import akka.actor.ActorRef;
import akka.actor.ActorSelection;
import akka.japi.Procedure;
-import akka.persistence.RecoveryCompleted;
-import akka.persistence.SaveSnapshotFailure;
-import akka.persistence.SaveSnapshotSuccess;
-import akka.persistence.SnapshotOffer;
import akka.persistence.SnapshotSelectionCriteria;
import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Objects;
import com.google.common.base.Optional;
-import com.google.common.base.Stopwatch;
-import com.google.protobuf.ByteString;
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Lists;
import java.io.Serializable;
+import java.util.Collection;
+import java.util.List;
import java.util.Map;
import java.util.concurrent.TimeUnit;
+import javax.annotation.Nonnull;
+import org.apache.commons.lang3.time.DurationFormatUtils;
import org.opendaylight.controller.cluster.DataPersistenceProvider;
+import org.opendaylight.controller.cluster.DelegatingPersistentDataProvider;
+import org.opendaylight.controller.cluster.NonPersistentDataProvider;
+import org.opendaylight.controller.cluster.PersistentDataProvider;
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.ApplyLogEntries;
-import org.opendaylight.controller.cluster.raft.base.messages.ApplySnapshot;
+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.CaptureSnapshot;
-import org.opendaylight.controller.cluster.raft.base.messages.CaptureSnapshotReply;
import org.opendaylight.controller.cluster.raft.base.messages.Replicate;
-import org.opendaylight.controller.cluster.raft.base.messages.SendInstallSnapshot;
-import org.opendaylight.controller.cluster.raft.behaviors.AbstractRaftActorBehavior;
+import org.opendaylight.controller.cluster.raft.behaviors.AbstractLeader;
+import org.opendaylight.controller.cluster.raft.behaviors.DelegatingRaftActorBehavior;
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.FindLeaderReply;
+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.protobuff.client.messages.Payload;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
* The current state determines the current behavior of a RaftActor
* A Raft Actor always starts off in the Follower State
*/
- private RaftActorBehavior currentBehavior;
+ 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 RaftActorContext context;
+ private final RaftActorContextImpl context;
- /**
- * The in-memory journal
- */
- private ReplicatedLogImpl replicatedLog = new ReplicatedLogImpl();
+ private final DelegatingPersistentDataProvider delegatingPersistenceProvider = new DelegatingPersistentDataProvider(null);
- private CaptureSnapshot captureSnapshot = null;
+ private RaftActorRecoverySupport raftRecovery;
- private Stopwatch recoveryTimer;
+ private RaftActorSnapshotMessageSupport snapshotSupport;
- private int currentRecoveryBatchCount;
+ private final BehaviorStateHolder reusableBehaviorStateHolder = new BehaviorStateHolder();
public RaftActor(String id, Map<String, String> peerAddresses) {
this(id, peerAddresses, Optional.<ConfigParams>absent());
Optional<ConfigParams> configParams) {
context = new RaftActorContextImpl(this.getSelf(),
- this.getContext(), id, new ElectionTermImpl(),
- -1, -1, replicatedLog, peerAddresses,
- (configParams.isPresent() ? configParams.get(): new DefaultConfigParamsImpl()),
- LOG);
- }
+ this.getContext(), id, new ElectionTermImpl(delegatingPersistenceProvider, id, LOG),
+ -1, -1, peerAddresses,
+ (configParams.isPresent() ? configParams.get(): new DefaultConfigParamsImpl()), LOG);
- private void initRecoveryTimer() {
- if(recoveryTimer == null) {
- recoveryTimer = Stopwatch.createStarted();
- }
+ context.setReplicatedLog(ReplicatedLogImpl.newInstance(context, delegatingPersistenceProvider, currentBehavior));
}
@Override
}
@Override
- public void handleRecover(Object message) {
- if(persistence().isRecoveryApplicable()) {
- if (message instanceof SnapshotOffer) {
- onRecoveredSnapshot((SnapshotOffer) message);
- } else if (message instanceof ReplicatedLogEntry) {
- onRecoveredJournalLogEntry((ReplicatedLogEntry) message);
- } else if (message instanceof ApplyLogEntries) {
- onRecoveredApplyLogEntries((ApplyLogEntries) message);
- } else if (message instanceof DeleteEntries) {
- replicatedLog.removeFrom(((DeleteEntries) message).getFromIndex());
- } else if (message instanceof UpdateElectionTerm) {
- context.getTermInformation().update(((UpdateElectionTerm) message).getCurrentTerm(),
- ((UpdateElectionTerm) message).getVotedFor());
- } else if (message instanceof RecoveryCompleted) {
- onRecoveryCompletedMessage();
+ public void postStop() {
+ if(currentBehavior.getDelegate() != null) {
+ try {
+ currentBehavior.close();
+ } catch (Exception e) {
+ LOG.debug("{}: Error closing behavior {}", persistenceId(), currentBehavior.state());
}
- } else {
- if (message instanceof RecoveryCompleted) {
+ }
+
+ super.postStop();
+ }
+
+ @Override
+ public void handleRecover(Object message) {
+ if(raftRecovery == null) {
+ raftRecovery = new RaftActorRecoverySupport(delegatingPersistenceProvider, context, currentBehavior,
+ getRaftActorRecoveryCohort());
+ }
+
+ boolean recoveryComplete = raftRecovery.handleRecoveryMessage(message);
+ 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();
}
- }
- }
-
- private void onRecoveredSnapshot(SnapshotOffer offer) {
- if(LOG.isDebugEnabled()) {
- LOG.debug("{}: SnapshotOffer called..", persistenceId());
- }
-
- initRecoveryTimer();
-
- Snapshot snapshot = (Snapshot) offer.snapshot();
-
- // Create a replicated log with the snapshot information
- // The replicated log can be used later on to retrieve this snapshot
- // when we need to install it on a peer
- replicatedLog = new ReplicatedLogImpl(snapshot);
-
- context.setReplicatedLog(replicatedLog);
- context.setLastApplied(snapshot.getLastAppliedIndex());
- context.setCommitIndex(snapshot.getLastAppliedIndex());
-
- Stopwatch timer = Stopwatch.createStarted();
- // Apply the snapshot to the actors state
- applyRecoverySnapshot(snapshot.getState());
+ onRecoveryComplete();
- timer.stop();
- LOG.info("Recovery snapshot applied for {} in {}: snapshotIndex={}, snapshotTerm={}, journal-size=" +
- replicatedLog.size(), persistenceId(), timer.toString(),
- replicatedLog.getSnapshotIndex(), replicatedLog.getSnapshotTerm());
- }
+ initializeBehavior();
- private void onRecoveredJournalLogEntry(ReplicatedLogEntry logEntry) {
- if(LOG.isDebugEnabled()) {
- LOG.debug("{}: Received ReplicatedLogEntry for recovery: {}", persistenceId(), logEntry.getIndex());
+ raftRecovery = null;
}
-
- replicatedLog.append(logEntry);
}
- private void onRecoveredApplyLogEntries(ApplyLogEntries ale) {
- if(LOG.isDebugEnabled()) {
- LOG.debug("{}: Received ApplyLogEntries for recovery, applying to state: {} to {}",
- persistenceId(), context.getLastApplied() + 1, ale.getToIndex());
- }
-
- for (long i = context.getLastApplied() + 1; i <= ale.getToIndex(); i++) {
- batchRecoveredLogEntry(replicatedLog.get(i));
- }
-
- context.setLastApplied(ale.getToIndex());
- context.setCommitIndex(ale.getToIndex());
- }
-
- private void batchRecoveredLogEntry(ReplicatedLogEntry logEntry) {
- initRecoveryTimer();
-
- int batchSize = context.getConfigParams().getJournalRecoveryLogBatchSize();
- if(currentRecoveryBatchCount == 0) {
- startLogRecoveryBatch(batchSize);
- }
-
- appendRecoveredLogEntry(logEntry.getData());
-
- if(++currentRecoveryBatchCount >= batchSize) {
- endCurrentLogRecoveryBatch();
- }
+ protected void initializeBehavior(){
+ changeCurrentBehavior(new Follower(context));
}
- private void endCurrentLogRecoveryBatch() {
- applyCurrentLogRecoveryBatch();
- currentRecoveryBatchCount = 0;
+ protected void changeCurrentBehavior(RaftActorBehavior newBehavior){
+ reusableBehaviorStateHolder.init(getCurrentBehavior());
+ setCurrentBehavior(newBehavior);
+ handleBehaviorChange(reusableBehaviorStateHolder, getCurrentBehavior());
}
- private void onRecoveryCompletedMessage() {
- if(currentRecoveryBatchCount > 0) {
- endCurrentLogRecoveryBatch();
+ @Override
+ public void handleCommand(Object message) {
+ if(snapshotSupport == null) {
+ snapshotSupport = new RaftActorSnapshotMessageSupport(delegatingPersistenceProvider, context,
+ currentBehavior, getRaftActorSnapshotCohort(), self());
}
- onRecoveryComplete();
-
- String recoveryTime = "";
- if(recoveryTimer != null) {
- recoveryTimer.stop();
- recoveryTime = " in " + recoveryTimer.toString();
- recoveryTimer = null;
+ boolean handled = snapshotSupport.handleSnapshotMessage(message);
+ if(handled) {
+ return;
}
- LOG.info(
- "Recovery completed" + recoveryTime + " - Switching actor to Follower - " +
- "Persistence Id = " + persistenceId() +
- " Last index in log={}, snapshotIndex={}, snapshotTerm={}, " +
- "journal-size={}",
- replicatedLog.lastIndex(), replicatedLog.getSnapshotIndex(),
- replicatedLog.getSnapshotTerm(), replicatedLog.size());
-
- initializeBehavior();
- }
-
- protected void initializeBehavior(){
- changeCurrentBehavior(new Follower(context));
- }
-
- protected void changeCurrentBehavior(RaftActorBehavior newBehavior){
- RaftActorBehavior oldBehavior = currentBehavior;
- currentBehavior = newBehavior;
- handleBehaviorChange(oldBehavior, currentBehavior);
- }
-
- @Override public void handleCommand(Object message) {
if (message instanceof ApplyState){
ApplyState applyState = (ApplyState) message;
applyState(applyState.getClientActor(), applyState.getIdentifier(),
applyState.getReplicatedLogEntry().getData());
- } else if (message instanceof ApplyLogEntries){
- ApplyLogEntries ale = (ApplyLogEntries) message;
+ } else if (message instanceof ApplyJournalEntries){
+ ApplyJournalEntries applyEntries = (ApplyJournalEntries) message;
if(LOG.isDebugEnabled()) {
- LOG.debug("{}: Persisting ApplyLogEntries with index={}", persistenceId(), ale.getToIndex());
+ LOG.debug("{}: Persisting ApplyLogEntries with index={}", persistenceId(), applyEntries.getToIndex());
}
- persistence().persist(new ApplyLogEntries(ale.getToIndex()), new Procedure<ApplyLogEntries>() {
- @Override
- public void apply(ApplyLogEntries param) throws Exception {
- }
- });
- } else if(message instanceof ApplySnapshot ) {
- Snapshot snapshot = ((ApplySnapshot) message).getSnapshot();
-
- if(LOG.isDebugEnabled()) {
- LOG.debug("{}: ApplySnapshot called on Follower Actor " +
- "snapshotIndex:{}, snapshotTerm:{}", persistenceId(), snapshot.getLastAppliedIndex(),
- snapshot.getLastAppliedTerm()
- );
- }
-
- applySnapshot(snapshot.getState());
-
- //clears the followers log, sets the snapshot index to ensure adjusted-index works
- replicatedLog = new ReplicatedLogImpl(snapshot);
- context.setReplicatedLog(replicatedLog);
- context.setLastApplied(snapshot.getLastAppliedIndex());
+ persistence().persist(applyEntries, NoopProcedure.instance());
} else if (message instanceof FindLeader) {
getSender().tell(
new FindLeaderReply(getLeaderAddress()),
getSelf()
);
-
- } else if (message instanceof SaveSnapshotSuccess) {
- SaveSnapshotSuccess success = (SaveSnapshotSuccess) message;
- LOG.info("{}: SaveSnapshotSuccess received for snapshot", persistenceId());
-
- long sequenceNumber = success.metadata().sequenceNr();
-
- commitSnapshot(sequenceNumber);
-
- } else if (message instanceof SaveSnapshotFailure) {
- SaveSnapshotFailure saveSnapshotFailure = (SaveSnapshotFailure) message;
-
- LOG.error("{}: SaveSnapshotFailure received for snapshot Cause:",
- persistenceId(), saveSnapshotFailure.cause());
-
- context.getReplicatedLog().snapshotRollback();
-
- LOG.info("{}: Replicated Log rollbacked. Snapshot will be attempted in the next cycle." +
- "snapshotIndex:{}, snapshotTerm:{}, log-size:{}", persistenceId(),
- context.getReplicatedLog().getSnapshotIndex(),
- context.getReplicatedLog().getSnapshotTerm(),
- context.getReplicatedLog().size());
-
- } else if (message instanceof CaptureSnapshot) {
- LOG.info("{}: CaptureSnapshot received by actor", persistenceId());
-
- if(captureSnapshot == null) {
- captureSnapshot = (CaptureSnapshot)message;
- createSnapshot();
+ } else if(message instanceof GetOnDemandRaftState) {
+ onGetOnDemandRaftStats();
+ } else {
+ reusableBehaviorStateHolder.init(getCurrentBehavior());
+
+ setCurrentBehavior(currentBehavior.handleMessage(getSender(), message));
+
+ handleBehaviorChange(reusableBehaviorStateHolder, getCurrentBehavior());
+ }
+ }
+
+ private void onGetOnDemandRaftStats() {
+ // Debugging message to retrieve raft stats.
+
+ OnDemandRaftState.Builder builder = OnDemandRaftState.builder()
+ .commitIndex(context.getCommitIndex())
+ .currentTerm(context.getTermInformation().getCurrentTerm())
+ .inMemoryJournalDataSize(replicatedLog().dataSize())
+ .inMemoryJournalLogSize(replicatedLog().size())
+ .isSnapshotCaptureInitiated(context.getSnapshotManager().isCapturing())
+ .lastApplied(context.getLastApplied())
+ .lastIndex(replicatedLog().lastIndex())
+ .lastTerm(replicatedLog().lastTerm())
+ .leader(getLeaderId())
+ .raftState(currentBehavior.state().toString())
+ .replicatedToAllIndex(currentBehavior.getReplicatedToAllIndex())
+ .snapshotIndex(replicatedLog().getSnapshotIndex())
+ .snapshotTerm(replicatedLog().getSnapshotTerm())
+ .votedFor(context.getTermInformation().getVotedFor())
+ .peerAddresses(ImmutableMap.copyOf(context.getPeerAddresses()));
+
+ ReplicatedLogEntry lastLogEntry = getLastLogEntry();
+ if (lastLogEntry != null) {
+ builder.lastLogIndex(lastLogEntry.getIndex());
+ builder.lastLogTerm(lastLogEntry.getTerm());
+ }
+
+ if(getCurrentBehavior() instanceof AbstractLeader) {
+ AbstractLeader leader = (AbstractLeader)getCurrentBehavior();
+ Collection<String> followerIds = leader.getFollowerIds();
+ List<FollowerInfo> followerInfoList = Lists.newArrayListWithCapacity(followerIds.size());
+ 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())));
}
- } else if (message instanceof CaptureSnapshotReply){
- handleCaptureSnapshotReply(((CaptureSnapshotReply) message).getSnapshot());
+ builder.followerInfoList(followerInfoList);
+ }
- } else {
- RaftActorBehavior oldBehavior = currentBehavior;
- currentBehavior = currentBehavior.handleMessage(getSender(), message);
+ sender().tell(builder.build(), self());
- handleBehaviorChange(oldBehavior, currentBehavior);
- }
}
- private void handleBehaviorChange(RaftActorBehavior oldBehavior, RaftActorBehavior currentBehavior) {
+ private void handleBehaviorChange(BehaviorStateHolder oldBehaviorState, RaftActorBehavior currentBehavior) {
+ RaftActorBehavior oldBehavior = oldBehaviorState.getBehavior();
+
if (oldBehavior != currentBehavior){
onStateChanged();
}
- String oldBehaviorLeaderId = oldBehavior == null? null : oldBehavior.getLeaderId();
- String oldBehaviorState = oldBehavior == null? null : oldBehavior.state().name();
+ String oldBehaviorLeaderId = oldBehavior == null ? null : oldBehaviorState.getLeaderId();
+ String oldBehaviorStateName = oldBehavior == null ? null : oldBehavior.state().name();
// it can happen that the state has not changed but the leader has changed.
- onLeaderChanged(oldBehaviorLeaderId, currentBehavior.getLeaderId());
+ Optional<ActorRef> roleChangeNotifier = getRoleChangeNotifier();
+ if(!Objects.equal(oldBehaviorLeaderId, currentBehavior.getLeaderId())) {
+ if(roleChangeNotifier.isPresent()) {
+ roleChangeNotifier.get().tell(new LeaderStateChanged(getId(), currentBehavior.getLeaderId()), getSelf());
+ }
+
+ onLeaderChanged(oldBehaviorLeaderId, currentBehavior.getLeaderId());
+ }
- if (getRoleChangeNotifier().isPresent() &&
+ if (roleChangeNotifier.isPresent() &&
(oldBehavior == null || (oldBehavior.state() != currentBehavior.state()))) {
- getRoleChangeNotifier().get().tell(
- new RoleChanged(getId(), oldBehaviorState , currentBehavior.state().name()),
- getSelf());
+ roleChangeNotifier.get().tell(new RoleChanged(getId(), oldBehaviorStateName ,
+ currentBehavior.state().name()), getSelf());
}
}
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());
-
- // Apply the state immediately
- applyState(clientActor, identifier, data);
-
- // Send a ApplyLogEntries message so that we write the fact that we applied
- // the state to durable storage
- self().tell(new ApplyLogEntries((int) replicatedLogEntry.getIndex()), self());
-
- // Check if the "real" snapshot capture has been initiated. If no then do the fake snapshot
- if(!context.isSnapshotCaptureInitiated()){
- raftContext.getReplicatedLog().snapshotPreCommit(raftContext.getLastApplied(),
- raftContext.getTermInformation().getCurrentTerm());
- raftContext.getReplicatedLog().snapshotCommit();
- } else {
- LOG.debug("{}: Skipping fake snapshotting for {} because real snapshotting is in progress",
- persistenceId(), getId());
- }
- } else if (clientActor != null) {
- // Send message for replication
- currentBehavior.handleMessage(getSelf(),
- new Replicate(clientActor, identifier,
- replicatedLogEntry)
- );
- }
-
- }
- }); }
+ 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());
+
+ // Apply the state immediately
+ applyState(clientActor, identifier, data);
+
+ // 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());
+
+ context.getSnapshotManager().trimLog(context.getLastApplied(), currentBehavior);
+
+ } else if (clientActor != null) {
+ // Send message for replication
+ currentBehavior.handleMessage(getSelf(),
+ new Replicate(clientActor, identifier, replicatedLogEntry));
+ }
+ }
+ });
+ }
+
+ private ReplicatedLog replicatedLog() {
+ return context.getReplicatedLog();
+ }
protected String getId() {
return context.getId();
}
+ @VisibleForTesting
+ void setCurrentBehavior(RaftActorBehavior behavior) {
+ currentBehavior.setDelegate(behavior);
+ }
+
+ protected RaftActorBehavior getCurrentBehavior() {
+ return currentBehavior.getDelegate();
+ }
+
/**
* Derived actors can call the isLeader method to check if the current
* RaftActor is the Leader or not
}
protected ReplicatedLogEntry getLastLogEntry() {
- return replicatedLog.last();
+ return replicatedLog().last();
}
protected Long getCurrentTerm(){
return context;
}
+ protected void updateConfigParams(ConfigParams configParams) {
+ context.setConfigParams(configParams);
+ }
+
+ public final DataPersistenceProvider persistence() {
+ return delegatingPersistenceProvider.getDelegate();
+ }
+
+ public void setPersistence(DataPersistenceProvider provider) {
+ delegatingPersistenceProvider.setDelegate(provider);
+ }
+
+ protected void setPersistence(boolean persistent) {
+ if(persistent) {
+ setPersistence(new PersistentDataProvider(this));
+ } else {
+ setPersistence(new NonPersistentDataProvider() {
+ /**
+ * The way snapshotting works is,
+ * <ol>
+ * <li> RaftActor calls createSnapshot on the Shard
+ * <li> Shard sends a CaptureSnapshotReply and RaftActor then calls saveSnapshot
+ * <li> When saveSnapshot is invoked on the akka-persistence API it uses the SnapshotStore to save
+ * the snapshot. The SnapshotStore sends SaveSnapshotSuccess or SaveSnapshotFailure. When the
+ * RaftActor gets SaveSnapshot success it commits the snapshot to the in-memory journal. This
+ * commitSnapshot is mimicking what is done in SaveSnapshotSuccess.
+ * </ol>
+ */
+ @Override
+ public void saveSnapshot(Object o) {
+ // Make saving Snapshot successful
+ // Committing the snapshot here would end up calling commit in the creating state which would
+ // be a state violation. That's why now we send a message to commit the snapshot.
+ self().tell(RaftActorSnapshotMessageSupport.COMMIT_SNAPSHOT, self());
+ }
+ });
+ }
+ }
+
/**
* setPeerAddress sets the address of a known peer at a later time.
* <p>
context.setPeerAddress(peerId, peerAddress);
}
- protected void commitSnapshot(long sequenceNumber) {
- context.getReplicatedLog().snapshotCommit();
-
- // TODO: Not sure if we want to be this aggressive with trimming stuff
- trimPersistentData(sequenceNumber);
- }
-
/**
* The applyState method will be called by the RaftActor when some data
* needs to be applied to the actor's state
Object data);
/**
- * This method is called during recovery at the start of a batch of state entries. Derived
- * classes should perform any initialization needed to start a batch.
- */
- protected abstract void startLogRecoveryBatch(int maxBatchSize);
-
- /**
- * This method is called during recovery to append state data to the current batch. This method
- * is called 1 or more times after {@link #startLogRecoveryBatch}.
- *
- * @param data the state data
- */
- protected abstract void appendRecoveredLogEntry(Payload data);
-
- /**
- * This method is called during recovery to reconstruct the state of the actor.
- *
- * @param snapshotBytes A snapshot of the state of the actor
- */
- protected abstract void applyRecoverySnapshot(byte[] snapshotBytes);
-
- /**
- * This method is called during recovery at the end of a batch to apply the current batched
- * log entries. This method is called after {@link #appendRecoveredLogEntry}.
+ * Returns the RaftActorRecoveryCohort to participate in persistence recovery.
*/
- protected abstract void applyCurrentLogRecoveryBatch();
+ @Nonnull
+ protected abstract RaftActorRecoveryCohort getRaftActorRecoveryCohort();
/**
* This method is called when recovery is complete.
protected abstract void onRecoveryComplete();
/**
- * This method will be called by the RaftActor when a snapshot needs to be
- * created. The derived actor should respond with its current state.
- * <p/>
- * During recovery the state that is returned by the derived actor will
- * be passed back to it by calling the applySnapshot method
- *
- * @return The current state of the actor
- */
- protected abstract void createSnapshot();
-
- /**
- * This method can be called at any other point during normal
- * operations when the derived actor is out of sync with it's peers
- * and the only way to bring it in sync is by applying a snapshot
- *
- * @param snapshotBytes A snapshot of the state of the actor
+ * Returns the RaftActorSnapshotCohort to participate in persistence recovery.
*/
- protected abstract void applySnapshot(byte[] snapshotBytes);
+ @Nonnull
+ protected abstract RaftActorSnapshotCohort getRaftActorSnapshotCohort();
/**
* This method will be called by the RaftActor when the state of the
*/
protected abstract void onStateChanged();
- protected abstract DataPersistenceProvider persistence();
-
/**
* Notifier Actor for this RaftActor to notify when a role change happens
* @return ActorRef - ActorRef of the notifier or Optional.absent if none.
protected void onLeaderChanged(String oldLeader, String newLeader){};
- private void trimPersistentData(long sequenceNumber) {
- // Trim akka snapshots
- // FIXME : Not sure how exactly the SnapshotSelectionCriteria is applied
- // For now guessing that it is ANDed.
- persistence().deleteSnapshots(new SnapshotSelectionCriteria(
- sequenceNumber - context.getConfigParams().getSnapshotBatchCount(), 43200000));
-
- // Trim akka journal
- persistence().deleteMessages(sequenceNumber);
- }
-
private String getLeaderAddress(){
if(isLeader()){
return getSelf().path().toString();
return peerAddress;
}
- private void handleCaptureSnapshotReply(byte[] snapshotBytes) {
- LOG.info("{}: CaptureSnapshotReply received by actor: snapshot size {}", persistenceId(), snapshotBytes.length);
-
- // create a snapshot object from the state provided and save it
- // when snapshot is saved async, SaveSnapshotSuccess is raised.
-
- Snapshot sn = Snapshot.create(snapshotBytes,
- context.getReplicatedLog().getFrom(captureSnapshot.getLastAppliedIndex() + 1),
- captureSnapshot.getLastIndex(), captureSnapshot.getLastTerm(),
- captureSnapshot.getLastAppliedIndex(), captureSnapshot.getLastAppliedTerm());
-
- persistence().saveSnapshot(sn);
-
- LOG.info("{}: Persisting of snapshot done:{}", persistenceId(), sn.getLogMessage());
-
- long dataThreshold = Runtime.getRuntime().totalMemory() *
- getRaftActorContext().getConfigParams().getSnapshotDataThresholdPercentage() / 100;
- if (context.getReplicatedLog().dataSize() > dataThreshold) {
- // if memory is less, clear the log based on lastApplied.
- // this could/should only happen if one of the followers is down
- // as normally we keep removing from the log when its replicated to all.
- context.getReplicatedLog().snapshotPreCommit(captureSnapshot.getLastAppliedIndex(),
- captureSnapshot.getLastAppliedTerm());
-
- } else {
- // clear the log based on replicatedToAllIndex
- context.getReplicatedLog().snapshotPreCommit(captureSnapshot.getReplicatedToAllIndex(),
- captureSnapshot.getReplicatedToAllTerm());
- }
- getCurrentBehavior().setReplicatedToAllIndex(captureSnapshot.getReplicatedToAllIndex());
-
- LOG.info("{}: Removed in-memory snapshotted entries, adjusted snaphsotIndex:{} " +
- "and term:{}", persistenceId(), captureSnapshot.getLastAppliedIndex(),
- captureSnapshot.getLastAppliedTerm());
-
- if (isLeader() && captureSnapshot.isInstallSnapshotInitiated()) {
- // this would be call straight to the leader and won't initiate in serialization
- currentBehavior.handleMessage(getSelf(), new SendInstallSnapshot(
- ByteString.copyFrom(snapshotBytes)));
- }
-
- captureSnapshot = null;
- context.setSnapshotCaptureInitiated(false);
- }
-
protected boolean hasFollowers(){
- return getRaftActorContext().getPeerAddresses().keySet().size() > 0;
- }
-
- private class ReplicatedLogImpl extends AbstractReplicatedLogImpl {
-
- private static final int DATA_SIZE_DIVIDER = 5;
- private long dataSizeSinceLastSnapshot = 0;
-
- public ReplicatedLogImpl(Snapshot snapshot) {
- super(snapshot.getLastAppliedIndex(), snapshot.getLastAppliedTerm(),
- snapshot.getUnAppliedEntries());
- }
-
- public ReplicatedLogImpl() {
- super();
- }
-
- @Override public void removeFromAndPersist(long logEntryIndex) {
- int adjustedIndex = adjustedIndex(logEntryIndex);
-
- if (adjustedIndex < 0) {
- return;
- }
-
- // FIXME: Maybe this should be done after the command is saved
- journal.subList(adjustedIndex , journal.size()).clear();
-
- persistence().persist(new DeleteEntries(adjustedIndex), new Procedure<DeleteEntries>() {
-
- @Override
- public void apply(DeleteEntries param)
- throws Exception {
- //FIXME : Doing nothing for now
- dataSize = 0;
- for (ReplicatedLogEntry entry : journal) {
- dataSize += entry.size();
- }
- }
- });
- }
-
- @Override public void appendAndPersist(
- final ReplicatedLogEntry replicatedLogEntry) {
- appendAndPersist(replicatedLogEntry, null);
- }
-
- public void appendAndPersist(
- final ReplicatedLogEntry replicatedLogEntry,
- final Procedure<ReplicatedLogEntry> callback) {
-
- if(LOG.isDebugEnabled()) {
- LOG.debug("{}: Append log entry and persist {} ", persistenceId(), replicatedLogEntry);
- }
-
- // FIXME : By adding the replicated log entry to the in-memory journal we are not truly ensuring durability of the logs
- journal.add(replicatedLogEntry);
-
- // When persisting events with persist it is guaranteed that the
- // persistent actor will not receive further commands between the
- // persist call and the execution(s) of the associated event
- // handler. This also holds for multiple persist calls in context
- // of a single command.
- persistence().persist(replicatedLogEntry,
- new Procedure<ReplicatedLogEntry>() {
- @Override
- public void apply(ReplicatedLogEntry evt) throws Exception {
- int logEntrySize = replicatedLogEntry.size();
-
- dataSize += logEntrySize;
- long dataSizeForCheck = dataSize;
-
- dataSizeSinceLastSnapshot += logEntrySize;
- long journalSize = lastIndex() + 1;
-
- if(!hasFollowers()) {
- // When we do not have followers we do not maintain an in-memory log
- // due to this the journalSize will never become anything close to the
- // snapshot batch count. In fact will mostly be 1.
- // Similarly since the journal's dataSize depends on the entries in the
- // journal the journal's dataSize will never reach a value close to the
- // memory threshold.
- // By maintaining the dataSize outside the journal we are tracking essentially
- // what we have written to the disk however since we no longer are in
- // need of doing a snapshot just for the sake of freeing up memory we adjust
- // the real size of data by the DATA_SIZE_DIVIDER so that we do not snapshot as often
- // as if we were maintaining a real snapshot
- dataSizeForCheck = dataSizeSinceLastSnapshot / DATA_SIZE_DIVIDER;
- }
-
- long dataThreshold = Runtime.getRuntime().totalMemory() *
- getRaftActorContext().getConfigParams().getSnapshotDataThresholdPercentage() / 100;
-
- // when a snaphsot is being taken, captureSnapshot != null
- if (!context.isSnapshotCaptureInitiated() &&
- ( journalSize % context.getConfigParams().getSnapshotBatchCount() == 0 ||
- dataSizeForCheck > dataThreshold)) {
-
- dataSizeSinceLastSnapshot = 0;
-
- LOG.info("{}: Initiating Snapshot Capture, journalSize = {}, dataSizeForCheck = {}," +
- " dataThreshold = {}", persistenceId(), journalSize, dataSizeForCheck, dataThreshold);
-
- long lastAppliedIndex = -1;
- long lastAppliedTerm = -1;
-
- ReplicatedLogEntry lastAppliedEntry = get(context.getLastApplied());
- if (!hasFollowers()) {
- lastAppliedIndex = replicatedLogEntry.getIndex();
- lastAppliedTerm = replicatedLogEntry.getTerm();
- } else if (lastAppliedEntry != null) {
- lastAppliedIndex = lastAppliedEntry.getIndex();
- lastAppliedTerm = lastAppliedEntry.getTerm();
- }
-
- if(LOG.isDebugEnabled()) {
- LOG.debug("{}: Snapshot Capture logSize: {}", persistenceId(), journal.size());
- LOG.debug("{}: Snapshot Capture lastApplied:{} ",
- persistenceId(), context.getLastApplied());
- LOG.debug("{}: Snapshot Capture lastAppliedIndex:{}", persistenceId(),
- lastAppliedIndex);
- LOG.debug("{}: Snapshot Capture lastAppliedTerm:{}", persistenceId(),
- lastAppliedTerm);
- }
-
- // send a CaptureSnapshot to self to make the expensive operation async.
- long replicatedToAllIndex = getCurrentBehavior().getReplicatedToAllIndex();
- ReplicatedLogEntry replicatedToAllEntry = context.getReplicatedLog().get(replicatedToAllIndex);
- getSelf().tell(new CaptureSnapshot(lastIndex(), lastTerm(), lastAppliedIndex, lastAppliedTerm,
- (replicatedToAllEntry != null ? replicatedToAllEntry.getIndex() : -1),
- (replicatedToAllEntry != null ? replicatedToAllEntry.getTerm() : -1)),
- null);
- context.setSnapshotCaptureInitiated(true);
- }
- if (callback != null){
- callback.apply(replicatedLogEntry);
- }
- }
- }
- );
- }
-
+ return getRaftActorContext().hasFollowers();
}
static class DeleteEntries implements Serializable {
}
}
-
- private class ElectionTermImpl implements ElectionTerm {
- /**
- * Identifier of the actor whose election term information this is
- */
- private long currentTerm = 0;
- private String votedFor = null;
-
- @Override
- public long getCurrentTerm() {
- return currentTerm;
- }
-
- @Override
- public String getVotedFor() {
- return votedFor;
- }
-
- @Override public void update(long currentTerm, String votedFor) {
- if(LOG.isDebugEnabled()) {
- LOG.debug("{}: Set currentTerm={}, votedFor={}", persistenceId(), currentTerm, votedFor);
- }
- this.currentTerm = currentTerm;
- this.votedFor = votedFor;
- }
-
- @Override
- public void updateAndPersist(long currentTerm, String votedFor){
- update(currentTerm, votedFor);
- // FIXME : Maybe first persist then update the state
- persistence().persist(new UpdateElectionTerm(this.currentTerm, this.votedFor), new Procedure<UpdateElectionTerm>(){
-
- @Override public void apply(UpdateElectionTerm param)
- throws Exception {
-
- }
- });
- }
- }
-
static class UpdateElectionTerm implements Serializable {
private static final long serialVersionUID = 1L;
private final long currentTerm;
}
}
- protected class NonPersistentRaftDataProvider extends NonPersistentDataProvider {
-
- public NonPersistentRaftDataProvider(){
+ private static class BehaviorStateHolder {
+ private RaftActorBehavior behavior;
+ private String leaderId;
+ void init(RaftActorBehavior behavior) {
+ this.behavior = behavior;
+ this.leaderId = behavior != null ? behavior.getLeaderId() : null;
}
- /**
- * The way snapshotting works is,
- * <ol>
- * <li> RaftActor calls createSnapshot on the Shard
- * <li> Shard sends a CaptureSnapshotReply and RaftActor then calls saveSnapshot
- * <li> When saveSnapshot is invoked on the akka-persistence API it uses the SnapshotStore to save the snapshot.
- * The SnapshotStore sends SaveSnapshotSuccess or SaveSnapshotFailure. When the RaftActor gets SaveSnapshot
- * success it commits the snapshot to the in-memory journal. This commitSnapshot is mimicking what is done
- * in SaveSnapshotSuccess.
- * </ol>
- * @param o
- */
- @Override
- public void saveSnapshot(Object o) {
- // Make saving Snapshot successful
- commitSnapshot(-1L);
+ RaftActorBehavior getBehavior() {
+ return behavior;
}
- }
- @VisibleForTesting
- void setCurrentBehavior(AbstractRaftActorBehavior behavior) {
- currentBehavior = behavior;
- }
-
- protected RaftActorBehavior getCurrentBehavior() {
- return currentBehavior;
+ String getLeaderId() {
+ return leaderId;
+ }
}
-
}