.controller.cluster.notifications.LeaderStateChanged;
import org.opendaylight.controller.cluster.notifications.RoleChanged;
-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.persisted.ApplyJournalEntries;
+import org.opendaylight.controller.cluster.raft.persisted.NoopPayload;
import org.opendaylight.controller.cluster.raft.protobuff.client.messages.Payload;
+import org.opendaylight.yangtools.concepts.Identifier;
+import org.opendaylight.yangtools.concepts.Immutable;
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 final RaftActorContextImpl context;
- private final DelegatingPersistentDataProvider delegatingPersistenceProvider = new DelegatingPersistentDataProvider(null);
+ private final DelegatingPersistentDataProvider delegatingPersistenceProvider;
+
+ private final PersistentDataProvider persistentProvider;
+
+ private final BehaviorStateTracker behaviorStateTracker = new BehaviorStateTracker();
private RaftActorRecoverySupport raftRecovery;
private RaftActorSnapshotMessageSupport snapshotSupport;
- private final BehaviorStateHolder reusableBehaviorStateHolder = new BehaviorStateHolder();
+ private RaftActorServerConfigurationSupport serverConfigurationSupport;
- public RaftActor(String id, Map<String, String> peerAddresses) {
- this(id, peerAddresses, Optional.<ConfigParams>absent());
- }
+ private RaftActorLeadershipTransferCohort leadershipTransferInProgress;
+
+ private boolean shuttingDown;
public RaftActor(String id, Map<String, String> peerAddresses,
- Optional<ConfigParams> configParams) {
+ Optional<ConfigParams> configParams, short payloadVersion) {
+
+ persistentProvider = new PersistentDataProvider(this);
+ delegatingPersistenceProvider = new RaftActorDelegatingPersistentDataProvider(null, persistentProvider);
context = new RaftActorContextImpl(this.getSelf(),
- this.getContext(), id, new ElectionTermImpl(delegatingPersistenceProvider, id, LOG),
+ this.getContext(), id, new ElectionTermImpl(persistentProvider, id, LOG),
-1, -1, peerAddresses,
- (configParams.isPresent() ? configParams.get(): new DefaultConfigParamsImpl()),
+ configParams.isPresent() ? configParams.get(): new DefaultConfigParamsImpl(),
delegatingPersistenceProvider, LOG);
- context.setReplicatedLog(ReplicatedLogImpl.newInstance(context, currentBehavior));
+ context.setPayloadVersion(payloadVersion);
+ context.setReplicatedLog(ReplicatedLogImpl.newInstance(context));
}
@Override
super.preStart();
snapshotSupport = newRaftActorSnapshotMessageSupport();
+ 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();
}
- boolean recoveryComplete = raftRecovery.handleRecoveryMessage(message);
+ boolean recoveryComplete = raftRecovery.handleRecoveryMessage(message, persistentProvider);
if(recoveryComplete) {
- if(!persistence().isRecoveryApplicable()) {
- // Delete all the messages from the akka journal so that we do not end up with consistency issues
- // Note I am not using the dataPersistenceProvider and directly using the akka api here
- deleteMessages(lastSequenceNr());
-
- // Delete all the akka snapshots as they will not be needed
- deleteSnapshots(new SnapshotSelectionCriteria(scala.Long.MaxValue(), scala.Long.MaxValue()));
- }
-
onRecoveryComplete();
initializeBehavior();
}
protected RaftActorRecoverySupport newRaftActorRecoverySupport() {
- return new RaftActorRecoverySupport(context, currentBehavior, getRaftActorRecoveryCohort());
+ return new RaftActorRecoverySupport(context, getRaftActorRecoveryCohort());
}
- protected void initializeBehavior(){
+ @VisibleForTesting
+ void initializeBehavior(){
changeCurrentBehavior(new Follower(context));
}
- protected void changeCurrentBehavior(RaftActorBehavior newBehavior){
- reusableBehaviorStateHolder.init(getCurrentBehavior());
+ @VisibleForTesting
+ protected void changeCurrentBehavior(RaftActorBehavior newBehavior) {
+ final RaftActorBehavior currentBehavior = getCurrentBehavior();
+ if (currentBehavior != null) {
+ try {
+ currentBehavior.close();
+ } catch (Exception e) {
+ LOG.warn("{}: Error closing behavior {}", persistence(), currentBehavior, e);
+ }
+ }
+
+ final BehaviorState state = behaviorStateTracker.capture(currentBehavior);
setCurrentBehavior(newBehavior);
- handleBehaviorChange(reusableBehaviorStateHolder, getCurrentBehavior());
+ handleBehaviorChange(state, newBehavior);
}
+ /**
+ * Method exposed for subclasses to plug-in their logic. This method is invoked by {@link #handleCommand(Object)}
+ * for messages which are not handled by this class. Subclasses overriding this class should fall back to this
+ * implementation for messages which they do not handle
+ *
+ * @param message Incoming command message
+ */
+ protected void handleNonRaftCommand(final Object message) {
+ unhandled(message);
+ }
+
+ /**
+ * @deprecated This method is not final for testing purposes. DO NOT OVERRIDE IT, override
+ * {@link #handleNonRaftCommand(Object)} instead.
+ */
+ @Deprecated
@Override
- public void handleCommand(Object message) {
- if (message instanceof ApplyState){
+ // FIXME: make this method final once our unit tests do not need to override it
+ protected void handleCommand(final Object message) {
+ if (serverConfigurationSupport.handleMessage(message, getSender())) {
+ return;
+ }
+ if (snapshotSupport.handleSnapshotMessage(message, getSender())) {
+ return;
+ }
+
+ if (message instanceof ApplyState) {
ApplyState applyState = (ApplyState) message;
- long elapsedTime = (System.nanoTime() - applyState.getStartTime());
- if(elapsedTime >= APPLY_STATE_DELAY_THRESHOLD_IN_NANOS){
- LOG.warn("ApplyState took more time than expected. Elapsed Time = {} ms ApplyState = {}",
- TimeUnit.NANOSECONDS.toMillis(elapsedTime), applyState);
- }
+ long startTime = System.nanoTime();
if(LOG.isDebugEnabled()) {
LOG.debug("{}: Applying state for log index {} data {}",
applyState.getReplicatedLogEntry().getData());
}
- applyState(applyState.getClientActor(), applyState.getIdentifier(),
- applyState.getReplicatedLogEntry().getData());
+ if (!(applyState.getReplicatedLogEntry().getData() instanceof NoopPayload)) {
+ applyState(applyState.getClientActor(), applyState.getIdentifier(),
+ applyState.getReplicatedLogEntry().getData());
+ }
+
+ long elapsedTime = System.nanoTime() - startTime;
+ if(elapsedTime >= APPLY_STATE_DELAY_THRESHOLD_IN_NANOS){
+ LOG.debug("ApplyState took more time than expected. Elapsed Time = {} ms ApplyState = {}",
+ TimeUnit.NANOSECONDS.toMillis(elapsedTime), applyState);
+ }
- } else if (message instanceof ApplyJournalEntries){
+ if (!hasFollowers()) {
+ // for single node, the capture should happen after the apply state
+ // as we delete messages from the persistent journal which have made it to the snapshot
+ // capturing the snapshot before applying makes the persistent journal and snapshot out of sync
+ // and recovery shows data missing
+ context.getReplicatedLog().captureSnapshotIfReady(applyState.getReplicatedLogEntry());
+
+ context.getSnapshotManager().trimLog(context.getLastApplied());
+ }
+
+ // Send it to the current behavior - some behaviors like PreLeader need to be notified of ApplyState.
+ possiblyHandleBehaviorMessage(message);
+
+ } 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());
);
} else if(message instanceof GetOnDemandRaftState) {
onGetOnDemandRaftStats();
- } else if(!snapshotSupport.handleSnapshotMessage(message)) {
- reusableBehaviorStateHolder.init(getCurrentBehavior());
+ } else if(message instanceof InitiateCaptureSnapshot) {
+ captureSnapshot();
+ } else if(message instanceof SwitchBehavior) {
+ switchBehavior((SwitchBehavior) message);
+ } else if(message instanceof LeaderTransitioning) {
+ onLeaderTransitioning();
+ } else if(message instanceof Shutdown) {
+ onShutDown();
+ } else if(message instanceof Runnable) {
+ ((Runnable)message).run();
+ } else if(message instanceof NoopPayload) {
+ persistData(null, null, (NoopPayload)message);
+ } else if (!possiblyHandleBehaviorMessage(message)) {
+ handleNonRaftCommand(message);
+ }
+ }
+
+ private boolean possiblyHandleBehaviorMessage(final Object message) {
+ final RaftActorBehavior currentBehavior = getCurrentBehavior();
+ final BehaviorState state = behaviorStateTracker.capture(currentBehavior);
+
+ // A behavior indicates that it processed the change by returning a reference to the next behavior
+ // to be used. A null return indicates it has not processed the message and we should be passing it to
+ // the subclass for handling.
+ final RaftActorBehavior nextBehavior = currentBehavior.handleMessage(getSender(), message);
+ if (nextBehavior != null) {
+ switchBehavior(state, nextBehavior);
+ return true;
+ }
+
+ return false;
+ }
+
+ private void initiateLeadershipTransfer(final RaftActorLeadershipTransferCohort.OnComplete onComplete) {
+ LOG.debug("{}: Initiating leader transfer", persistenceId());
+
+ if(leadershipTransferInProgress == null) {
+ leadershipTransferInProgress = new RaftActorLeadershipTransferCohort(this);
+ leadershipTransferInProgress.addOnComplete(new RaftActorLeadershipTransferCohort.OnComplete() {
+ @Override
+ public void onSuccess(ActorRef raftActorRef) {
+ leadershipTransferInProgress = null;
+ }
+
+ @Override
+ public void onFailure(ActorRef raftActorRef) {
+ 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;
- setCurrentBehavior(currentBehavior.handleMessage(getSender(), message));
+ final RaftActorBehavior currentBehavior = context.getCurrentBehavior();
+ if (currentBehavior.state() != RaftState.Leader) {
+ // For non-leaders shutdown is a no-op
+ self().tell(PoisonPill.getInstance(), self());
+ return;
+ }
+
+ if (context.hasFollowers()) {
+ initiateLeadershipTransfer(new RaftActorLeadershipTransferCohort.OnComplete() {
+ @Override
+ public void onSuccess(ActorRef raftActorRef) {
+ LOG.debug("{}: leader transfer succeeded - sending PoisonPill", persistenceId());
+ raftActorRef.tell(PoisonPill.getInstance(), raftActorRef);
+ }
+
+ @Override
+ public void onFailure(ActorRef raftActorRef) {
+ LOG.debug("{}: leader transfer failed - sending PoisonPill", persistenceId());
+ raftActorRef.tell(PoisonPill.getInstance(), raftActorRef);
+ }
+ });
+ } else {
+ pauseLeader(new TimedRunnable(context.getConfigParams().getElectionTimeOutInterval(), this) {
+ @Override
+ protected void doRun() {
+ self().tell(PoisonPill.getInstance(), self());
+ }
- handleBehaviorChange(reusableBehaviorStateHolder, getCurrentBehavior());
+ @Override
+ protected void doCancel() {
+ self().tell(PoisonPill.getInstance(), self());
+ }
+ });
}
}
- protected RaftActorSnapshotMessageSupport newRaftActorSnapshotMessageSupport() {
- return new RaftActorSnapshotMessageSupport(context, currentBehavior,
- getRaftActorSnapshotCohort());
+ 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();
+ if( newState == RaftState.Leader || newState == RaftState.Follower) {
+ switchBehavior(behaviorStateTracker.capture(getCurrentBehavior()),
+ AbstractRaftActorBehavior.createBehavior(context, message.getNewState()));
+ getRaftActorContext().getTermInformation().updateAndPersist(message.getNewTerm(), "");
+ } else {
+ LOG.warn("Switching to behavior : {} - not supported", newState);
+ }
+ }
+ }
+
+ private void switchBehavior(final BehaviorState oldBehaviorState, final RaftActorBehavior nextBehavior) {
+ setCurrentBehavior(nextBehavior);
+ handleBehaviorChange(oldBehaviorState, nextBehavior);
+ }
+
+ @VisibleForTesting
+ RaftActorSnapshotMessageSupport newRaftActorSnapshotMessageSupport() {
+ return new RaftActorSnapshotMessageSupport(context, getRaftActorSnapshotCohort());
}
private void onGetOnDemandRaftStats() {
// Debugging message to retrieve raft stats.
+ Map<String, String> peerAddresses = new HashMap<>();
+ Map<String, Boolean> peerVotingStates = new HashMap<>();
+ for(PeerInfo info: context.getPeers()) {
+ peerVotingStates.put(info.getId(), info.isVoting());
+ peerAddresses.put(info.getId(), info.getAddress() != null ? info.getAddress() : "");
+ }
+
+ 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(new HashMap<>(context.getPeerAddresses()));
+ .isVoting(context.isVotingMember())
+ .peerAddresses(peerAddresses)
+ .peerVotingStates(peerVotingStates)
+ .customRaftPolicyClassName(context.getConfigParams().getCustomRaftPolicyImplementationClass());
- ReplicatedLogEntry lastLogEntry = getLastLogEntry();
+ ReplicatedLogEntry lastLogEntry = replicatedLog().last();
if (lastLogEntry != null) {
builder.lastLogIndex(lastLogEntry.getIndex());
builder.lastLogTerm(lastLogEntry.getTerm());
for(String id: followerIds) {
final FollowerLogInformation info = leader.getFollower(id);
followerInfoList.add(new FollowerInfo(id, info.getNextIndex(), info.getMatchIndex(),
- info.isFollowerActive(), DurationFormatUtils.formatDurationHMS(info.timeSinceLastActivity())));
+ info.isFollowerActive(), DurationFormatUtils.formatDurationHMS(info.timeSinceLastActivity()),
+ context.getPeerInfo(info.getId()).isVoting()));
}
builder.followerInfoList(followerInfoList);
}
- private void handleBehaviorChange(BehaviorStateHolder oldBehaviorState, RaftActorBehavior currentBehavior) {
+ private void handleBehaviorChange(BehaviorState oldBehaviorState, RaftActorBehavior currentBehavior) {
RaftActorBehavior oldBehavior = oldBehaviorState.getBehavior();
if (oldBehavior != currentBehavior){
onStateChanged();
}
- String oldBehaviorLeaderId = oldBehavior == null ? null : oldBehaviorState.getLeaderId();
+ String lastLeaderId = oldBehavior == null ? null : oldBehaviorState.getLastLeaderId();
+ String lastValidLeaderId = oldBehavior == null ? null : oldBehaviorState.getLastValidLeaderId();
String oldBehaviorStateName = oldBehavior == null ? null : oldBehavior.state().name();
// it can happen that the state has not changed but the leader has changed.
Optional<ActorRef> roleChangeNotifier = getRoleChangeNotifier();
- if(!Objects.equal(oldBehaviorLeaderId, currentBehavior.getLeaderId())) {
+ if(!Objects.equals(lastLeaderId, currentBehavior.getLeaderId()) ||
+ oldBehaviorState.getLeaderPayloadVersion() != currentBehavior.getLeaderPayloadVersion()) {
if(roleChangeNotifier.isPresent()) {
- roleChangeNotifier.get().tell(newLeaderStateChanged(getId(), currentBehavior.getLeaderId()), getSelf());
+ roleChangeNotifier.get().tell(newLeaderStateChanged(getId(), currentBehavior.getLeaderId(),
+ currentBehavior.getLeaderPayloadVersion()), getSelf());
+ }
+
+ onLeaderChanged(lastValidLeaderId, currentBehavior.getLeaderId());
+
+ if(leadershipTransferInProgress != null) {
+ leadershipTransferInProgress.onNewLeader(currentBehavior.getLeaderId());
}
- onLeaderChanged(oldBehaviorLeaderId, currentBehavior.getLeaderId());
+ serverConfigurationSupport.onNewLeader(currentBehavior.getLeaderId());
}
if (roleChangeNotifier.isPresent() &&
- (oldBehavior == null || (oldBehavior.state() != currentBehavior.state()))) {
+ (oldBehavior == null || oldBehavior.state() != currentBehavior.state())) {
roleChangeNotifier.get().tell(new RoleChanged(getId(), oldBehaviorStateName ,
currentBehavior.state().name()), getSelf());
}
}
- protected LeaderStateChanged newLeaderStateChanged(String memberId, String leaderId) {
- return new LeaderStateChanged(memberId, leaderId);
+ protected LeaderStateChanged newLeaderStateChanged(String memberId, String leaderId, short leaderPayloadVersion) {
+ return new LeaderStateChanged(memberId, leaderId, leaderPayloadVersion);
+ }
+
+ @Override
+ public long snapshotSequenceNr() {
+ // When we do a snapshot capture, we also capture and save the sequence-number of the persistent journal,
+ // so that we can delete the persistent journal based on the saved sequence-number
+ // However , when akka replays the journal during recovery, it replays it from the sequence number when the snapshot
+ // was saved and not the number we saved.
+ // We would want to override it , by asking akka to use the last-sequence number known to us.
+ return context.getSnapshotManager().getLastSequenceNumber();
}
/**
* @param identifier
* @param data
*/
- protected void persistData(final ActorRef clientActor, final String identifier,
- final Payload data) {
+ protected final void persistData(final ActorRef clientActor, final Identifier identifier, final Payload data) {
ReplicatedLogEntry replicatedLogEntry = new ReplicatedLogImplEntry(
context.getReplicatedLog().lastIndex() + 1,
final RaftActorContext raftContext = getRaftActorContext();
- replicatedLog().appendAndPersist(replicatedLogEntry, new Procedure<ReplicatedLogEntry>() {
- @Override
- public void apply(ReplicatedLogEntry replicatedLogEntry) throws Exception {
- if(!hasFollowers()){
- // Increment the Commit Index and the Last Applied values
- raftContext.setCommitIndex(replicatedLogEntry.getIndex());
- raftContext.setLastApplied(replicatedLogEntry.getIndex());
+ replicatedLog().appendAndPersist(replicatedLogEntry, replicatedLogEntry1 -> {
+ if (!hasFollowers()){
+ // Increment the Commit Index and the Last Applied values
+ raftContext.setCommitIndex(replicatedLogEntry1.getIndex());
+ raftContext.setLastApplied(replicatedLogEntry1.getIndex());
- // Apply the state immediately
- applyState(clientActor, identifier, data);
+ // Apply the state immediately.
+ self().tell(new ApplyState(clientActor, identifier, replicatedLogEntry1), self());
- // Send a ApplyJournalEntries message so that we write the fact that we applied
- // the state to durable storage
- self().tell(new ApplyJournalEntries(replicatedLogEntry.getIndex()), self());
+ // Send a ApplyJournalEntries message so that we write the fact that we applied
+ // the state to durable storage
+ self().tell(new ApplyJournalEntries(replicatedLogEntry1.getIndex()), self());
- context.getSnapshotManager().trimLog(context.getLastApplied(), currentBehavior);
+ } else {
+ context.getReplicatedLog().captureSnapshotIfReady(replicatedLogEntry1);
- } else if (clientActor != null) {
- // Send message for replication
- currentBehavior.handleMessage(getSelf(),
- new Replicate(clientActor, identifier, replicatedLogEntry));
- }
+ // Send message for replication
+ getCurrentBehavior().handleMessage(getSelf(),
+ new Replicate(clientActor, identifier, replicatedLogEntry1));
}
});
}
@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 && getRaftState() != RaftState.PreLeader &&
+ !shuttingDown && !isLeadershipTransferInProgress();
+ }
+
+ private boolean isLeadershipTransferInProgress() {
+ return leadershipTransferInProgress != null && leadershipTransferInProgress.isTransferring();
}
/**
*
* @return A reference to the leader if known, null otherwise
*/
- protected ActorSelection getLeader(){
+ public ActorSelection getLeader(){
String leaderAddress = getLeaderAddress();
if(leaderAddress == null){
*
* @return the current leader's id
*/
- protected String getLeaderId(){
- return currentBehavior.getLeaderId();
+ protected final String getLeaderId(){
+ return getCurrentBehavior().getLeaderId();
}
- protected RaftState getRaftState() {
- return currentBehavior.state();
- }
-
- 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;
}
protected void updateConfigParams(ConfigParams configParams) {
+
+ // obtain the RaftPolicy for oldConfigParams and the updated one.
+ String oldRaftPolicy = context.getConfigParams().
+ getCustomRaftPolicyImplementationClass();
+ String newRaftPolicy = configParams.
+ getCustomRaftPolicyImplementationClass();
+
+ LOG.debug("{}: RaftPolicy used with prev.config {}, RaftPolicy used with newConfig {}", persistenceId(),
+ oldRaftPolicy, newRaftPolicy);
context.setConfigParams(configParams);
+ if (!Objects.equals(oldRaftPolicy, newRaftPolicy)) {
+ // 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 != null && behavior.state() == RaftState.Follower) {
+ String previousLeaderId = 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();
+ }
+ }
}
public final DataPersistenceProvider persistence() {
}
protected void setPersistence(boolean persistent) {
- if(persistent) {
+ DataPersistenceProvider currentPersistence = persistence();
+ if(persistent && (currentPersistence == null || !currentPersistence.isRecoveryApplicable())) {
setPersistence(new PersistentDataProvider(this));
- } else {
+
+ if(getCurrentBehavior() != null) {
+ LOG.info("{}: Persistence has been enabled - capturing snapshot", persistenceId());
+ captureSnapshot();
+ }
+ } else if(!persistent && (currentPersistence == null || currentPersistence.isRecoveryApplicable())) {
setPersistence(new NonPersistentDataProvider() {
/**
* The way snapshotting works is,
* @param data A piece of data that was persisted by the persistData call.
* This should NEVER be null.
*/
- protected abstract void applyState(ActorRef clientActor, String identifier,
- Object data);
+ protected abstract void applyState(ActorRef clientActor, Identifier identifier, Object data);
/**
* Returns the RaftActorRecoveryCohort to participate in persistence recovery.
*/
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;
}
return getRaftActorContext().hasFollowers();
}
+ private void captureSnapshot() {
+ SnapshotManager snapshotManager = context.getSnapshotManager();
+
+ if (!snapshotManager.isCapturing()) {
+ final long idx = getCurrentBehavior().getReplicatedToAllIndex();
+ LOG.debug("Take a snapshot of current state. lastReplicatedLog is {} and replicatedToAllIndex is {}",
+ replicatedLog().last(), idx);
+
+ snapshotManager.capture(replicatedLog().last(), idx);
+ }
+ }
+
/**
- * @deprecated Deprecated in favor of {@link org.opendaylight.controller.cluster.raft.base.messages.DeleteEntriesTest}
- * whose type for fromIndex is long instead of int. This class was kept for backwards
- * compatibility with Helium.
+ * 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.
*/
- @Deprecated
- static class DeleteEntries implements Serializable {
- private static final long serialVersionUID = 1L;
- private final int fromIndex;
+ void becomeNonVoting() {
+ if (isLeader()) {
+ initiateLeadershipTransfer(new RaftActorLeadershipTransferCohort.OnComplete() {
+ @Override
+ public void onSuccess(ActorRef raftActorRef) {
+ LOG.debug("{}: leader transfer succeeded after change to non-voting", persistenceId());
+ ensureFollowerState();
+ }
- public DeleteEntries(int fromIndex) {
- this.fromIndex = fromIndex;
- }
+ @Override
+ public void onFailure(ActorRef raftActorRef) {
+ LOG.debug("{}: leader transfer failed after change to non-voting", persistenceId());
+ ensureFollowerState();
+ }
- public int getFromIndex() {
- return fromIndex;
+ 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();
+ }
+ }
+ });
}
}
- static class UpdateElectionTerm implements Serializable {
- private static final long serialVersionUID = 1L;
- private final long currentTerm;
- private final String votedFor;
+ /**
+ * A point-in-time capture of {@link RaftActorBehavior} state critical for transitioning between behaviors.
+ */
+ private static abstract class BehaviorState implements Immutable {
+ @Nullable abstract RaftActorBehavior getBehavior();
+ @Nullable abstract String getLastValidLeaderId();
+ @Nullable abstract String getLastLeaderId();
+ @Nullable abstract short getLeaderPayloadVersion();
+ }
- public UpdateElectionTerm(long currentTerm, String votedFor) {
- this.currentTerm = currentTerm;
- this.votedFor = votedFor;
+ /**
+ * A {@link BehaviorState} corresponding to non-null {@link RaftActorBehavior} state.
+ */
+ private static final class SimpleBehaviorState extends BehaviorState {
+ private final RaftActorBehavior behavior;
+ private final String lastValidLeaderId;
+ private final String lastLeaderId;
+ private final short leaderPayloadVersion;
+
+ SimpleBehaviorState(final String lastValidLeaderId, final String lastLeaderId,
+ final RaftActorBehavior behavior) {
+ this.lastValidLeaderId = lastValidLeaderId;
+ this.lastLeaderId = lastLeaderId;
+ this.behavior = Preconditions.checkNotNull(behavior);
+ this.leaderPayloadVersion = behavior.getLeaderPayloadVersion();
}
- public long getCurrentTerm() {
- return currentTerm;
+ @Override
+ RaftActorBehavior getBehavior() {
+ return behavior;
}
- public String getVotedFor() {
- return votedFor;
+ @Override
+ String getLastValidLeaderId() {
+ return lastValidLeaderId;
}
- }
- private static class BehaviorStateHolder {
- private RaftActorBehavior behavior;
- private String leaderId;
-
- void init(RaftActorBehavior behavior) {
- this.behavior = behavior;
- this.leaderId = behavior != null ? behavior.getLeaderId() : null;
+ @Override
+ short getLeaderPayloadVersion() {
+ return leaderPayloadVersion;
}
- RaftActorBehavior getBehavior() {
- return behavior;
+ @Override
+ String getLastLeaderId() {
+ return lastLeaderId;
}
+ }
+
+ /**
+ * Class tracking behavior-related information, which we need to keep around and pass across behavior switches.
+ * An instance is created for each RaftActor. It has two functions:
+ * - it keeps track of the last leader ID we have encountered since we have been created
+ * - it creates state capture needed to transition from one behavior to the next
+ */
+ private static final class BehaviorStateTracker {
+ /**
+ * A {@link BehaviorState} corresponding to null {@link RaftActorBehavior} state. Since null behavior is only
+ * allowed before we receive the first message, we know the leader ID to be null.
+ */
+ private static final BehaviorState NULL_BEHAVIOR_STATE = new BehaviorState() {
+ @Override
+ RaftActorBehavior getBehavior() {
+ return null;
+ }
+
+ @Override
+ String getLastValidLeaderId() {
+ return null;
+ }
+
+ @Override
+ short getLeaderPayloadVersion() {
+ return -1;
+ }
+
+ @Override
+ String getLastLeaderId() {
+ return null;
+ }
+ };
+
+ private String lastValidLeaderId;
+ private String lastLeaderId;
- String getLeaderId() {
- return leaderId;
+ BehaviorState capture(final RaftActorBehavior behavior) {
+ if (behavior == null) {
+ Verify.verify(lastValidLeaderId == null, "Null behavior with non-null last leader");
+ return NULL_BEHAVIOR_STATE;
+ }
+
+ lastLeaderId = behavior.getLeaderId();
+ if (lastLeaderId != null) {
+ lastValidLeaderId = lastLeaderId;
+ }
+
+ return new SimpleBehaviorState(lastValidLeaderId, lastLeaderId, behavior);
}
}
+
}
Code Review / controller.git / blobdiff