X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?a=blobdiff_plain;f=opendaylight%2Fmd-sal%2Fsal-akka-raft%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fcontroller%2Fcluster%2Fraft%2Fbehaviors%2FFollower.java;h=db62dfc2ac1cd4f10c59849c0666b9291ca946a3;hb=07ba9a998f0b3c3045ed8e31afda5c96de141b3b;hp=823d563a74e2d6d6ac7132f3adfed10b0a866170;hpb=00570ac6512cdeea8d3c1da85e4a2e118a6f925c;p=controller.git diff --git a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/Follower.java b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/Follower.java index 823d563a74..db62dfc2ac 100644 --- a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/Follower.java +++ b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/Follower.java @@ -12,8 +12,8 @@ import akka.actor.ActorRef; 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.internal.messages.ApplySnapshot; -import org.opendaylight.controller.cluster.raft.internal.messages.ElectionTimeout; +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.AppendEntries; import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply; import org.opendaylight.controller.cluster.raft.messages.InstallSnapshot; @@ -40,20 +40,38 @@ public class Follower extends AbstractRaftActorBehavior { @Override protected RaftState handleAppendEntries(ActorRef sender, AppendEntries appendEntries) { + if(appendEntries.getEntries() != null && appendEntries.getEntries().size() > 0) { + context.getLogger() + .info("Follower: Received {}", appendEntries.toString()); + } + + // TODO : Refactor this method into a bunch of smaller methods + // 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(); // 2. Reply false if log doesn’t contain an entry at prevLogIndex // whose term matches prevLogTerm (§5.3) + ReplicatedLogEntry previousEntry = context.getReplicatedLog() .get(appendEntries.getPrevLogIndex()); - boolean noMatchingTerms = true; + boolean outOfSync = true; + // First check if the logs are in sync or not 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. + context.getLogger().debug( "The followers log is empty and the senders prevLogIndex is {}", appendEntries.getPrevLogIndex()); @@ -62,6 +80,9 @@ public class Follower extends AbstractRaftActorBehavior { && appendEntries.getPrevLogIndex() != -1 && previousEntry == null) { + // The follower's log is out of sync because the Leader's + // prevLogIndex entry was not found in it's log + context.getLogger().debug( "The log is not empty but the prevLogIndex {} was not found in it", appendEntries.getPrevLogIndex()); @@ -70,15 +91,21 @@ public class Follower extends AbstractRaftActorBehavior { && previousEntry != null && previousEntry.getTerm()!= 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 + context.getLogger().debug( "Cannot append entries because previous entry term {} is not equal to append entries prevLogTerm {}" , previousEntry.getTerm() , appendEntries.getPrevLogTerm()); } else { - noMatchingTerms = false; + outOfSync = false; } - if (noMatchingTerms) { + if (outOfSync) { + // We found that the log was out of sync so just send a negative + // reply and return sender.tell( new AppendEntriesReply(context.getId(), currentTerm(), false, lastIndex(), lastTerm()), actor() @@ -98,6 +125,9 @@ public class Follower extends AbstractRaftActorBehavior { // follow it (§5.3) int addEntriesFrom = 0; if (context.getReplicatedLog().size() > 0) { + + // Find the entry up until which the one that is not in the + // follower's log for (int i = 0; i < appendEntries.getEntries() .size(); i++, addEntriesFrom++) { @@ -111,20 +141,20 @@ public class Follower extends AbstractRaftActorBehavior { break; } - if (newEntry != null && newEntry.getTerm() == matchEntry + if (newEntry.getTerm() == matchEntry .getTerm()) { continue; } - if (newEntry != null && newEntry.getTerm() != matchEntry - .getTerm()) { - context.getLogger().debug( - "Removing entries from log starting at " - + matchEntry.getIndex() - ); - context.getReplicatedLog() - .removeFrom(matchEntry.getIndex()); - break; - } + + context.getLogger().debug( + "Removing entries from log starting at " + + matchEntry.getIndex() + ); + + // Entries do not match so remove all subsequent entries + context.getReplicatedLog() + .removeFromAndPersist(matchEntry.getIndex()); + break; } } @@ -136,8 +166,10 @@ public class Follower extends AbstractRaftActorBehavior { // 4. Append any new entries not already in the log for (int i = addEntriesFrom; i < appendEntries.getEntries().size(); i++) { - context.getLogger().debug( - "Append entry to log " + appendEntries.getEntries().get(i).getData() + + context.getLogger().info( + "Append entry to log " + appendEntries.getEntries().get( + i).getData() .toString() ); context.getReplicatedLog() @@ -188,22 +220,26 @@ public class Follower extends AbstractRaftActorBehavior { return RaftState.Follower; } - @Override public RaftState handleMessage(ActorRef sender, Object message) { + @Override public RaftState handleMessage(ActorRef sender, Object originalMessage) { + + Object message = fromSerializableMessage(originalMessage); + 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()) { - context.getTermInformation().update(rpc.getTerm(), null); + context.getTermInformation().updateAndPersist(rpc.getTerm(), null); } } if (message instanceof ElectionTimeout) { return RaftState.Candidate; + } else if (message instanceof InstallSnapshot) { - InstallSnapshot snapshot = (InstallSnapshot) message; - actor().tell(new ApplySnapshot(snapshot), actor()); + InstallSnapshot installSnapshot = (InstallSnapshot) message; + actor().tell(new ApplySnapshot(installSnapshot.getData()), actor()); } scheduleElection(electionDuration());