Fixup comparison formatting

[controller.git] / opendaylight / md-sal / sal-akka-raft / src / main / java / org / opendaylight / controller / cluster / raft / behaviors / AbstractRaftActorBehavior.java

diff --git a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/AbstractRaftActorBehavior.java b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/AbstractRaftActorBehavior.java
index 2b28c372488709646f96c3db5d31a7e9e267ef1e..e714fddb749ad902d9fada289d4cc3425fa6cb04 100644 (file)
--- a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/AbstractRaftActorBehavior.java
+++ b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/AbstractRaftActorBehavior.java
@@ -11,10 +11,13 @@ import static java.util.Objects.requireNonNull;
 
 import akka.actor.ActorRef;
 import akka.actor.Cancellable;
+import akka.cluster.Cluster;
+import akka.cluster.Member;
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
-import java.util.Random;
+import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.ThreadLocalRandom;
 import java.util.concurrent.TimeUnit;
-import org.opendaylight.controller.cluster.raft.ClientRequestTracker;
 import org.opendaylight.controller.cluster.raft.RaftActorContext;
 import org.opendaylight.controller.cluster.raft.RaftState;
 import org.opendaylight.controller.cluster.raft.ReplicatedLogEntry;
@@ -22,6 +25,7 @@ import org.opendaylight.controller.cluster.raft.base.messages.ApplyState;
 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.RaftRPC;
 import org.opendaylight.controller.cluster.raft.messages.RequestVote;
 import org.opendaylight.controller.cluster.raft.messages.RequestVoteReply;
 import org.opendaylight.controller.cluster.raft.persisted.ApplyJournalEntries;
@@ -66,7 +70,7 @@ public abstract class AbstractRaftActorBehavior implements RaftActorBehavior {
     AbstractRaftActorBehavior(final RaftActorContext context, final RaftState state) {
         this.context = requireNonNull(context);
         this.state = requireNonNull(state);
-        this.log = context.getLogger();
+        log = context.getLogger();
 
         logName = String.format("%s (%s)", context.getId(), state);
     }
@@ -208,10 +212,8 @@ public abstract class AbstractRaftActorBehavior implements RaftActorBehavior {
             // the log with the later term is more up-to-date. If the logs
             // end with the same term, then whichever log is longer is
             // more up-to-date.
-            if (requestVote.getLastLogTerm() > lastTerm()) {
-                candidateLatest = true;
-            } else if (requestVote.getLastLogTerm() == lastTerm()
-                    && requestVote.getLastLogIndex() >= lastIndex()) {
+            if (requestVote.getLastLogTerm() > lastTerm()
+                || requestVote.getLastLogTerm() == lastTerm() && requestVote.getLastLogIndex() >= lastIndex()) {
                 candidateLatest = true;
             }
 
@@ -243,7 +245,7 @@ public abstract class AbstractRaftActorBehavior implements RaftActorBehavior {
      * @return a random election duration
      */
     protected FiniteDuration electionDuration() {
-        long variance = new Random().nextInt(context.getConfigParams().getElectionTimeVariance());
+        long variance = ThreadLocalRandom.current().nextInt(context.getConfigParams().getElectionTimeVariance());
         return context.getConfigParams().getElectionTimeOutInterval().$plus(
                 new FiniteDuration(variance, TimeUnit.MILLISECONDS));
     }
@@ -266,6 +268,7 @@ public abstract class AbstractRaftActorBehavior implements RaftActorBehavior {
      *
      * @param interval the duration after which we should trigger a new election
      */
+    // Non-final for testing
     protected void scheduleElection(final FiniteDuration interval) {
         stopElection();
 
@@ -297,7 +300,7 @@ public abstract class AbstractRaftActorBehavior implements RaftActorBehavior {
      *
      * @return the actor
      */
-    protected ActorRef actor() {
+    protected final ActorRef actor() {
         return context.getActor();
     }
 
@@ -319,15 +322,6 @@ public abstract class AbstractRaftActorBehavior implements RaftActorBehavior {
         return context.getReplicatedLog().lastIndex();
     }
 
-    /**
-     * Removes and returns the ClientRequestTracker for the specified log index.
-     * @param logIndex the log index
-     * @return the ClientRequestTracker or null if none available
-     */
-    protected ClientRequestTracker removeClientRequestTracker(final long logIndex) {
-        return null;
-    }
-
     /**
      * Returns the actual index of the entry in replicated log for the given index or -1 if not found.
      *
@@ -392,13 +386,7 @@ public abstract class AbstractRaftActorBehavior implements RaftActorBehavior {
                 // Send a local message to the local RaftActor (it's derived class to be
                 // specific to apply the log to it's index)
 
-                final ApplyState applyState;
-                final ClientRequestTracker tracker = removeClientRequestTracker(i);
-                if (tracker != null) {
-                    applyState = new ApplyState(tracker.getClientActor(), tracker.getIdentifier(), replicatedLogEntry);
-                } else {
-                    applyState = new ApplyState(null, null, replicatedLogEntry);
-                }
+                final ApplyState applyState = getApplyStateFor(replicatedLogEntry);
 
                 log.debug("{}: Setting last applied to {}", logName(), i);
 
@@ -420,6 +408,14 @@ public abstract class AbstractRaftActorBehavior implements RaftActorBehavior {
         actor().tell(new ApplyJournalEntries(context.getLastApplied()), actor());
     }
 
+    /**
+     * Create an ApplyState message for a particular log entry so we can determine how to apply this entry.
+     *
+     * @param entry the log entry
+     * @return ApplyState for this entry
+     */
+    abstract ApplyState getApplyStateFor(ReplicatedLogEntry entry);
+
     @Override
     public RaftActorBehavior handleMessage(final ActorRef sender, final Object message) {
         if (message instanceof AppendEntries) {
@@ -499,7 +495,41 @@ public abstract class AbstractRaftActorBehavior implements RaftActorBehavior {
         }
     }
 
-    protected String getId() {
+    protected final String getId() {
         return context.getId();
     }
+
+    // Check whether we should update the term. In case of half-connected nodes, we want to ignore RequestVote
+    // messages, as the candidate is not able to receive our response.
+    protected boolean shouldUpdateTerm(final RaftRPC rpc) {
+        if (!(rpc instanceof RequestVote)) {
+            return true;
+        }
+
+        final RequestVote requestVote = (RequestVote) rpc;
+        log.debug("{}: Found higher term in RequestVote rpc, verifying whether it's safe to update term.", logName());
+        final Optional<Cluster> maybeCluster = context.getCluster();
+        if (!maybeCluster.isPresent()) {
+            return true;
+        }
+
+        final Cluster cluster = maybeCluster.get();
+
+        final Set<Member> unreachable = cluster.state().getUnreachable();
+        log.debug("{}: Cluster state: {}", logName(), unreachable);
+
+        for (Member member : unreachable) {
+            for (String role : member.getRoles()) {
+                if (requestVote.getCandidateId().startsWith(role)) {
+                    log.debug("{}: Unreachable member: {}, matches candidateId in: {}, not updating term", logName(),
+                        member, requestVote);
+                    return false;
+                }
+            }
+        }
+
+        log.debug("{}: Candidate in requestVote:{} with higher term appears reachable, updating term.", logName(),
+            requestVote);
+        return true;
+    }
 }