Bug 2948: Perform create snapshot synchronously
[controller.git] / opendaylight / md-sal / sal-akka-raft / src / test / java / org / opendaylight / controller / cluster / raft / behaviors / LeaderTest.java
index 34e1ed9b3b3478032c86e9058998ac23610c7c97..0255020328655dfe0dee151207f66f9a51eddcc5 100644 (file)
@@ -27,7 +27,7 @@ import org.opendaylight.controller.cluster.raft.RaftActorContext;
 import org.opendaylight.controller.cluster.raft.RaftState;
 import org.opendaylight.controller.cluster.raft.ReplicatedLogImplEntry;
 import org.opendaylight.controller.cluster.raft.SerializationUtils;
-import org.opendaylight.controller.cluster.raft.base.messages.ApplyLogEntries;
+import org.opendaylight.controller.cluster.raft.base.messages.ApplyJournalEntries;
 import org.opendaylight.controller.cluster.raft.base.messages.ApplyState;
 import org.opendaylight.controller.cluster.raft.base.messages.CaptureSnapshot;
 import org.opendaylight.controller.cluster.raft.base.messages.IsolatedLeaderCheck;
@@ -41,13 +41,14 @@ 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.RequestVoteReply;
+import org.opendaylight.controller.cluster.raft.utils.ForwardMessageToBehaviorActor;
 import org.opendaylight.controller.cluster.raft.utils.MessageCollectorActor;
-import org.opendaylight.controller.protobuff.messages.cluster.raft.InstallSnapshotMessages;
 import scala.concurrent.duration.FiniteDuration;
 
-public class LeaderTest extends AbstractRaftActorBehaviorTest {
+public class LeaderTest extends AbstractLeaderTest {
 
     static final String FOLLOWER_ID = "follower";
+    public static final String LEADER_ID = "leader";
 
     private final TestActorRef<ForwardMessageToBehaviorActor> leaderActor = actorFactory.createTestActor(
             Props.create(ForwardMessageToBehaviorActor.class), actorFactory.generateActorId("leader"));
@@ -119,6 +120,15 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
         assertEquals("Entry getTerm", term, appendEntries.getEntries().get(0).getTerm());
     }
 
+
+    private RaftActorBehavior sendReplicate(MockRaftActorContext actorContext, long index){
+        MockRaftActorContext.MockPayload payload = new MockRaftActorContext.MockPayload("foo");
+        MockRaftActorContext.MockReplicatedLogEntry newEntry = new MockRaftActorContext.MockReplicatedLogEntry(
+                1, index, payload);
+        actorContext.getReplicatedLog().append(newEntry);
+        return leader.handleMessage(leaderActor, new Replicate(null, null, newEntry));
+    }
+
     @Test
     public void testHandleReplicateMessageSendAppendEntriesToFollower() throws Exception {
         logStart("testHandleReplicateMessageSendAppendEntriesToFollower");
@@ -145,8 +155,7 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
         MockRaftActorContext.MockReplicatedLogEntry newEntry = new MockRaftActorContext.MockReplicatedLogEntry(
                 1, lastIndex + 1, payload);
         actorContext.getReplicatedLog().append(newEntry);
-        RaftActorBehavior raftBehavior = leader.handleMessage(leaderActor,
-                new Replicate(null, null, newEntry));
+        RaftActorBehavior raftBehavior = sendReplicate(actorContext, lastIndex+1);
 
         // State should not change
         assertTrue(raftBehavior instanceof Leader);
@@ -160,6 +169,218 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
         assertEquals("Entry payload", payload, appendEntries.getEntries().get(0).getData());
     }
 
+    @Test
+    public void testMultipleReplicateShouldNotCauseDuplicateAppendEntriesToBeSent() throws Exception {
+        logStart("testHandleReplicateMessageSendAppendEntriesToFollower");
+
+        MockRaftActorContext actorContext = createActorContextWithFollower();
+        actorContext.setConfigParams(new DefaultConfigParamsImpl() {
+            @Override
+            public FiniteDuration getHeartBeatInterval() {
+                return FiniteDuration.apply(5, TimeUnit.SECONDS);
+            }
+        });
+
+        long term = 1;
+        actorContext.getTermInformation().update(term, "");
+
+        leader = new Leader(actorContext);
+
+        // Leader will send an immediate heartbeat - ignore it.
+        MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
+
+        // The follower would normally reply - simulate that explicitly here.
+        long lastIndex = actorContext.getReplicatedLog().lastIndex();
+        leader.handleMessage(followerActor, new AppendEntriesReply(
+                FOLLOWER_ID, term, true, lastIndex, term));
+        assertEquals("isFollowerActive", true, leader.getFollower(FOLLOWER_ID).isFollowerActive());
+
+        followerActor.underlyingActor().clear();
+
+        for(int i=0;i<5;i++) {
+            sendReplicate(actorContext, lastIndex+i+1);
+        }
+
+        List<AppendEntries> allMessages = MessageCollectorActor.getAllMatching(followerActor, AppendEntries.class);
+        // We expect only 1 message to be sent because of two reasons,
+        // - an append entries reply was not received
+        // - the heartbeat interval has not expired
+        // In this scenario if multiple messages are sent they would likely be duplicates
+        assertEquals("The number of append entries collected should be 1", 1, allMessages.size());
+    }
+
+    @Test
+    public void testMultipleReplicateWithReplyShouldResultInAppendEntries() throws Exception {
+        logStart("testMultipleReplicateWithReplyShouldResultInAppendEntries");
+
+        MockRaftActorContext actorContext = createActorContextWithFollower();
+        actorContext.setConfigParams(new DefaultConfigParamsImpl() {
+            @Override
+            public FiniteDuration getHeartBeatInterval() {
+                return FiniteDuration.apply(5, TimeUnit.SECONDS);
+            }
+        });
+
+        long term = 1;
+        actorContext.getTermInformation().update(term, "");
+
+        leader = new Leader(actorContext);
+
+        // Leader will send an immediate heartbeat - ignore it.
+        MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
+
+        // The follower would normally reply - simulate that explicitly here.
+        long lastIndex = actorContext.getReplicatedLog().lastIndex();
+        leader.handleMessage(followerActor, new AppendEntriesReply(
+                FOLLOWER_ID, term, true, lastIndex, term));
+        assertEquals("isFollowerActive", true, leader.getFollower(FOLLOWER_ID).isFollowerActive());
+
+        followerActor.underlyingActor().clear();
+
+        for(int i=0;i<3;i++) {
+            sendReplicate(actorContext, lastIndex+i+1);
+            leader.handleMessage(followerActor, new AppendEntriesReply(
+                    FOLLOWER_ID, term, true, lastIndex + i + 1, term));
+
+        }
+
+        for(int i=3;i<5;i++) {
+            sendReplicate(actorContext, lastIndex + i + 1);
+        }
+
+        List<AppendEntries> allMessages = MessageCollectorActor.getAllMatching(followerActor, AppendEntries.class);
+        // We expect 4 here because the first 3 replicate got a reply and so the 4th entry would
+        // get sent to the follower - but not the 5th
+        assertEquals("The number of append entries collected should be 4", 4, allMessages.size());
+
+        for(int i=0;i<4;i++) {
+            long expected = allMessages.get(i).getEntries().get(0).getIndex();
+            assertEquals(expected, i+2);
+        }
+    }
+
+    @Test
+    public void testDuplicateAppendEntriesWillBeSentOnHeartBeat() throws Exception {
+        logStart("testDuplicateAppendEntriesWillBeSentOnHeartBeat");
+
+        MockRaftActorContext actorContext = createActorContextWithFollower();
+        actorContext.setConfigParams(new DefaultConfigParamsImpl() {
+            @Override
+            public FiniteDuration getHeartBeatInterval() {
+                return FiniteDuration.apply(500, TimeUnit.MILLISECONDS);
+            }
+        });
+
+        long term = 1;
+        actorContext.getTermInformation().update(term, "");
+
+        leader = new Leader(actorContext);
+
+        // Leader will send an immediate heartbeat - ignore it.
+        MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
+
+        // The follower would normally reply - simulate that explicitly here.
+        long lastIndex = actorContext.getReplicatedLog().lastIndex();
+        leader.handleMessage(followerActor, new AppendEntriesReply(
+                FOLLOWER_ID, term, true, lastIndex, term));
+        assertEquals("isFollowerActive", true, leader.getFollower(FOLLOWER_ID).isFollowerActive());
+
+        followerActor.underlyingActor().clear();
+
+        sendReplicate(actorContext, lastIndex+1);
+
+        // Wait slightly longer than heartbeat duration
+        Uninterruptibles.sleepUninterruptibly(750, TimeUnit.MILLISECONDS);
+
+        leader.handleMessage(leaderActor, new SendHeartBeat());
+
+        List<AppendEntries> allMessages = MessageCollectorActor.getAllMatching(followerActor, AppendEntries.class);
+        assertEquals("The number of append entries collected should be 2", 2, allMessages.size());
+
+        assertEquals(1, allMessages.get(0).getEntries().size());
+        assertEquals(lastIndex+1, allMessages.get(0).getEntries().get(0).getIndex());
+        assertEquals(1, allMessages.get(1).getEntries().size());
+        assertEquals(lastIndex+1, allMessages.get(0).getEntries().get(0).getIndex());
+
+    }
+
+    @Test
+    public void testHeartbeatsAreAlwaysSentIfTheHeartbeatIntervalHasElapsed() throws Exception {
+        logStart("testHeartbeatsAreAlwaysSentIfTheHeartbeatIntervalHasElapsed");
+
+        MockRaftActorContext actorContext = createActorContextWithFollower();
+        actorContext.setConfigParams(new DefaultConfigParamsImpl() {
+            @Override
+            public FiniteDuration getHeartBeatInterval() {
+                return FiniteDuration.apply(100, TimeUnit.MILLISECONDS);
+            }
+        });
+
+        long term = 1;
+        actorContext.getTermInformation().update(term, "");
+
+        leader = new Leader(actorContext);
+
+        // Leader will send an immediate heartbeat - ignore it.
+        MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
+
+        // The follower would normally reply - simulate that explicitly here.
+        long lastIndex = actorContext.getReplicatedLog().lastIndex();
+        leader.handleMessage(followerActor, new AppendEntriesReply(
+                FOLLOWER_ID, term, true, lastIndex, term));
+        assertEquals("isFollowerActive", true, leader.getFollower(FOLLOWER_ID).isFollowerActive());
+
+        followerActor.underlyingActor().clear();
+
+        for(int i=0;i<3;i++) {
+            Uninterruptibles.sleepUninterruptibly(150, TimeUnit.MILLISECONDS);
+            leader.handleMessage(leaderActor, new SendHeartBeat());
+        }
+
+        List<AppendEntries> allMessages = MessageCollectorActor.getAllMatching(followerActor, AppendEntries.class);
+        assertEquals("The number of append entries collected should be 3", 3, allMessages.size());
+    }
+
+    @Test
+    public void testSendingReplicateImmediatelyAfterHeartbeatDoesReplicate() throws Exception {
+        logStart("testSendingReplicateImmediatelyAfterHeartbeatDoesReplicate");
+
+        MockRaftActorContext actorContext = createActorContextWithFollower();
+        actorContext.setConfigParams(new DefaultConfigParamsImpl() {
+            @Override
+            public FiniteDuration getHeartBeatInterval() {
+                return FiniteDuration.apply(100, TimeUnit.MILLISECONDS);
+            }
+        });
+
+        long term = 1;
+        actorContext.getTermInformation().update(term, "");
+
+        leader = new Leader(actorContext);
+
+        // Leader will send an immediate heartbeat - ignore it.
+        MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
+
+        // The follower would normally reply - simulate that explicitly here.
+        long lastIndex = actorContext.getReplicatedLog().lastIndex();
+        leader.handleMessage(followerActor, new AppendEntriesReply(
+                FOLLOWER_ID, term, true, lastIndex, term));
+        assertEquals("isFollowerActive", true, leader.getFollower(FOLLOWER_ID).isFollowerActive());
+
+        followerActor.underlyingActor().clear();
+
+        Uninterruptibles.sleepUninterruptibly(150, TimeUnit.MILLISECONDS);
+        leader.handleMessage(leaderActor, new SendHeartBeat());
+        sendReplicate(actorContext, lastIndex+1);
+
+        List<AppendEntries> allMessages = MessageCollectorActor.getAllMatching(followerActor, AppendEntries.class);
+        assertEquals("The number of append entries collected should be 2", 2, allMessages.size());
+
+        assertEquals(0, allMessages.get(0).getEntries().size());
+        assertEquals(1, allMessages.get(1).getEntries().size());
+    }
+
+
     @Test
     public void testHandleReplicateMessageWhenThereAreNoFollowers() throws Exception {
         logStart("testHandleReplicateMessageWhenThereAreNoFollowers");
@@ -264,10 +485,7 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
 
         leader.handleMessage(leaderActor, new SendHeartBeat());
 
-        InstallSnapshotMessages.InstallSnapshot isproto = MessageCollectorActor.expectFirstMatching(followerActor,
-                InstallSnapshot.SERIALIZABLE_CLASS);
-
-        InstallSnapshot is = (InstallSnapshot) SerializationUtils.fromSerializable(isproto);
+        InstallSnapshot is = MessageCollectorActor.expectFirstMatching(followerActor, InstallSnapshot.class);
 
         assertEquals(snapshotIndex, is.getLastIncludedIndex());
     }
@@ -307,6 +525,8 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
                 new ReplicatedLogImplEntry(newEntryIndex, currentTerm,
                         new MockRaftActorContext.MockPayload("D"));
 
+        actorContext.getReplicatedLog().append(entry);
+
         //update follower timestamp
         leader.markFollowerActive(FOLLOWER_ID);
 
@@ -316,7 +536,7 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
 
         assertTrue(raftBehavior instanceof Leader);
 
-        MessageCollectorActor.expectFirstMatching(leaderActor, CaptureSnapshot.class);
+        assertEquals("isCapturing", true, actorContext.getSnapshotManager().isCapturing());
     }
 
     @Test
@@ -364,7 +584,9 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
 
         leader.handleMessage(leaderActor, new Replicate(null, "state-id", entry));
 
-        CaptureSnapshot cs = MessageCollectorActor.expectFirstMatching(leaderActor, CaptureSnapshot.class);
+        assertEquals("isCapturing", true, actorContext.getSnapshotManager().isCapturing());
+
+        CaptureSnapshot cs = actorContext.getSnapshotManager().getCaptureSnapshot();
 
         assertTrue(cs.isInstallSnapshotInitiated());
         assertEquals(3, cs.getLastAppliedIndex());
@@ -375,8 +597,7 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
         // if an initiate is started again when first is in progress, it shouldnt initiate Capture
         leader.handleMessage(leaderActor, new Replicate(null, "state-id", entry));
 
-        List<CaptureSnapshot> captureSnapshots = MessageCollectorActor.getAllMatching(leaderActor, CaptureSnapshot.class);
-        assertEquals("CaptureSnapshot should not get invoked when  initiate is in progress", 1, captureSnapshots.size());
+        Assert.assertSame("CaptureSnapshot instance", cs, actorContext.getSnapshotManager().getCaptureSnapshot());
     }
 
     @Test
@@ -416,8 +637,7 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
 
         // check if installsnapshot gets called with the correct values.
 
-        InstallSnapshot installSnapshot = (InstallSnapshot) SerializationUtils.fromSerializable(
-                MessageCollectorActor.expectFirstMatching(followerActor, InstallSnapshotMessages.InstallSnapshot.class));
+        InstallSnapshot installSnapshot = MessageCollectorActor.expectFirstMatching(followerActor, InstallSnapshot.class);
 
         assertNotNull(installSnapshot.getData());
         assertEquals(snapshotIndex, installSnapshot.getLastIncludedIndex());
@@ -521,8 +741,7 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
 
         leader.handleMessage(leaderActor, new SendInstallSnapshot(bs));
 
-        InstallSnapshotMessages.InstallSnapshot installSnapshot = MessageCollectorActor.expectFirstMatching(
-                followerActor, InstallSnapshotMessages.InstallSnapshot.class);
+        InstallSnapshot installSnapshot = MessageCollectorActor.expectFirstMatching(followerActor, InstallSnapshot.class);
 
         assertEquals(1, installSnapshot.getChunkIndex());
         assertEquals(3, installSnapshot.getTotalChunks());
@@ -531,8 +750,7 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
         leader.handleMessage(followerActor, new InstallSnapshotReply(actorContext.getTermInformation().getCurrentTerm(),
                 FOLLOWER_ID, installSnapshot.getChunkIndex(), true));
 
-        installSnapshot = MessageCollectorActor.expectFirstMatching(
-                followerActor, InstallSnapshotMessages.InstallSnapshot.class);
+        installSnapshot = MessageCollectorActor.expectFirstMatching(followerActor, InstallSnapshot.class);
 
         assertEquals(2, installSnapshot.getChunkIndex());
         assertEquals(3, installSnapshot.getTotalChunks());
@@ -541,16 +759,14 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
         leader.handleMessage(followerActor, new InstallSnapshotReply(actorContext.getTermInformation().getCurrentTerm(),
                 FOLLOWER_ID, installSnapshot.getChunkIndex(), true));
 
-        installSnapshot = MessageCollectorActor.expectFirstMatching(
-                followerActor, InstallSnapshotMessages.InstallSnapshot.class);
+        installSnapshot = MessageCollectorActor.expectFirstMatching(followerActor, InstallSnapshot.class);
 
         // Send snapshot reply one more time and make sure that a new snapshot message should not be sent to follower
         followerActor.underlyingActor().clear();
         leader.handleMessage(followerActor, new InstallSnapshotReply(actorContext.getTermInformation().getCurrentTerm(),
                 FOLLOWER_ID, installSnapshot.getChunkIndex(), true));
 
-        installSnapshot = MessageCollectorActor.getFirstMatching(
-                followerActor, InstallSnapshotMessages.InstallSnapshot.class);
+        installSnapshot = MessageCollectorActor.getFirstMatching(followerActor, InstallSnapshot.class);
 
         Assert.assertNull(installSnapshot);
     }
@@ -591,10 +807,10 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
         ByteString bs = toByteString(leadersSnapshot);
         leader.setSnapshot(Optional.of(bs));
 
+        Uninterruptibles.sleepUninterruptibly(1, TimeUnit.SECONDS);
         leader.handleMessage(leaderActor, new SendInstallSnapshot(bs));
 
-        InstallSnapshotMessages.InstallSnapshot installSnapshot = MessageCollectorActor.expectFirstMatching(
-                followerActor, InstallSnapshotMessages.InstallSnapshot.class);
+        InstallSnapshot installSnapshot = MessageCollectorActor.expectFirstMatching(followerActor, InstallSnapshot.class);
 
         assertEquals(1, installSnapshot.getChunkIndex());
         assertEquals(3, installSnapshot.getTotalChunks());
@@ -609,8 +825,7 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
 
         leader.handleMessage(leaderActor, new SendHeartBeat());
 
-        installSnapshot = MessageCollectorActor.expectFirstMatching(
-                followerActor, InstallSnapshotMessages.InstallSnapshot.class);
+        installSnapshot = MessageCollectorActor.expectFirstMatching(followerActor, InstallSnapshot.class);
 
         assertEquals(1, installSnapshot.getChunkIndex());
         assertEquals(3, installSnapshot.getTotalChunks());
@@ -653,12 +868,11 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
 
         leader.handleMessage(leaderActor, new SendInstallSnapshot(bs));
 
-        InstallSnapshotMessages.InstallSnapshot installSnapshot = MessageCollectorActor.expectFirstMatching(
-                followerActor, InstallSnapshotMessages.InstallSnapshot.class);
+        InstallSnapshot installSnapshot = MessageCollectorActor.expectFirstMatching(followerActor, InstallSnapshot.class);
 
         assertEquals(1, installSnapshot.getChunkIndex());
         assertEquals(3, installSnapshot.getTotalChunks());
-        assertEquals(AbstractLeader.INITIAL_LAST_CHUNK_HASH_CODE, installSnapshot.getLastChunkHashCode());
+        assertEquals(AbstractLeader.INITIAL_LAST_CHUNK_HASH_CODE, installSnapshot.getLastChunkHashCode().get().intValue());
 
         int hashCode = installSnapshot.getData().hashCode();
 
@@ -667,12 +881,11 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
         leader.handleMessage(followerActor, new InstallSnapshotReply(installSnapshot.getTerm(),
                 FOLLOWER_ID, 1, true));
 
-        installSnapshot = MessageCollectorActor.expectFirstMatching(
-                followerActor, InstallSnapshotMessages.InstallSnapshot.class);
+        installSnapshot = MessageCollectorActor.expectFirstMatching(followerActor, InstallSnapshot.class);
 
         assertEquals(2, installSnapshot.getChunkIndex());
         assertEquals(3, installSnapshot.getTotalChunks());
-        assertEquals(hashCode, installSnapshot.getLastChunkHashCode());
+        assertEquals(hashCode, installSnapshot.getLastChunkHashCode().get().intValue());
     }
 
     @Test
@@ -737,12 +950,12 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
 
     @Override
     protected MockRaftActorContext createActorContext(ActorRef actorRef) {
-        return createActorContext("leader", actorRef);
+        return createActorContext(LEADER_ID, actorRef);
     }
 
     private MockRaftActorContext createActorContextWithFollower() {
         MockRaftActorContext actorContext = createActorContext();
-        actorContext.setPeerAddresses(ImmutableMap.<String,String>builder().put(FOLLOWER_ID,
+        actorContext.setPeerAddresses(ImmutableMap.<String, String>builder().put(FOLLOWER_ID,
                 followerActor.path().toString()).build());
         return actorContext;
     }
@@ -756,22 +969,6 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
         return context;
     }
 
-    public static class ForwardMessageToBehaviorActor extends MessageCollectorActor {
-        AbstractRaftActorBehavior behavior;
-
-        @Override public void onReceive(Object message) throws Exception {
-            if(behavior != null) {
-                behavior.handleMessage(sender(), message);
-            }
-
-            super.onReceive(message);
-        }
-
-        public static Props props() {
-            return Props.create(ForwardMessageToBehaviorActor.class);
-        }
-    }
-
     @Test
     public void testLeaderCreatedWithCommitIndexLessThanLastIndex() throws Exception {
         logStart("testLeaderCreatedWithCommitIndexLessThanLastIndex");
@@ -781,7 +978,7 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
         MockRaftActorContext followerActorContext = createActorContext(FOLLOWER_ID, followerActor);
 
         Follower follower = new Follower(followerActorContext);
-        followerActor.underlyingActor().behavior = follower;
+        followerActor.underlyingActor().setBehavior(follower);
 
         Map<String, String> peerAddresses = new HashMap<>();
         peerAddresses.put(FOLLOWER_ID, followerActor.path().toString());
@@ -832,14 +1029,15 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
         MockRaftActorContext leaderActorContext = createActorContext();
 
         MockRaftActorContext followerActorContext = createActorContext(FOLLOWER_ID, followerActor);
+        followerActorContext.setPeerAddresses(ImmutableMap.of(LEADER_ID, leaderActor.path().toString()));
 
         Follower follower = new Follower(followerActorContext);
-        followerActor.underlyingActor().behavior = follower;
+        followerActor.underlyingActor().setBehavior(follower);
 
-        Map<String, String> peerAddresses = new HashMap<>();
-        peerAddresses.put(FOLLOWER_ID, followerActor.path().toString());
+        Map<String, String> leaderPeerAddresses = new HashMap<>();
+        leaderPeerAddresses.put(FOLLOWER_ID, followerActor.path().toString());
 
-        leaderActorContext.setPeerAddresses(peerAddresses);
+        leaderActorContext.setPeerAddresses(leaderPeerAddresses);
 
         leaderActorContext.getReplicatedLog().removeFrom(0);
 
@@ -871,7 +1069,7 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
         assertEquals(2, appendEntriesReply.getLogLastIndex());
         assertEquals(1, appendEntriesReply.getLogLastTerm());
 
-        leaderActor.underlyingActor().behavior = leader;
+        leaderActor.underlyingActor().setBehavior(follower);
         leader.handleMessage(followerActor, appendEntriesReply);
 
         leaderActor.underlyingActor().clear();
@@ -944,12 +1142,12 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
 
         assertEquals(2, leaderActorContext.getCommitIndex());
 
-        ApplyLogEntries applyLogEntries = MessageCollectorActor.expectFirstMatching(
-                leaderActor, ApplyLogEntries.class);
+        ApplyJournalEntries applyJournalEntries = MessageCollectorActor.expectFirstMatching(
+                leaderActor, ApplyJournalEntries.class);
 
         assertEquals(2, leaderActorContext.getLastApplied());
 
-        assertEquals(2, applyLogEntries.getToIndex());
+        assertEquals(2, applyJournalEntries.getToIndex());
 
         List<ApplyState> applyStateList = MessageCollectorActor.getAllMatching(leaderActor,
                 ApplyState.class);
@@ -1074,9 +1272,10 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
         MockRaftActorContext followerActorContext = createActorContext(FOLLOWER_ID, followerActor);
 
         followerActorContext.setConfigParams(configParams);
+        followerActorContext.setPeerAddresses(ImmutableMap.of(LEADER_ID, leaderActor.path().toString()));
 
         Follower follower = new Follower(followerActorContext);
-        followerActor.underlyingActor().behavior = follower;
+        followerActor.underlyingActor().setBehavior(follower);
 
         leaderActorContext.getReplicatedLog().removeFrom(0);
         leaderActorContext.setCommitIndex(-1);
@@ -1134,6 +1333,66 @@ public class LeaderTest extends AbstractRaftActorBehaviorTest {
         follower.close();
     }
 
+    @Test
+    public void testLaggingFollowerStarvation() throws Exception {
+        logStart("testLaggingFollowerStarvation");
+        new JavaTestKit(getSystem()) {{
+            String leaderActorId = actorFactory.generateActorId("leader");
+            String follower1ActorId = actorFactory.generateActorId("follower");
+            String follower2ActorId = actorFactory.generateActorId("follower");
+
+            TestActorRef<ForwardMessageToBehaviorActor> leaderActor =
+                    actorFactory.createTestActor(ForwardMessageToBehaviorActor.props(), leaderActorId);
+            ActorRef follower1Actor = actorFactory.createActor(MessageCollectorActor.props(), follower1ActorId);
+            ActorRef follower2Actor = actorFactory.createActor(MessageCollectorActor.props(), follower2ActorId);
+
+            MockRaftActorContext leaderActorContext =
+                    new MockRaftActorContext(leaderActorId, getSystem(), leaderActor);
+
+            DefaultConfigParamsImpl configParams = new DefaultConfigParamsImpl();
+            configParams.setHeartBeatInterval(new FiniteDuration(200, TimeUnit.MILLISECONDS));
+            configParams.setIsolatedLeaderCheckInterval(new FiniteDuration(10, TimeUnit.SECONDS));
+
+            leaderActorContext.setConfigParams(configParams);
+
+            leaderActorContext.setReplicatedLog(
+                    new MockRaftActorContext.MockReplicatedLogBuilder().createEntries(1,5,1).build());
+
+            Map<String, String> peerAddresses = new HashMap<>();
+            peerAddresses.put(follower1ActorId,
+                    follower1Actor.path().toString());
+            peerAddresses.put(follower2ActorId,
+                    follower2Actor.path().toString());
+
+            leaderActorContext.setPeerAddresses(peerAddresses);
+            leaderActorContext.getTermInformation().update(1, leaderActorId);
+
+            RaftActorBehavior leader = createBehavior(leaderActorContext);
+
+            leaderActor.underlyingActor().setBehavior(leader);
+
+            for(int i=1;i<6;i++) {
+                // Each AppendEntriesReply could end up rescheduling the heartbeat (without the fix for bug 2733)
+                RaftActorBehavior newBehavior = leader.handleMessage(follower1Actor, new AppendEntriesReply(follower1ActorId, 1, true, i, 1));
+                assertTrue(newBehavior == leader);
+                Uninterruptibles.sleepUninterruptibly(200, TimeUnit.MILLISECONDS);
+            }
+
+            // Check if the leader has been receiving SendHeartbeat messages despite getting AppendEntriesReply
+            List<SendHeartBeat> heartbeats = MessageCollectorActor.getAllMatching(leaderActor, SendHeartBeat.class);
+
+            assertTrue(String.format("%s heartbeat(s) is less than expected", heartbeats.size()),
+                    heartbeats.size() > 1);
+
+            // Check if follower-2 got AppendEntries during this time and was not starved
+            List<AppendEntries> appendEntries = MessageCollectorActor.getAllMatching(follower2Actor, AppendEntries.class);
+
+            assertTrue(String.format("%s append entries is less than expected", appendEntries.size()),
+                    appendEntries.size() > 1);
+
+        }};
+    }
+
     @Override
     protected void assertStateChangesToFollowerWhenRaftRPCHasNewerTerm(RaftActorContext actorContext,
             ActorRef actorRef, RaftRPC rpc) throws Exception {