import akka.japi.Procedure;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Stopwatch;
+import java.io.IOException;
import java.util.ArrayList;
import java.util.Optional;
import java.util.Set;
import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
import javax.annotation.Nullable;
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.Snapshot;
import org.opendaylight.controller.cluster.raft.base.messages.ApplySnapshot;
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.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 state
- * <p/>
+ * The behavior of a RaftActor in the Follower raft state.
* <ul>
* <li> Respond to RPCs from candidates and leaders
* <li> If election timeout elapses without receiving AppendEntries
private final SyncStatusTracker initialSyncStatusTracker;
- private final Procedure<ReplicatedLogEntry> appendAndPersistCallback =
- logEntry -> context.getReplicatedLog().captureSnapshotIfReady(logEntry);
-
private final Stopwatch lastLeaderMessageTimer = Stopwatch.createStarted();
private SnapshotTracker snapshotTracker = null;
private String leaderId;
lastLeaderMessageTimer.start();
}
- private boolean isLogEntryPresent(long index){
- if(context.getReplicatedLog().isInSnapshot(index)) {
+ private boolean isLogEntryPresent(long index) {
+ if (context.getReplicatedLog().isInSnapshot(index)) {
return true;
}
}
- private void updateInitialSyncStatus(long currentLeaderCommit, String leaderId){
- initialSyncStatusTracker.update(leaderId, currentLeaderCommit, context.getCommitIndex());
+ private void updateInitialSyncStatus(long currentLeaderCommit, String newLeaderId) {
+ initialSyncStatusTracker.update(newLeaderId, currentLeaderCommit, context.getCommitIndex());
}
@Override
protected RaftActorBehavior handleAppendEntries(ActorRef sender, AppendEntries appendEntries) {
int numLogEntries = appendEntries.getEntries() != null ? appendEntries.getEntries().size() : 0;
- if(LOG.isTraceEnabled()) {
- LOG.trace("{}: handleAppendEntries: {}", logName(), appendEntries);
- } else if(LOG.isDebugEnabled() && numLogEntries > 0) {
- LOG.debug("{}: handleAppendEntries: {}", logName(), appendEntries);
+ if (log.isTraceEnabled()) {
+ log.trace("{}: handleAppendEntries: {}", logName(), appendEntries);
+ } else if (log.isDebugEnabled() && numLogEntries > 0) {
+ log.debug("{}: handleAppendEntries: {}", logName(), appendEntries);
}
// TODO : Refactor this method into a bunch of smaller methods
// cover the code properly
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());
- snapshotTracker = null;
+ 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()) {
AppendEntriesReply reply = new AppendEntriesReply(context.getId(), currentTerm(), true,
lastIndex(), lastTerm(), context.getPayloadVersion());
- if(LOG.isDebugEnabled()) {
- LOG.debug("{}: snapshot install is in progress, replying immediately with {}", logName(), reply);
- }
+ log.debug("{}: snapshot install is in progress, replying immediately with {}", logName(), reply);
sender.tell(reply, actor());
return this;
// We found that the log was out of sync so just send a negative
// reply and return
- LOG.debug("{}: Follower is out-of-sync, so sending negative reply, lastIndex: {}, lastTerm: {}",
- logName(), lastIndex, lastTerm());
+ final AppendEntriesReply reply = new AppendEntriesReply(context.getId(), currentTerm(), false, lastIndex,
+ lastTerm(), context.getPayloadVersion());
+
+ log.info("{}: Follower is out-of-sync so sending negative reply: {}", logName(), reply);
- sender.tell(new AppendEntriesReply(context.getId(), currentTerm(), false, lastIndex,
- lastTerm(), context.getPayloadVersion()), actor());
+ sender.tell(reply, actor());
return this;
}
if (appendEntries.getEntries() != null && appendEntries.getEntries().size() > 0) {
- LOG.debug("{}: Number of entries to be appended = {}", logName(),
+ log.debug("{}: Number of entries to be appended = {}", logName(),
appendEntries.getEntries().size());
// 3. If an existing entry conflicts with a new one (same index
for (int i = 0;i < appendEntries.getEntries().size(); i++, addEntriesFrom++) {
ReplicatedLogEntry matchEntry = appendEntries.getEntries().get(i);
- if(!isLogEntryPresent(matchEntry.getIndex())) {
+ if (!isLogEntryPresent(matchEntry.getIndex())) {
// newEntry not found in the log
break;
}
long existingEntryTerm = getLogEntryTerm(matchEntry.getIndex());
- LOG.debug("{}: matchEntry {} is present: existingEntryTerm: {}", logName(), matchEntry,
+ 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()) {
+ if (existingEntryTerm == -1 || existingEntryTerm == matchEntry.getTerm()) {
continue;
}
- if(!context.getRaftPolicy().applyModificationToStateBeforeConsensus()) {
+ if (!context.getRaftPolicy().applyModificationToStateBeforeConsensus()) {
- LOG.debug("{}: Removing entries from log starting at {}", logName(),
- matchEntry.getIndex());
+ log.info("{}: Removing entries from log starting at {}", logName(), matchEntry.getIndex());
// Entries do not match so remove all subsequent entries
- if(!context.getReplicatedLog().removeFromAndPersist(matchEntry.getIndex())) {
+ if (!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.debug("{}: Could not remove entries - sending reply to force snapshot", logName());
+ 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), actor());
return this;
}
lastIndex = lastIndex();
- LOG.debug("{}: After cleanup, lastIndex: {}, entries to be added from: {}", logName(),
+ 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 Procedure<ReplicatedLogEntry> appendAndPersistCallback = logEntry -> {
+ final ReplicatedLogEntry lastEntryToAppend = appendEntries.getEntries().get(
+ appendEntries.getEntries().size() - 1);
+ if (shouldCaptureSnapshot.get() && logEntry == lastEntryToAppend) {
+ context.getSnapshotManager().capture(context.getReplicatedLog().last(), getReplicatedToAllIndex());
+ }
+ };
+
// 4. Append any new entries not already in the log
for (int i = addEntriesFrom; i < appendEntries.getEntries().size(); i++) {
ReplicatedLogEntry entry = appendEntries.getEntries().get(i);
- LOG.debug("{}: Append entry to log {}", logName(), entry.getData());
+ log.debug("{}: Append entry to log {}", logName(), entry.getData());
+
+ context.getReplicatedLog().appendAndPersist(entry, appendAndPersistCallback, false);
- context.getReplicatedLog().appendAndPersist(entry, appendAndPersistCallback);
+ shouldCaptureSnapshot.compareAndSet(false,
+ context.getReplicatedLog().shouldCaptureSnapshot(entry.getIndex()));
- if(entry.getData() instanceof ServerConfigurationPayload) {
+ if (entry.getData() instanceof ServerConfigurationPayload) {
context.updatePeerIds((ServerConfigurationPayload)entry.getData());
}
}
- LOG.debug("{}: Log size is now {}", logName(), context.getReplicatedLog().size());
+ log.debug("{}: Log size is now {}", logName(), context.getReplicatedLog().size());
}
// 5. If leaderCommit > commitIndex, set commitIndex =
lastIndex = lastIndex();
long prevCommitIndex = context.getCommitIndex();
- if(appendEntries.getLeaderCommit() > prevCommitIndex) {
+ if (appendEntries.getLeaderCommit() > prevCommitIndex) {
context.setCommitIndex(Math.min(appendEntries.getLeaderCommit(), lastIndex));
}
if (prevCommitIndex != context.getCommitIndex()) {
- LOG.debug("{}: Commit index set to {}", logName(), context.getCommitIndex());
+ log.debug("{}: Commit index set to {}", logName(), context.getCommitIndex());
}
// If commitIndex > lastApplied: increment lastApplied, apply
// log[lastApplied] to state machine (§5.3)
// check if there are any entries to be applied. last-applied can be equal to last-index
- if (appendEntries.getLeaderCommit() > context.getLastApplied() &&
- context.getLastApplied() < lastIndex) {
- if(LOG.isDebugEnabled()) {
- LOG.debug("{}: applyLogToStateMachine, " +
- "appendEntries.getLeaderCommit(): {}," +
- "context.getLastApplied(): {}, lastIndex(): {}", logName(),
+ 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);
}
AppendEntriesReply reply = new AppendEntriesReply(context.getId(), currentTerm(), true,
lastIndex, lastTerm(), context.getPayloadVersion());
- if(LOG.isTraceEnabled()) {
- LOG.trace("{}: handleAppendEntries returning : {}", logName(), reply);
- } else if(LOG.isDebugEnabled() && numLogEntries > 0) {
- LOG.debug("{}: handleAppendEntries returning : {}", logName(), reply);
+ if (log.isTraceEnabled()) {
+ log.trace("{}: handleAppendEntries returning : {}", logName(), reply);
+ } else if (log.isDebugEnabled() && numLogEntries > 0) {
+ log.debug("{}: handleAppendEntries returning : {}", logName(), reply);
}
sender.tell(reply, actor());
// an entry at prevLogIndex and this follower has no entries in
// it's log.
- LOG.debug("{}: The followers log is empty and the senders prevLogIndex is {}",
+ log.info("{}: The followers log is empty and the senders prevLogIndex is {}",
logName(), appendEntries.getPrevLogIndex());
} else if (lastIndex > -1 && appendEntries.getPrevLogIndex() != -1 && !prevEntryPresent) {
// The follower's log is out of sync because the Leader's
// prevLogIndex entry was not found in it's log
- LOG.debug("{}: The log is not empty but the prevLogIndex {} was not found in it - lastIndex: {}, snapshotIndex: {}",
- logName(), appendEntries.getPrevLogIndex(), lastIndex, context.getReplicatedLog().getSnapshotIndex());
+ log.info("{}: The log is not empty but the prevLogIndex {} was not found in it - "
+ + "lastIndex: {}, snapshotIndex: {}", logName(), appendEntries.getPrevLogIndex(), lastIndex,
+ context.getReplicatedLog().getSnapshotIndex());
} else if (lastIndex > -1 && prevEntryPresent && prevLogTerm != appendEntries.getPrevLogTerm()) {
// The follower's log is out of sync because the Leader's
// prevLogIndex entry does exist in the follower's log but it has
// a different term in it
- LOG.debug("{}: The prevLogIndex {} was found in the log but the term {} is not equal to the append entries " +
- "prevLogTerm {} - lastIndex: {}, snapshotIndex: {}", logName(), appendEntries.getPrevLogIndex(),
- prevLogTerm, appendEntries.getPrevLogTerm(), lastIndex, context.getReplicatedLog().getSnapshotIndex());
- } else if(appendEntries.getPrevLogIndex() == -1 && appendEntries.getPrevLogTerm() == -1
+ log.info("{}: The prevLogIndex {} was found in the log but the term {} is not equal to the append entries"
+ + "prevLogTerm {} - lastIndex: {}, snapshotIndex: {}", logName(), appendEntries.getPrevLogIndex(),
+ prevLogTerm, appendEntries.getPrevLogTerm(), lastIndex,
+ context.getReplicatedLog().getSnapshotIndex());
+ } else if (appendEntries.getPrevLogIndex() == -1 && appendEntries.getPrevLogTerm() == -1
&& appendEntries.getReplicatedToAllIndex() != -1
&& !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.debug(
- "{}: Cannot append entries because the replicatedToAllIndex {} does not appear to be in the in-memory journal",
- logName(), appendEntries.getReplicatedToAllIndex());
- } else if(appendEntries.getPrevLogIndex() == -1 && appendEntries.getPrevLogTerm() == -1
+ log.info("{}: Cannot append entries because the replicatedToAllIndex {} does not appear to be in the"
+ + " in-memory journal", logName(), appendEntries.getReplicatedToAllIndex());
+ } else if (appendEntries.getPrevLogIndex() == -1 && appendEntries.getPrevLogTerm() == -1
&& appendEntries.getReplicatedToAllIndex() != -1 && numLogEntries > 0
&& !isLogEntryPresent(appendEntries.getEntries().get(0).getIndex() - 1)) {
- LOG.debug(
- "{}: Cannot append entries because the calculated previousIndex {} was not found in the in-memory journal",
- logName(), appendEntries.getEntries().get(0).getIndex() - 1);
+ log.info("{}: Cannot append entries because the calculated previousIndex {} was not found in the "
+ + " in-memory journal", logName(), appendEntries.getEntries().get(0).getIndex() - 1);
} else {
outOfSync = false;
}
// set currentTerm = T, convert to follower (§5.1)
// This applies to all RPC messages and responses
if (rpc.getTerm() > context.getTermInformation().getCurrentTerm()) {
- LOG.debug("{}: Term {} in \"{}\" message is greater than follower's term {} - updating term",
+ 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);
// lastLeaderMessageTimer.
long lastLeaderMessageInterval = lastLeaderMessageTimer.elapsed(TimeUnit.MILLISECONDS);
long electionTimeoutInMillis = context.getConfigParams().getElectionTimeOutInterval().toMillis();
- boolean noLeaderMessageReceived = !lastLeaderMessageTimer.isRunning() ||
- lastLeaderMessageInterval >= electionTimeoutInMillis;
+ boolean noLeaderMessageReceived = !lastLeaderMessageTimer.isRunning()
+ || lastLeaderMessageInterval >= electionTimeoutInMillis;
- if(canStartElection()) {
- if(message instanceof TimeoutNow) {
- LOG.debug("{}: Received TimeoutNow - switching to Candidate", logName());
+ if (canStartElection()) {
+ if (message instanceof TimeoutNow) {
+ log.debug("{}: Received TimeoutNow - switching to Candidate", logName());
return internalSwitchBehavior(RaftState.Candidate);
- } else if(noLeaderMessageReceived) {
+ } 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());
+ if (isLeaderAvailabilityKnown() && lastLeaderMessageInterval < maxElectionTimeout) {
+ log.debug("{}: Received ElectionTimeout but leader appears to be available", logName());
scheduleElection(electionDuration());
} else {
- LOG.debug("{}: Received ElectionTimeout - switching to Candidate", logName());
+ log.debug("{}: Received ElectionTimeout - switching to Candidate", logName());
return internalSwitchBehavior(RaftState.Candidate);
}
} else {
- LOG.debug("{}: Received ElectionTimeout but lastLeaderMessageInterval {} < election timeout {}",
+ log.debug("{}: Received ElectionTimeout but lastLeaderMessageInterval {} < election timeout {}",
logName(), lastLeaderMessageInterval, context.getConfigParams().getElectionTimeOutInterval());
scheduleElection(electionDuration());
}
- } else if(message instanceof ElectionTimeout) {
- if(noLeaderMessageReceived) {
+ } else if (message instanceof ElectionTimeout) {
+ if (noLeaderMessageReceived) {
setLeaderId(null);
}
}
private boolean isLeaderAvailabilityKnown() {
- if(leaderId == null) {
+ if (leaderId == null) {
return false;
}
Optional<Cluster> cluster = context.getCluster();
- if(!cluster.isPresent()) {
+ if (!cluster.isPresent()) {
return false;
}
ActorSelection leaderActor = context.getPeerActorSelection(leaderId);
- if(leaderActor == null) {
+ if (leaderActor == null) {
return false;
}
CurrentClusterState state = cluster.get().state();
Set<Member> unreachable = state.getUnreachable();
- LOG.debug("{}: Checking for leader {} in the cluster unreachable set {}", logName(), leaderAddress,
+ 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);
+ 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(),
+ 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(),
+ 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);
+ log.debug("{}: Leader {} not found in the cluster member set", logName(), leaderAddress);
return false;
}
private void handleInstallSnapshot(final ActorRef sender, InstallSnapshot installSnapshot) {
- LOG.debug("{}: handleInstallSnapshot: {}", logName(), installSnapshot);
+ log.debug("{}: handleInstallSnapshot: {}", logName(), installSnapshot);
leaderId = installSnapshot.getLeaderId();
- if(snapshotTracker == null){
- snapshotTracker = new SnapshotTracker(LOG, installSnapshot.getTotalChunks(), installSnapshot.getLeaderId());
+ if (snapshotTracker == null) {
+ snapshotTracker = new SnapshotTracker(log, installSnapshot.getTotalChunks(), installSnapshot.getLeaderId(),
+ context);
}
updateInitialSyncStatus(installSnapshot.getLastIncludedIndex(), installSnapshot.getLeaderId());
final InstallSnapshotReply reply = new InstallSnapshotReply(
currentTerm(), context.getId(), installSnapshot.getChunkIndex(), true);
- if(snapshotTracker.addChunk(installSnapshot.getChunkIndex(), installSnapshot.getData(),
- installSnapshot.getLastChunkHashCode())){
- Snapshot snapshot = Snapshot.create(snapshotTracker.getSnapshot(),
+ 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(),
ApplySnapshot.Callback applySnapshotCallback = new ApplySnapshot.Callback() {
@Override
public void onSuccess() {
- LOG.debug("{}: handleInstallSnapshot returning: {}", logName(), reply);
+ log.debug("{}: handleInstallSnapshot returning: {}", logName(), reply);
sender.tell(reply, actor());
}
actor().tell(new ApplySnapshot(snapshot, applySnapshotCallback), actor());
- snapshotTracker = null;
+ closeSnapshotTracker();
} else {
- LOG.debug("{}: handleInstallSnapshot returning: {}", logName(), reply);
+ log.debug("{}: handleInstallSnapshot returning: {}", logName(), reply);
sender.tell(reply, actor());
}
- } catch (SnapshotTracker.InvalidChunkException e) {
- LOG.debug("{}: Exception in InstallSnapshot of follower", logName(), e);
+ } catch (IOException e) {
+ log.debug("{}: Exception in InstallSnapshot of follower", logName(), e);
sender.tell(new InstallSnapshotReply(currentTerm(), context.getId(),
-1, false), actor());
- snapshotTracker = null;
-
- } catch (Exception e){
- LOG.error("{}: Exception in InstallSnapshot of follower", logName(), e);
- //send reply with success as false. The chunk will be sent again on failure
- sender.tell(new InstallSnapshotReply(currentTerm(), context.getId(),
- installSnapshot.getChunkIndex(), false), actor());
+ closeSnapshotTracker();
+ }
+ }
+ private void closeSnapshotTracker() {
+ if (snapshotTracker != null) {
+ snapshotTracker.close();
+ snapshotTracker = null;
}
}
@Override
public void close() {
+ closeSnapshotTracker();
stopElection();
}
@VisibleForTesting
- SnapshotTracker getSnapshotTracker(){
+ SnapshotTracker getSnapshotTracker() {
return snapshotTracker;
}
}
Code Review / controller.git / blobdiff