package org.opendaylight.controller.cluster.raft.behaviors;
import akka.actor.ActorRef;
+import akka.japi.Procedure;
import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Preconditions;
import java.util.ArrayList;
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.ServerConfigurationPayload;
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.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;
/**
* </ul>
*/
public class Follower extends AbstractRaftActorBehavior {
+ private static final int SYNC_THRESHOLD = 10;
+
+ private final SyncStatusTracker initialSyncStatusTracker;
+
+ private final Procedure<ReplicatedLogEntry> appendAndPersistCallback = new Procedure<ReplicatedLogEntry>() {
+ @Override
+ public void apply(ReplicatedLogEntry logEntry) {
+ context.getReplicatedLog().captureSnapshotIfReady(logEntry);
+ }
+ };
private SnapshotTracker snapshotTracker = null;
+ private String leaderId;
+ private short leaderPayloadVersion;
public Follower(RaftActorContext context) {
+ this(context, null, (short)-1);
+ }
+
+ public Follower(RaftActorContext context, String initialLeaderId, short initialLeaderPayloadVersion) {
super(context, RaftState.Follower);
+ this.leaderId = initialLeaderId;
+ this.leaderPayloadVersion = initialLeaderPayloadVersion;
+
+ initialSyncStatusTracker = new SyncStatusTracker(context.getActor(), getId(), SYNC_THRESHOLD);
+
+ if(canStartElection()) {
+ if (context.getPeerIds().isEmpty() && getLeaderId() == null) {
+ actor().tell(ElectionTimeout.INSTANCE, actor());
+ } else {
+ scheduleElection(electionDuration());
+ }
+ }
+ }
+
+ @Override
+ public final String getLeaderId() {
+ return leaderId;
+ }
+
+ @VisibleForTesting
+ protected final void setLeaderId(final String leaderId) {
+ this.leaderId = Preconditions.checkNotNull(leaderId);
+ }
- scheduleElection(electionDuration());
+ @Override
+ public short getLeaderPayloadVersion() {
+ return leaderPayloadVersion;
+ }
+
+ @VisibleForTesting
+ protected final void setLeaderPayloadVersion(short leaderPayloadVersion) {
+ this.leaderPayloadVersion = leaderPayloadVersion;
}
private boolean isLogEntryPresent(long index){
return -1;
}
- @Override protected RaftActorBehavior handleAppendEntries(ActorRef sender,
- AppendEntries appendEntries) {
+ private void updateInitialSyncStatus(long currentLeaderCommit, String leaderId){
+ initialSyncStatusTracker.update(leaderId, currentLeaderCommit, context.getCommitIndex());
+ }
+
+ @Override
+ protected RaftActorBehavior handleAppendEntries(ActorRef sender, AppendEntries appendEntries) {
int numLogEntries = appendEntries.getEntries() != null ? appendEntries.getEntries().size() : 0;
if(LOG.isTraceEnabled()) {
// to make it easier to read. Before refactoring ensure tests
// cover the code properly
- // 1. Reply false if term < currentTerm (§5.1)
- // This is handled in the appendEntries method of the base class
-
- // If we got here then we do appear to be talking to the leader
- leaderId = appendEntries.getLeaderId();
+ 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());
- // 2. Reply false if log doesn’t contain an entry at prevLogIndex
- // whose term matches prevLogTerm (§5.3)
-
- long prevLogTerm = getLogEntryTerm(appendEntries.getPrevLogIndex());
- boolean prevEntryPresent = isLogEntryPresent(appendEntries.getPrevLogIndex());
+ if(LOG.isDebugEnabled()) {
+ LOG.debug("{}: snapshot install is in progress, replying immediately with {}", logName(), reply);
+ }
+ sender.tell(reply, actor());
+ return this;
+ }
- boolean outOfSync = true;
+ // If we got here then we do appear to be talking to the leader
+ leaderId = appendEntries.getLeaderId();
+ leaderPayloadVersion = appendEntries.getPayloadVersion();
+ updateInitialSyncStatus(appendEntries.getLeaderCommit(), appendEntries.getLeaderId());
// First check if the logs are in sync or not
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.debug("{}: 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",
- logName(), appendEntries.getPrevLogIndex());
- } 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(
- "{}: Cannot append entries because previous entry term {} is not equal to append entries prevLogTerm {}",
- logName(), prevLogTerm, appendEntries.getPrevLogTerm());
- } else {
- outOfSync = false;
- }
- if (outOfSync) {
+ if (isOutOfSync(appendEntries)) {
// We found that the log was out of sync so just send a negative
// reply and return
logName(), lastIndex, lastTerm());
sender.tell(new AppendEntriesReply(context.getId(), currentTerm(), false, lastIndex,
- lastTerm()), actor());
+ lastTerm(), context.getPayloadVersion()), actor());
return this;
}
int addEntriesFrom = 0;
if (context.getReplicatedLog().size() > 0) {
- // Find the entry up until which the one that is not in the follower's log
+ // Find the entry up until the one that is not in the follower's log
for (int i = 0;i < appendEntries.getEntries().size(); i++, addEntriesFrom++) {
ReplicatedLogEntry matchEntry = appendEntries.getEntries().get(i);
ReplicatedLogEntry newEntry = context.getReplicatedLog().get(matchEntry.getIndex());
continue;
}
- LOG.debug("{}: Removing entries from log starting at {}", logName(),
+ if(!context.getRaftPolicy().applyModificationToStateBeforeConsensus()) {
+
+ LOG.debug("{}: Removing entries from log starting at {}", logName(),
matchEntry.getIndex());
- // Entries do not match so remove all subsequent entries
- context.getReplicatedLog().removeFromAndPersist(matchEntry.getIndex());
- break;
+ // Entries do not match so remove all subsequent entries
+ context.getReplicatedLog().removeFromAndPersist(matchEntry.getIndex());
+ break;
+ } else {
+ sender.tell(new AppendEntriesReply(context.getId(), currentTerm(), false, lastIndex,
+ lastTerm(), context.getPayloadVersion(), true), actor());
+ return this;
+ }
}
}
LOG.debug("{}: Append entry to log {}", logName(), entry.getData());
- context.getReplicatedLog().appendAndPersist(entry);
+ context.getReplicatedLog().appendAndPersist(entry, appendAndPersistCallback);
+
+ if(entry.getData() instanceof ServerConfigurationPayload) {
+ context.updatePeerIds((ServerConfigurationPayload)entry.getData());
+ }
}
LOG.debug("{}: Log size is now {}", logName(), context.getReplicatedLog().size());
}
AppendEntriesReply reply = new AppendEntriesReply(context.getId(), currentTerm(), true,
- lastIndex, lastTerm());
+ lastIndex, lastTerm(), context.getPayloadVersion());
if(LOG.isTraceEnabled()) {
LOG.trace("{}: handleAppendEntries returning : {}", logName(), reply);
sender.tell(reply, actor());
- if (!context.isSnapshotCaptureInitiated()) {
+ if (!context.getSnapshotManager().isCapturing()) {
super.performSnapshotWithoutCapture(appendEntries.getReplicatedToAllIndex());
}
return this;
}
- @Override protected RaftActorBehavior handleAppendEntriesReply(ActorRef sender,
+ private boolean isOutOfSync(AppendEntries appendEntries) {
+
+ long prevLogTerm = getLogEntryTerm(appendEntries.getPrevLogIndex());
+ boolean prevEntryPresent = isLogEntryPresent(appendEntries.getPrevLogIndex());
+ long lastIndex = lastIndex();
+ int numLogEntries = appendEntries.getEntries() != null ? appendEntries.getEntries().size() : 0;
+ boolean outOfSync = true;
+
+ 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.debug("{}: 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",
+ logName(), appendEntries.getPrevLogIndex());
+ } 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(
+ "{}: Cannot append entries because previous entry term {} is not equal to append entries prevLogTerm {}",
+ logName(), prevLogTerm, appendEntries.getPrevLogTerm());
+ } else if(appendEntries.getPrevLogIndex() == -1 && appendEntries.getPrevLogTerm() == -1
+ && appendEntries.getReplicatedToAllIndex() != -1
+ && !isLogEntryPresent(appendEntries.getReplicatedToAllIndex())
+ && !context.getReplicatedLog().isInSnapshot(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
+ && appendEntries.getReplicatedToAllIndex() != -1 && numLogEntries > 0
+ && !isLogEntryPresent(appendEntries.getEntries().get(0).getIndex() - 1)
+ && !context.getReplicatedLog().isInSnapshot(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);
+ } else {
+ outOfSync = false;
+ }
+ return outOfSync;
+ }
+
+ @Override
+ protected RaftActorBehavior handleAppendEntriesReply(ActorRef sender,
AppendEntriesReply appendEntriesReply) {
return this;
}
- @Override protected RaftActorBehavior handleRequestVoteReply(ActorRef sender,
+ @Override
+ protected RaftActorBehavior handleRequestVoteReply(ActorRef sender,
RequestVoteReply requestVoteReply) {
return this;
}
- @Override public RaftActorBehavior handleMessage(ActorRef sender, Object originalMessage) {
+ @Override
+ public RaftActorBehavior handleMessage(ActorRef sender, Object originalMessage) {
+ if (originalMessage instanceof ElectionTimeout) {
+ if (canStartElection()) {
+ LOG.debug("{}: Received ElectionTimeout - switching to Candidate", logName());
+ return internalSwitchBehavior(RaftState.Candidate);
+ } else {
+ return this;
+ }
+ }
- Object message = fromSerializableMessage(originalMessage);
+ final Object message = fromSerializableMessage(originalMessage);
+ if (!(message instanceof RaftRPC)) {
+ // The rest of the processing requires the message to be a RaftRPC
+ return null;
+ }
- if (message instanceof RaftRPC) {
- RaftRPC rpc = (RaftRPC) message;
- // 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()) {
- LOG.debug("{}: Term {} in \"{}\" message is greater than follower's term {} - updating term",
- logName(), rpc.getTerm(), rpc, context.getTermInformation().getCurrentTerm());
+ final RaftRPC rpc = (RaftRPC) message;
+ // 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()) {
+ LOG.debug("{}: Term {} in \"{}\" message is greater than follower's term {} - updating term",
+ logName(), rpc.getTerm(), rpc, context.getTermInformation().getCurrentTerm());
- context.getTermInformation().updateAndPersist(rpc.getTerm(), null);
- }
+ context.getTermInformation().updateAndPersist(rpc.getTerm(), null);
}
- if (message instanceof ElectionTimeout) {
- LOG.debug("{}: Received ElectionTimeout - switching to Candidate", logName());
- return switchBehavior(new Candidate(context));
-
- } else if (message instanceof InstallSnapshot) {
- InstallSnapshot installSnapshot = (InstallSnapshot) message;
+ if (rpc instanceof InstallSnapshot) {
+ InstallSnapshot installSnapshot = (InstallSnapshot) rpc;
handleInstallSnapshot(sender, installSnapshot);
+ scheduleElection(electionDuration());
+ return this;
}
- scheduleElection(electionDuration());
+ if (!(rpc instanceof RequestVote) || canGrantVote((RequestVote) rpc)) {
+ scheduleElection(electionDuration());
+ }
- return super.handleMessage(sender, message);
+ return super.handleMessage(sender, rpc);
}
- private void handleInstallSnapshot(ActorRef sender, InstallSnapshot installSnapshot) {
+ private void handleInstallSnapshot(final ActorRef sender, InstallSnapshot installSnapshot) {
+ LOG.debug("{}: handleInstallSnapshot: {}", logName(), installSnapshot);
- LOG.debug("{}: InstallSnapshot received from leader {}, datasize: {} , Chunk: {}/{}",
- logName(), installSnapshot.getLeaderId(), installSnapshot.getData().size(),
- installSnapshot.getChunkIndex(), installSnapshot.getTotalChunks());
+ leaderId = installSnapshot.getLeaderId();
if(snapshotTracker == null){
snapshotTracker = new SnapshotTracker(LOG, installSnapshot.getTotalChunks());
}
+ 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())){
Snapshot snapshot = Snapshot.create(snapshotTracker.getSnapshot(),
installSnapshot.getLastIncludedIndex(),
installSnapshot.getLastIncludedTerm(),
installSnapshot.getLastIncludedIndex(),
- installSnapshot.getLastIncludedTerm());
-
- actor().tell(new ApplySnapshot(snapshot), actor());
+ installSnapshot.getLastIncludedTerm(),
+ context.getTermInformation().getCurrentTerm(),
+ context.getTermInformation().getVotedFor(),
+ context.getPeerServerInfo(true));
- snapshotTracker = null;
+ ApplySnapshot.Callback applySnapshotCallback = new ApplySnapshot.Callback() {
+ @Override
+ public void onSuccess() {
+ LOG.debug("{}: handleInstallSnapshot returning: {}", logName(), reply);
- }
+ sender.tell(reply, actor());
+ }
- InstallSnapshotReply reply = new InstallSnapshotReply(
- currentTerm(), context.getId(), installSnapshot.getChunkIndex(), true);
+ @Override
+ public void onFailure() {
+ sender.tell(new InstallSnapshotReply(currentTerm(), context.getId(), -1, false), actor());
+ }
+ };
- LOG.debug("{}: handleInstallSnapshot returning: {}", logName(), reply);
+ actor().tell(new ApplySnapshot(snapshot, applySnapshotCallback), actor());
- sender.tell(reply, actor());
+ snapshotTracker = null;
+ } else {
+ LOG.debug("{}: handleInstallSnapshot returning: {}", logName(), reply);
+ sender.tell(reply, actor());
+ }
} catch (SnapshotTracker.InvalidChunkException e) {
LOG.debug("{}: Exception in InstallSnapshot of follower", logName(), e);
}
@Override
- public void close() throws Exception {
+ public void close() {
stopElection();
}
Code Review / controller.git / blobdiff