opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/behaviors/LeaderTest.java

   1 /*
   2  * Copyright (c) 2014, 2015 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8
   9 package org.opendaylight.controller.cluster.raft.behaviors;
  10
  11 import static org.junit.Assert.assertEquals;
  12 import static org.junit.Assert.assertNotNull;
  13 import static org.junit.Assert.assertNull;
  14 import static org.junit.Assert.assertSame;
  15 import static org.junit.Assert.assertTrue;
  16 import static org.mockito.Mockito.mock;
  17 import static org.mockito.Mockito.never;
  18 import static org.mockito.Mockito.verify;
  19 import akka.actor.ActorRef;
  20 import akka.actor.PoisonPill;
  21 import akka.actor.Props;
  22 import akka.actor.Terminated;
  23 import akka.testkit.JavaTestKit;
  24 import akka.testkit.TestActorRef;
  25 import com.google.common.collect.ImmutableMap;
  26 import com.google.common.util.concurrent.Uninterruptibles;
  27 import com.google.protobuf.ByteString;
  28 import java.util.Arrays;
  29 import java.util.Collections;
  30 import java.util.HashMap;
  31 import java.util.List;
  32 import java.util.Map;
  33 import java.util.concurrent.TimeUnit;
  34 import org.junit.After;
  35 import org.junit.Test;
  36 import org.opendaylight.controller.cluster.raft.DefaultConfigParamsImpl;
  37 import org.opendaylight.controller.cluster.raft.FollowerLogInformation;
  38 import org.opendaylight.controller.cluster.raft.MockRaftActorContext;
  39 import org.opendaylight.controller.cluster.raft.RaftActorContext;
  40 import org.opendaylight.controller.cluster.raft.RaftActorLeadershipTransferCohort;
  41 import org.opendaylight.controller.cluster.raft.RaftState;
  42 import org.opendaylight.controller.cluster.raft.RaftVersions;
  43 import org.opendaylight.controller.cluster.raft.ReplicatedLogEntry;
  44 import org.opendaylight.controller.cluster.raft.ReplicatedLogImplEntry;
  45 import org.opendaylight.controller.cluster.raft.SerializationUtils;
  46 import org.opendaylight.controller.cluster.raft.Snapshot;
  47 import org.opendaylight.controller.cluster.raft.VotingState;
  48 import org.opendaylight.controller.cluster.raft.base.messages.ApplyJournalEntries;
  49 import org.opendaylight.controller.cluster.raft.base.messages.ApplyState;
  50 import org.opendaylight.controller.cluster.raft.base.messages.CaptureSnapshot;
  51 import org.opendaylight.controller.cluster.raft.base.messages.ElectionTimeout;
  52 import org.opendaylight.controller.cluster.raft.base.messages.Replicate;
  53 import org.opendaylight.controller.cluster.raft.base.messages.SendHeartBeat;
  54 import org.opendaylight.controller.cluster.raft.base.messages.SendInstallSnapshot;
  55 import org.opendaylight.controller.cluster.raft.base.messages.TimeoutNow;
  56 import org.opendaylight.controller.cluster.raft.behaviors.AbstractLeader.FollowerToSnapshot;
  57 import org.opendaylight.controller.cluster.raft.messages.AppendEntries;
  58 import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply;
  59 import org.opendaylight.controller.cluster.raft.messages.InstallSnapshot;
  60 import org.opendaylight.controller.cluster.raft.messages.InstallSnapshotReply;
  61 import org.opendaylight.controller.cluster.raft.messages.RaftRPC;
  62 import org.opendaylight.controller.cluster.raft.messages.RequestVoteReply;
  63 import org.opendaylight.controller.cluster.raft.policy.DefaultRaftPolicy;
  64 import org.opendaylight.controller.cluster.raft.policy.RaftPolicy;
  65 import org.opendaylight.controller.cluster.raft.utils.ForwardMessageToBehaviorActor;
  66 import org.opendaylight.controller.cluster.raft.utils.MessageCollectorActor;
  67 import org.opendaylight.yangtools.concepts.Identifier;
  68 import scala.concurrent.duration.FiniteDuration;
  69
  70 public class LeaderTest extends AbstractLeaderTest<Leader> {
  71
  72     static final String FOLLOWER_ID = "follower";
  73     public static final String LEADER_ID = "leader";
  74
  75     private final TestActorRef<ForwardMessageToBehaviorActor> leaderActor = actorFactory.createTestActor(
  76             Props.create(ForwardMessageToBehaviorActor.class), actorFactory.generateActorId("leader"));
  77
  78     private final TestActorRef<ForwardMessageToBehaviorActor> followerActor = actorFactory.createTestActor(
  79             Props.create(ForwardMessageToBehaviorActor.class), actorFactory.generateActorId("follower"));
  80
  81     private Leader leader;
  82     private final short payloadVersion = 5;
  83
  84     @Override
  85     @After
  86     public void tearDown() throws Exception {
  87         if(leader != null) {
  88             leader.close();
  89         }
  90
  91         super.tearDown();
  92     }
  93
  94     @Test
  95     public void testHandleMessageForUnknownMessage() throws Exception {
  96         logStart("testHandleMessageForUnknownMessage");
  97
  98         leader = new Leader(createActorContext());
  99
 100         // handle message should null when it receives an unknown message
 101         assertNull(leader.handleMessage(followerActor, "foo"));
 102     }
 103
 104     @Test
 105     public void testThatLeaderSendsAHeartbeatMessageToAllFollowers() throws Exception {
 106         logStart("testThatLeaderSendsAHeartbeatMessageToAllFollowers");
 107
 108         MockRaftActorContext actorContext = createActorContextWithFollower();
 109         actorContext.setCommitIndex(-1);
 110         short payloadVersion = (short)5;
 111         actorContext.setPayloadVersion(payloadVersion);
 112
 113         long term = 1;
 114         actorContext.getTermInformation().update(term, "");
 115
 116         leader = new Leader(actorContext);
 117         actorContext.setCurrentBehavior(leader);
 118
 119         // Leader should send an immediate heartbeat with no entries as follower is inactive.
 120         long lastIndex = actorContext.getReplicatedLog().lastIndex();
 121         AppendEntries appendEntries = MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
 122         assertEquals("getTerm", term, appendEntries.getTerm());
 123         assertEquals("getPrevLogIndex", -1, appendEntries.getPrevLogIndex());
 124         assertEquals("getPrevLogTerm", -1, appendEntries.getPrevLogTerm());
 125         assertEquals("Entries size", 0, appendEntries.getEntries().size());
 126         assertEquals("getPayloadVersion", payloadVersion, appendEntries.getPayloadVersion());
 127
 128         // The follower would normally reply - simulate that explicitly here.
 129         leader.handleMessage(followerActor, new AppendEntriesReply(
 130                 FOLLOWER_ID, term, true, lastIndex - 1, term, (short)0));
 131         assertEquals("isFollowerActive", true, leader.getFollower(FOLLOWER_ID).isFollowerActive());
 132
 133         followerActor.underlyingActor().clear();
 134
 135         // Sleep for the heartbeat interval so AppendEntries is sent.
 136         Uninterruptibles.sleepUninterruptibly(actorContext.getConfigParams().
 137                 getHeartBeatInterval().toMillis(), TimeUnit.MILLISECONDS);
 138
 139         leader.handleMessage(leaderActor, SendHeartBeat.INSTANCE);
 140
 141         appendEntries = MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
 142         assertEquals("getPrevLogIndex", lastIndex - 1, appendEntries.getPrevLogIndex());
 143         assertEquals("getPrevLogTerm", term, appendEntries.getPrevLogTerm());
 144         assertEquals("Entries size", 1, appendEntries.getEntries().size());
 145         assertEquals("Entry getIndex", lastIndex, appendEntries.getEntries().get(0).getIndex());
 146         assertEquals("Entry getTerm", term, appendEntries.getEntries().get(0).getTerm());
 147         assertEquals("getPayloadVersion", payloadVersion, appendEntries.getPayloadVersion());
 148     }
 149
 150
 151     private RaftActorBehavior sendReplicate(MockRaftActorContext actorContext, long index){
 152         return sendReplicate(actorContext, 1, index);
 153     }
 154
 155     private RaftActorBehavior sendReplicate(MockRaftActorContext actorContext, long term, long index){
 156         MockRaftActorContext.MockPayload payload = new MockRaftActorContext.MockPayload("foo");
 157         MockRaftActorContext.MockReplicatedLogEntry newEntry = new MockRaftActorContext.MockReplicatedLogEntry(
 158                 term, index, payload);
 159         actorContext.getReplicatedLog().append(newEntry);
 160         return leader.handleMessage(leaderActor, new Replicate(null, null, newEntry));
 161     }
 162
 163     @Test
 164     public void testHandleReplicateMessageSendAppendEntriesToFollower() throws Exception {
 165         logStart("testHandleReplicateMessageSendAppendEntriesToFollower");
 166
 167         MockRaftActorContext actorContext = createActorContextWithFollower();
 168
 169         long term = 1;
 170         actorContext.getTermInformation().update(term, "");
 171
 172         leader = new Leader(actorContext);
 173
 174         // Leader will send an immediate heartbeat - ignore it.
 175         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
 176
 177         // The follower would normally reply - simulate that explicitly here.
 178         long lastIndex = actorContext.getReplicatedLog().lastIndex();
 179         leader.handleMessage(followerActor, new AppendEntriesReply(
 180                 FOLLOWER_ID, term, true, lastIndex, term, (short)0));
 181         assertEquals("isFollowerActive", true, leader.getFollower(FOLLOWER_ID).isFollowerActive());
 182
 183         followerActor.underlyingActor().clear();
 184
 185         RaftActorBehavior raftBehavior = sendReplicate(actorContext, lastIndex + 1);
 186
 187         // State should not change
 188         assertTrue(raftBehavior instanceof Leader);
 189
 190         AppendEntries appendEntries = MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
 191         assertEquals("getPrevLogIndex", lastIndex, appendEntries.getPrevLogIndex());
 192         assertEquals("getPrevLogTerm", term, appendEntries.getPrevLogTerm());
 193         assertEquals("Entries size", 1, appendEntries.getEntries().size());
 194         assertEquals("Entry getIndex", lastIndex + 1, appendEntries.getEntries().get(0).getIndex());
 195         assertEquals("Entry getTerm", term, appendEntries.getEntries().get(0).getTerm());
 196         assertEquals("Entry payload", "foo", appendEntries.getEntries().get(0).getData().toString());
 197         assertEquals("Commit Index", lastIndex, actorContext.getCommitIndex());
 198     }
 199
 200     @Test
 201     public void testHandleReplicateMessageWithHigherTermThanPreviousEntry() throws Exception {
 202         logStart("testHandleReplicateMessageWithHigherTermThanPreviousEntry");
 203
 204         MockRaftActorContext actorContext = createActorContextWithFollower();
 205         actorContext.setCommitIndex(-1);
 206
 207         // The raft context is initialized with a couple log entries. However the commitIndex
 208         // is -1, simulating that the leader previously didn't get consensus and thus the log entries weren't
 209         // committed and applied. Now it regains leadership with a higher term (2).
 210         long prevTerm = actorContext.getTermInformation().getCurrentTerm();
 211         long newTerm = prevTerm + 1;
 212         actorContext.getTermInformation().update(newTerm, "");
 213
 214         leader = new Leader(actorContext);
 215         actorContext.setCurrentBehavior(leader);
 216
 217         // Leader will send an immediate heartbeat - ignore it.
 218         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
 219
 220         // The follower replies with the leader's current last index and term, simulating that it is
 221         // up to date with the leader.
 222         long lastIndex = actorContext.getReplicatedLog().lastIndex();
 223         leader.handleMessage(followerActor, new AppendEntriesReply(
 224                 FOLLOWER_ID, newTerm, true, lastIndex, prevTerm, (short)0));
 225
 226         // The commit index should not get updated even though consensus was reached. This is b/c the
 227         // last entry's term does match the current term. As per §5.4.1, "Raft never commits log entries
 228         // from previous terms by counting replicas".
 229         assertEquals("Commit Index", -1, actorContext.getCommitIndex());
 230
 231         followerActor.underlyingActor().clear();
 232
 233         // Now replicate a new entry with the new term 2.
 234         long newIndex = lastIndex + 1;
 235         sendReplicate(actorContext, newTerm, newIndex);
 236
 237         AppendEntries appendEntries = MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
 238         assertEquals("getPrevLogIndex", lastIndex, appendEntries.getPrevLogIndex());
 239         assertEquals("getPrevLogTerm", prevTerm, appendEntries.getPrevLogTerm());
 240         assertEquals("Entries size", 1, appendEntries.getEntries().size());
 241         assertEquals("Entry getIndex", newIndex, appendEntries.getEntries().get(0).getIndex());
 242         assertEquals("Entry getTerm", newTerm, appendEntries.getEntries().get(0).getTerm());
 243         assertEquals("Entry payload", "foo", appendEntries.getEntries().get(0).getData().toString());
 244
 245         // The follower replies with success. The leader should now update the commit index to the new index
 246         // as per §5.4.1 "once an entry from the current term is committed by counting replicas, then all
 247         // prior entries are committed indirectly".
 248         leader.handleMessage(followerActor, new AppendEntriesReply(
 249                 FOLLOWER_ID, newTerm, true, newIndex, newTerm, (short)0));
 250
 251         assertEquals("Commit Index", newIndex, actorContext.getCommitIndex());
 252     }
 253
 254     @Test
 255     public void testHandleReplicateMessageCommitIndexIncrementedBeforeConsensus() throws Exception {
 256         logStart("testHandleReplicateMessageCommitIndexIncrementedBeforeConsensus");
 257
 258         MockRaftActorContext actorContext = createActorContextWithFollower();
 259         actorContext.setRaftPolicy(createRaftPolicy(true, true));
 260
 261         long term = 1;
 262         actorContext.getTermInformation().update(term, "");
 263
 264         leader = new Leader(actorContext);
 265
 266         // Leader will send an immediate heartbeat - ignore it.
 267         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
 268
 269         // The follower would normally reply - simulate that explicitly here.
 270         long lastIndex = actorContext.getReplicatedLog().lastIndex();
 271         leader.handleMessage(followerActor, new AppendEntriesReply(
 272                 FOLLOWER_ID, term, true, lastIndex, term, (short) 0));
 273         assertEquals("isFollowerActive", true, leader.getFollower(FOLLOWER_ID).isFollowerActive());
 274
 275         followerActor.underlyingActor().clear();
 276
 277         RaftActorBehavior raftBehavior = sendReplicate(actorContext, lastIndex + 1);
 278
 279         // State should not change
 280         assertTrue(raftBehavior instanceof Leader);
 281
 282         AppendEntries appendEntries = MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
 283         assertEquals("getPrevLogIndex", lastIndex, appendEntries.getPrevLogIndex());
 284         assertEquals("getPrevLogTerm", term, appendEntries.getPrevLogTerm());
 285         assertEquals("Entries size", 1, appendEntries.getEntries().size());
 286         assertEquals("Entry getIndex", lastIndex + 1, appendEntries.getEntries().get(0).getIndex());
 287         assertEquals("Entry getTerm", term, appendEntries.getEntries().get(0).getTerm());
 288         assertEquals("Entry payload", "foo", appendEntries.getEntries().get(0).getData().toString());
 289         assertEquals("Commit Index", lastIndex+1, actorContext.getCommitIndex());
 290     }
 291
 292     @Test
 293     public void testMultipleReplicateShouldNotCauseDuplicateAppendEntriesToBeSent() throws Exception {
 294         logStart("testHandleReplicateMessageSendAppendEntriesToFollower");
 295
 296         MockRaftActorContext actorContext = createActorContextWithFollower();
 297         actorContext.setConfigParams(new DefaultConfigParamsImpl() {
 298             @Override
 299             public FiniteDuration getHeartBeatInterval() {
 300                 return FiniteDuration.apply(5, TimeUnit.SECONDS);
 301             }
 302         });
 303
 304         long term = 1;
 305         actorContext.getTermInformation().update(term, "");
 306
 307         leader = new Leader(actorContext);
 308
 309         // Leader will send an immediate heartbeat - ignore it.
 310         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
 311
 312         // The follower would normally reply - simulate that explicitly here.
 313         long lastIndex = actorContext.getReplicatedLog().lastIndex();
 314         leader.handleMessage(followerActor, new AppendEntriesReply(
 315                 FOLLOWER_ID, term, true, lastIndex, term, (short)0));
 316         assertEquals("isFollowerActive", true, leader.getFollower(FOLLOWER_ID).isFollowerActive());
 317
 318         followerActor.underlyingActor().clear();
 319
 320         for(int i=0;i<5;i++) {
 321             sendReplicate(actorContext, lastIndex+i+1);
 322         }
 323
 324         List<AppendEntries> allMessages = MessageCollectorActor.getAllMatching(followerActor, AppendEntries.class);
 325         // We expect only 1 message to be sent because of two reasons,
 326         // - an append entries reply was not received
 327         // - the heartbeat interval has not expired
 328         // In this scenario if multiple messages are sent they would likely be duplicates
 329         assertEquals("The number of append entries collected should be 1", 1, allMessages.size());
 330     }
 331
 332     @Test
 333     public void testMultipleReplicateWithReplyShouldResultInAppendEntries() throws Exception {
 334         logStart("testMultipleReplicateWithReplyShouldResultInAppendEntries");
 335
 336         MockRaftActorContext actorContext = createActorContextWithFollower();
 337         actorContext.setConfigParams(new DefaultConfigParamsImpl() {
 338             @Override
 339             public FiniteDuration getHeartBeatInterval() {
 340                 return FiniteDuration.apply(5, TimeUnit.SECONDS);
 341             }
 342         });
 343
 344         long term = 1;
 345         actorContext.getTermInformation().update(term, "");
 346
 347         leader = new Leader(actorContext);
 348
 349         // Leader will send an immediate heartbeat - ignore it.
 350         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
 351
 352         // The follower would normally reply - simulate that explicitly here.
 353         long lastIndex = actorContext.getReplicatedLog().lastIndex();
 354         leader.handleMessage(followerActor, new AppendEntriesReply(
 355                 FOLLOWER_ID, term, true, lastIndex, term, (short)0));
 356         assertEquals("isFollowerActive", true, leader.getFollower(FOLLOWER_ID).isFollowerActive());
 357
 358         followerActor.underlyingActor().clear();
 359
 360         for(int i=0;i<3;i++) {
 361             sendReplicate(actorContext, lastIndex+i+1);
 362             leader.handleMessage(followerActor, new AppendEntriesReply(
 363                     FOLLOWER_ID, term, true, lastIndex + i + 1, term, (short)0));
 364
 365         }
 366
 367         for(int i=3;i<5;i++) {
 368             sendReplicate(actorContext, lastIndex + i + 1);
 369         }
 370
 371         List<AppendEntries> allMessages = MessageCollectorActor.getAllMatching(followerActor, AppendEntries.class);
 372         // We expect 4 here because the first 3 replicate got a reply and so the 4th entry would
 373         // get sent to the follower - but not the 5th
 374         assertEquals("The number of append entries collected should be 4", 4, allMessages.size());
 375
 376         for(int i=0;i<4;i++) {
 377             long expected = allMessages.get(i).getEntries().get(0).getIndex();
 378             assertEquals(expected, i+2);
 379         }
 380     }
 381
 382     @Test
 383     public void testDuplicateAppendEntriesWillBeSentOnHeartBeat() throws Exception {
 384         logStart("testDuplicateAppendEntriesWillBeSentOnHeartBeat");
 385
 386         MockRaftActorContext actorContext = createActorContextWithFollower();
 387         actorContext.setConfigParams(new DefaultConfigParamsImpl() {
 388             @Override
 389             public FiniteDuration getHeartBeatInterval() {
 390                 return FiniteDuration.apply(500, TimeUnit.MILLISECONDS);
 391             }
 392         });
 393
 394         long term = 1;
 395         actorContext.getTermInformation().update(term, "");
 396
 397         leader = new Leader(actorContext);
 398
 399         // Leader will send an immediate heartbeat - ignore it.
 400         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
 401
 402         // The follower would normally reply - simulate that explicitly here.
 403         long lastIndex = actorContext.getReplicatedLog().lastIndex();
 404         leader.handleMessage(followerActor, new AppendEntriesReply(
 405                 FOLLOWER_ID, term, true, lastIndex, term, (short)0));
 406         assertEquals("isFollowerActive", true, leader.getFollower(FOLLOWER_ID).isFollowerActive());
 407
 408         followerActor.underlyingActor().clear();
 409
 410         sendReplicate(actorContext, lastIndex+1);
 411
 412         // Wait slightly longer than heartbeat duration
 413         Uninterruptibles.sleepUninterruptibly(750, TimeUnit.MILLISECONDS);
 414
 415         leader.handleMessage(leaderActor, SendHeartBeat.INSTANCE);
 416
 417         List<AppendEntries> allMessages = MessageCollectorActor.getAllMatching(followerActor, AppendEntries.class);
 418         assertEquals("The number of append entries collected should be 2", 2, allMessages.size());
 419
 420         assertEquals(1, allMessages.get(0).getEntries().size());
 421         assertEquals(lastIndex+1, allMessages.get(0).getEntries().get(0).getIndex());
 422         assertEquals(1, allMessages.get(1).getEntries().size());
 423         assertEquals(lastIndex+1, allMessages.get(0).getEntries().get(0).getIndex());
 424
 425     }
 426
 427     @Test
 428     public void testHeartbeatsAreAlwaysSentIfTheHeartbeatIntervalHasElapsed() throws Exception {
 429         logStart("testHeartbeatsAreAlwaysSentIfTheHeartbeatIntervalHasElapsed");
 430
 431         MockRaftActorContext actorContext = createActorContextWithFollower();
 432         actorContext.setConfigParams(new DefaultConfigParamsImpl() {
 433             @Override
 434             public FiniteDuration getHeartBeatInterval() {
 435                 return FiniteDuration.apply(100, TimeUnit.MILLISECONDS);
 436             }
 437         });
 438
 439         long term = 1;
 440         actorContext.getTermInformation().update(term, "");
 441
 442         leader = new Leader(actorContext);
 443
 444         // Leader will send an immediate heartbeat - ignore it.
 445         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
 446
 447         // The follower would normally reply - simulate that explicitly here.
 448         long lastIndex = actorContext.getReplicatedLog().lastIndex();
 449         leader.handleMessage(followerActor, new AppendEntriesReply(
 450                 FOLLOWER_ID, term, true, lastIndex, term, (short)0));
 451         assertEquals("isFollowerActive", true, leader.getFollower(FOLLOWER_ID).isFollowerActive());
 452
 453         followerActor.underlyingActor().clear();
 454
 455         for(int i=0;i<3;i++) {
 456             Uninterruptibles.sleepUninterruptibly(150, TimeUnit.MILLISECONDS);
 457             leader.handleMessage(leaderActor, SendHeartBeat.INSTANCE);
 458         }
 459
 460         List<AppendEntries> allMessages = MessageCollectorActor.getAllMatching(followerActor, AppendEntries.class);
 461         assertEquals("The number of append entries collected should be 3", 3, allMessages.size());
 462     }
 463
 464     @Test
 465     public void testSendingReplicateImmediatelyAfterHeartbeatDoesReplicate() throws Exception {
 466         logStart("testSendingReplicateImmediatelyAfterHeartbeatDoesReplicate");
 467
 468         MockRaftActorContext actorContext = createActorContextWithFollower();
 469         actorContext.setConfigParams(new DefaultConfigParamsImpl() {
 470             @Override
 471             public FiniteDuration getHeartBeatInterval() {
 472                 return FiniteDuration.apply(100, TimeUnit.MILLISECONDS);
 473             }
 474         });
 475
 476         long term = 1;
 477         actorContext.getTermInformation().update(term, "");
 478
 479         leader = new Leader(actorContext);
 480
 481         // Leader will send an immediate heartbeat - ignore it.
 482         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
 483
 484         // The follower would normally reply - simulate that explicitly here.
 485         long lastIndex = actorContext.getReplicatedLog().lastIndex();
 486         leader.handleMessage(followerActor, new AppendEntriesReply(
 487                 FOLLOWER_ID, term, true, lastIndex, term, (short)0));
 488         assertEquals("isFollowerActive", true, leader.getFollower(FOLLOWER_ID).isFollowerActive());
 489
 490         followerActor.underlyingActor().clear();
 491
 492         Uninterruptibles.sleepUninterruptibly(150, TimeUnit.MILLISECONDS);
 493         leader.handleMessage(leaderActor, SendHeartBeat.INSTANCE);
 494         sendReplicate(actorContext, lastIndex+1);
 495
 496         List<AppendEntries> allMessages = MessageCollectorActor.getAllMatching(followerActor, AppendEntries.class);
 497         assertEquals("The number of append entries collected should be 2", 2, allMessages.size());
 498
 499         assertEquals(0, allMessages.get(0).getEntries().size());
 500         assertEquals(1, allMessages.get(1).getEntries().size());
 501     }
 502
 503
 504     @Test
 505     public void testHandleReplicateMessageWhenThereAreNoFollowers() throws Exception {
 506         logStart("testHandleReplicateMessageWhenThereAreNoFollowers");
 507
 508         MockRaftActorContext actorContext = createActorContext();
 509
 510         leader = new Leader(actorContext);
 511
 512         actorContext.setLastApplied(0);
 513
 514         long newLogIndex = actorContext.getReplicatedLog().lastIndex() + 1;
 515         long term = actorContext.getTermInformation().getCurrentTerm();
 516         MockRaftActorContext.MockReplicatedLogEntry newEntry = new MockRaftActorContext.MockReplicatedLogEntry(
 517                 term, newLogIndex, new MockRaftActorContext.MockPayload("foo"));
 518
 519         actorContext.getReplicatedLog().append(newEntry);
 520
 521         final Identifier id = new MockIdentifier("state-id");
 522         RaftActorBehavior raftBehavior = leader.handleMessage(leaderActor, new Replicate(leaderActor, id, newEntry));
 523
 524         // State should not change
 525         assertTrue(raftBehavior instanceof Leader);
 526
 527         assertEquals("getCommitIndex", newLogIndex, actorContext.getCommitIndex());
 528
 529         // We should get 2 ApplyState messages - 1 for new log entry and 1 for the previous
 530         // one since lastApplied state is 0.
 531         List<ApplyState> applyStateList = MessageCollectorActor.getAllMatching(
 532                 leaderActor, ApplyState.class);
 533         assertEquals("ApplyState count", newLogIndex, applyStateList.size());
 534
 535         for(int i = 0; i <= newLogIndex - 1; i++ ) {
 536             ApplyState applyState = applyStateList.get(i);
 537             assertEquals("getIndex", i + 1, applyState.getReplicatedLogEntry().getIndex());
 538             assertEquals("getTerm", term, applyState.getReplicatedLogEntry().getTerm());
 539         }
 540
 541         ApplyState last = applyStateList.get((int) newLogIndex - 1);
 542         assertEquals("getData", newEntry.getData(), last.getReplicatedLogEntry().getData());
 543         assertEquals("getIdentifier", id, last.getIdentifier());
 544     }
 545
 546     @Test
 547     public void testSendAppendEntriesOnAnInProgressInstallSnapshot() throws Exception {
 548         logStart("testSendAppendEntriesOnAnInProgressInstallSnapshot");
 549
 550         MockRaftActorContext actorContext = createActorContextWithFollower();
 551
 552         Map<String, String> leadersSnapshot = new HashMap<>();
 553         leadersSnapshot.put("1", "A");
 554         leadersSnapshot.put("2", "B");
 555         leadersSnapshot.put("3", "C");
 556
 557         //clears leaders log
 558         actorContext.getReplicatedLog().removeFrom(0);
 559
 560         final int commitIndex = 3;
 561         final int snapshotIndex = 2;
 562         final int newEntryIndex = 4;
 563         final int snapshotTerm = 1;
 564         final int currentTerm = 2;
 565
 566         // set the snapshot variables in replicatedlog
 567         actorContext.getReplicatedLog().setSnapshotIndex(snapshotIndex);
 568         actorContext.getReplicatedLog().setSnapshotTerm(snapshotTerm);
 569         actorContext.setCommitIndex(commitIndex);
 570         //set follower timeout to 2 mins, helps during debugging
 571         actorContext.setConfigParams(new MockConfigParamsImpl(120000L, 10));
 572
 573         leader = new Leader(actorContext);
 574
 575         leader.getFollower(FOLLOWER_ID).setMatchIndex(-1);
 576         leader.getFollower(FOLLOWER_ID).setNextIndex(0);
 577
 578         // new entry
 579         ReplicatedLogImplEntry entry =
 580                 new ReplicatedLogImplEntry(newEntryIndex, currentTerm,
 581                         new MockRaftActorContext.MockPayload("D"));
 582
 583         //update follower timestamp
 584         leader.markFollowerActive(FOLLOWER_ID);
 585
 586         ByteString bs = toByteString(leadersSnapshot);
 587         leader.setSnapshot(Snapshot.create(bs.toByteArray(), Collections.<ReplicatedLogEntry>emptyList(),
 588                 commitIndex, snapshotTerm, commitIndex, snapshotTerm));
 589         FollowerToSnapshot fts = leader.new FollowerToSnapshot(bs);
 590         leader.setFollowerSnapshot(FOLLOWER_ID, fts);
 591
 592         //send first chunk and no InstallSnapshotReply received yet
 593         fts.getNextChunk();
 594         fts.incrementChunkIndex();
 595
 596         Uninterruptibles.sleepUninterruptibly(actorContext.getConfigParams().getHeartBeatInterval().toMillis(),
 597                 TimeUnit.MILLISECONDS);
 598
 599         leader.handleMessage(leaderActor, SendHeartBeat.INSTANCE);
 600
 601         AppendEntries aeproto = MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
 602
 603         AppendEntries ae = (AppendEntries) SerializationUtils.fromSerializable(aeproto);
 604
 605         assertTrue("AppendEntries should be sent with empty entries", ae.getEntries().isEmpty());
 606
 607         //InstallSnapshotReply received
 608         fts.markSendStatus(true);
 609
 610         leader.handleMessage(leaderActor, SendHeartBeat.INSTANCE);
 611
 612         InstallSnapshot is = MessageCollectorActor.expectFirstMatching(followerActor, InstallSnapshot.class);
 613
 614         assertEquals(commitIndex, is.getLastIncludedIndex());
 615     }
 616
 617     @Test
 618     public void testSendAppendEntriesSnapshotScenario() throws Exception {
 619         logStart("testSendAppendEntriesSnapshotScenario");
 620
 621         MockRaftActorContext actorContext = createActorContextWithFollower();
 622
 623         Map<String, String> leadersSnapshot = new HashMap<>();
 624         leadersSnapshot.put("1", "A");
 625         leadersSnapshot.put("2", "B");
 626         leadersSnapshot.put("3", "C");
 627
 628         //clears leaders log
 629         actorContext.getReplicatedLog().removeFrom(0);
 630
 631         final int followersLastIndex = 2;
 632         final int snapshotIndex = 3;
 633         final int newEntryIndex = 4;
 634         final int snapshotTerm = 1;
 635         final int currentTerm = 2;
 636
 637         // set the snapshot variables in replicatedlog
 638         actorContext.getReplicatedLog().setSnapshotIndex(snapshotIndex);
 639         actorContext.getReplicatedLog().setSnapshotTerm(snapshotTerm);
 640         actorContext.setCommitIndex(followersLastIndex);
 641
 642         leader = new Leader(actorContext);
 643
 644         // Leader will send an immediate heartbeat - ignore it.
 645         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
 646
 647         // new entry
 648         ReplicatedLogImplEntry entry =
 649                 new ReplicatedLogImplEntry(newEntryIndex, currentTerm,
 650                         new MockRaftActorContext.MockPayload("D"));
 651
 652         actorContext.getReplicatedLog().append(entry);
 653
 654         //update follower timestamp
 655         leader.markFollowerActive(FOLLOWER_ID);
 656
 657         // this should invoke a sendinstallsnapshot as followersLastIndex < snapshotIndex
 658         RaftActorBehavior raftBehavior = leader.handleMessage(
 659                 leaderActor, new Replicate(null, new MockIdentifier("state-id"), entry));
 660
 661         assertTrue(raftBehavior instanceof Leader);
 662
 663         assertEquals("isCapturing", true, actorContext.getSnapshotManager().isCapturing());
 664     }
 665
 666     @Test
 667     public void testInitiateInstallSnapshot() throws Exception {
 668         logStart("testInitiateInstallSnapshot");
 669
 670         MockRaftActorContext actorContext = createActorContextWithFollower();
 671
 672         //clears leaders log
 673         actorContext.getReplicatedLog().removeFrom(0);
 674
 675         final int followersLastIndex = 2;
 676         final int snapshotIndex = 3;
 677         final int newEntryIndex = 4;
 678         final int snapshotTerm = 1;
 679         final int currentTerm = 2;
 680
 681         // set the snapshot variables in replicatedlog
 682         actorContext.getReplicatedLog().setSnapshotIndex(snapshotIndex);
 683         actorContext.getReplicatedLog().setSnapshotTerm(snapshotTerm);
 684         actorContext.setLastApplied(3);
 685         actorContext.setCommitIndex(followersLastIndex);
 686
 687         leader = new Leader(actorContext);
 688
 689         // Leader will send an immediate heartbeat - ignore it.
 690         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
 691
 692         // set the snapshot as absent and check if capture-snapshot is invoked.
 693         leader.setSnapshot(null);
 694
 695         // new entry
 696         ReplicatedLogImplEntry entry = new ReplicatedLogImplEntry(newEntryIndex, currentTerm,
 697                 new MockRaftActorContext.MockPayload("D"));
 698
 699         actorContext.getReplicatedLog().append(entry);
 700
 701         //update follower timestamp
 702         leader.markFollowerActive(FOLLOWER_ID);
 703
 704         leader.handleMessage(leaderActor, new Replicate(null, new MockIdentifier("state-id"), entry));
 705
 706         assertEquals("isCapturing", true, actorContext.getSnapshotManager().isCapturing());
 707
 708         CaptureSnapshot cs = actorContext.getSnapshotManager().getCaptureSnapshot();
 709
 710         assertTrue(cs.isInstallSnapshotInitiated());
 711         assertEquals(3, cs.getLastAppliedIndex());
 712         assertEquals(1, cs.getLastAppliedTerm());
 713         assertEquals(4, cs.getLastIndex());
 714         assertEquals(2, cs.getLastTerm());
 715
 716         // if an initiate is started again when first is in progress, it shouldnt initiate Capture
 717         leader.handleMessage(leaderActor, new Replicate(null, new MockIdentifier("state-id"), entry));
 718
 719         assertSame("CaptureSnapshot instance", cs, actorContext.getSnapshotManager().getCaptureSnapshot());
 720     }
 721
 722     @Test
 723     public void testInitiateForceInstallSnapshot() throws Exception {
 724         logStart("testInitiateForceInstallSnapshot");
 725
 726         MockRaftActorContext actorContext = createActorContextWithFollower();
 727
 728         final int followersLastIndex = 2;
 729         final int snapshotIndex = -1;
 730         final int newEntryIndex = 4;
 731         final int snapshotTerm = -1;
 732         final int currentTerm = 2;
 733
 734         // set the snapshot variables in replicatedlog
 735         actorContext.getReplicatedLog().setSnapshotIndex(snapshotIndex);
 736         actorContext.getReplicatedLog().setSnapshotTerm(snapshotTerm);
 737         actorContext.setLastApplied(3);
 738         actorContext.setCommitIndex(followersLastIndex);
 739
 740         actorContext.getReplicatedLog().removeFrom(0);
 741
 742         leader = new Leader(actorContext);
 743
 744         // Leader will send an immediate heartbeat - ignore it.
 745         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
 746
 747         // set the snapshot as absent and check if capture-snapshot is invoked.
 748         leader.setSnapshot(null);
 749
 750         for(int i=0;i<4;i++) {
 751             actorContext.getReplicatedLog().append(new ReplicatedLogImplEntry(i, 1,
 752                     new MockRaftActorContext.MockPayload("X" + i)));
 753         }
 754
 755         // new entry
 756         ReplicatedLogImplEntry entry = new ReplicatedLogImplEntry(newEntryIndex, currentTerm,
 757                 new MockRaftActorContext.MockPayload("D"));
 758
 759         actorContext.getReplicatedLog().append(entry);
 760
 761         //update follower timestamp
 762         leader.markFollowerActive(FOLLOWER_ID);
 763
 764         // Sending this AppendEntriesReply forces the Leader to capture a snapshot, which subsequently gets
 765         // installed with a SendInstallSnapshot
 766         leader.handleMessage(leaderActor, new AppendEntriesReply(FOLLOWER_ID, 1, false, 100, 1, (short) 1, true));
 767
 768         assertEquals("isCapturing", true, actorContext.getSnapshotManager().isCapturing());
 769
 770         CaptureSnapshot cs = actorContext.getSnapshotManager().getCaptureSnapshot();
 771
 772         assertTrue(cs.isInstallSnapshotInitiated());
 773         assertEquals(3, cs.getLastAppliedIndex());
 774         assertEquals(1, cs.getLastAppliedTerm());
 775         assertEquals(4, cs.getLastIndex());
 776         assertEquals(2, cs.getLastTerm());
 777
 778         // if an initiate is started again when first is in progress, it should not initiate Capture
 779         leader.handleMessage(leaderActor, new Replicate(null, new MockIdentifier("state-id"), entry));
 780
 781         assertSame("CaptureSnapshot instance", cs, actorContext.getSnapshotManager().getCaptureSnapshot());
 782     }
 783
 784
 785     @Test
 786     public void testInstallSnapshot() throws Exception {
 787         logStart("testInstallSnapshot");
 788
 789         MockRaftActorContext actorContext = createActorContextWithFollower();
 790
 791         Map<String, String> leadersSnapshot = new HashMap<>();
 792         leadersSnapshot.put("1", "A");
 793         leadersSnapshot.put("2", "B");
 794         leadersSnapshot.put("3", "C");
 795
 796         //clears leaders log
 797         actorContext.getReplicatedLog().removeFrom(0);
 798
 799         final int lastAppliedIndex = 3;
 800         final int snapshotIndex = 2;
 801         final int snapshotTerm = 1;
 802         final int currentTerm = 2;
 803
 804         // set the snapshot variables in replicatedlog
 805         actorContext.getReplicatedLog().setSnapshotIndex(snapshotIndex);
 806         actorContext.getReplicatedLog().setSnapshotTerm(snapshotTerm);
 807         actorContext.getTermInformation().update(currentTerm, leaderActor.path().toString());
 808         actorContext.setCommitIndex(lastAppliedIndex);
 809         actorContext.setLastApplied(lastAppliedIndex);
 810
 811         leader = new Leader(actorContext);
 812
 813         // Initial heartbeat.
 814         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
 815
 816         leader.getFollower(FOLLOWER_ID).setMatchIndex(-1);
 817         leader.getFollower(FOLLOWER_ID).setNextIndex(0);
 818
 819         Snapshot snapshot = Snapshot.create(toByteString(leadersSnapshot).toByteArray(),
 820                 Collections.<ReplicatedLogEntry>emptyList(),
 821                 lastAppliedIndex, snapshotTerm, lastAppliedIndex, snapshotTerm);
 822
 823         RaftActorBehavior raftBehavior = leader.handleMessage(leaderActor, new SendInstallSnapshot(snapshot));
 824
 825         assertTrue(raftBehavior instanceof Leader);
 826
 827         // check if installsnapshot gets called with the correct values.
 828
 829         InstallSnapshot installSnapshot = MessageCollectorActor.expectFirstMatching(followerActor, InstallSnapshot.class);
 830
 831         assertNotNull(installSnapshot.getData());
 832         assertEquals(lastAppliedIndex, installSnapshot.getLastIncludedIndex());
 833         assertEquals(snapshotTerm, installSnapshot.getLastIncludedTerm());
 834
 835         assertEquals(currentTerm, installSnapshot.getTerm());
 836     }
 837
 838     @Test
 839     public void testForceInstallSnapshot() throws Exception {
 840         logStart("testForceInstallSnapshot");
 841
 842         MockRaftActorContext actorContext = createActorContextWithFollower();
 843
 844         Map<String, String> leadersSnapshot = new HashMap<>();
 845         leadersSnapshot.put("1", "A");
 846         leadersSnapshot.put("2", "B");
 847         leadersSnapshot.put("3", "C");
 848
 849         final int lastAppliedIndex = 3;
 850         final int snapshotIndex = -1;
 851         final int snapshotTerm = -1;
 852         final int currentTerm = 2;
 853
 854         // set the snapshot variables in replicatedlog
 855         actorContext.getReplicatedLog().setSnapshotIndex(snapshotIndex);
 856         actorContext.getReplicatedLog().setSnapshotTerm(snapshotTerm);
 857         actorContext.getTermInformation().update(currentTerm, leaderActor.path().toString());
 858         actorContext.setCommitIndex(lastAppliedIndex);
 859         actorContext.setLastApplied(lastAppliedIndex);
 860
 861         leader = new Leader(actorContext);
 862
 863         // Initial heartbeat.
 864         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
 865
 866         leader.getFollower(FOLLOWER_ID).setMatchIndex(-1);
 867         leader.getFollower(FOLLOWER_ID).setNextIndex(-1);
 868
 869         Snapshot snapshot = Snapshot.create(toByteString(leadersSnapshot).toByteArray(),
 870                 Collections.<ReplicatedLogEntry>emptyList(),
 871                 lastAppliedIndex, snapshotTerm, lastAppliedIndex, snapshotTerm);
 872
 873         RaftActorBehavior raftBehavior = leader.handleMessage(leaderActor, new SendInstallSnapshot(snapshot));
 874
 875         assertTrue(raftBehavior instanceof Leader);
 876
 877         // check if installsnapshot gets called with the correct values.
 878
 879         InstallSnapshot installSnapshot = MessageCollectorActor.expectFirstMatching(followerActor, InstallSnapshot.class);
 880
 881         assertNotNull(installSnapshot.getData());
 882         assertEquals(lastAppliedIndex, installSnapshot.getLastIncludedIndex());
 883         assertEquals(snapshotTerm, installSnapshot.getLastIncludedTerm());
 884
 885         assertEquals(currentTerm, installSnapshot.getTerm());
 886     }
 887
 888     @Test
 889     public void testHandleInstallSnapshotReplyLastChunk() throws Exception {
 890         logStart("testHandleInstallSnapshotReplyLastChunk");
 891
 892         MockRaftActorContext actorContext = createActorContextWithFollower();
 893
 894         final int commitIndex = 3;
 895         final int snapshotIndex = 2;
 896         final int snapshotTerm = 1;
 897         final int currentTerm = 2;
 898
 899         actorContext.setCommitIndex(commitIndex);
 900
 901         leader = new Leader(actorContext);
 902         actorContext.setCurrentBehavior(leader);
 903
 904         leader.getFollower(FOLLOWER_ID).setMatchIndex(-1);
 905         leader.getFollower(FOLLOWER_ID).setNextIndex(0);
 906
 907         // Ignore initial heartbeat.
 908         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
 909
 910         Map<String, String> leadersSnapshot = new HashMap<>();
 911         leadersSnapshot.put("1", "A");
 912         leadersSnapshot.put("2", "B");
 913         leadersSnapshot.put("3", "C");
 914
 915         // set the snapshot variables in replicatedlog
 916
 917         actorContext.getReplicatedLog().setSnapshotIndex(snapshotIndex);
 918         actorContext.getReplicatedLog().setSnapshotTerm(snapshotTerm);
 919         actorContext.getTermInformation().update(currentTerm, leaderActor.path().toString());
 920
 921         ByteString bs = toByteString(leadersSnapshot);
 922         leader.setSnapshot(Snapshot.create(bs.toByteArray(), Collections.<ReplicatedLogEntry>emptyList(),
 923                 commitIndex, snapshotTerm, commitIndex, snapshotTerm));
 924         FollowerToSnapshot fts = leader.new FollowerToSnapshot(bs);
 925         leader.setFollowerSnapshot(FOLLOWER_ID, fts);
 926         while(!fts.isLastChunk(fts.getChunkIndex())) {
 927             fts.getNextChunk();
 928             fts.incrementChunkIndex();
 929         }
 930
 931         //clears leaders log
 932         actorContext.getReplicatedLog().removeFrom(0);
 933
 934         RaftActorBehavior raftBehavior = leader.handleMessage(followerActor,
 935                 new InstallSnapshotReply(currentTerm, FOLLOWER_ID, fts.getChunkIndex(), true));
 936
 937         assertTrue(raftBehavior instanceof Leader);
 938
 939         assertEquals(0, leader.followerSnapshotSize());
 940         assertEquals(1, leader.followerLogSize());
 941         FollowerLogInformation fli = leader.getFollower(FOLLOWER_ID);
 942         assertNotNull(fli);
 943         assertEquals(commitIndex, fli.getMatchIndex());
 944         assertEquals(commitIndex + 1, fli.getNextIndex());
 945     }
 946
 947     @Test
 948     public void testSendSnapshotfromInstallSnapshotReply() throws Exception {
 949         logStart("testSendSnapshotfromInstallSnapshotReply");
 950
 951         MockRaftActorContext actorContext = createActorContextWithFollower();
 952
 953         final int commitIndex = 3;
 954         final int snapshotIndex = 2;
 955         final int snapshotTerm = 1;
 956         final int currentTerm = 2;
 957
 958         DefaultConfigParamsImpl configParams = new DefaultConfigParamsImpl(){
 959             @Override
 960             public int getSnapshotChunkSize() {
 961                 return 50;
 962             }
 963         };
 964         configParams.setHeartBeatInterval(new FiniteDuration(9, TimeUnit.SECONDS));
 965         configParams.setIsolatedLeaderCheckInterval(new FiniteDuration(10, TimeUnit.SECONDS));
 966
 967         actorContext.setConfigParams(configParams);
 968         actorContext.setCommitIndex(commitIndex);
 969
 970         leader = new Leader(actorContext);
 971         actorContext.setCurrentBehavior(leader);
 972
 973         leader.getFollower(FOLLOWER_ID).setMatchIndex(-1);
 974         leader.getFollower(FOLLOWER_ID).setNextIndex(0);
 975
 976         Map<String, String> leadersSnapshot = new HashMap<>();
 977         leadersSnapshot.put("1", "A");
 978         leadersSnapshot.put("2", "B");
 979         leadersSnapshot.put("3", "C");
 980
 981         // set the snapshot variables in replicatedlog
 982         actorContext.getReplicatedLog().setSnapshotIndex(snapshotIndex);
 983         actorContext.getReplicatedLog().setSnapshotTerm(snapshotTerm);
 984         actorContext.getTermInformation().update(currentTerm, leaderActor.path().toString());
 985
 986         ByteString bs = toByteString(leadersSnapshot);
 987         Snapshot snapshot = Snapshot.create(bs.toByteArray(), Collections.<ReplicatedLogEntry>emptyList(),
 988                 commitIndex, snapshotTerm, commitIndex, snapshotTerm);
 989         leader.setSnapshot(snapshot);
 990
 991         leader.handleMessage(leaderActor, new SendInstallSnapshot(snapshot));
 992
 993         InstallSnapshot installSnapshot = MessageCollectorActor.expectFirstMatching(followerActor, InstallSnapshot.class);
 994
 995         assertEquals(1, installSnapshot.getChunkIndex());
 996         assertEquals(3, installSnapshot.getTotalChunks());
 997
 998         followerActor.underlyingActor().clear();
 999         leader.handleMessage(followerActor, new InstallSnapshotReply(actorContext.getTermInformation().getCurrentTerm(),
1000                 FOLLOWER_ID, installSnapshot.getChunkIndex(), true));
1001
1002         installSnapshot = MessageCollectorActor.expectFirstMatching(followerActor, InstallSnapshot.class);
1003
1004         assertEquals(2, installSnapshot.getChunkIndex());
1005         assertEquals(3, installSnapshot.getTotalChunks());
1006
1007         followerActor.underlyingActor().clear();
1008         leader.handleMessage(followerActor, new InstallSnapshotReply(actorContext.getTermInformation().getCurrentTerm(),
1009                 FOLLOWER_ID, installSnapshot.getChunkIndex(), true));
1010
1011         installSnapshot = MessageCollectorActor.expectFirstMatching(followerActor, InstallSnapshot.class);
1012
1013         // Send snapshot reply one more time and make sure that a new snapshot message should not be sent to follower
1014         followerActor.underlyingActor().clear();
1015         leader.handleMessage(followerActor, new InstallSnapshotReply(actorContext.getTermInformation().getCurrentTerm(),
1016                 FOLLOWER_ID, installSnapshot.getChunkIndex(), true));
1017
1018         installSnapshot = MessageCollectorActor.getFirstMatching(followerActor, InstallSnapshot.class);
1019
1020         assertNull(installSnapshot);
1021     }
1022
1023
1024     @Test
1025     public void testHandleInstallSnapshotReplyWithInvalidChunkIndex() throws Exception{
1026         logStart("testHandleInstallSnapshotReplyWithInvalidChunkIndex");
1027
1028         MockRaftActorContext actorContext = createActorContextWithFollower();
1029
1030         final int commitIndex = 3;
1031         final int snapshotIndex = 2;
1032         final int snapshotTerm = 1;
1033         final int currentTerm = 2;
1034
1035         actorContext.setConfigParams(new DefaultConfigParamsImpl(){
1036             @Override
1037             public int getSnapshotChunkSize() {
1038                 return 50;
1039             }
1040         });
1041
1042         actorContext.setCommitIndex(commitIndex);
1043
1044         leader = new Leader(actorContext);
1045
1046         leader.getFollower(FOLLOWER_ID).setMatchIndex(-1);
1047         leader.getFollower(FOLLOWER_ID).setNextIndex(0);
1048
1049         Map<String, String> leadersSnapshot = new HashMap<>();
1050         leadersSnapshot.put("1", "A");
1051         leadersSnapshot.put("2", "B");
1052         leadersSnapshot.put("3", "C");
1053
1054         // set the snapshot variables in replicatedlog
1055         actorContext.getReplicatedLog().setSnapshotIndex(snapshotIndex);
1056         actorContext.getReplicatedLog().setSnapshotTerm(snapshotTerm);
1057         actorContext.getTermInformation().update(currentTerm, leaderActor.path().toString());
1058
1059         ByteString bs = toByteString(leadersSnapshot);
1060         Snapshot snapshot = Snapshot.create(bs.toByteArray(), Collections.<ReplicatedLogEntry>emptyList(),
1061                 commitIndex, snapshotTerm, commitIndex, snapshotTerm);
1062         leader.setSnapshot(snapshot);
1063
1064         Uninterruptibles.sleepUninterruptibly(1, TimeUnit.SECONDS);
1065         leader.handleMessage(leaderActor, new SendInstallSnapshot(snapshot));
1066
1067         InstallSnapshot installSnapshot = MessageCollectorActor.expectFirstMatching(followerActor, InstallSnapshot.class);
1068
1069         assertEquals(1, installSnapshot.getChunkIndex());
1070         assertEquals(3, installSnapshot.getTotalChunks());
1071
1072         followerActor.underlyingActor().clear();
1073
1074         leader.handleMessage(followerActor, new InstallSnapshotReply(actorContext.getTermInformation().getCurrentTerm(),
1075                 FOLLOWER_ID, -1, false));
1076
1077         Uninterruptibles.sleepUninterruptibly(actorContext.getConfigParams().getHeartBeatInterval().toMillis(),
1078                 TimeUnit.MILLISECONDS);
1079
1080         leader.handleMessage(leaderActor, SendHeartBeat.INSTANCE);
1081
1082         installSnapshot = MessageCollectorActor.expectFirstMatching(followerActor, InstallSnapshot.class);
1083
1084         assertEquals(1, installSnapshot.getChunkIndex());
1085         assertEquals(3, installSnapshot.getTotalChunks());
1086     }
1087
1088     @Test
1089     public void testHandleSnapshotSendsPreviousChunksHashCodeWhenSendingNextChunk() throws Exception {
1090         logStart("testHandleSnapshotSendsPreviousChunksHashCodeWhenSendingNextChunk");
1091
1092         MockRaftActorContext actorContext = createActorContextWithFollower();
1093
1094         final int commitIndex = 3;
1095         final int snapshotIndex = 2;
1096         final int snapshotTerm = 1;
1097         final int currentTerm = 2;
1098
1099         actorContext.setConfigParams(new DefaultConfigParamsImpl() {
1100             @Override
1101             public int getSnapshotChunkSize() {
1102                 return 50;
1103             }
1104         });
1105
1106         actorContext.setCommitIndex(commitIndex);
1107
1108         leader = new Leader(actorContext);
1109
1110         leader.getFollower(FOLLOWER_ID).setMatchIndex(-1);
1111         leader.getFollower(FOLLOWER_ID).setNextIndex(0);
1112
1113         Map<String, String> leadersSnapshot = new HashMap<>();
1114         leadersSnapshot.put("1", "A");
1115         leadersSnapshot.put("2", "B");
1116         leadersSnapshot.put("3", "C");
1117
1118         // set the snapshot variables in replicatedlog
1119         actorContext.getReplicatedLog().setSnapshotIndex(snapshotIndex);
1120         actorContext.getReplicatedLog().setSnapshotTerm(snapshotTerm);
1121         actorContext.getTermInformation().update(currentTerm, leaderActor.path().toString());
1122
1123         ByteString bs = toByteString(leadersSnapshot);
1124         Snapshot snapshot = Snapshot.create(bs.toByteArray(), Collections.<ReplicatedLogEntry>emptyList(),
1125                 commitIndex, snapshotTerm, commitIndex, snapshotTerm);
1126         leader.setSnapshot(snapshot);
1127
1128         leader.handleMessage(leaderActor, new SendInstallSnapshot(snapshot));
1129
1130         InstallSnapshot installSnapshot = MessageCollectorActor.expectFirstMatching(followerActor, InstallSnapshot.class);
1131
1132         assertEquals(1, installSnapshot.getChunkIndex());
1133         assertEquals(3, installSnapshot.getTotalChunks());
1134         assertEquals(AbstractLeader.INITIAL_LAST_CHUNK_HASH_CODE, installSnapshot.getLastChunkHashCode().get().intValue());
1135
1136         int hashCode = Arrays.hashCode(installSnapshot.getData());
1137
1138         followerActor.underlyingActor().clear();
1139
1140         leader.handleMessage(followerActor, new InstallSnapshotReply(installSnapshot.getTerm(),
1141                 FOLLOWER_ID, 1, true));
1142
1143         installSnapshot = MessageCollectorActor.expectFirstMatching(followerActor, InstallSnapshot.class);
1144
1145         assertEquals(2, installSnapshot.getChunkIndex());
1146         assertEquals(3, installSnapshot.getTotalChunks());
1147         assertEquals(hashCode, installSnapshot.getLastChunkHashCode().get().intValue());
1148     }
1149
1150     @Test
1151     public void testFollowerToSnapshotLogic() {
1152         logStart("testFollowerToSnapshotLogic");
1153
1154         MockRaftActorContext actorContext = createActorContext();
1155
1156         actorContext.setConfigParams(new DefaultConfigParamsImpl() {
1157             @Override
1158             public int getSnapshotChunkSize() {
1159                 return 50;
1160             }
1161         });
1162
1163         leader = new Leader(actorContext);
1164
1165         Map<String, String> leadersSnapshot = new HashMap<>();
1166         leadersSnapshot.put("1", "A");
1167         leadersSnapshot.put("2", "B");
1168         leadersSnapshot.put("3", "C");
1169
1170         ByteString bs = toByteString(leadersSnapshot);
1171         byte[] barray = bs.toByteArray();
1172
1173         FollowerToSnapshot fts = leader.new FollowerToSnapshot(bs);
1174         leader.setFollowerSnapshot(FOLLOWER_ID, fts);
1175
1176         assertEquals(bs.size(), barray.length);
1177
1178         int chunkIndex=0;
1179         for (int i=0; i < barray.length; i = i + 50) {
1180             int j = i + 50;
1181             chunkIndex++;
1182
1183             if (i + 50 > barray.length) {
1184                 j = barray.length;
1185             }
1186
1187             byte[] chunk = fts.getNextChunk();
1188             assertEquals("bytestring size not matching for chunk:"+ chunkIndex, j-i, chunk.length);
1189             assertEquals("chunkindex not matching", chunkIndex, fts.getChunkIndex());
1190
1191             fts.markSendStatus(true);
1192             if (!fts.isLastChunk(chunkIndex)) {
1193                 fts.incrementChunkIndex();
1194             }
1195         }
1196
1197         assertEquals("totalChunks not matching", chunkIndex, fts.getTotalChunks());
1198     }
1199
1200     @Override
1201     protected Leader createBehavior(final RaftActorContext actorContext) {
1202         return new Leader(actorContext);
1203     }
1204
1205     @Override
1206     protected MockRaftActorContext createActorContext() {
1207         return createActorContext(leaderActor);
1208     }
1209
1210     @Override
1211     protected MockRaftActorContext createActorContext(ActorRef actorRef) {
1212         return createActorContext(LEADER_ID, actorRef);
1213     }
1214
1215     private MockRaftActorContext createActorContextWithFollower() {
1216         MockRaftActorContext actorContext = createActorContext();
1217         actorContext.setPeerAddresses(ImmutableMap.<String, String>builder().put(FOLLOWER_ID,
1218                 followerActor.path().toString()).build());
1219         return actorContext;
1220     }
1221
1222     private MockRaftActorContext createActorContext(String id, ActorRef actorRef) {
1223         DefaultConfigParamsImpl configParams = new DefaultConfigParamsImpl();
1224         configParams.setHeartBeatInterval(new FiniteDuration(50, TimeUnit.MILLISECONDS));
1225         configParams.setElectionTimeoutFactor(100000);
1226         MockRaftActorContext context = new MockRaftActorContext(id, getSystem(), actorRef);
1227         context.setConfigParams(configParams);
1228         context.setPayloadVersion(payloadVersion);
1229         return context;
1230     }
1231
1232     private MockRaftActorContext createFollowerActorContextWithLeader() {
1233         MockRaftActorContext followerActorContext = createActorContext(FOLLOWER_ID, followerActor);
1234         DefaultConfigParamsImpl followerConfig = new DefaultConfigParamsImpl();
1235         followerConfig.setElectionTimeoutFactor(10000);
1236         followerActorContext.setConfigParams(followerConfig);
1237         followerActorContext.setPeerAddresses(ImmutableMap.of(LEADER_ID, leaderActor.path().toString()));
1238         return followerActorContext;
1239     }
1240
1241     @Test
1242     public void testLeaderCreatedWithCommitIndexLessThanLastIndex() throws Exception {
1243         logStart("testLeaderCreatedWithCommitIndexLessThanLastIndex");
1244
1245         MockRaftActorContext leaderActorContext = createActorContextWithFollower();
1246
1247         MockRaftActorContext followerActorContext = createActorContext(FOLLOWER_ID, followerActor);
1248
1249         Follower follower = new Follower(followerActorContext);
1250         followerActor.underlyingActor().setBehavior(follower);
1251         followerActorContext.setCurrentBehavior(follower);
1252
1253         Map<String, String> peerAddresses = new HashMap<>();
1254         peerAddresses.put(FOLLOWER_ID, followerActor.path().toString());
1255
1256         leaderActorContext.setPeerAddresses(peerAddresses);
1257
1258         leaderActorContext.getReplicatedLog().removeFrom(0);
1259
1260         //create 3 entries
1261         leaderActorContext.setReplicatedLog(
1262                 new MockRaftActorContext.MockReplicatedLogBuilder().createEntries(0, 3, 1).build());
1263
1264         leaderActorContext.setCommitIndex(1);
1265
1266         followerActorContext.getReplicatedLog().removeFrom(0);
1267
1268         // follower too has the exact same log entries and has the same commit index
1269         followerActorContext.setReplicatedLog(
1270                 new MockRaftActorContext.MockReplicatedLogBuilder().createEntries(0, 3, 1).build());
1271
1272         followerActorContext.setCommitIndex(1);
1273
1274         leader = new Leader(leaderActorContext);
1275         leaderActorContext.setCurrentBehavior(leader);
1276
1277         AppendEntries appendEntries = MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
1278
1279         assertEquals(1, appendEntries.getLeaderCommit());
1280         assertEquals(0, appendEntries.getEntries().size());
1281         assertEquals(0, appendEntries.getPrevLogIndex());
1282
1283         AppendEntriesReply appendEntriesReply = MessageCollectorActor.expectFirstMatching(
1284                 leaderActor, AppendEntriesReply.class);
1285
1286         assertEquals(2, appendEntriesReply.getLogLastIndex());
1287         assertEquals(1, appendEntriesReply.getLogLastTerm());
1288
1289         // follower returns its next index
1290         assertEquals(2, appendEntriesReply.getLogLastIndex());
1291         assertEquals(1, appendEntriesReply.getLogLastTerm());
1292
1293         follower.close();
1294     }
1295
1296     @Test
1297     public void testLeaderCreatedWithCommitIndexLessThanFollowersCommitIndex() throws Exception {
1298         logStart("testLeaderCreatedWithCommitIndexLessThanFollowersCommitIndex");
1299
1300         MockRaftActorContext leaderActorContext = createActorContext();
1301
1302         MockRaftActorContext followerActorContext = createActorContext(FOLLOWER_ID, followerActor);
1303         followerActorContext.setPeerAddresses(ImmutableMap.of(LEADER_ID, leaderActor.path().toString()));
1304
1305         Follower follower = new Follower(followerActorContext);
1306         followerActor.underlyingActor().setBehavior(follower);
1307         followerActorContext.setCurrentBehavior(follower);
1308
1309         Map<String, String> leaderPeerAddresses = new HashMap<>();
1310         leaderPeerAddresses.put(FOLLOWER_ID, followerActor.path().toString());
1311
1312         leaderActorContext.setPeerAddresses(leaderPeerAddresses);
1313
1314         leaderActorContext.getReplicatedLog().removeFrom(0);
1315
1316         leaderActorContext.setReplicatedLog(
1317                 new MockRaftActorContext.MockReplicatedLogBuilder().createEntries(0, 3, 1).build());
1318
1319         leaderActorContext.setCommitIndex(1);
1320
1321         followerActorContext.getReplicatedLog().removeFrom(0);
1322
1323         followerActorContext.setReplicatedLog(
1324                 new MockRaftActorContext.MockReplicatedLogBuilder().createEntries(0, 3, 1).build());
1325
1326         // follower has the same log entries but its commit index > leaders commit index
1327         followerActorContext.setCommitIndex(2);
1328
1329         leader = new Leader(leaderActorContext);
1330
1331         // Initial heartbeat
1332         AppendEntries appendEntries = MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
1333
1334         assertEquals(1, appendEntries.getLeaderCommit());
1335         assertEquals(0, appendEntries.getEntries().size());
1336         assertEquals(0, appendEntries.getPrevLogIndex());
1337
1338         AppendEntriesReply appendEntriesReply = MessageCollectorActor.expectFirstMatching(
1339                 leaderActor, AppendEntriesReply.class);
1340
1341         assertEquals(2, appendEntriesReply.getLogLastIndex());
1342         assertEquals(1, appendEntriesReply.getLogLastTerm());
1343
1344         leaderActor.underlyingActor().setBehavior(follower);
1345         leader.handleMessage(followerActor, appendEntriesReply);
1346
1347         leaderActor.underlyingActor().clear();
1348         followerActor.underlyingActor().clear();
1349
1350         Uninterruptibles.sleepUninterruptibly(leaderActorContext.getConfigParams().getHeartBeatInterval().toMillis(),
1351                 TimeUnit.MILLISECONDS);
1352
1353         leader.handleMessage(leaderActor, SendHeartBeat.INSTANCE);
1354
1355         appendEntries = MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
1356
1357         assertEquals(2, appendEntries.getLeaderCommit());
1358         assertEquals(0, appendEntries.getEntries().size());
1359         assertEquals(2, appendEntries.getPrevLogIndex());
1360
1361         appendEntriesReply = MessageCollectorActor.expectFirstMatching(leaderActor, AppendEntriesReply.class);
1362
1363         assertEquals(2, appendEntriesReply.getLogLastIndex());
1364         assertEquals(1, appendEntriesReply.getLogLastTerm());
1365
1366         assertEquals(2, followerActorContext.getCommitIndex());
1367
1368         follower.close();
1369     }
1370
1371     @Test
1372     public void testHandleAppendEntriesReplyFailureWithFollowersLogBehindTheLeader(){
1373         logStart("testHandleAppendEntriesReplyFailureWithFollowersLogBehindTheLeader");
1374
1375         MockRaftActorContext leaderActorContext = createActorContextWithFollower();
1376         ((DefaultConfigParamsImpl)leaderActorContext.getConfigParams()).setHeartBeatInterval(
1377                 new FiniteDuration(1000, TimeUnit.SECONDS));
1378
1379         leaderActorContext.setReplicatedLog(
1380                 new MockRaftActorContext.MockReplicatedLogBuilder().createEntries(0, 3, 1).build());
1381         long leaderCommitIndex = 2;
1382         leaderActorContext.setCommitIndex(leaderCommitIndex);
1383         leaderActorContext.setLastApplied(leaderCommitIndex);
1384
1385         ReplicatedLogEntry leadersSecondLogEntry = leaderActorContext.getReplicatedLog().get(1);
1386         ReplicatedLogEntry leadersThirdLogEntry = leaderActorContext.getReplicatedLog().get(2);
1387
1388         MockRaftActorContext followerActorContext = createFollowerActorContextWithLeader();
1389
1390         followerActorContext.setReplicatedLog(
1391                 new MockRaftActorContext.MockReplicatedLogBuilder().createEntries(0, 1, 1).build());
1392         followerActorContext.setCommitIndex(0);
1393         followerActorContext.setLastApplied(0);
1394
1395         Follower follower = new Follower(followerActorContext);
1396         followerActor.underlyingActor().setBehavior(follower);
1397
1398         leader = new Leader(leaderActorContext);
1399
1400         AppendEntries appendEntries = MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
1401         AppendEntriesReply appendEntriesReply = MessageCollectorActor.expectFirstMatching(leaderActor, AppendEntriesReply.class);
1402
1403         MessageCollectorActor.clearMessages(followerActor);
1404         MessageCollectorActor.clearMessages(leaderActor);
1405
1406         // Verify initial AppendEntries sent with the leader's current commit index.
1407         assertEquals("getLeaderCommit", leaderCommitIndex, appendEntries.getLeaderCommit());
1408         assertEquals("Log entries size", 0, appendEntries.getEntries().size());
1409         assertEquals("getPrevLogIndex", 1, appendEntries.getPrevLogIndex());
1410
1411         leaderActor.underlyingActor().setBehavior(leader);
1412
1413         leader.handleMessage(followerActor, appendEntriesReply);
1414
1415         MessageCollectorActor.expectMatching(leaderActor, AppendEntriesReply.class, 1);
1416         appendEntries = MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
1417
1418         assertEquals("getLeaderCommit", leaderCommitIndex, appendEntries.getLeaderCommit());
1419         assertEquals("getPrevLogIndex", 0, appendEntries.getPrevLogIndex());
1420         assertEquals("Log entries size", 2, appendEntries.getEntries().size());
1421
1422         assertEquals("First entry index", 1, appendEntries.getEntries().get(0).getIndex());
1423         assertEquals("First entry data", leadersSecondLogEntry.getData(),
1424                 appendEntries.getEntries().get(0).getData());
1425         assertEquals("Second entry index", 2, appendEntries.getEntries().get(1).getIndex());
1426         assertEquals("Second entry data", leadersThirdLogEntry.getData(),
1427                 appendEntries.getEntries().get(1).getData());
1428
1429         FollowerLogInformation followerInfo = leader.getFollower(FOLLOWER_ID);
1430         assertEquals("getNextIndex", 3, followerInfo.getNextIndex());
1431
1432         List<ApplyState> applyStateList = MessageCollectorActor.expectMatching(followerActor, ApplyState.class, 2);
1433
1434         ApplyState applyState = applyStateList.get(0);
1435         assertEquals("Follower's first ApplyState index", 1, applyState.getReplicatedLogEntry().getIndex());
1436         assertEquals("Follower's first ApplyState term", 1, applyState.getReplicatedLogEntry().getTerm());
1437         assertEquals("Follower's first ApplyState data", leadersSecondLogEntry.getData(),
1438                 applyState.getReplicatedLogEntry().getData());
1439
1440         applyState = applyStateList.get(1);
1441         assertEquals("Follower's second ApplyState index", 2, applyState.getReplicatedLogEntry().getIndex());
1442         assertEquals("Follower's second ApplyState term", 1, applyState.getReplicatedLogEntry().getTerm());
1443         assertEquals("Follower's second ApplyState data", leadersThirdLogEntry.getData(),
1444                 applyState.getReplicatedLogEntry().getData());
1445
1446         assertEquals("Follower's commit index", 2, followerActorContext.getCommitIndex());
1447         assertEquals("Follower's lastIndex", 2, followerActorContext.getReplicatedLog().lastIndex());
1448     }
1449
1450     @Test
1451     public void testHandleAppendEntriesReplyFailureWithFollowersLogEmpty() {
1452         logStart("testHandleAppendEntriesReplyFailureWithFollowersLogEmpty");
1453
1454         MockRaftActorContext leaderActorContext = createActorContextWithFollower();
1455         ((DefaultConfigParamsImpl)leaderActorContext.getConfigParams()).setHeartBeatInterval(
1456                 new FiniteDuration(1000, TimeUnit.SECONDS));
1457
1458         leaderActorContext.setReplicatedLog(
1459                 new MockRaftActorContext.MockReplicatedLogBuilder().createEntries(0, 2, 1).build());
1460         long leaderCommitIndex = 1;
1461         leaderActorContext.setCommitIndex(leaderCommitIndex);
1462         leaderActorContext.setLastApplied(leaderCommitIndex);
1463
1464         ReplicatedLogEntry leadersFirstLogEntry = leaderActorContext.getReplicatedLog().get(0);
1465         ReplicatedLogEntry leadersSecondLogEntry = leaderActorContext.getReplicatedLog().get(1);
1466
1467         MockRaftActorContext followerActorContext = createFollowerActorContextWithLeader();
1468
1469         followerActorContext.setReplicatedLog(new MockRaftActorContext.MockReplicatedLogBuilder().build());
1470         followerActorContext.setCommitIndex(-1);
1471         followerActorContext.setLastApplied(-1);
1472
1473         Follower follower = new Follower(followerActorContext);
1474         followerActor.underlyingActor().setBehavior(follower);
1475         followerActorContext.setCurrentBehavior(follower);
1476
1477         leader = new Leader(leaderActorContext);
1478
1479         AppendEntries appendEntries = MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
1480         AppendEntriesReply appendEntriesReply = MessageCollectorActor.expectFirstMatching(leaderActor, AppendEntriesReply.class);
1481
1482         MessageCollectorActor.clearMessages(followerActor);
1483         MessageCollectorActor.clearMessages(leaderActor);
1484
1485         // Verify initial AppendEntries sent with the leader's current commit index.
1486         assertEquals("getLeaderCommit", leaderCommitIndex, appendEntries.getLeaderCommit());
1487         assertEquals("Log entries size", 0, appendEntries.getEntries().size());
1488         assertEquals("getPrevLogIndex", 0, appendEntries.getPrevLogIndex());
1489
1490         leaderActor.underlyingActor().setBehavior(leader);
1491         leaderActorContext.setCurrentBehavior(leader);
1492
1493         leader.handleMessage(followerActor, appendEntriesReply);
1494
1495         MessageCollectorActor.expectMatching(leaderActor, AppendEntriesReply.class, 1);
1496         appendEntries = MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
1497
1498         assertEquals("getLeaderCommit", leaderCommitIndex, appendEntries.getLeaderCommit());
1499         assertEquals("getPrevLogIndex", -1, appendEntries.getPrevLogIndex());
1500         assertEquals("Log entries size", 2, appendEntries.getEntries().size());
1501
1502         assertEquals("First entry index", 0, appendEntries.getEntries().get(0).getIndex());
1503         assertEquals("First entry data", leadersFirstLogEntry.getData(),
1504                 appendEntries.getEntries().get(0).getData());
1505         assertEquals("Second entry index", 1, appendEntries.getEntries().get(1).getIndex());
1506         assertEquals("Second entry data", leadersSecondLogEntry.getData(),
1507                 appendEntries.getEntries().get(1).getData());
1508
1509         FollowerLogInformation followerInfo = leader.getFollower(FOLLOWER_ID);
1510         assertEquals("getNextIndex", 2, followerInfo.getNextIndex());
1511
1512         List<ApplyState> applyStateList = MessageCollectorActor.expectMatching(followerActor, ApplyState.class, 2);
1513
1514         ApplyState applyState = applyStateList.get(0);
1515         assertEquals("Follower's first ApplyState index", 0, applyState.getReplicatedLogEntry().getIndex());
1516         assertEquals("Follower's first ApplyState term", 1, applyState.getReplicatedLogEntry().getTerm());
1517         assertEquals("Follower's first ApplyState data", leadersFirstLogEntry.getData(),
1518                 applyState.getReplicatedLogEntry().getData());
1519
1520         applyState = applyStateList.get(1);
1521         assertEquals("Follower's second ApplyState index", 1, applyState.getReplicatedLogEntry().getIndex());
1522         assertEquals("Follower's second ApplyState term", 1, applyState.getReplicatedLogEntry().getTerm());
1523         assertEquals("Follower's second ApplyState data", leadersSecondLogEntry.getData(),
1524                 applyState.getReplicatedLogEntry().getData());
1525
1526         assertEquals("Follower's commit index", 1, followerActorContext.getCommitIndex());
1527         assertEquals("Follower's lastIndex", 1, followerActorContext.getReplicatedLog().lastIndex());
1528     }
1529
1530     @Test
1531     public void testHandleAppendEntriesReplyFailureWithFollowersLogTermDifferent(){
1532         logStart("testHandleAppendEntriesReplyFailureWithFollowersLogTermDifferent");
1533
1534         MockRaftActorContext leaderActorContext = createActorContextWithFollower();
1535         ((DefaultConfigParamsImpl)leaderActorContext.getConfigParams()).setHeartBeatInterval(
1536                 new FiniteDuration(1000, TimeUnit.SECONDS));
1537
1538         leaderActorContext.setReplicatedLog(
1539                 new MockRaftActorContext.MockReplicatedLogBuilder().createEntries(0, 2, 2).build());
1540         long leaderCommitIndex = 1;
1541         leaderActorContext.setCommitIndex(leaderCommitIndex);
1542         leaderActorContext.setLastApplied(leaderCommitIndex);
1543
1544         ReplicatedLogEntry leadersFirstLogEntry = leaderActorContext.getReplicatedLog().get(0);
1545         ReplicatedLogEntry leadersSecondLogEntry = leaderActorContext.getReplicatedLog().get(1);
1546
1547         MockRaftActorContext followerActorContext = createFollowerActorContextWithLeader();
1548
1549         followerActorContext.setReplicatedLog(
1550                 new MockRaftActorContext.MockReplicatedLogBuilder().createEntries(0, 1, 1).build());
1551         followerActorContext.setCommitIndex(-1);
1552         followerActorContext.setLastApplied(-1);
1553
1554         Follower follower = new Follower(followerActorContext);
1555         followerActor.underlyingActor().setBehavior(follower);
1556         followerActorContext.setCurrentBehavior(follower);
1557
1558         leader = new Leader(leaderActorContext);
1559
1560         AppendEntries appendEntries = MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
1561         AppendEntriesReply appendEntriesReply = MessageCollectorActor.expectFirstMatching(leaderActor, AppendEntriesReply.class);
1562
1563         MessageCollectorActor.clearMessages(followerActor);
1564         MessageCollectorActor.clearMessages(leaderActor);
1565
1566         // Verify initial AppendEntries sent with the leader's current commit index.
1567         assertEquals("getLeaderCommit", leaderCommitIndex, appendEntries.getLeaderCommit());
1568         assertEquals("Log entries size", 0, appendEntries.getEntries().size());
1569         assertEquals("getPrevLogIndex", 0, appendEntries.getPrevLogIndex());
1570
1571         leaderActor.underlyingActor().setBehavior(leader);
1572         leaderActorContext.setCurrentBehavior(leader);
1573
1574         leader.handleMessage(followerActor, appendEntriesReply);
1575
1576         MessageCollectorActor.expectMatching(leaderActor, AppendEntriesReply.class, 1);
1577         appendEntries = MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
1578
1579         assertEquals("getLeaderCommit", leaderCommitIndex, appendEntries.getLeaderCommit());
1580         assertEquals("getPrevLogIndex", -1, appendEntries.getPrevLogIndex());
1581         assertEquals("Log entries size", 2, appendEntries.getEntries().size());
1582
1583         assertEquals("First entry index", 0, appendEntries.getEntries().get(0).getIndex());
1584         assertEquals("First entry term", 2, appendEntries.getEntries().get(0).getTerm());
1585         assertEquals("First entry data", leadersFirstLogEntry.getData(),
1586                 appendEntries.getEntries().get(0).getData());
1587         assertEquals("Second entry index", 1, appendEntries.getEntries().get(1).getIndex());
1588         assertEquals("Second entry term", 2, appendEntries.getEntries().get(1).getTerm());
1589         assertEquals("Second entry data", leadersSecondLogEntry.getData(),
1590                 appendEntries.getEntries().get(1).getData());
1591
1592         FollowerLogInformation followerInfo = leader.getFollower(FOLLOWER_ID);
1593         assertEquals("getNextIndex", 2, followerInfo.getNextIndex());
1594
1595         List<ApplyState> applyStateList = MessageCollectorActor.expectMatching(followerActor, ApplyState.class, 2);
1596
1597         ApplyState applyState = applyStateList.get(0);
1598         assertEquals("Follower's first ApplyState index", 0, applyState.getReplicatedLogEntry().getIndex());
1599         assertEquals("Follower's first ApplyState term", 2, applyState.getReplicatedLogEntry().getTerm());
1600         assertEquals("Follower's first ApplyState data", leadersFirstLogEntry.getData(),
1601                 applyState.getReplicatedLogEntry().getData());
1602
1603         applyState = applyStateList.get(1);
1604         assertEquals("Follower's second ApplyState index", 1, applyState.getReplicatedLogEntry().getIndex());
1605         assertEquals("Follower's second ApplyState term", 2, applyState.getReplicatedLogEntry().getTerm());
1606         assertEquals("Follower's second ApplyState data", leadersSecondLogEntry.getData(),
1607                 applyState.getReplicatedLogEntry().getData());
1608
1609         assertEquals("Follower's commit index", 1, followerActorContext.getCommitIndex());
1610         assertEquals("Follower's lastIndex", 1, followerActorContext.getReplicatedLog().lastIndex());
1611         assertEquals("Follower's lastTerm", 2, followerActorContext.getReplicatedLog().lastTerm());
1612     }
1613
1614     @Test
1615     public void testHandleAppendEntriesReplyWithNewerTerm(){
1616         logStart("testHandleAppendEntriesReplyWithNewerTerm");
1617
1618         MockRaftActorContext leaderActorContext = createActorContext();
1619         ((DefaultConfigParamsImpl)leaderActorContext.getConfigParams()).setHeartBeatInterval(
1620                 new FiniteDuration(10000, TimeUnit.SECONDS));
1621
1622         leaderActorContext.setReplicatedLog(
1623                 new MockRaftActorContext.MockReplicatedLogBuilder().createEntries(0, 2, 2).build());
1624
1625         leader = new Leader(leaderActorContext);
1626         leaderActor.underlyingActor().setBehavior(leader);
1627         leaderActor.tell(new AppendEntriesReply("foo", 20, false, 1000, 10, (short) 1), ActorRef.noSender());
1628
1629         AppendEntriesReply appendEntriesReply = MessageCollectorActor.expectFirstMatching(leaderActor, AppendEntriesReply.class);
1630
1631         assertEquals(false, appendEntriesReply.isSuccess());
1632         assertEquals(RaftState.Follower, leaderActor.underlyingActor().getFirstBehaviorChange().state());
1633
1634         MessageCollectorActor.clearMessages(leaderActor);
1635     }
1636
1637     @Test
1638     public void testHandleAppendEntriesReplyWithNewerTermWhenElectionsAreDisabled(){
1639         logStart("testHandleAppendEntriesReplyWithNewerTermWhenElectionsAreDisabled");
1640
1641         MockRaftActorContext leaderActorContext = createActorContext();
1642         ((DefaultConfigParamsImpl)leaderActorContext.getConfigParams()).setHeartBeatInterval(
1643                 new FiniteDuration(10000, TimeUnit.SECONDS));
1644
1645         leaderActorContext.setReplicatedLog(
1646                 new MockRaftActorContext.MockReplicatedLogBuilder().createEntries(0, 2, 2).build());
1647         leaderActorContext.setRaftPolicy(createRaftPolicy(false, false));
1648
1649         leader = new Leader(leaderActorContext);
1650         leaderActor.underlyingActor().setBehavior(leader);
1651         leaderActor.tell(new AppendEntriesReply("foo", 20, false, 1000, 10, (short) 1), ActorRef.noSender());
1652
1653         AppendEntriesReply appendEntriesReply = MessageCollectorActor.expectFirstMatching(leaderActor, AppendEntriesReply.class);
1654
1655         assertEquals(false, appendEntriesReply.isSuccess());
1656         assertEquals(RaftState.Leader, leaderActor.underlyingActor().getFirstBehaviorChange().state());
1657
1658         MessageCollectorActor.clearMessages(leaderActor);
1659     }
1660
1661     @Test
1662     public void testHandleAppendEntriesReplySuccess() throws Exception {
1663         logStart("testHandleAppendEntriesReplySuccess");
1664
1665         MockRaftActorContext leaderActorContext = createActorContextWithFollower();
1666
1667         leaderActorContext.setReplicatedLog(
1668                 new MockRaftActorContext.MockReplicatedLogBuilder().createEntries(0, 3, 1).build());
1669
1670         leaderActorContext.setCommitIndex(1);
1671         leaderActorContext.setLastApplied(1);
1672         leaderActorContext.getTermInformation().update(1, "leader");
1673
1674         leader = new Leader(leaderActorContext);
1675
1676         FollowerLogInformation followerInfo = leader.getFollower(FOLLOWER_ID);
1677
1678         assertEquals(payloadVersion, leader.getLeaderPayloadVersion());
1679         assertEquals(RaftVersions.HELIUM_VERSION, followerInfo.getRaftVersion());
1680
1681         short payloadVersion = 5;
1682         AppendEntriesReply reply = new AppendEntriesReply(FOLLOWER_ID, 1, true, 2, 1, payloadVersion);
1683
1684         RaftActorBehavior raftActorBehavior = leader.handleAppendEntriesReply(followerActor, reply);
1685
1686         assertEquals(RaftState.Leader, raftActorBehavior.state());
1687
1688         assertEquals(2, leaderActorContext.getCommitIndex());
1689
1690         ApplyJournalEntries applyJournalEntries = MessageCollectorActor.expectFirstMatching(
1691                 leaderActor, ApplyJournalEntries.class);
1692
1693         assertEquals(2, leaderActorContext.getLastApplied());
1694
1695         assertEquals(2, applyJournalEntries.getToIndex());
1696
1697         List<ApplyState> applyStateList = MessageCollectorActor.getAllMatching(leaderActor,
1698                 ApplyState.class);
1699
1700         assertEquals(1,applyStateList.size());
1701
1702         ApplyState applyState = applyStateList.get(0);
1703
1704         assertEquals(2, applyState.getReplicatedLogEntry().getIndex());
1705
1706         assertEquals(2, followerInfo.getMatchIndex());
1707         assertEquals(3, followerInfo.getNextIndex());
1708         assertEquals(payloadVersion, followerInfo.getPayloadVersion());
1709         assertEquals(RaftVersions.CURRENT_VERSION, followerInfo.getRaftVersion());
1710     }
1711
1712     @Test
1713     public void testHandleAppendEntriesReplyUnknownFollower(){
1714         logStart("testHandleAppendEntriesReplyUnknownFollower");
1715
1716         MockRaftActorContext leaderActorContext = createActorContext();
1717
1718         leader = new Leader(leaderActorContext);
1719
1720         AppendEntriesReply reply = new AppendEntriesReply("unkown-follower", 1, false, 10, 1, (short)0);
1721
1722         RaftActorBehavior raftActorBehavior = leader.handleAppendEntriesReply(followerActor, reply);
1723
1724         assertEquals(RaftState.Leader, raftActorBehavior.state());
1725     }
1726
1727     @Test
1728     public void testFollowerCatchUpWithAppendEntriesMaxDataSizeExceeded() {
1729         logStart("testFollowerCatchUpWithAppendEntriesMaxDataSizeExceeded");
1730
1731         MockRaftActorContext leaderActorContext = createActorContextWithFollower();
1732         ((DefaultConfigParamsImpl)leaderActorContext.getConfigParams()).setHeartBeatInterval(
1733                 new FiniteDuration(1000, TimeUnit.SECONDS));
1734         ((DefaultConfigParamsImpl)leaderActorContext.getConfigParams()).setSnapshotChunkSize(2);
1735
1736         leaderActorContext.setReplicatedLog(
1737                 new MockRaftActorContext.MockReplicatedLogBuilder().createEntries(0, 4, 1).build());
1738         long leaderCommitIndex = 3;
1739         leaderActorContext.setCommitIndex(leaderCommitIndex);
1740         leaderActorContext.setLastApplied(leaderCommitIndex);
1741
1742         ReplicatedLogEntry leadersFirstLogEntry = leaderActorContext.getReplicatedLog().get(0);
1743         ReplicatedLogEntry leadersSecondLogEntry = leaderActorContext.getReplicatedLog().get(1);
1744         ReplicatedLogEntry leadersThirdLogEntry = leaderActorContext.getReplicatedLog().get(2);
1745         ReplicatedLogEntry leadersFourthLogEntry = leaderActorContext.getReplicatedLog().get(3);
1746
1747         MockRaftActorContext followerActorContext = createFollowerActorContextWithLeader();
1748
1749         followerActorContext.setReplicatedLog(new MockRaftActorContext.MockReplicatedLogBuilder().build());
1750         followerActorContext.setCommitIndex(-1);
1751         followerActorContext.setLastApplied(-1);
1752
1753         Follower follower = new Follower(followerActorContext);
1754         followerActor.underlyingActor().setBehavior(follower);
1755         followerActorContext.setCurrentBehavior(follower);
1756
1757         leader = new Leader(leaderActorContext);
1758
1759         AppendEntries appendEntries = MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
1760         AppendEntriesReply appendEntriesReply = MessageCollectorActor.expectFirstMatching(leaderActor, AppendEntriesReply.class);
1761
1762         MessageCollectorActor.clearMessages(followerActor);
1763         MessageCollectorActor.clearMessages(leaderActor);
1764
1765         // Verify initial AppendEntries sent with the leader's current commit index.
1766         assertEquals("getLeaderCommit", leaderCommitIndex, appendEntries.getLeaderCommit());
1767         assertEquals("Log entries size", 0, appendEntries.getEntries().size());
1768         assertEquals("getPrevLogIndex", 2, appendEntries.getPrevLogIndex());
1769
1770         leaderActor.underlyingActor().setBehavior(leader);
1771         leaderActorContext.setCurrentBehavior(leader);
1772
1773         leader.handleMessage(followerActor, appendEntriesReply);
1774
1775         List<AppendEntries> appendEntriesList = MessageCollectorActor.expectMatching(followerActor, AppendEntries.class, 2);
1776         MessageCollectorActor.expectMatching(leaderActor, AppendEntriesReply.class, 2);
1777
1778         appendEntries = appendEntriesList.get(0);
1779         assertEquals("getLeaderCommit", leaderCommitIndex, appendEntries.getLeaderCommit());
1780         assertEquals("getPrevLogIndex", -1, appendEntries.getPrevLogIndex());
1781         assertEquals("Log entries size", 2, appendEntries.getEntries().size());
1782
1783         assertEquals("First entry index", 0, appendEntries.getEntries().get(0).getIndex());
1784         assertEquals("First entry data", leadersFirstLogEntry.getData(),
1785                 appendEntries.getEntries().get(0).getData());
1786         assertEquals("Second entry index", 1, appendEntries.getEntries().get(1).getIndex());
1787         assertEquals("Second entry data", leadersSecondLogEntry.getData(),
1788                 appendEntries.getEntries().get(1).getData());
1789
1790         appendEntries = appendEntriesList.get(1);
1791         assertEquals("getLeaderCommit", leaderCommitIndex, appendEntries.getLeaderCommit());
1792         assertEquals("getPrevLogIndex", 1, appendEntries.getPrevLogIndex());
1793         assertEquals("Log entries size", 2, appendEntries.getEntries().size());
1794
1795         assertEquals("First entry index", 2, appendEntries.getEntries().get(0).getIndex());
1796         assertEquals("First entry data", leadersThirdLogEntry.getData(),
1797                 appendEntries.getEntries().get(0).getData());
1798         assertEquals("Second entry index", 3, appendEntries.getEntries().get(1).getIndex());
1799         assertEquals("Second entry data", leadersFourthLogEntry.getData(),
1800                 appendEntries.getEntries().get(1).getData());
1801
1802         FollowerLogInformation followerInfo = leader.getFollower(FOLLOWER_ID);
1803         assertEquals("getNextIndex", 4, followerInfo.getNextIndex());
1804
1805         MessageCollectorActor.expectMatching(followerActor, ApplyState.class, 4);
1806
1807         assertEquals("Follower's commit index", 3, followerActorContext.getCommitIndex());
1808         assertEquals("Follower's lastIndex", 3, followerActorContext.getReplicatedLog().lastIndex());
1809     }
1810
1811     @Test
1812     public void testHandleRequestVoteReply(){
1813         logStart("testHandleRequestVoteReply");
1814
1815         MockRaftActorContext leaderActorContext = createActorContext();
1816
1817         leader = new Leader(leaderActorContext);
1818
1819         // Should be a no-op.
1820         RaftActorBehavior raftActorBehavior = leader.handleRequestVoteReply(followerActor,
1821                 new RequestVoteReply(1, true));
1822
1823         assertEquals(RaftState.Leader, raftActorBehavior.state());
1824
1825         raftActorBehavior = leader.handleRequestVoteReply(followerActor, new RequestVoteReply(1, false));
1826
1827         assertEquals(RaftState.Leader, raftActorBehavior.state());
1828     }
1829
1830     @Test
1831     public void testIsolatedLeaderCheckNoFollowers() {
1832         logStart("testIsolatedLeaderCheckNoFollowers");
1833
1834         MockRaftActorContext leaderActorContext = createActorContext();
1835
1836         leader = new Leader(leaderActorContext);
1837         RaftActorBehavior behavior = leader.handleMessage(leaderActor, Leader.ISOLATED_LEADER_CHECK);
1838         assertTrue(behavior instanceof Leader);
1839     }
1840
1841     @Test
1842     public void testIsolatedLeaderCheckNoVotingFollowers() {
1843         logStart("testIsolatedLeaderCheckNoVotingFollowers");
1844
1845         MockRaftActorContext followerActorContext = createFollowerActorContextWithLeader();
1846         Follower follower = new Follower(followerActorContext);
1847         followerActor.underlyingActor().setBehavior(follower);
1848
1849         MockRaftActorContext leaderActorContext = createActorContextWithFollower();
1850         ((DefaultConfigParamsImpl)leaderActorContext.getConfigParams()).setHeartBeatInterval(
1851                 new FiniteDuration(1000, TimeUnit.SECONDS));
1852         leaderActorContext.getPeerInfo(FOLLOWER_ID).setVotingState(VotingState.NON_VOTING);
1853
1854         leader = new Leader(leaderActorContext);
1855         leader.getFollower(FOLLOWER_ID).markFollowerActive();
1856         RaftActorBehavior behavior = leader.handleMessage(leaderActor, Leader.ISOLATED_LEADER_CHECK);
1857         assertTrue("Expected Leader", behavior instanceof Leader);
1858     }
1859
1860     private RaftActorBehavior setupIsolatedLeaderCheckTestWithTwoFollowers(RaftPolicy raftPolicy){
1861         ActorRef followerActor1 = getSystem().actorOf(MessageCollectorActor.props(), "follower-1");
1862         ActorRef followerActor2 = getSystem().actorOf(MessageCollectorActor.props(), "follower-2");
1863
1864         MockRaftActorContext leaderActorContext = createActorContext();
1865
1866         Map<String, String> peerAddresses = new HashMap<>();
1867         peerAddresses.put("follower-1", followerActor1.path().toString());
1868         peerAddresses.put("follower-2", followerActor2.path().toString());
1869
1870         leaderActorContext.setPeerAddresses(peerAddresses);
1871         leaderActorContext.setRaftPolicy(raftPolicy);
1872
1873         leader = new Leader(leaderActorContext);
1874
1875         leader.markFollowerActive("follower-1");
1876         leader.markFollowerActive("follower-2");
1877         RaftActorBehavior behavior = leader.handleMessage(leaderActor, Leader.ISOLATED_LEADER_CHECK);
1878         assertTrue("Behavior not instance of Leader when all followers are active", behavior instanceof Leader);
1879
1880         // kill 1 follower and verify if that got killed
1881         final JavaTestKit probe = new JavaTestKit(getSystem());
1882         probe.watch(followerActor1);
1883         followerActor1.tell(PoisonPill.getInstance(), ActorRef.noSender());
1884         final Terminated termMsg1 = probe.expectMsgClass(Terminated.class);
1885         assertEquals(termMsg1.getActor(), followerActor1);
1886
1887         leader.markFollowerInActive("follower-1");
1888         leader.markFollowerActive("follower-2");
1889         behavior = leader.handleMessage(leaderActor, Leader.ISOLATED_LEADER_CHECK);
1890         assertTrue("Behavior not instance of Leader when majority of followers are active", behavior instanceof Leader);
1891
1892         // kill 2nd follower and leader should change to Isolated leader
1893         followerActor2.tell(PoisonPill.getInstance(), null);
1894         probe.watch(followerActor2);
1895         followerActor2.tell(PoisonPill.getInstance(), ActorRef.noSender());
1896         final Terminated termMsg2 = probe.expectMsgClass(Terminated.class);
1897         assertEquals(termMsg2.getActor(), followerActor2);
1898
1899         leader.markFollowerInActive("follower-2");
1900         return leader.handleMessage(leaderActor, Leader.ISOLATED_LEADER_CHECK);
1901     }
1902
1903     @Test
1904     public void testIsolatedLeaderCheckTwoFollowers() throws Exception {
1905         logStart("testIsolatedLeaderCheckTwoFollowers");
1906
1907         RaftActorBehavior behavior = setupIsolatedLeaderCheckTestWithTwoFollowers(DefaultRaftPolicy.INSTANCE);
1908
1909         assertTrue("Behavior not instance of IsolatedLeader when majority followers are inactive",
1910             behavior instanceof IsolatedLeader);
1911     }
1912
1913     @Test
1914     public void testIsolatedLeaderCheckTwoFollowersWhenElectionsAreDisabled() throws Exception {
1915         logStart("testIsolatedLeaderCheckTwoFollowersWhenElectionsAreDisabled");
1916
1917         RaftActorBehavior behavior = setupIsolatedLeaderCheckTestWithTwoFollowers(createRaftPolicy(false, true));
1918
1919         assertTrue("Behavior should not switch to IsolatedLeader because elections are disabled",
1920                 behavior instanceof Leader);
1921     }
1922
1923     @Test
1924     public void testLaggingFollowerStarvation() throws Exception {
1925         logStart("testLaggingFollowerStarvation");
1926         new JavaTestKit(getSystem()) {{
1927             String leaderActorId = actorFactory.generateActorId("leader");
1928             String follower1ActorId = actorFactory.generateActorId("follower");
1929             String follower2ActorId = actorFactory.generateActorId("follower");
1930
1931             TestActorRef<ForwardMessageToBehaviorActor> leaderActor =
1932                     actorFactory.createTestActor(ForwardMessageToBehaviorActor.props(), leaderActorId);
1933             ActorRef follower1Actor = actorFactory.createActor(MessageCollectorActor.props(), follower1ActorId);
1934             ActorRef follower2Actor = actorFactory.createActor(MessageCollectorActor.props(), follower2ActorId);
1935
1936             MockRaftActorContext leaderActorContext =
1937                     new MockRaftActorContext(leaderActorId, getSystem(), leaderActor);
1938
1939             DefaultConfigParamsImpl configParams = new DefaultConfigParamsImpl();
1940             configParams.setHeartBeatInterval(new FiniteDuration(200, TimeUnit.MILLISECONDS));
1941             configParams.setIsolatedLeaderCheckInterval(new FiniteDuration(10, TimeUnit.SECONDS));
1942
1943             leaderActorContext.setConfigParams(configParams);
1944
1945             leaderActorContext.setReplicatedLog(
1946                     new MockRaftActorContext.MockReplicatedLogBuilder().createEntries(1,5,1).build());
1947
1948             Map<String, String> peerAddresses = new HashMap<>();
1949             peerAddresses.put(follower1ActorId,
1950                     follower1Actor.path().toString());
1951             peerAddresses.put(follower2ActorId,
1952                     follower2Actor.path().toString());
1953
1954             leaderActorContext.setPeerAddresses(peerAddresses);
1955             leaderActorContext.getTermInformation().update(1, leaderActorId);
1956
1957             RaftActorBehavior leader = createBehavior(leaderActorContext);
1958
1959             leaderActor.underlyingActor().setBehavior(leader);
1960
1961             for(int i=1;i<6;i++) {
1962                 // Each AppendEntriesReply could end up rescheduling the heartbeat (without the fix for bug 2733)
1963                 RaftActorBehavior newBehavior = leader.handleMessage(follower1Actor, new AppendEntriesReply(follower1ActorId, 1, true, i, 1, (short)0));
1964                 assertTrue(newBehavior == leader);
1965                 Uninterruptibles.sleepUninterruptibly(200, TimeUnit.MILLISECONDS);
1966             }
1967
1968             // Check if the leader has been receiving SendHeartbeat messages despite getting AppendEntriesReply
1969             List<SendHeartBeat> heartbeats = MessageCollectorActor.getAllMatching(leaderActor, SendHeartBeat.class);
1970
1971             assertTrue(String.format("%s heartbeat(s) is less than expected", heartbeats.size()),
1972                     heartbeats.size() > 1);
1973
1974             // Check if follower-2 got AppendEntries during this time and was not starved
1975             List<AppendEntries> appendEntries = MessageCollectorActor.getAllMatching(follower2Actor, AppendEntries.class);
1976
1977             assertTrue(String.format("%s append entries is less than expected", appendEntries.size()),
1978                     appendEntries.size() > 1);
1979
1980         }};
1981     }
1982
1983     @Test
1984     public void testReplicationConsensusWithNonVotingFollower() {
1985         logStart("testReplicationConsensusWithNonVotingFollower");
1986
1987         MockRaftActorContext leaderActorContext = createActorContextWithFollower();
1988         ((DefaultConfigParamsImpl)leaderActorContext.getConfigParams()).setHeartBeatInterval(
1989                 new FiniteDuration(1000, TimeUnit.SECONDS));
1990
1991         leaderActorContext.setReplicatedLog(new MockRaftActorContext.MockReplicatedLogBuilder().build());
1992         leaderActorContext.setCommitIndex(-1);
1993
1994         String nonVotingFollowerId = "nonvoting-follower";
1995         TestActorRef<ForwardMessageToBehaviorActor> nonVotingFollowerActor = actorFactory.createTestActor(
1996                 Props.create(MessageCollectorActor.class), actorFactory.generateActorId(nonVotingFollowerId));
1997
1998         leaderActorContext.addToPeers(nonVotingFollowerId, nonVotingFollowerActor.path().toString(), VotingState.NON_VOTING);
1999
2000         leader = new Leader(leaderActorContext);
2001         leaderActorContext.setCurrentBehavior(leader);
2002
2003         // Ignore initial heartbeats
2004         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
2005         MessageCollectorActor.expectFirstMatching(nonVotingFollowerActor, AppendEntries.class);
2006
2007         MessageCollectorActor.clearMessages(followerActor);
2008         MessageCollectorActor.clearMessages(nonVotingFollowerActor);
2009         MessageCollectorActor.clearMessages(leaderActor);
2010
2011         // Send a Replicate message and wait for AppendEntries.
2012         sendReplicate(leaderActorContext, 0);
2013
2014         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
2015         MessageCollectorActor.expectFirstMatching(nonVotingFollowerActor, AppendEntries.class);
2016
2017         // Send reply only from the voting follower and verify consensus via ApplyState.
2018         leader.handleMessage(leaderActor, new AppendEntriesReply(FOLLOWER_ID, 1, true, 0, 1, (short)0));
2019
2020         MessageCollectorActor.expectFirstMatching(leaderActor, ApplyState.class);
2021
2022         leader.handleMessage(leaderActor, new AppendEntriesReply(nonVotingFollowerId, 1, true, 0, 1, (short)0));
2023
2024         MessageCollectorActor.clearMessages(followerActor);
2025         MessageCollectorActor.clearMessages(nonVotingFollowerActor);
2026         MessageCollectorActor.clearMessages(leaderActor);
2027
2028         // Send another Replicate message
2029         sendReplicate(leaderActorContext, 1);
2030
2031         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
2032         AppendEntries appendEntries = MessageCollectorActor.expectFirstMatching(nonVotingFollowerActor,
2033                 AppendEntries.class);
2034         assertEquals("Log entries size", 1, appendEntries.getEntries().size());
2035         assertEquals("Log entry index", 1, appendEntries.getEntries().get(0).getIndex());
2036
2037         // Send reply only from the non-voting follower and verify no consensus via no ApplyState.
2038         leader.handleMessage(leaderActor, new AppendEntriesReply(nonVotingFollowerId, 1, true, 1, 1, (short)0));
2039
2040         MessageCollectorActor.assertNoneMatching(leaderActor, ApplyState.class, 500);
2041
2042         // Send reply from the voting follower and verify consensus.
2043         leader.handleMessage(leaderActor, new AppendEntriesReply(FOLLOWER_ID, 1, true, 1, 1, (short)0));
2044
2045         MessageCollectorActor.expectFirstMatching(leaderActor, ApplyState.class);
2046     }
2047
2048     @Test
2049     public void testTransferLeadershipWithFollowerInSync() {
2050         logStart("testTransferLeadershipWithFollowerInSync");
2051
2052         MockRaftActorContext leaderActorContext = createActorContextWithFollower();
2053         ((DefaultConfigParamsImpl)leaderActorContext.getConfigParams()).setHeartBeatInterval(
2054                 new FiniteDuration(1000, TimeUnit.SECONDS));
2055         leaderActorContext.setReplicatedLog(new MockRaftActorContext.MockReplicatedLogBuilder().build());
2056
2057         leader = new Leader(leaderActorContext);
2058         leaderActorContext.setCurrentBehavior(leader);
2059
2060         // Initial heartbeat
2061         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
2062         leader.handleMessage(leaderActor, new AppendEntriesReply(FOLLOWER_ID, 1, true, -1, -1, (short)0));
2063         MessageCollectorActor.clearMessages(followerActor);
2064
2065         sendReplicate(leaderActorContext, 0);
2066         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
2067
2068         leader.handleMessage(leaderActor, new AppendEntriesReply(FOLLOWER_ID, 1, true, 0, 1, (short)0));
2069         MessageCollectorActor.expectFirstMatching(leaderActor, ApplyState.class);
2070         MessageCollectorActor.clearMessages(followerActor);
2071
2072         RaftActorLeadershipTransferCohort mockTransferCohort = mock(RaftActorLeadershipTransferCohort.class);
2073         leader.transferLeadership(mockTransferCohort);
2074
2075         verify(mockTransferCohort, never()).transferComplete();
2076         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
2077         leader.handleMessage(leaderActor, new AppendEntriesReply(FOLLOWER_ID, 1, true, 0, 1, (short)0));
2078
2079         // Expect a final AppendEntries to ensure the follower's lastApplied index is up-to-date
2080         MessageCollectorActor.expectMatching(followerActor, AppendEntries.class, 2);
2081
2082         // Leader should force an election timeout
2083         MessageCollectorActor.expectFirstMatching(followerActor, TimeoutNow.class);
2084
2085         verify(mockTransferCohort).transferComplete();
2086     }
2087
2088     @Test
2089     public void testTransferLeadershipWithEmptyLog() {
2090         logStart("testTransferLeadershipWithEmptyLog");
2091
2092         MockRaftActorContext leaderActorContext = createActorContextWithFollower();
2093         ((DefaultConfigParamsImpl)leaderActorContext.getConfigParams()).setHeartBeatInterval(
2094                 new FiniteDuration(1000, TimeUnit.SECONDS));
2095         leaderActorContext.setReplicatedLog(new MockRaftActorContext.MockReplicatedLogBuilder().build());
2096
2097         leader = new Leader(leaderActorContext);
2098         leaderActorContext.setCurrentBehavior(leader);
2099
2100         // Initial heartbeat
2101         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
2102         leader.handleMessage(leaderActor, new AppendEntriesReply(FOLLOWER_ID, 1, true, -1, -1, (short)0));
2103         MessageCollectorActor.clearMessages(followerActor);
2104
2105         RaftActorLeadershipTransferCohort mockTransferCohort = mock(RaftActorLeadershipTransferCohort.class);
2106         leader.transferLeadership(mockTransferCohort);
2107
2108         verify(mockTransferCohort, never()).transferComplete();
2109         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
2110         leader.handleMessage(leaderActor, new AppendEntriesReply(FOLLOWER_ID, 1, true, -1, -1, (short)0));
2111
2112         // Expect a final AppendEntries to ensure the follower's lastApplied index is up-to-date
2113         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
2114
2115         // Leader should force an election timeout
2116         MessageCollectorActor.expectFirstMatching(followerActor, TimeoutNow.class);
2117
2118         verify(mockTransferCohort).transferComplete();
2119     }
2120
2121     @Test
2122     public void testTransferLeadershipWithFollowerInitiallyOutOfSync() {
2123         logStart("testTransferLeadershipWithFollowerInitiallyOutOfSync");
2124
2125         MockRaftActorContext leaderActorContext = createActorContextWithFollower();
2126         ((DefaultConfigParamsImpl)leaderActorContext.getConfigParams()).setHeartBeatInterval(
2127                 new FiniteDuration(200, TimeUnit.MILLISECONDS));
2128
2129         leader = new Leader(leaderActorContext);
2130         leaderActorContext.setCurrentBehavior(leader);
2131
2132         // Initial heartbeat
2133         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
2134         MessageCollectorActor.clearMessages(followerActor);
2135
2136         RaftActorLeadershipTransferCohort mockTransferCohort = mock(RaftActorLeadershipTransferCohort.class);
2137         leader.transferLeadership(mockTransferCohort);
2138
2139         verify(mockTransferCohort, never()).transferComplete();
2140
2141         // Sync up the follower.
2142         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
2143         leader.handleMessage(leaderActor, new AppendEntriesReply(FOLLOWER_ID, 1, true, -1, -1, (short)0));
2144         MessageCollectorActor.clearMessages(followerActor);
2145
2146         Uninterruptibles.sleepUninterruptibly(leaderActorContext.getConfigParams().
2147                 getHeartBeatInterval().toMillis() + 1, TimeUnit.MILLISECONDS);
2148         leader.handleMessage(leaderActor, SendHeartBeat.INSTANCE);
2149         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
2150         leader.handleMessage(leaderActor, new AppendEntriesReply(FOLLOWER_ID, 1, true, 1, 1, (short)0));
2151
2152         // Leader should force an election timeout
2153         MessageCollectorActor.expectFirstMatching(followerActor, TimeoutNow.class);
2154
2155         verify(mockTransferCohort).transferComplete();
2156     }
2157
2158     @Test
2159     public void testTransferLeadershipWithFollowerSyncTimeout() {
2160         logStart("testTransferLeadershipWithFollowerSyncTimeout");
2161
2162         MockRaftActorContext leaderActorContext = createActorContextWithFollower();
2163         ((DefaultConfigParamsImpl)leaderActorContext.getConfigParams()).setHeartBeatInterval(
2164                 new FiniteDuration(200, TimeUnit.MILLISECONDS));
2165         ((DefaultConfigParamsImpl)leaderActorContext.getConfigParams()).setElectionTimeoutFactor(2);
2166         leaderActorContext.setReplicatedLog(new MockRaftActorContext.MockReplicatedLogBuilder().build());
2167
2168         leader = new Leader(leaderActorContext);
2169         leaderActorContext.setCurrentBehavior(leader);
2170
2171         // Initial heartbeat
2172         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
2173         leader.handleMessage(leaderActor, new AppendEntriesReply(FOLLOWER_ID, 1, true, -1, -1, (short)0));
2174         MessageCollectorActor.clearMessages(followerActor);
2175
2176         sendReplicate(leaderActorContext, 0);
2177         MessageCollectorActor.expectFirstMatching(followerActor, AppendEntries.class);
2178
2179         MessageCollectorActor.clearMessages(followerActor);
2180
2181         RaftActorLeadershipTransferCohort mockTransferCohort = mock(RaftActorLeadershipTransferCohort.class);
2182         leader.transferLeadership(mockTransferCohort);
2183
2184         verify(mockTransferCohort, never()).transferComplete();
2185
2186         // Send heartbeats to time out the transfer.
2187         for(int i = 0; i < leaderActorContext.getConfigParams().getElectionTimeoutFactor(); i++) {
2188             Uninterruptibles.sleepUninterruptibly(leaderActorContext.getConfigParams().
2189                     getHeartBeatInterval().toMillis() + 1, TimeUnit.MILLISECONDS);
2190             leader.handleMessage(leaderActor, SendHeartBeat.INSTANCE);
2191         }
2192
2193         verify(mockTransferCohort).abortTransfer();
2194         verify(mockTransferCohort, never()).transferComplete();
2195         MessageCollectorActor.assertNoneMatching(followerActor, ElectionTimeout.class, 100);
2196     }
2197
2198     @Override
2199     protected void assertStateChangesToFollowerWhenRaftRPCHasNewerTerm(MockRaftActorContext actorContext,
2200             ActorRef actorRef, RaftRPC rpc) throws Exception {
2201         super.assertStateChangesToFollowerWhenRaftRPCHasNewerTerm(actorContext, actorRef, rpc);
2202         assertEquals("New votedFor", null, actorContext.getTermInformation().getVotedFor());
2203     }
2204
2205     private class MockConfigParamsImpl extends DefaultConfigParamsImpl {
2206
2207         private final long electionTimeOutIntervalMillis;
2208         private final int snapshotChunkSize;
2209
2210         public MockConfigParamsImpl(long electionTimeOutIntervalMillis, int snapshotChunkSize) {
2211             super();
2212             this.electionTimeOutIntervalMillis = electionTimeOutIntervalMillis;
2213             this.snapshotChunkSize = snapshotChunkSize;
2214         }
2215
2216         @Override
2217         public FiniteDuration getElectionTimeOutInterval() {
2218             return new FiniteDuration(electionTimeOutIntervalMillis, TimeUnit.MILLISECONDS);
2219         }
2220
2221         @Override
2222         public int getSnapshotChunkSize() {
2223             return snapshotChunkSize;
2224         }
2225     }
2226 }