Clear leaderId when election timeout occurs in non-voting follower

We need to enable election timeouts on non-voting follower and clear the
leaderId when it occurs to mimic the behavior when it goes to Candidate
on election timeout.

Signed-off-by: Sai MarapaReddy <sai.marapareddy@gmail.com>
Author: Sai MarapaReddy <sai.marapareddy@gmail.com>
Change-Id: I8b3316e14315a47e09b48af2e3ea16a391ec6c5a

diff --git a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/RaftActorServerConfigurationSupport.java b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/RaftActorServerConfigurationSupport.java
index 1fe31f49df24ada141a2be0088a21c5dca8c41bb..2fd1da347d7497deede560619c8c3dc1bc1c39a3 100644 (file)
--- a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/RaftActorServerConfigurationSupport.java
+++ b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/RaftActorServerConfigurationSupport.java
@@ -824,6 +824,10 @@ class RaftActorServerConfigurationSupport {
 
         @Override
         public void onNewLeader(String newLeader) {
+            if(newLeader == null) {
+                return;
+            }
+
             LOG.debug("{}: New leader {} elected", raftContext.getId(), newLeader);
 
             timer.cancel();

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 d17fba03d4ba58e77168602ffe388431b0a64a1a..60ab8ccb2eb799c77cc3a8cc36202547e1293e8f 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
@@ -61,6 +61,10 @@ public abstract class AbstractRaftActorBehavior implements RaftActorBehavior {
      */
     protected String leaderId = null;
 
+    protected void setLeaderId(String leaderId) {
+        this.leaderId = leaderId;
+    }
+
     private short leaderPayloadVersion = -1;
 
     private long replicatedToAllIndex = -1;
@@ -263,12 +267,9 @@ public abstract class AbstractRaftActorBehavior implements RaftActorBehavior {
      */
     protected void scheduleElection(FiniteDuration interval) {
         stopElection();
-
-        if(canStartElection()) {
-            // Schedule an election. When the scheduler triggers an ElectionTimeout message is sent to itself
-            electionCancel = context.getActorSystem().scheduler().scheduleOnce(interval, context.getActor(),
-                    ELECTION_TIMEOUT,context.getActorSystem().dispatcher(), context.getActor());
-        }
+        // Schedule an election. When the scheduler triggers an ElectionTimeout message is sent to itself
+        electionCancel = context.getActorSystem().scheduler().scheduleOnce(interval, context.getActor(),
+                ELECTION_TIMEOUT,context.getActorSystem().dispatcher(), context.getActor());
     }
 
     /**

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 e4b1755fbfc991d557c57be3571ea38ff52a8de6..75aff85932a8fa3dbf50fae289aaeae6db0562f5 100644 (file)
--- 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
@@ -61,14 +61,11 @@ public class Follower extends AbstractRaftActorBehavior {
 
         initialSyncStatusTracker = new SyncStatusTracker(context.getActor(), getId(), SYNC_THRESHOLD);
 
-        if(canStartElection()) {
-            if (context.getPeerIds().isEmpty() && getLeaderId() == null) {
-                actor().tell(ELECTION_TIMEOUT, actor());
-            } else {
-                scheduleElection(electionDuration());
-            }
+        if (context.getPeerIds().isEmpty() && getLeaderId() == null) {
+            actor().tell(ELECTION_TIMEOUT, actor());
+        } else {
+            scheduleElection(electionDuration());
         }
-
     }
 
     private boolean isLogEntryPresent(long index){
@@ -341,6 +338,8 @@ public class Follower extends AbstractRaftActorBehavior {
                 LOG.debug("{}: Received ElectionTimeout - switching to Candidate", logName());
                 return internalSwitchBehavior(RaftState.Candidate);
             } else {
+                setLeaderId(null);
+                scheduleElection(electionDuration());
                 return this;
             }
 

diff --git a/opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/RaftActorServerConfigurationSupportTest.java b/opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/RaftActorServerConfigurationSupportTest.java
index 073249fed2d19f7f395d1a5ca1cc43d290dc32af..36c94c0e536844d57a9d22dfa73b1bde2e8fae3d 100644 (file)
--- a/opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/RaftActorServerConfigurationSupportTest.java
+++ b/opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/RaftActorServerConfigurationSupportTest.java
@@ -1103,6 +1103,7 @@ public class RaftActorServerConfigurationSupportTest extends AbstractActorTest {
 
         DefaultConfigParamsImpl configParams = new DefaultConfigParamsImpl();
         configParams.setHeartBeatInterval(new FiniteDuration(100, TimeUnit.MILLISECONDS));
+        configParams.setElectionTimeoutFactor(5);
 
         final String node1ID = "node1";
         final String node2ID = "node2";
@@ -1118,8 +1119,10 @@ public class RaftActorServerConfigurationSupportTest extends AbstractActorTest {
 
         InMemoryJournal.addEntry(node1ID, 1, new UpdateElectionTerm(1, "downNode1"));
         InMemoryJournal.addEntry(node1ID, 2, persistedServerConfigEntry);
+        InMemoryJournal.addEntry(node1ID, 3, new ApplyJournalEntries(0));
         InMemoryJournal.addEntry(node2ID, 1, new UpdateElectionTerm(1, "downNode2"));
         InMemoryJournal.addEntry(node2ID, 2, persistedServerConfigEntry);
+        InMemoryJournal.addEntry(node2ID, 3, new ApplyJournalEntries(0));
 
         TestActorRef<MessageCollectorActor> node1Collector = actorFactory.createTestActor(
                 MessageCollectorActor.props().withDispatcher(Dispatchers.DefaultDispatcherId()),
@@ -1166,6 +1169,19 @@ public class RaftActorServerConfigurationSupportTest extends AbstractActorTest {
         ServerChangeReply reply = testKit.expectMsgClass(JavaTestKit.duration("5 seconds"), ServerChangeReply.class);
         assertEquals("getStatus", ServerChangeStatus.NO_LEADER, reply.getStatus());
 
+        // Send an AppendEntries so node1 has a leaderId
+
+        MessageCollectorActor.clearMessages(node1Collector);
+
+        long term = node1RaftActor.getRaftActorContext().getTermInformation().getCurrentTerm();
+        node1RaftActorRef.tell(new AppendEntries(term, "downNode1", -1L, -1L,
+                Collections.<ReplicatedLogEntry>emptyList(), 0, -1, (short)1), ActorRef.noSender());
+
+        // Wait for the ElectionTimeout to clear the leaderId. he leaderId must be null so on the
+        // ChangeServersVotingStatus message, it will try to elect a leader.
+
+        MessageCollectorActor.expectFirstMatching(node1Collector, ElectionTimeout.class);
+
         // Update node2's peer address and send the message again
 
         node1RaftActor.setPeerAddress(node2ID, node2RaftActorRef.path().toString());

diff --git a/opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/behaviors/FollowerTest.java b/opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/behaviors/FollowerTest.java
index 537101e8dc013ac4bc5e5254f1908995b19433e1..d32bae97db2c6d32572187e5ece4b3ea2eef921e 100644 (file)
--- a/opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/behaviors/FollowerTest.java
+++ b/opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/behaviors/FollowerTest.java
@@ -12,6 +12,7 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.mock;
@@ -34,7 +35,9 @@ import org.opendaylight.controller.cluster.raft.DefaultConfigParamsImpl;
 import org.opendaylight.controller.cluster.raft.MockRaftActorContext;
 import org.opendaylight.controller.cluster.raft.RaftActorContext;
 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.ServerConfigurationPayload.ServerInfo;
 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.FollowerInitialSyncUpStatus;
@@ -938,15 +941,19 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest {
 
         follower = createBehavior(context);
 
-        MessageCollectorActor.expectFirstMatching(followerActor, ElectionTimeout.class);
+        ElectionTimeout electionTimeout = MessageCollectorActor.expectFirstMatching(followerActor,
+                ElectionTimeout.class);
 
         long elapsed = stopwatch.elapsed(TimeUnit.MILLISECONDS);
 
         assertTrue(elapsed < context.getConfigParams().getElectionTimeOutInterval().toMillis());
+
+        RaftActorBehavior newBehavior = follower.handleMessage(ActorRef.noSender(), electionTimeout);
+        assertTrue("Expected Candidate", newBehavior instanceof Candidate);
     }
 
     @Test
-    public void testFollowerDoesNotScheduleAnElectionIfAutomaticElectionsAreDisabled(){
+    public void testFollowerSchedulesElectionIfAutomaticElectionsAreDisabled(){
         MockRaftActorContext context = createActorContext();
         context.setConfigParams(new DefaultConfigParamsImpl(){
             @Override
@@ -959,7 +966,27 @@ public class FollowerTest extends AbstractRaftActorBehaviorTest {
 
         follower = createBehavior(context);
 
-        MessageCollectorActor.assertNoneMatching(followerActor, ElectionTimeout.class, 500);
+        ElectionTimeout electionTimeout = MessageCollectorActor.expectFirstMatching(followerActor,
+                ElectionTimeout.class);
+        RaftActorBehavior newBehavior = follower.handleMessage(ActorRef.noSender(), electionTimeout);
+        assertSame("handleMessage result", follower, newBehavior);
+    }
+
+    @Test
+    public void testFollowerSchedulesElectionIfNonVoting(){
+        MockRaftActorContext context = createActorContext();
+        context.updatePeerIds(new ServerConfigurationPayload(Arrays.asList(new ServerInfo(context.getId(), false))));
+        ((DefaultConfigParamsImpl)context.getConfigParams()).setHeartBeatInterval(
+                FiniteDuration.apply(100, TimeUnit.MILLISECONDS));
+        ((DefaultConfigParamsImpl)context.getConfigParams()).setElectionTimeoutFactor(1);
+
+        follower = new Follower(context, "leader");
+
+        ElectionTimeout electionTimeout = MessageCollectorActor.expectFirstMatching(followerActor,
+                ElectionTimeout.class);
+        RaftActorBehavior newBehavior = follower.handleMessage(ActorRef.noSender(), electionTimeout);
+        assertSame("handleMessage result", follower, newBehavior);
+        assertNull("Expected null leaderId", follower.getLeaderId());
     }
 
     @Test