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;
/**
*/
public class Follower extends AbstractRaftActorBehavior {
-
-
private SnapshotTracker snapshotTracker = null;
private final InitialSyncStatusTracker initialSyncStatusTracker;
public Follower(RaftActorContext context) {
super(context, RaftState.Follower);
- scheduleElection(electionDuration());
-
initialSyncStatusTracker = new InitialSyncStatusTracker(context.getActor());
+
+ if(context.getRaftPolicy().automaticElectionsEnabled()) {
+ if (context.getPeerAddresses().isEmpty()) {
+ actor().tell(ELECTION_TIMEOUT, actor());
+ } else {
+ scheduleElection(electionDuration());
+ }
+ }
+
}
private boolean isLogEntryPresent(long index){
// 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 (snapshotTracker != null) {
+ // 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());
+
+ if(LOG.isDebugEnabled()) {
+ 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();
- // 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());
+ setLeaderPayloadVersion(appendEntries.getPayloadVersion());
updateInitialSyncStatus(appendEntries.getLeaderCommit(), appendEntries.getLeaderId());
-
- boolean outOfSync = true;
-
// 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;
+ }
}
}
}
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;
}
+ 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())) {
+ // 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)){
+ 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;
if (message instanceof ElectionTimeout) {
LOG.debug("{}: Received ElectionTimeout - switching to Candidate", logName());
- return switchBehavior(new Candidate(context));
+ return internalSwitchBehavior(RaftState.Candidate);
} else if (message instanceof InstallSnapshot) {
InstallSnapshot installSnapshot = (InstallSnapshot) message;
handleInstallSnapshot(sender, installSnapshot);
}
- scheduleElection(electionDuration());
+ if(message instanceof RaftRPC && (!(message instanceof RequestVote) || (canGrantVote((RequestVote) message)))){
+ scheduleElection(electionDuration());
+ }
return super.handleMessage(sender, message);
}
Code Review / controller.git / blobdiff