2 * Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
9 package org.opendaylight.controller.cluster.raft;
11 import akka.actor.ActorRef;
12 import akka.actor.ActorSelection;
13 import akka.event.Logging;
14 import akka.event.LoggingAdapter;
15 import akka.japi.Procedure;
16 import akka.persistence.RecoveryCompleted;
17 import akka.persistence.SaveSnapshotFailure;
18 import akka.persistence.SaveSnapshotSuccess;
19 import akka.persistence.SnapshotOffer;
20 import akka.persistence.SnapshotSelectionCriteria;
21 import akka.persistence.UntypedPersistentActor;
22 import com.google.common.base.Optional;
23 import com.google.common.base.Stopwatch;
24 import com.google.protobuf.ByteString;
25 import org.opendaylight.controller.cluster.raft.base.messages.ApplyLogEntries;
26 import org.opendaylight.controller.cluster.raft.base.messages.ApplySnapshot;
27 import org.opendaylight.controller.cluster.raft.base.messages.ApplyState;
28 import org.opendaylight.controller.cluster.raft.base.messages.CaptureSnapshot;
29 import org.opendaylight.controller.cluster.raft.base.messages.CaptureSnapshotReply;
30 import org.opendaylight.controller.cluster.raft.base.messages.Replicate;
31 import org.opendaylight.controller.cluster.raft.base.messages.SendHeartBeat;
32 import org.opendaylight.controller.cluster.raft.behaviors.Candidate;
33 import org.opendaylight.controller.cluster.raft.behaviors.Follower;
34 import org.opendaylight.controller.cluster.raft.behaviors.Leader;
35 import org.opendaylight.controller.cluster.raft.behaviors.RaftActorBehavior;
36 import org.opendaylight.controller.cluster.raft.client.messages.AddRaftPeer;
37 import org.opendaylight.controller.cluster.raft.client.messages.FindLeader;
38 import org.opendaylight.controller.cluster.raft.client.messages.FindLeaderReply;
39 import org.opendaylight.controller.cluster.raft.client.messages.RemoveRaftPeer;
40 import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply;
41 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.Payload;
42 import org.opendaylight.controller.protobuff.messages.cluster.raft.AppendEntriesMessages;
43 import java.io.Serializable;
47 * RaftActor encapsulates a state machine that needs to be kept synchronized
48 * in a cluster. It implements the RAFT algorithm as described in the paper
49 * <a href='https://ramcloud.stanford.edu/wiki/download/attachments/11370504/raft.pdf'>
50 * In Search of an Understandable Consensus Algorithm</a>
52 * RaftActor has 3 states and each state has a certain behavior associated
53 * with it. A Raft actor can behave as,
56 * <li> A Follower (or) </li>
57 * <li> A Candidate </li>
61 * A RaftActor MUST be a Leader in order to accept requests from clients to
62 * change the state of it's encapsulated state machine. Once a RaftActor becomes
63 * a Leader it is also responsible for ensuring that all followers ultimately
64 * have the same log and therefore the same state machine as itself.
67 * The current behavior of a RaftActor determines how election for leadership
68 * is initiated and how peer RaftActors react to request for votes.
71 * Each RaftActor also needs to know the current election term. It uses this
72 * information for a couple of things. One is to simply figure out who it
73 * voted for in the last election. Another is to figure out if the message
74 * it received to update it's state is stale.
77 * The RaftActor uses akka-persistence to store it's replicated log.
78 * Furthermore through it's behaviors a Raft Actor determines
81 * <li> when a log entry should be persisted </li>
82 * <li> when a log entry should be applied to the state machine (and) </li>
83 * <li> when a snapshot should be saved </li>
86 public abstract class RaftActor extends UntypedPersistentActor {
87 protected final LoggingAdapter LOG =
88 Logging.getLogger(getContext().system(), this);
91 * The current state determines the current behavior of a RaftActor
92 * A Raft Actor always starts off in the Follower State
94 private RaftActorBehavior currentBehavior;
97 * This context should NOT be passed directly to any other actor it is
98 * only to be consumed by the RaftActorBehaviors
100 private final RaftActorContext context;
103 * The in-memory journal
105 private ReplicatedLogImpl replicatedLog = new ReplicatedLogImpl();
107 private CaptureSnapshot captureSnapshot = null;
109 private volatile boolean hasSnapshotCaptureInitiated = false;
111 private Stopwatch recoveryTimer;
113 private int currentRecoveryBatchCount;
115 public RaftActor(String id, Map<String, String> peerAddresses) {
116 this(id, peerAddresses, Optional.<ConfigParams>absent());
119 public RaftActor(String id, Map<String, String> peerAddresses,
120 Optional<ConfigParams> configParams) {
122 context = new RaftActorContextImpl(this.getSelf(),
123 this.getContext(), id, new ElectionTermImpl(),
124 -1, -1, replicatedLog, peerAddresses,
125 (configParams.isPresent() ? configParams.get(): new DefaultConfigParamsImpl()),
129 private void initRecoveryTimer() {
130 if(recoveryTimer == null) {
131 recoveryTimer = new Stopwatch();
132 recoveryTimer.start();
137 public void preStart() throws Exception {
138 LOG.info("Starting recovery for {} with journal batch size {}", persistenceId(),
139 context.getConfigParams().getJournalRecoveryLogBatchSize());
144 public void onReceiveRecover(Object message) {
145 if (message instanceof SnapshotOffer) {
146 onRecoveredSnapshot((SnapshotOffer)message);
147 } else if (message instanceof ReplicatedLogEntry) {
148 onRecoveredJournalLogEntry((ReplicatedLogEntry)message);
149 } else if (message instanceof ApplyLogEntries) {
150 onRecoveredApplyLogEntries((ApplyLogEntries)message);
151 } else if (message instanceof DeleteEntries) {
152 replicatedLog.removeFrom(((DeleteEntries) message).getFromIndex());
153 } else if (message instanceof UpdateElectionTerm) {
154 context.getTermInformation().update(((UpdateElectionTerm) message).getCurrentTerm(),
155 ((UpdateElectionTerm) message).getVotedFor());
156 } else if (message instanceof RecoveryCompleted) {
157 onRecoveryCompletedMessage();
161 private void onRecoveredSnapshot(SnapshotOffer offer) {
162 LOG.debug("SnapshotOffer called..");
166 Snapshot snapshot = (Snapshot) offer.snapshot();
168 // Create a replicated log with the snapshot information
169 // The replicated log can be used later on to retrieve this snapshot
170 // when we need to install it on a peer
171 replicatedLog = new ReplicatedLogImpl(snapshot);
173 context.setReplicatedLog(replicatedLog);
174 context.setLastApplied(snapshot.getLastAppliedIndex());
175 context.setCommitIndex(snapshot.getLastAppliedIndex());
177 Stopwatch timer = new Stopwatch();
180 // Apply the snapshot to the actors state
181 applyRecoverySnapshot(ByteString.copyFrom(snapshot.getState()));
184 LOG.info("Recovery snapshot applied for {} in {}: snapshotIndex={}, snapshotTerm={}, journal-size=" +
185 replicatedLog.size(), persistenceId(), timer.toString(),
186 replicatedLog.snapshotIndex, replicatedLog.snapshotTerm);
189 private void onRecoveredJournalLogEntry(ReplicatedLogEntry logEntry) {
190 if(LOG.isDebugEnabled()) {
191 LOG.debug("Received ReplicatedLogEntry for recovery: {}", logEntry.getIndex());
194 replicatedLog.append(logEntry);
197 private void onRecoveredApplyLogEntries(ApplyLogEntries ale) {
198 if(LOG.isDebugEnabled()) {
199 LOG.debug("Received ApplyLogEntries for recovery, applying to state: {} to {}",
200 context.getLastApplied() + 1, ale.getToIndex());
203 for (long i = context.getLastApplied() + 1; i <= ale.getToIndex(); i++) {
204 batchRecoveredLogEntry(replicatedLog.get(i));
207 context.setLastApplied(ale.getToIndex());
208 context.setCommitIndex(ale.getToIndex());
211 private void batchRecoveredLogEntry(ReplicatedLogEntry logEntry) {
214 int batchSize = context.getConfigParams().getJournalRecoveryLogBatchSize();
215 if(currentRecoveryBatchCount == 0) {
216 startLogRecoveryBatch(batchSize);
219 appendRecoveredLogEntry(logEntry.getData());
221 if(++currentRecoveryBatchCount >= batchSize) {
222 endCurrentLogRecoveryBatch();
226 private void endCurrentLogRecoveryBatch() {
227 applyCurrentLogRecoveryBatch();
228 currentRecoveryBatchCount = 0;
231 private void onRecoveryCompletedMessage() {
232 if(currentRecoveryBatchCount > 0) {
233 endCurrentLogRecoveryBatch();
236 onRecoveryComplete();
238 String recoveryTime = "";
239 if(recoveryTimer != null) {
240 recoveryTimer.stop();
241 recoveryTime = " in " + recoveryTimer.toString();
242 recoveryTimer = null;
246 "Recovery completed" + recoveryTime + " - Switching actor to Follower - " +
247 "Persistence Id = " + persistenceId() +
248 " Last index in log={}, snapshotIndex={}, snapshotTerm={}, " +
250 replicatedLog.lastIndex(), replicatedLog.snapshotIndex,
251 replicatedLog.snapshotTerm, replicatedLog.size());
253 currentBehavior = switchBehavior(RaftState.Follower);
257 @Override public void onReceiveCommand(Object message) {
258 if (message instanceof ApplyState){
259 ApplyState applyState = (ApplyState) message;
261 if(LOG.isDebugEnabled()) {
262 LOG.debug("Applying state for log index {} data {}",
263 applyState.getReplicatedLogEntry().getIndex(),
264 applyState.getReplicatedLogEntry().getData());
267 applyState(applyState.getClientActor(), applyState.getIdentifier(),
268 applyState.getReplicatedLogEntry().getData());
270 } else if (message instanceof ApplyLogEntries){
271 ApplyLogEntries ale = (ApplyLogEntries) message;
272 if(LOG.isDebugEnabled()) {
273 LOG.debug("Persisting ApplyLogEntries with index={}", ale.getToIndex());
275 persist(new ApplyLogEntries(ale.getToIndex()), new Procedure<ApplyLogEntries>() {
277 public void apply(ApplyLogEntries param) throws Exception {
281 } else if(message instanceof ApplySnapshot ) {
282 Snapshot snapshot = ((ApplySnapshot) message).getSnapshot();
284 if(LOG.isDebugEnabled()) {
285 LOG.debug("ApplySnapshot called on Follower Actor " +
286 "snapshotIndex:{}, snapshotTerm:{}", snapshot.getLastAppliedIndex(),
287 snapshot.getLastAppliedTerm()
290 applySnapshot(ByteString.copyFrom(snapshot.getState()));
292 //clears the followers log, sets the snapshot index to ensure adjusted-index works
293 replicatedLog = new ReplicatedLogImpl(snapshot);
294 context.setReplicatedLog(replicatedLog);
295 context.setLastApplied(snapshot.getLastAppliedIndex());
297 } else if (message instanceof FindLeader) {
299 new FindLeaderReply(getLeaderAddress()),
303 } else if (message instanceof SaveSnapshotSuccess) {
304 SaveSnapshotSuccess success = (SaveSnapshotSuccess) message;
305 LOG.info("SaveSnapshotSuccess received for snapshot");
307 context.getReplicatedLog().snapshotCommit();
309 // TODO: Not sure if we want to be this aggressive with trimming stuff
310 trimPersistentData(success.metadata().sequenceNr());
312 } else if (message instanceof SaveSnapshotFailure) {
313 SaveSnapshotFailure saveSnapshotFailure = (SaveSnapshotFailure) message;
315 LOG.info("saveSnapshotFailure.metadata():{}", saveSnapshotFailure.metadata().toString());
316 LOG.error(saveSnapshotFailure.cause(), "SaveSnapshotFailure received for snapshot Cause:");
318 context.getReplicatedLog().snapshotRollback();
320 LOG.info("Replicated Log rollbacked. Snapshot will be attempted in the next cycle." +
321 "snapshotIndex:{}, snapshotTerm:{}, log-size:{}",
322 context.getReplicatedLog().getSnapshotIndex(),
323 context.getReplicatedLog().getSnapshotTerm(),
324 context.getReplicatedLog().size());
326 } else if (message instanceof AddRaftPeer){
328 // FIXME : Do not add raft peers like this.
329 // When adding a new Peer we have to ensure that the a majority of
330 // the peers know about the new Peer. Doing it this way may cause
331 // a situation where multiple Leaders may emerge
332 AddRaftPeer arp = (AddRaftPeer)message;
333 context.addToPeers(arp.getName(), arp.getAddress());
335 } else if (message instanceof RemoveRaftPeer){
337 RemoveRaftPeer rrp = (RemoveRaftPeer)message;
338 context.removePeer(rrp.getName());
340 } else if (message instanceof CaptureSnapshot) {
341 LOG.info("CaptureSnapshot received by actor");
342 CaptureSnapshot cs = (CaptureSnapshot)message;
343 captureSnapshot = cs;
346 } else if (message instanceof CaptureSnapshotReply){
347 LOG.info("CaptureSnapshotReply received by actor");
348 CaptureSnapshotReply csr = (CaptureSnapshotReply) message;
350 ByteString stateInBytes = csr.getSnapshot();
351 LOG.info("CaptureSnapshotReply stateInBytes size:{}", stateInBytes.size());
352 handleCaptureSnapshotReply(stateInBytes);
355 if (!(message instanceof AppendEntriesMessages.AppendEntries)
356 && !(message instanceof AppendEntriesReply) && !(message instanceof SendHeartBeat)) {
357 if(LOG.isDebugEnabled()) {
358 LOG.debug("onReceiveCommand: message:" + message.getClass());
363 currentBehavior.handleMessage(getSender(), message);
364 RaftActorBehavior oldBehavior = currentBehavior;
365 currentBehavior = switchBehavior(state);
366 if(oldBehavior != currentBehavior){
370 onLeaderChanged(oldBehavior.getLeaderId(), currentBehavior.getLeaderId());
374 public java.util.Set<String> getPeers() {
375 return context.getPeerAddresses().keySet();
378 protected String getReplicatedLogState() {
379 return "snapshotIndex=" + context.getReplicatedLog().getSnapshotIndex()
380 + ", snapshotTerm=" + context.getReplicatedLog().getSnapshotTerm()
381 + ", im-mem journal size=" + context.getReplicatedLog().size();
386 * When a derived RaftActor needs to persist something it must call
393 protected void persistData(ActorRef clientActor, String identifier,
396 ReplicatedLogEntry replicatedLogEntry = new ReplicatedLogImplEntry(
397 context.getReplicatedLog().lastIndex() + 1,
398 context.getTermInformation().getCurrentTerm(), data);
400 if(LOG.isDebugEnabled()) {
401 LOG.debug("Persist data {}", replicatedLogEntry);
405 .appendAndPersist(clientActor, identifier, replicatedLogEntry);
408 protected String getId() {
409 return context.getId();
413 * Derived actors can call the isLeader method to check if the current
414 * RaftActor is the Leader or not
416 * @return true it this RaftActor is a Leader false otherwise
418 protected boolean isLeader() {
419 return context.getId().equals(currentBehavior.getLeaderId());
423 * Derived actor can call getLeader if they need a reference to the Leader.
424 * This would be useful for example in forwarding a request to an actor
425 * which is the leader
427 * @return A reference to the leader if known, null otherwise
429 protected ActorSelection getLeader(){
430 String leaderAddress = getLeaderAddress();
432 if(leaderAddress == null){
436 return context.actorSelection(leaderAddress);
441 * @return the current leader's id
443 protected String getLeaderId(){
444 return currentBehavior.getLeaderId();
447 protected RaftState getRaftState() {
448 return currentBehavior.state();
451 protected ReplicatedLogEntry getLastLogEntry() {
452 return replicatedLog.last();
455 protected Long getCurrentTerm(){
456 return context.getTermInformation().getCurrentTerm();
459 protected Long getCommitIndex(){
460 return context.getCommitIndex();
463 protected Long getLastApplied(){
464 return context.getLastApplied();
467 protected RaftActorContext getRaftActorContext() {
472 * setPeerAddress sets the address of a known peer at a later time.
474 * This is to account for situations where a we know that a peer
475 * exists but we do not know an address up-front. This may also be used in
476 * situations where a known peer starts off in a different location and we
477 * need to change it's address
479 * Note that if the peerId does not match the list of peers passed to
480 * this actor during construction an IllegalStateException will be thrown.
485 protected void setPeerAddress(String peerId, String peerAddress){
486 context.setPeerAddress(peerId, peerAddress);
492 * The applyState method will be called by the RaftActor when some data
493 * needs to be applied to the actor's state
495 * @param clientActor A reference to the client who sent this message. This
496 * is the same reference that was passed to persistData
497 * by the derived actor. clientActor may be null when
498 * the RaftActor is behaving as a follower or during
500 * @param identifier The identifier of the persisted data. This is also
501 * the same identifier that was passed to persistData by
502 * the derived actor. identifier may be null when
503 * the RaftActor is behaving as a follower or during
505 * @param data A piece of data that was persisted by the persistData call.
506 * This should NEVER be null.
508 protected abstract void applyState(ActorRef clientActor, String identifier,
512 * This method is called during recovery at the start of a batch of state entries. Derived
513 * classes should perform any initialization needed to start a batch.
515 protected abstract void startLogRecoveryBatch(int maxBatchSize);
518 * This method is called during recovery to append state data to the current batch. This method
519 * is called 1 or more times after {@link #startRecoveryStateBatch}.
521 * @param data the state data
523 protected abstract void appendRecoveredLogEntry(Payload data);
526 * This method is called during recovery to reconstruct the state of the actor.
528 * @param snapshot A snapshot of the state of the actor
530 protected abstract void applyRecoverySnapshot(ByteString snapshot);
533 * This method is called during recovery at the end of a batch to apply the current batched
534 * log entries. This method is called after {@link #appendRecoveryLogEntry}.
536 protected abstract void applyCurrentLogRecoveryBatch();
539 * This method is called when recovery is complete.
541 protected abstract void onRecoveryComplete();
544 * This method will be called by the RaftActor when a snapshot needs to be
545 * created. The derived actor should respond with its current state.
547 * During recovery the state that is returned by the derived actor will
548 * be passed back to it by calling the applySnapshot method
550 * @return The current state of the actor
552 protected abstract void createSnapshot();
555 * This method can be called at any other point during normal
556 * operations when the derived actor is out of sync with it's peers
557 * and the only way to bring it in sync is by applying a snapshot
559 * @param snapshot A snapshot of the state of the actor
561 protected abstract void applySnapshot(ByteString snapshot);
564 * This method will be called by the RaftActor when the state of the
565 * RaftActor changes. The derived actor can then use methods like
566 * isLeader or getLeader to do something useful
568 protected abstract void onStateChanged();
570 protected void onLeaderChanged(String oldLeader, String newLeader){};
572 private RaftActorBehavior switchBehavior(RaftState state) {
573 if (currentBehavior != null) {
574 if (currentBehavior.state() == state) {
575 return currentBehavior;
577 LOG.info("Switching from state " + currentBehavior.state() + " to "
581 currentBehavior.close();
582 } catch (Exception e) {
584 "Failed to close behavior : " + currentBehavior.state());
588 LOG.info("Switching behavior to " + state);
590 RaftActorBehavior behavior = null;
591 if (state == RaftState.Candidate) {
592 behavior = new Candidate(context);
593 } else if (state == RaftState.Follower) {
594 behavior = new Follower(context);
596 behavior = new Leader(context);
604 private void trimPersistentData(long sequenceNumber) {
605 // Trim akka snapshots
606 // FIXME : Not sure how exactly the SnapshotSelectionCriteria is applied
607 // For now guessing that it is ANDed.
608 deleteSnapshots(new SnapshotSelectionCriteria(
609 sequenceNumber - context.getConfigParams().getSnapshotBatchCount(), 43200000));
612 deleteMessages(sequenceNumber);
615 private String getLeaderAddress(){
617 return getSelf().path().toString();
619 String leaderId = currentBehavior.getLeaderId();
620 if (leaderId == null) {
623 String peerAddress = context.getPeerAddress(leaderId);
624 if(LOG.isDebugEnabled()) {
625 LOG.debug("getLeaderAddress leaderId = " + leaderId + " peerAddress = "
632 private void handleCaptureSnapshotReply(ByteString stateInBytes) {
633 // create a snapshot object from the state provided and save it
634 // when snapshot is saved async, SaveSnapshotSuccess is raised.
636 Snapshot sn = Snapshot.create(stateInBytes.toByteArray(),
637 context.getReplicatedLog().getFrom(captureSnapshot.getLastAppliedIndex() + 1),
638 captureSnapshot.getLastIndex(), captureSnapshot.getLastTerm(),
639 captureSnapshot.getLastAppliedIndex(), captureSnapshot.getLastAppliedTerm());
643 LOG.info("Persisting of snapshot done:{}", sn.getLogMessage());
645 //be greedy and remove entries from in-mem journal which are in the snapshot
646 // and update snapshotIndex and snapshotTerm without waiting for the success,
648 context.getReplicatedLog().snapshotPreCommit(stateInBytes,
649 captureSnapshot.getLastAppliedIndex(),
650 captureSnapshot.getLastAppliedTerm());
652 LOG.info("Removed in-memory snapshotted entries, adjusted snaphsotIndex:{} " +
653 "and term:{}", captureSnapshot.getLastAppliedIndex(),
654 captureSnapshot.getLastAppliedTerm());
656 captureSnapshot = null;
657 hasSnapshotCaptureInitiated = false;
661 private class ReplicatedLogImpl extends AbstractReplicatedLogImpl {
663 public ReplicatedLogImpl(Snapshot snapshot) {
664 super(ByteString.copyFrom(snapshot.getState()),
665 snapshot.getLastAppliedIndex(), snapshot.getLastAppliedTerm(),
666 snapshot.getUnAppliedEntries());
669 public ReplicatedLogImpl() {
673 @Override public void removeFromAndPersist(long logEntryIndex) {
674 int adjustedIndex = adjustedIndex(logEntryIndex);
676 if (adjustedIndex < 0) {
680 // FIXME: Maybe this should be done after the command is saved
681 journal.subList(adjustedIndex , journal.size()).clear();
683 persist(new DeleteEntries(adjustedIndex), new Procedure<DeleteEntries>(){
685 @Override public void apply(DeleteEntries param)
687 //FIXME : Doing nothing for now
692 @Override public void appendAndPersist(
693 final ReplicatedLogEntry replicatedLogEntry) {
694 appendAndPersist(null, null, replicatedLogEntry);
697 public void appendAndPersist(final ActorRef clientActor,
698 final String identifier,
699 final ReplicatedLogEntry replicatedLogEntry) {
700 context.getLogger().debug(
701 "Append log entry and persist {} ", replicatedLogEntry);
702 // FIXME : By adding the replicated log entry to the in-memory journal we are not truly ensuring durability of the logs
703 journal.add(replicatedLogEntry);
705 // When persisting events with persist it is guaranteed that the
706 // persistent actor will not receive further commands between the
707 // persist call and the execution(s) of the associated event
708 // handler. This also holds for multiple persist calls in context
709 // of a single command.
710 persist(replicatedLogEntry,
711 new Procedure<ReplicatedLogEntry>() {
713 public void apply(ReplicatedLogEntry evt) throws Exception {
714 // when a snaphsot is being taken, captureSnapshot != null
715 if (hasSnapshotCaptureInitiated == false &&
716 journal.size() % context.getConfigParams().getSnapshotBatchCount() == 0) {
718 LOG.info("Initiating Snapshot Capture..");
719 long lastAppliedIndex = -1;
720 long lastAppliedTerm = -1;
722 ReplicatedLogEntry lastAppliedEntry = get(context.getLastApplied());
723 if (lastAppliedEntry != null) {
724 lastAppliedIndex = lastAppliedEntry.getIndex();
725 lastAppliedTerm = lastAppliedEntry.getTerm();
728 if(LOG.isDebugEnabled()) {
729 LOG.debug("Snapshot Capture logSize: {}", journal.size());
730 LOG.debug("Snapshot Capture lastApplied:{} ",
731 context.getLastApplied());
732 LOG.debug("Snapshot Capture lastAppliedIndex:{}", lastAppliedIndex);
733 LOG.debug("Snapshot Capture lastAppliedTerm:{}", lastAppliedTerm);
736 // send a CaptureSnapshot to self to make the expensive operation async.
737 getSelf().tell(new CaptureSnapshot(
738 lastIndex(), lastTerm(), lastAppliedIndex, lastAppliedTerm),
740 hasSnapshotCaptureInitiated = true;
742 // Send message for replication
743 if (clientActor != null) {
744 currentBehavior.handleMessage(getSelf(),
745 new Replicate(clientActor, identifier,
756 private static class DeleteEntries implements Serializable {
757 private final int fromIndex;
760 public DeleteEntries(int fromIndex) {
761 this.fromIndex = fromIndex;
764 public int getFromIndex() {
770 private class ElectionTermImpl implements ElectionTerm {
772 * Identifier of the actor whose election term information this is
774 private long currentTerm = 0;
775 private String votedFor = null;
778 public long getCurrentTerm() {
783 public String getVotedFor() {
787 @Override public void update(long currentTerm, String votedFor) {
788 if(LOG.isDebugEnabled()) {
789 LOG.debug("Set currentTerm={}, votedFor={}", currentTerm, votedFor);
791 this.currentTerm = currentTerm;
792 this.votedFor = votedFor;
796 public void updateAndPersist(long currentTerm, String votedFor){
797 update(currentTerm, votedFor);
798 // FIXME : Maybe first persist then update the state
799 persist(new UpdateElectionTerm(this.currentTerm, this.votedFor), new Procedure<UpdateElectionTerm>(){
801 @Override public void apply(UpdateElectionTerm param)
809 private static class UpdateElectionTerm implements Serializable {
810 private final long currentTerm;
811 private final String votedFor;
813 public UpdateElectionTerm(long currentTerm, String votedFor) {
814 this.currentTerm = currentTerm;
815 this.votedFor = votedFor;
818 public long getCurrentTerm() {
822 public String getVotedFor() {