/*
* Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/epl-v10.html
*/
package org.opendaylight.controller.cluster.raft.behaviors;
import akka.actor.ActorRef;
import akka.actor.ActorSelection;
import akka.actor.Address;
import akka.cluster.Cluster;
import akka.cluster.ClusterEvent.CurrentClusterState;
import akka.cluster.Member;
import akka.cluster.MemberStatus;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Stopwatch;
import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Optional;
import java.util.Set;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.function.Consumer;
import org.eclipse.jdt.annotation.Nullable;
import org.opendaylight.controller.cluster.messaging.MessageAssembler;
import org.opendaylight.controller.cluster.raft.RaftActorContext;
import org.opendaylight.controller.cluster.raft.RaftState;
import org.opendaylight.controller.cluster.raft.ReplicatedLogEntry;
import org.opendaylight.controller.cluster.raft.base.messages.ApplySnapshot;
import org.opendaylight.controller.cluster.raft.base.messages.ApplyState;
import org.opendaylight.controller.cluster.raft.base.messages.ElectionTimeout;
import org.opendaylight.controller.cluster.raft.base.messages.TimeoutNow;
import org.opendaylight.controller.cluster.raft.messages.AppendEntries;
import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply;
import org.opendaylight.controller.cluster.raft.messages.InstallSnapshot;
import org.opendaylight.controller.cluster.raft.messages.InstallSnapshotReply;
import org.opendaylight.controller.cluster.raft.messages.RaftRPC;
import org.opendaylight.controller.cluster.raft.messages.RequestVote;
import org.opendaylight.controller.cluster.raft.messages.RequestVoteReply;
import org.opendaylight.controller.cluster.raft.persisted.ServerConfigurationPayload;
import org.opendaylight.controller.cluster.raft.persisted.Snapshot;
/**
* The behavior of a RaftActor in the Follower raft state.
*
* - Respond to RPCs from candidates and leaders
*
- If election timeout elapses without receiving AppendEntries
* RPC from current leader or granting vote to candidate:
* convert to candidate
*
*/
// Non-final for testing
public class Follower extends AbstractRaftActorBehavior {
private static final long MAX_ELECTION_TIMEOUT_FACTOR = 18;
private final SyncStatusTracker initialSyncStatusTracker;
private final MessageAssembler appendEntriesMessageAssembler;
private final Stopwatch lastLeaderMessageTimer = Stopwatch.createStarted();
private SnapshotTracker snapshotTracker = null;
private String leaderId;
private short leaderPayloadVersion;
public Follower(final RaftActorContext context) {
this(context, null, (short)-1);
}
@SuppressFBWarnings(value = "MC_OVERRIDABLE_METHOD_CALL_IN_CONSTRUCTOR",
justification = "electionDuration() is not final for Candidate override")
public Follower(final RaftActorContext context, final String initialLeaderId,
final short initialLeaderPayloadVersion) {
super(context, RaftState.Follower);
leaderId = initialLeaderId;
leaderPayloadVersion = initialLeaderPayloadVersion;
initialSyncStatusTracker = new SyncStatusTracker(context.getActor(), getId(), context.getConfigParams()
.getSyncIndexThreshold());
appendEntriesMessageAssembler = MessageAssembler.builder().logContext(logName())
.fileBackedStreamFactory(context.getFileBackedOutputStreamFactory())
.assembledMessageCallback((message, sender) -> handleMessage(sender, message)).build();
if (context.getPeerIds().isEmpty() && getLeaderId() == null) {
actor().tell(TimeoutNow.INSTANCE, actor());
} else {
scheduleElection(electionDuration());
}
}
@Override
public final String getLeaderId() {
return leaderId;
}
@VisibleForTesting
protected final void setLeaderId(final @Nullable String leaderId) {
this.leaderId = leaderId;
}
@Override
public short getLeaderPayloadVersion() {
return leaderPayloadVersion;
}
@VisibleForTesting
protected final void setLeaderPayloadVersion(final short leaderPayloadVersion) {
this.leaderPayloadVersion = leaderPayloadVersion;
}
private void restartLastLeaderMessageTimer() {
if (lastLeaderMessageTimer.isRunning()) {
lastLeaderMessageTimer.reset();
}
lastLeaderMessageTimer.start();
}
private boolean isLogEntryPresent(final long index) {
if (context.getReplicatedLog().isInSnapshot(index)) {
return true;
}
ReplicatedLogEntry entry = context.getReplicatedLog().get(index);
return entry != null;
}
private void updateInitialSyncStatus(final long currentLeaderCommit, final String newLeaderId) {
initialSyncStatusTracker.update(newLeaderId, currentLeaderCommit, context.getCommitIndex());
}
@Override
protected RaftActorBehavior handleAppendEntries(final ActorRef sender, final AppendEntries appendEntries) {
int numLogEntries = appendEntries.getEntries().size();
if (log.isTraceEnabled()) {
log.trace("{}: handleAppendEntries: {}", logName(), appendEntries);
} else if (log.isDebugEnabled() && numLogEntries > 0) {
log.debug("{}: handleAppendEntries: {}", logName(), appendEntries);
}
if (snapshotTracker != null && !snapshotTracker.getLeaderId().equals(appendEntries.getLeaderId())) {
log.debug("{}: snapshot install is in progress but the prior snapshot leaderId {} does not match the "
+ "AppendEntries leaderId {}", logName(), snapshotTracker.getLeaderId(), appendEntries.getLeaderId());
closeSnapshotTracker();
}
if (snapshotTracker != null || context.getSnapshotManager().isApplying()) {
// if snapshot install is in progress, follower should just acknowledge append entries with a reply.
AppendEntriesReply reply = new AppendEntriesReply(context.getId(), currentTerm(), true,
lastIndex(), lastTerm(), context.getPayloadVersion(), false, needsLeaderAddress(),
appendEntries.getLeaderRaftVersion());
log.debug("{}: snapshot install is in progress, replying immediately with {}", logName(), reply);
sender.tell(reply, actor());
return this;
}
// If we got here then we do appear to be talking to the leader
leaderId = appendEntries.getLeaderId();
leaderPayloadVersion = appendEntries.getPayloadVersion();
if (appendEntries.getLeaderAddress().isPresent()) {
final String address = appendEntries.getLeaderAddress().get();
log.debug("New leader address: {}", address);
context.setPeerAddress(leaderId, address);
context.getConfigParams().getPeerAddressResolver().setResolved(leaderId, address);
}
// First check if the logs are in sync or not
if (isOutOfSync(appendEntries, sender)) {
updateInitialSyncStatus(appendEntries.getLeaderCommit(), appendEntries.getLeaderId());
return this;
}
if (!processNewEntries(appendEntries, sender)) {
updateInitialSyncStatus(appendEntries.getLeaderCommit(), appendEntries.getLeaderId());
return this;
}
long lastIndex = lastIndex();
long prevCommitIndex = context.getCommitIndex();
// If leaderCommit > commitIndex, set commitIndex = min(leaderCommit, index of last new entry)
if (appendEntries.getLeaderCommit() > prevCommitIndex) {
context.setCommitIndex(Math.min(appendEntries.getLeaderCommit(), lastIndex));
}
if (prevCommitIndex != context.getCommitIndex()) {
log.debug("{}: Commit index set to {}", logName(), context.getCommitIndex());
}
AppendEntriesReply reply = new AppendEntriesReply(context.getId(), currentTerm(), true,
lastIndex, lastTerm(), context.getPayloadVersion(), false, needsLeaderAddress(),
appendEntries.getLeaderRaftVersion());
if (log.isTraceEnabled()) {
log.trace("{}: handleAppendEntries returning : {}", logName(), reply);
} else if (log.isDebugEnabled() && numLogEntries > 0) {
log.debug("{}: handleAppendEntries returning : {}", logName(), reply);
}
// Reply to the leader before applying any previous state so as not to hold up leader consensus.
sender.tell(reply, actor());
updateInitialSyncStatus(appendEntries.getLeaderCommit(), appendEntries.getLeaderId());
// If leaderCommit > lastApplied, increment lastApplied and apply log[lastApplied] to state machine (§5.3).
// lastApplied can be equal to lastIndex.
if (appendEntries.getLeaderCommit() > context.getLastApplied() && context.getLastApplied() < lastIndex) {
if (log.isDebugEnabled()) {
log.debug("{}: applyLogToStateMachine, appendEntries.getLeaderCommit(): {}, "
+ "context.getLastApplied(): {}, lastIndex(): {}", logName(),
appendEntries.getLeaderCommit(), context.getLastApplied(), lastIndex);
}
applyLogToStateMachine(appendEntries.getLeaderCommit());
}
if (!context.getSnapshotManager().isCapturing()) {
super.performSnapshotWithoutCapture(appendEntries.getReplicatedToAllIndex());
}
appendEntriesMessageAssembler.checkExpiredAssembledMessageState();
return this;
}
private boolean processNewEntries(final AppendEntries appendEntries, final ActorRef sender) {
int numLogEntries = appendEntries.getEntries().size();
if (numLogEntries == 0) {
return true;
}
log.debug("{}: Number of entries to be appended = {}", logName(), numLogEntries);
long lastIndex = lastIndex();
int addEntriesFrom = 0;
// First check for conflicting entries. If an existing entry conflicts with a new one (same index but different
// term), delete the existing entry and all that follow it (§5.3)
if (context.getReplicatedLog().size() > 0) {
// Find the entry up until the one that is not in the follower's log
for (int i = 0;i < numLogEntries; i++, addEntriesFrom++) {
ReplicatedLogEntry matchEntry = appendEntries.getEntries().get(i);
if (!isLogEntryPresent(matchEntry.getIndex())) {
// newEntry not found in the log
break;
}
long existingEntryTerm = getLogEntryTerm(matchEntry.getIndex());
log.debug("{}: matchEntry {} is present: existingEntryTerm: {}", logName(), matchEntry,
existingEntryTerm);
// existingEntryTerm == -1 means it's in the snapshot and not in the log. We don't know
// what the term was so we'll assume it matches.
if (existingEntryTerm == -1 || existingEntryTerm == matchEntry.getTerm()) {
continue;
}
if (!context.getRaftPolicy().applyModificationToStateBeforeConsensus()) {
log.info("{}: Removing entries from log starting at {}, commitIndex: {}, lastApplied: {}",
logName(), matchEntry.getIndex(), context.getCommitIndex(), context.getLastApplied());
// Entries do not match so remove all subsequent entries but only if the existing entries haven't
// been applied to the state yet.
if (matchEntry.getIndex() <= context.getLastApplied()
|| !context.getReplicatedLog().removeFromAndPersist(matchEntry.getIndex())) {
// Could not remove the entries - this means the matchEntry index must be in the
// snapshot and not the log. In this case the prior entries are part of the state
// so we must send back a reply to force a snapshot to completely re-sync the
// follower's log and state.
log.info("{}: Could not remove entries - sending reply to force snapshot", logName());
sender.tell(new AppendEntriesReply(context.getId(), currentTerm(), false, lastIndex,
lastTerm(), context.getPayloadVersion(), true, needsLeaderAddress(),
appendEntries.getLeaderRaftVersion()), actor());
return false;
}
break;
} else {
sender.tell(new AppendEntriesReply(context.getId(), currentTerm(), false, lastIndex,
lastTerm(), context.getPayloadVersion(), true, needsLeaderAddress(),
appendEntries.getLeaderRaftVersion()), actor());
return false;
}
}
}
lastIndex = lastIndex();
log.debug("{}: After cleanup, lastIndex: {}, entries to be added from: {}", logName(), lastIndex,
addEntriesFrom);
// When persistence successfully completes for each new log entry appended, we need to determine if we
// should capture a snapshot to compact the persisted log. shouldCaptureSnapshot tracks whether or not
// one of the log entries has exceeded the log size threshold whereby a snapshot should be taken. However
// we don't initiate the snapshot at that log entry but rather after the last log entry has been persisted.
// This is done because subsequent log entries after the one that tripped the threshold may have been
// applied to the state already, as the persistence callback occurs async, and we want those entries
// purged from the persisted log as well.
final AtomicBoolean shouldCaptureSnapshot = new AtomicBoolean(false);
final Consumer appendAndPersistCallback = logEntry -> {
final List entries = appendEntries.getEntries();
final ReplicatedLogEntry lastEntryToAppend = entries.get(entries.size() - 1);
if (shouldCaptureSnapshot.get() && logEntry == lastEntryToAppend) {
context.getSnapshotManager().capture(context.getReplicatedLog().last(), getReplicatedToAllIndex());
}
};
// Append any new entries not already in the log
for (int i = addEntriesFrom; i < numLogEntries; i++) {
ReplicatedLogEntry entry = appendEntries.getEntries().get(i);
log.debug("{}: Append entry to log {}", logName(), entry.getData());
context.getReplicatedLog().appendAndPersist(entry, appendAndPersistCallback, false);
shouldCaptureSnapshot.compareAndSet(false,
context.getReplicatedLog().shouldCaptureSnapshot(entry.getIndex()));
if (entry.getData() instanceof ServerConfigurationPayload serverConfiguration) {
context.updatePeerIds(serverConfiguration);
}
}
log.debug("{}: Log size is now {}", logName(), context.getReplicatedLog().size());
return true;
}
private boolean isOutOfSync(final AppendEntries appendEntries, final ActorRef sender) {
final long lastIndex = lastIndex();
if (lastIndex == -1 && appendEntries.getPrevLogIndex() != -1) {
// The follower's log is out of sync because the leader does have an entry at prevLogIndex and this
// follower has no entries in it's log.
log.info("{}: The followers log is empty and the senders prevLogIndex is {}", logName(),
appendEntries.getPrevLogIndex());
sendOutOfSyncAppendEntriesReply(sender, false, appendEntries.getLeaderRaftVersion());
return true;
}
if (lastIndex > -1) {
if (isLogEntryPresent(appendEntries.getPrevLogIndex())) {
final long leadersPrevLogTermInFollowersLogOrSnapshot =
getLogEntryOrSnapshotTerm(appendEntries.getPrevLogIndex());
if (leadersPrevLogTermInFollowersLogOrSnapshot != appendEntries.getPrevLogTerm()) {
// The follower's log is out of sync because the Leader's prevLogIndex entry does exist
// in the follower's log or snapshot but it has a different term.
log.info("{}: The prevLogIndex {} was found in the log but the term {} is not equal to the append "
+ "entries prevLogTerm {} - lastIndex: {}, snapshotIndex: {}, snapshotTerm: {}", logName(),
appendEntries.getPrevLogIndex(), leadersPrevLogTermInFollowersLogOrSnapshot,
appendEntries.getPrevLogTerm(), lastIndex, context.getReplicatedLog().getSnapshotIndex(),
context.getReplicatedLog().getSnapshotTerm());
sendOutOfSyncAppendEntriesReply(sender, false, appendEntries.getLeaderRaftVersion());
return true;
}
} else if (appendEntries.getPrevLogIndex() != -1) {
// The follower's log is out of sync because the Leader's prevLogIndex entry was not found in it's log
log.info("{}: The log is not empty but the prevLogIndex {} was not found in it - lastIndex: {}, "
+ "snapshotIndex: {}, snapshotTerm: {}", logName(), appendEntries.getPrevLogIndex(), lastIndex,
context.getReplicatedLog().getSnapshotIndex(), context.getReplicatedLog().getSnapshotTerm());
sendOutOfSyncAppendEntriesReply(sender, false, appendEntries.getLeaderRaftVersion());
return true;
}
}
if (appendEntries.getPrevLogIndex() == -1 && appendEntries.getPrevLogTerm() == -1
&& appendEntries.getReplicatedToAllIndex() != -1) {
if (!isLogEntryPresent(appendEntries.getReplicatedToAllIndex())) {
// This append entry comes from a leader who has it's log aggressively trimmed and so does not have
// the previous entry in it's in-memory journal
log.info("{}: Cannot append entries because the replicatedToAllIndex {} does not appear to be in the "
+ "in-memory journal - lastIndex: {}, snapshotIndex: {}, snapshotTerm: {}", logName(),
appendEntries.getReplicatedToAllIndex(), lastIndex,
context.getReplicatedLog().getSnapshotIndex(), context.getReplicatedLog().getSnapshotTerm());
sendOutOfSyncAppendEntriesReply(sender, false, appendEntries.getLeaderRaftVersion());
return true;
}
final List entries = appendEntries.getEntries();
if (entries.size() > 0 && !isLogEntryPresent(entries.get(0).getIndex() - 1)) {
log.info("{}: Cannot append entries because the calculated previousIndex {} was not found in the "
+ "in-memory journal - lastIndex: {}, snapshotIndex: {}, snapshotTerm: {}", logName(),
entries.get(0).getIndex() - 1, lastIndex, context.getReplicatedLog().getSnapshotIndex(),
context.getReplicatedLog().getSnapshotTerm());
sendOutOfSyncAppendEntriesReply(sender, false, appendEntries.getLeaderRaftVersion());
return true;
}
}
return false;
}
private void sendOutOfSyncAppendEntriesReply(final ActorRef sender, final boolean forceInstallSnapshot,
final short leaderRaftVersion) {
// We found that the log was out of sync so just send a negative reply.
final AppendEntriesReply reply = new AppendEntriesReply(context.getId(), currentTerm(), false, lastIndex(),
lastTerm(), context.getPayloadVersion(), forceInstallSnapshot, needsLeaderAddress(),
leaderRaftVersion);
log.info("{}: Follower is out-of-sync so sending negative reply: {}", logName(), reply);
sender.tell(reply, actor());
}
private boolean needsLeaderAddress() {
return context.getPeerAddress(leaderId) == null;
}
@Override
protected RaftActorBehavior handleAppendEntriesReply(final ActorRef sender,
final AppendEntriesReply appendEntriesReply) {
return this;
}
@Override
protected RaftActorBehavior handleRequestVoteReply(final ActorRef sender,
final RequestVoteReply requestVoteReply) {
return this;
}
@Override
final ApplyState getApplyStateFor(final ReplicatedLogEntry entry) {
return new ApplyState(null, null, entry);
}
@Override
public RaftActorBehavior handleMessage(final ActorRef sender, final Object message) {
if (message instanceof ElectionTimeout || message instanceof TimeoutNow) {
return handleElectionTimeout(message);
}
if (appendEntriesMessageAssembler.handleMessage(message, actor())) {
return this;
}
if (!(message instanceof RaftRPC rpc)) {
// The rest of the processing requires the message to be a RaftRPC
return null;
}
// If RPC request or response contains term T > currentTerm:
// set currentTerm = T, convert to follower (§5.1)
// This applies to all RPC messages and responses
if (rpc.getTerm() > context.getTermInformation().getCurrentTerm() && shouldUpdateTerm(rpc)) {
log.info("{}: Term {} in \"{}\" message is greater than follower's term {} - updating term",
logName(), rpc.getTerm(), rpc, context.getTermInformation().getCurrentTerm());
context.getTermInformation().updateAndPersist(rpc.getTerm(), null);
}
if (rpc instanceof InstallSnapshot installSnapshot) {
handleInstallSnapshot(sender, installSnapshot);
restartLastLeaderMessageTimer();
scheduleElection(electionDuration());
return this;
}
if (!(rpc instanceof RequestVote requestVote) || canGrantVote(requestVote)) {
restartLastLeaderMessageTimer();
scheduleElection(electionDuration());
}
return super.handleMessage(sender, rpc);
}
private RaftActorBehavior handleElectionTimeout(final Object message) {
// If the message is ElectionTimeout, verify we haven't actually seen a message from the leader
// during the election timeout interval. It may that the election timer expired b/c this actor
// was busy and messages got delayed, in which case leader messages would be backed up in the
// queue but would be processed before the ElectionTimeout message and thus would restart the
// lastLeaderMessageTimer.
long lastLeaderMessageInterval = lastLeaderMessageTimer.elapsed(TimeUnit.MILLISECONDS);
long electionTimeoutInMillis = context.getConfigParams().getElectionTimeOutInterval().toMillis();
boolean noLeaderMessageReceived = !lastLeaderMessageTimer.isRunning()
|| lastLeaderMessageInterval >= electionTimeoutInMillis;
if (canStartElection()) {
if (message instanceof TimeoutNow) {
log.debug("{}: Received TimeoutNow - switching to Candidate", logName());
return internalSwitchBehavior(RaftState.Candidate);
} else if (noLeaderMessageReceived) {
// Check the cluster state to see if the leader is known to be up before we go to Candidate.
// However if we haven't heard from the leader in a long time even though the cluster state
// indicates it's up then something is wrong - leader might be stuck indefinitely - so switch
// to Candidate,
long maxElectionTimeout = electionTimeoutInMillis * MAX_ELECTION_TIMEOUT_FACTOR;
if (isLeaderAvailabilityKnown() && lastLeaderMessageInterval < maxElectionTimeout) {
log.debug("{}: Received ElectionTimeout but leader appears to be available", logName());
scheduleElection(electionDuration());
} else if (isThisFollowerIsolated()) {
log.debug("{}: this follower is isolated. Do not switch to Candidate for now.", logName());
setLeaderId(null);
scheduleElection(electionDuration());
} else {
log.debug("{}: Received ElectionTimeout - switching to Candidate", logName());
return internalSwitchBehavior(RaftState.Candidate);
}
} else {
log.debug("{}: Received ElectionTimeout but lastLeaderMessageInterval {} < election timeout {}",
logName(), lastLeaderMessageInterval, context.getConfigParams().getElectionTimeOutInterval());
scheduleElection(electionDuration());
}
} else if (message instanceof ElectionTimeout) {
if (noLeaderMessageReceived) {
setLeaderId(null);
}
scheduleElection(electionDuration());
}
return this;
}
private boolean isLeaderAvailabilityKnown() {
if (leaderId == null) {
return false;
}
Optional cluster = context.getCluster();
if (!cluster.isPresent()) {
return false;
}
ActorSelection leaderActor = context.getPeerActorSelection(leaderId);
if (leaderActor == null) {
return false;
}
Address leaderAddress = leaderActor.anchorPath().address();
CurrentClusterState state = cluster.get().state();
Set unreachable = state.getUnreachable();
log.debug("{}: Checking for leader {} in the cluster unreachable set {}", logName(), leaderAddress,
unreachable);
for (Member m: unreachable) {
if (leaderAddress.equals(m.address())) {
log.info("{}: Leader {} is unreachable", logName(), leaderAddress);
return false;
}
}
for (Member m: state.getMembers()) {
if (leaderAddress.equals(m.address())) {
if (m.status() == MemberStatus.up() || m.status() == MemberStatus.weaklyUp()) {
log.debug("{}: Leader {} cluster status is {} - leader is available", logName(),
leaderAddress, m.status());
return true;
} else {
log.debug("{}: Leader {} cluster status is {} - leader is unavailable", logName(),
leaderAddress, m.status());
return false;
}
}
}
log.debug("{}: Leader {} not found in the cluster member set", logName(), leaderAddress);
return false;
}
private boolean isThisFollowerIsolated() {
final Optional maybeCluster = context.getCluster();
if (!maybeCluster.isPresent()) {
return false;
}
final Cluster cluster = maybeCluster.get();
final Member selfMember = cluster.selfMember();
final CurrentClusterState state = cluster.state();
final Set unreachable = state.getUnreachable();
final Iterable members = state.getMembers();
log.debug("{}: Checking if this node is isolated in the cluster unreachable set {},"
+ "all members {} self member: {}", logName(), unreachable, members, selfMember);
// no unreachable peers means we cannot be isolated
if (unreachable.size() == 0) {
return false;
}
final Set membersToCheck = new HashSet<>();
members.forEach(membersToCheck::add);
membersToCheck.removeAll(unreachable);
// check if the only member not unreachable is us
if (membersToCheck.size() == 1 && membersToCheck.iterator().next().equals(selfMember)) {
return true;
}
return false;
}
private void handleInstallSnapshot(final ActorRef sender, final InstallSnapshot installSnapshot) {
log.debug("{}: handleInstallSnapshot: {}", logName(), installSnapshot);
leaderId = installSnapshot.getLeaderId();
if (snapshotTracker == null) {
snapshotTracker = new SnapshotTracker(log, installSnapshot.getTotalChunks(), installSnapshot.getLeaderId(),
context);
}
updateInitialSyncStatus(installSnapshot.getLastIncludedIndex(), installSnapshot.getLeaderId());
try {
final InstallSnapshotReply reply = new InstallSnapshotReply(
currentTerm(), context.getId(), installSnapshot.getChunkIndex(), true);
if (snapshotTracker.addChunk(installSnapshot.getChunkIndex(), installSnapshot.getData(),
installSnapshot.getLastChunkHashCode())) {
log.info("{}: Snapshot installed from leader: {}", logName(), installSnapshot.getLeaderId());
Snapshot snapshot = Snapshot.create(
context.getSnapshotManager().convertSnapshot(snapshotTracker.getSnapshotBytes()),
new ArrayList<>(),
installSnapshot.getLastIncludedIndex(),
installSnapshot.getLastIncludedTerm(),
installSnapshot.getLastIncludedIndex(),
installSnapshot.getLastIncludedTerm(),
context.getTermInformation().getCurrentTerm(),
context.getTermInformation().getVotedFor(),
installSnapshot.getServerConfig().orElse(null));
ApplySnapshot.Callback applySnapshotCallback = new ApplySnapshot.Callback() {
@Override
public void onSuccess() {
log.debug("{}: handleInstallSnapshot returning: {}", logName(), reply);
sender.tell(reply, actor());
}
@Override
public void onFailure() {
sender.tell(new InstallSnapshotReply(currentTerm(), context.getId(), -1, false), actor());
}
};
actor().tell(new ApplySnapshot(snapshot, applySnapshotCallback), actor());
closeSnapshotTracker();
} else {
log.debug("{}: handleInstallSnapshot returning: {}", logName(), reply);
sender.tell(reply, actor());
}
} catch (IOException e) {
log.debug("{}: Exception in InstallSnapshot of follower", logName(), e);
sender.tell(new InstallSnapshotReply(currentTerm(), context.getId(),
-1, false), actor());
closeSnapshotTracker();
}
}
private void closeSnapshotTracker() {
if (snapshotTracker != null) {
snapshotTracker.close();
snapshotTracker = null;
}
}
@Override
public void close() {
closeSnapshotTracker();
stopElection();
appendEntriesMessageAssembler.close();
}
@VisibleForTesting
SnapshotTracker getSnapshotTracker() {
return snapshotTracker;
}
}