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

   1 package org.opendaylight.controller.cluster.raft;
   2
   3 import static org.junit.Assert.assertEquals;
   4 import static org.junit.Assert.assertFalse;
   5 import static org.junit.Assert.assertNotEquals;
   6 import static org.junit.Assert.assertNotNull;
   7 import static org.junit.Assert.assertNull;
   8 import static org.junit.Assert.assertTrue;
   9 import static org.mockito.Matchers.any;
  10 import static org.mockito.Matchers.anyObject;
  11 import static org.mockito.Matchers.eq;
  12 import static org.mockito.Mockito.doReturn;
  13 import static org.mockito.Mockito.mock;
  14 import static org.mockito.Mockito.times;
  15 import static org.mockito.Mockito.verify;
  16 import akka.actor.ActorRef;
  17 import akka.actor.ActorSystem;
  18 import akka.actor.PoisonPill;
  19 import akka.actor.Props;
  20 import akka.actor.Terminated;
  21 import akka.japi.Creator;
  22 import akka.japi.Procedure;
  23 import akka.pattern.Patterns;
  24 import akka.persistence.RecoveryCompleted;
  25 import akka.persistence.SaveSnapshotFailure;
  26 import akka.persistence.SaveSnapshotSuccess;
  27 import akka.persistence.SnapshotMetadata;
  28 import akka.persistence.SnapshotOffer;
  29 import akka.persistence.SnapshotSelectionCriteria;
  30 import akka.testkit.JavaTestKit;
  31 import akka.testkit.TestActorRef;
  32 import akka.util.Timeout;
  33 import com.google.common.base.Optional;
  34 import com.google.common.collect.ImmutableMap;
  35 import com.google.common.collect.Lists;
  36 import com.google.common.util.concurrent.Uninterruptibles;
  37 import com.google.protobuf.ByteString;
  38 import java.io.ByteArrayInputStream;
  39 import java.io.ByteArrayOutputStream;
  40 import java.io.IOException;
  41 import java.io.ObjectInputStream;
  42 import java.io.ObjectOutputStream;
  43 import java.util.ArrayList;
  44 import java.util.Arrays;
  45 import java.util.Collections;
  46 import java.util.HashMap;
  47 import java.util.List;
  48 import java.util.Map;
  49 import java.util.concurrent.CountDownLatch;
  50 import java.util.concurrent.TimeUnit;
  51 import java.util.concurrent.TimeoutException;
  52 import javax.annotation.Nonnull;
  53 import org.junit.After;
  54 import org.junit.Assert;
  55 import org.junit.Before;
  56 import org.junit.Test;
  57 import org.opendaylight.controller.cluster.DataPersistenceProvider;
  58 import org.opendaylight.controller.cluster.NonPersistentDataProvider;
  59 import org.opendaylight.controller.cluster.datastore.DataPersistenceProviderMonitor;
  60 import org.opendaylight.controller.cluster.notifications.LeaderStateChanged;
  61 import org.opendaylight.controller.cluster.notifications.RoleChanged;
  62 import org.opendaylight.controller.cluster.raft.RaftActor.UpdateElectionTerm;
  63 import org.opendaylight.controller.cluster.raft.base.messages.ApplyJournalEntries;
  64 import org.opendaylight.controller.cluster.raft.base.messages.ApplyLogEntries;
  65 import org.opendaylight.controller.cluster.raft.base.messages.ApplySnapshot;
  66 import org.opendaylight.controller.cluster.raft.base.messages.ApplyState;
  67 import org.opendaylight.controller.cluster.raft.base.messages.CaptureSnapshotReply;
  68 import org.opendaylight.controller.cluster.raft.base.messages.SendHeartBeat;
  69 import org.opendaylight.controller.cluster.raft.behaviors.Follower;
  70 import org.opendaylight.controller.cluster.raft.behaviors.Leader;
  71 import org.opendaylight.controller.cluster.raft.behaviors.RaftActorBehavior;
  72 import org.opendaylight.controller.cluster.raft.client.messages.FindLeader;
  73 import org.opendaylight.controller.cluster.raft.client.messages.FindLeaderReply;
  74 import org.opendaylight.controller.cluster.raft.messages.AppendEntries;
  75 import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply;
  76 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.Payload;
  77 import org.opendaylight.controller.cluster.raft.utils.InMemoryJournal;
  78 import org.opendaylight.controller.cluster.raft.utils.InMemorySnapshotStore;
  79 import org.opendaylight.controller.cluster.raft.utils.MessageCollectorActor;
  80 import scala.concurrent.Await;
  81 import scala.concurrent.Future;
  82 import scala.concurrent.duration.Duration;
  83 import scala.concurrent.duration.FiniteDuration;
  84
  85 public class RaftActorTest extends AbstractActorTest {
  86
  87     private TestActorFactory factory;
  88
  89     @Before
  90     public void setUp(){
  91         factory = new TestActorFactory(getSystem());
  92     }
  93
  94     @After
  95     public void tearDown() throws Exception {
  96         factory.close();
  97         InMemoryJournal.clear();
  98         InMemorySnapshotStore.clear();
  99     }
 100
 101     public static class MockRaftActor extends RaftActor implements RaftActorRecoveryCohort, RaftActorSnapshotCohort {
 102
 103         private final RaftActor actorDelegate;
 104         private final RaftActorRecoveryCohort recoveryCohortDelegate;
 105         private final RaftActorSnapshotCohort snapshotCohortDelegate;
 106         private final CountDownLatch recoveryComplete = new CountDownLatch(1);
 107         private final List<Object> state;
 108         private ActorRef roleChangeNotifier;
 109         private final CountDownLatch initializeBehaviorComplete = new CountDownLatch(1);
 110
 111         public static final class MockRaftActorCreator implements Creator<MockRaftActor> {
 112             private static final long serialVersionUID = 1L;
 113             private final Map<String, String> peerAddresses;
 114             private final String id;
 115             private final Optional<ConfigParams> config;
 116             private final DataPersistenceProvider dataPersistenceProvider;
 117             private final ActorRef roleChangeNotifier;
 118
 119             private MockRaftActorCreator(Map<String, String> peerAddresses, String id,
 120                 Optional<ConfigParams> config, DataPersistenceProvider dataPersistenceProvider,
 121                 ActorRef roleChangeNotifier) {
 122                 this.peerAddresses = peerAddresses;
 123                 this.id = id;
 124                 this.config = config;
 125                 this.dataPersistenceProvider = dataPersistenceProvider;
 126                 this.roleChangeNotifier = roleChangeNotifier;
 127             }
 128
 129             @Override
 130             public MockRaftActor create() throws Exception {
 131                 MockRaftActor mockRaftActor = new MockRaftActor(id, peerAddresses, config,
 132                     dataPersistenceProvider);
 133                 mockRaftActor.roleChangeNotifier = this.roleChangeNotifier;
 134                 return mockRaftActor;
 135             }
 136         }
 137
 138         public MockRaftActor(String id, Map<String, String> peerAddresses, Optional<ConfigParams> config,
 139                              DataPersistenceProvider dataPersistenceProvider) {
 140             super(id, peerAddresses, config);
 141             state = new ArrayList<>();
 142             this.actorDelegate = mock(RaftActor.class);
 143             this.recoveryCohortDelegate = mock(RaftActorRecoveryCohort.class);
 144             this.snapshotCohortDelegate = mock(RaftActorSnapshotCohort.class);
 145             if(dataPersistenceProvider == null){
 146                 setPersistence(true);
 147             } else {
 148                 setPersistence(dataPersistenceProvider);
 149             }
 150         }
 151
 152         public void waitForRecoveryComplete() {
 153             try {
 154                 assertEquals("Recovery complete", true, recoveryComplete.await(5,  TimeUnit.SECONDS));
 155             } catch (InterruptedException e) {
 156                 e.printStackTrace();
 157             }
 158         }
 159
 160         public void waitForInitializeBehaviorComplete() {
 161             try {
 162                 assertEquals("Behavior initialized", true, initializeBehaviorComplete.await(5,  TimeUnit.SECONDS));
 163             } catch (InterruptedException e) {
 164                 e.printStackTrace();
 165             }
 166         }
 167
 168
 169         public void waitUntilLeader(){
 170             for(int i = 0;i < 10; i++){
 171                 if(isLeader()){
 172                     break;
 173                 }
 174                 Uninterruptibles.sleepUninterruptibly(100, TimeUnit.MILLISECONDS);
 175             }
 176         }
 177
 178         public List<Object> getState() {
 179             return state;
 180         }
 181
 182         public static Props props(final String id, final Map<String, String> peerAddresses,
 183                 Optional<ConfigParams> config){
 184             return Props.create(new MockRaftActorCreator(peerAddresses, id, config, null, null));
 185         }
 186
 187         public static Props props(final String id, final Map<String, String> peerAddresses,
 188                                   Optional<ConfigParams> config, DataPersistenceProvider dataPersistenceProvider){
 189             return Props.create(new MockRaftActorCreator(peerAddresses, id, config, dataPersistenceProvider, null));
 190         }
 191
 192         public static Props props(final String id, final Map<String, String> peerAddresses,
 193             Optional<ConfigParams> config, ActorRef roleChangeNotifier){
 194             return Props.create(new MockRaftActorCreator(peerAddresses, id, config, null, roleChangeNotifier));
 195         }
 196
 197         public static Props props(final String id, final Map<String, String> peerAddresses,
 198                                   Optional<ConfigParams> config, ActorRef roleChangeNotifier,
 199                                   DataPersistenceProvider dataPersistenceProvider){
 200             return Props.create(new MockRaftActorCreator(peerAddresses, id, config, dataPersistenceProvider, roleChangeNotifier));
 201         }
 202
 203
 204         @Override protected void applyState(ActorRef clientActor, String identifier, Object data) {
 205             actorDelegate.applyState(clientActor, identifier, data);
 206             LOG.info("{}: applyState called", persistenceId());
 207         }
 208
 209         @Override
 210         @Nonnull
 211         protected RaftActorRecoveryCohort getRaftActorRecoveryCohort() {
 212             return this;
 213         }
 214
 215         @Override
 216         protected RaftActorSnapshotCohort getRaftActorSnapshotCohort() {
 217             return this;
 218         }
 219
 220         @Override
 221         public void startLogRecoveryBatch(int maxBatchSize) {
 222         }
 223
 224         @Override
 225         public void appendRecoveredLogEntry(Payload data) {
 226             state.add(data);
 227         }
 228
 229         @Override
 230         public void applyCurrentLogRecoveryBatch() {
 231         }
 232
 233         @Override
 234         protected void onRecoveryComplete() {
 235             actorDelegate.onRecoveryComplete();
 236             recoveryComplete.countDown();
 237         }
 238
 239         @Override
 240         protected void initializeBehavior() {
 241             super.initializeBehavior();
 242             initializeBehaviorComplete.countDown();
 243         }
 244
 245         @Override
 246         public void applyRecoverySnapshot(byte[] bytes) {
 247             recoveryCohortDelegate.applyRecoverySnapshot(bytes);
 248             try {
 249                 Object data = toObject(bytes);
 250                 if (data instanceof List) {
 251                     state.addAll((List<?>) data);
 252                 }
 253             } catch (Exception e) {
 254                 e.printStackTrace();
 255             }
 256         }
 257
 258         @Override
 259         public void createSnapshot(ActorRef actorRef) {
 260             LOG.info("{}: createSnapshot called", persistenceId());
 261             snapshotCohortDelegate.createSnapshot(actorRef);
 262         }
 263
 264         @Override
 265         public void applySnapshot(byte [] snapshot) {
 266             LOG.info("{}: applySnapshot called", persistenceId());
 267             snapshotCohortDelegate.applySnapshot(snapshot);
 268         }
 269
 270         @Override
 271         protected void onStateChanged() {
 272             actorDelegate.onStateChanged();
 273         }
 274
 275         @Override
 276         protected Optional<ActorRef> getRoleChangeNotifier() {
 277             return Optional.fromNullable(roleChangeNotifier);
 278         }
 279
 280         @Override public String persistenceId() {
 281             return this.getId();
 282         }
 283
 284         private Object toObject(byte[] bs) throws ClassNotFoundException, IOException {
 285             Object obj = null;
 286             ByteArrayInputStream bis = null;
 287             ObjectInputStream ois = null;
 288             try {
 289                 bis = new ByteArrayInputStream(bs);
 290                 ois = new ObjectInputStream(bis);
 291                 obj = ois.readObject();
 292             } finally {
 293                 if (bis != null) {
 294                     bis.close();
 295                 }
 296                 if (ois != null) {
 297                     ois.close();
 298                 }
 299             }
 300             return obj;
 301         }
 302
 303         public ReplicatedLog getReplicatedLog(){
 304             return this.getRaftActorContext().getReplicatedLog();
 305         }
 306     }
 307
 308
 309     public static class RaftActorTestKit extends JavaTestKit {
 310         private final ActorRef raftActor;
 311
 312         public RaftActorTestKit(ActorSystem actorSystem, String actorName) {
 313             super(actorSystem);
 314
 315             raftActor = this.getSystem().actorOf(MockRaftActor.props(actorName,
 316                     Collections.<String,String>emptyMap(), Optional.<ConfigParams>absent()), actorName);
 317
 318         }
 319
 320
 321         public ActorRef getRaftActor() {
 322             return raftActor;
 323         }
 324
 325         public boolean waitForLogMessage(final Class<?> logEventClass, String message){
 326             // Wait for a specific log message to show up
 327             return
 328                 new JavaTestKit.EventFilter<Boolean>(logEventClass
 329                 ) {
 330                     @Override
 331                     protected Boolean run() {
 332                         return true;
 333                     }
 334                 }.from(raftActor.path().toString())
 335                     .message(message)
 336                     .occurrences(1).exec();
 337
 338
 339         }
 340
 341         protected void waitUntilLeader(){
 342             waitUntilLeader(raftActor);
 343         }
 344
 345         public static void waitUntilLeader(ActorRef actorRef) {
 346             FiniteDuration duration = Duration.create(100, TimeUnit.MILLISECONDS);
 347             for(int i = 0; i < 20 * 5; i++) {
 348                 Future<Object> future = Patterns.ask(actorRef, new FindLeader(), new Timeout(duration));
 349                 try {
 350                     FindLeaderReply resp = (FindLeaderReply) Await.result(future, duration);
 351                     if(resp.getLeaderActor() != null) {
 352                         return;
 353                     }
 354                 } catch(TimeoutException e) {
 355                 } catch(Exception e) {
 356                     System.err.println("FindLeader threw ex");
 357                     e.printStackTrace();
 358                 }
 359
 360
 361                 Uninterruptibles.sleepUninterruptibly(50, TimeUnit.MILLISECONDS);
 362             }
 363
 364             Assert.fail("Leader not found for actorRef " + actorRef.path());
 365         }
 366
 367     }
 368
 369
 370     @Test
 371     public void testConstruction() {
 372         new RaftActorTestKit(getSystem(), "testConstruction").waitUntilLeader();
 373     }
 374
 375     @Test
 376     public void testFindLeaderWhenLeaderIsSelf(){
 377         RaftActorTestKit kit = new RaftActorTestKit(getSystem(), "testFindLeader");
 378         kit.waitUntilLeader();
 379     }
 380
 381     @Test
 382     public void testRaftActorRecovery() throws Exception {
 383         new JavaTestKit(getSystem()) {{
 384             String persistenceId = factory.generateActorId("follower-");
 385
 386             DefaultConfigParamsImpl config = new DefaultConfigParamsImpl();
 387             // Set the heartbeat interval high to essentially disable election otherwise the test
 388             // may fail if the actor is switched to Leader and the commitIndex is set to the last
 389             // log entry.
 390             config.setHeartBeatInterval(new FiniteDuration(1, TimeUnit.DAYS));
 391
 392             ActorRef followerActor = factory.createActor(MockRaftActor.props(persistenceId,
 393                     Collections.<String, String>emptyMap(), Optional.<ConfigParams>of(config)), persistenceId);
 394
 395             watch(followerActor);
 396
 397             List<ReplicatedLogEntry> snapshotUnappliedEntries = new ArrayList<>();
 398             ReplicatedLogEntry entry1 = new MockRaftActorContext.MockReplicatedLogEntry(1, 4,
 399                     new MockRaftActorContext.MockPayload("E"));
 400             snapshotUnappliedEntries.add(entry1);
 401
 402             int lastAppliedDuringSnapshotCapture = 3;
 403             int lastIndexDuringSnapshotCapture = 4;
 404
 405             // 4 messages as part of snapshot, which are applied to state
 406             ByteString snapshotBytes = fromObject(Arrays.asList(
 407                     new MockRaftActorContext.MockPayload("A"),
 408                     new MockRaftActorContext.MockPayload("B"),
 409                     new MockRaftActorContext.MockPayload("C"),
 410                     new MockRaftActorContext.MockPayload("D")));
 411
 412             Snapshot snapshot = Snapshot.create(snapshotBytes.toByteArray(),
 413                     snapshotUnappliedEntries, lastIndexDuringSnapshotCapture, 1,
 414                     lastAppliedDuringSnapshotCapture, 1);
 415             InMemorySnapshotStore.addSnapshot(persistenceId, snapshot);
 416
 417             // add more entries after snapshot is taken
 418             List<ReplicatedLogEntry> entries = new ArrayList<>();
 419             ReplicatedLogEntry entry2 = new MockRaftActorContext.MockReplicatedLogEntry(1, 5,
 420                     new MockRaftActorContext.MockPayload("F"));
 421             ReplicatedLogEntry entry3 = new MockRaftActorContext.MockReplicatedLogEntry(1, 6,
 422                     new MockRaftActorContext.MockPayload("G"));
 423             ReplicatedLogEntry entry4 = new MockRaftActorContext.MockReplicatedLogEntry(1, 7,
 424                     new MockRaftActorContext.MockPayload("H"));
 425             entries.add(entry2);
 426             entries.add(entry3);
 427             entries.add(entry4);
 428
 429             int lastAppliedToState = 5;
 430             int lastIndex = 7;
 431
 432             InMemoryJournal.addEntry(persistenceId, 5, entry2);
 433             // 2 entries are applied to state besides the 4 entries in snapshot
 434             InMemoryJournal.addEntry(persistenceId, 6, new ApplyJournalEntries(lastAppliedToState));
 435             InMemoryJournal.addEntry(persistenceId, 7, entry3);
 436             InMemoryJournal.addEntry(persistenceId, 8, entry4);
 437
 438             // kill the actor
 439             followerActor.tell(PoisonPill.getInstance(), null);
 440             expectMsgClass(duration("5 seconds"), Terminated.class);
 441
 442             unwatch(followerActor);
 443
 444             //reinstate the actor
 445             TestActorRef<MockRaftActor> ref = factory.createTestActor(
 446                     MockRaftActor.props(persistenceId, Collections.<String, String>emptyMap(),
 447                             Optional.<ConfigParams>of(config)));
 448
 449             ref.underlyingActor().waitForRecoveryComplete();
 450
 451             RaftActorContext context = ref.underlyingActor().getRaftActorContext();
 452             assertEquals("Journal log size", snapshotUnappliedEntries.size() + entries.size(),
 453                     context.getReplicatedLog().size());
 454             assertEquals("Last index", lastIndex, context.getReplicatedLog().lastIndex());
 455             assertEquals("Last applied", lastAppliedToState, context.getLastApplied());
 456             assertEquals("Commit index", lastAppliedToState, context.getCommitIndex());
 457             assertEquals("Recovered state size", 6, ref.underlyingActor().getState().size());
 458         }};
 459     }
 460
 461     @Test
 462     public void testRaftActorRecoveryWithPreLithuimApplyLogEntries() throws Exception {
 463         new JavaTestKit(getSystem()) {{
 464             String persistenceId = factory.generateActorId("leader-");
 465
 466             DefaultConfigParamsImpl config = new DefaultConfigParamsImpl();
 467             config.setHeartBeatInterval(new FiniteDuration(1, TimeUnit.DAYS));
 468
 469             // Setup the persisted journal with some entries
 470             ReplicatedLogEntry entry0 = new MockRaftActorContext.MockReplicatedLogEntry(1, 0,
 471                     new MockRaftActorContext.MockPayload("zero"));
 472             ReplicatedLogEntry entry1 = new MockRaftActorContext.MockReplicatedLogEntry(1, 1,
 473                     new MockRaftActorContext.MockPayload("oen"));
 474             ReplicatedLogEntry entry2 = new MockRaftActorContext.MockReplicatedLogEntry(1, 2,
 475                     new MockRaftActorContext.MockPayload("two"));
 476
 477             long seqNr = 1;
 478             InMemoryJournal.addEntry(persistenceId, seqNr++, entry0);
 479             InMemoryJournal.addEntry(persistenceId, seqNr++, entry1);
 480             InMemoryJournal.addEntry(persistenceId, seqNr++, new ApplyLogEntries(1));
 481             InMemoryJournal.addEntry(persistenceId, seqNr++, entry2);
 482
 483             int lastAppliedToState = 1;
 484             int lastIndex = 2;
 485
 486             //reinstate the actor
 487             TestActorRef<MockRaftActor> leaderActor = factory.createTestActor(
 488                     MockRaftActor.props(persistenceId, Collections.<String, String>emptyMap(),
 489                             Optional.<ConfigParams>of(config)));
 490
 491             leaderActor.underlyingActor().waitForRecoveryComplete();
 492
 493             RaftActorContext context = leaderActor.underlyingActor().getRaftActorContext();
 494             assertEquals("Journal log size", 3, context.getReplicatedLog().size());
 495             assertEquals("Last index", lastIndex, context.getReplicatedLog().lastIndex());
 496             assertEquals("Last applied", lastAppliedToState, context.getLastApplied());
 497             assertEquals("Commit index", lastAppliedToState, context.getCommitIndex());
 498         }};
 499     }
 500
 501     /**
 502      * This test verifies that when recovery is applicable (typically when persistence is true) the RaftActor does
 503      * process recovery messages
 504      *
 505      * @throws Exception
 506      */
 507
 508     @Test
 509     public void testHandleRecoveryWhenDataPersistenceRecoveryApplicable() throws Exception {
 510         new JavaTestKit(getSystem()) {
 511             {
 512                 String persistenceId = factory.generateActorId("leader-");
 513
 514                 DefaultConfigParamsImpl config = new DefaultConfigParamsImpl();
 515
 516                 config.setHeartBeatInterval(new FiniteDuration(1, TimeUnit.DAYS));
 517
 518                 TestActorRef<MockRaftActor> mockActorRef = factory.createTestActor(MockRaftActor.props(persistenceId,
 519                         Collections.<String, String>emptyMap(), Optional.<ConfigParams>of(config)), persistenceId);
 520
 521                 MockRaftActor mockRaftActor = mockActorRef.underlyingActor();
 522
 523                 // Wait for akka's recovery to complete so it doesn't interfere.
 524                 mockRaftActor.waitForRecoveryComplete();
 525
 526                 ByteString snapshotBytes = fromObject(Arrays.asList(
 527                         new MockRaftActorContext.MockPayload("A"),
 528                         new MockRaftActorContext.MockPayload("B"),
 529                         new MockRaftActorContext.MockPayload("C"),
 530                         new MockRaftActorContext.MockPayload("D")));
 531
 532                 Snapshot snapshot = Snapshot.create(snapshotBytes.toByteArray(),
 533                         Lists.<ReplicatedLogEntry>newArrayList(), 3, 1, 3, 1);
 534
 535                 mockRaftActor.onReceiveRecover(new SnapshotOffer(new SnapshotMetadata(persistenceId, 100, 100), snapshot));
 536
 537                 verify(mockRaftActor.recoveryCohortDelegate).applyRecoverySnapshot(eq(snapshotBytes.toByteArray()));
 538
 539                 mockRaftActor.onReceiveRecover(new ReplicatedLogImplEntry(0, 1, new MockRaftActorContext.MockPayload("A")));
 540
 541                 ReplicatedLog replicatedLog = mockRaftActor.getReplicatedLog();
 542
 543                 assertEquals("add replicated log entry", 1, replicatedLog.size());
 544
 545                 mockRaftActor.onReceiveRecover(new ReplicatedLogImplEntry(1, 1, new MockRaftActorContext.MockPayload("A")));
 546
 547                 assertEquals("add replicated log entry", 2, replicatedLog.size());
 548
 549                 mockRaftActor.onReceiveRecover(new ApplyJournalEntries(1));
 550
 551                 assertEquals("commit index 1", 1, mockRaftActor.getRaftActorContext().getCommitIndex());
 552
 553                 // The snapshot had 4 items + we added 2 more items during the test
 554                 // We start removing from 5 and we should get 1 item in the replicated log
 555                 mockRaftActor.onReceiveRecover(new RaftActor.DeleteEntries(5));
 556
 557                 assertEquals("remove log entries", 1, replicatedLog.size());
 558
 559                 mockRaftActor.onReceiveRecover(new UpdateElectionTerm(10, "foobar"));
 560
 561                 assertEquals("election term", 10, mockRaftActor.getRaftActorContext().getTermInformation().getCurrentTerm());
 562                 assertEquals("voted for", "foobar", mockRaftActor.getRaftActorContext().getTermInformation().getVotedFor());
 563
 564                 mockRaftActor.onReceiveRecover(mock(RecoveryCompleted.class));
 565
 566             }};
 567     }
 568
 569     /**
 570      * This test verifies that when recovery is not applicable (typically when persistence is false) the RaftActor does
 571      * not process recovery messages
 572      *
 573      * @throws Exception
 574      */
 575     @Test
 576     public void testHandleRecoveryWhenDataPersistenceRecoveryNotApplicable() throws Exception {
 577         new JavaTestKit(getSystem()) {
 578             {
 579                 String persistenceId = factory.generateActorId("leader-");
 580
 581                 DefaultConfigParamsImpl config = new DefaultConfigParamsImpl();
 582
 583                 config.setHeartBeatInterval(new FiniteDuration(1, TimeUnit.DAYS));
 584
 585                 TestActorRef<MockRaftActor> mockActorRef = factory.createTestActor(MockRaftActor.props(persistenceId,
 586                         Collections.<String, String>emptyMap(), Optional.<ConfigParams>of(config), new DataPersistenceProviderMonitor()), persistenceId);
 587
 588                 MockRaftActor mockRaftActor = mockActorRef.underlyingActor();
 589
 590                 // Wait for akka's recovery to complete so it doesn't interfere.
 591                 mockRaftActor.waitForRecoveryComplete();
 592
 593                 ByteString snapshotBytes = fromObject(Arrays.asList(
 594                         new MockRaftActorContext.MockPayload("A"),
 595                         new MockRaftActorContext.MockPayload("B"),
 596                         new MockRaftActorContext.MockPayload("C"),
 597                         new MockRaftActorContext.MockPayload("D")));
 598
 599                 Snapshot snapshot = Snapshot.create(snapshotBytes.toByteArray(),
 600                         Lists.<ReplicatedLogEntry>newArrayList(), 3, 1, 3, 1);
 601
 602                 mockRaftActor.onReceiveRecover(new SnapshotOffer(new SnapshotMetadata(persistenceId, 100, 100), snapshot));
 603
 604                 verify(mockRaftActor.recoveryCohortDelegate, times(0)).applyRecoverySnapshot(any(byte[].class));
 605
 606                 mockRaftActor.onReceiveRecover(new ReplicatedLogImplEntry(0, 1, new MockRaftActorContext.MockPayload("A")));
 607
 608                 ReplicatedLog replicatedLog = mockRaftActor.getReplicatedLog();
 609
 610                 assertEquals("add replicated log entry", 0, replicatedLog.size());
 611
 612                 mockRaftActor.onReceiveRecover(new ReplicatedLogImplEntry(1, 1, new MockRaftActorContext.MockPayload("A")));
 613
 614                 assertEquals("add replicated log entry", 0, replicatedLog.size());
 615
 616                 mockRaftActor.onReceiveRecover(new ApplyJournalEntries(1));
 617
 618                 assertEquals("commit index -1", -1, mockRaftActor.getRaftActorContext().getCommitIndex());
 619
 620                 mockRaftActor.onReceiveRecover(new RaftActor.DeleteEntries(2));
 621
 622                 assertEquals("remove log entries", 0, replicatedLog.size());
 623
 624                 mockRaftActor.onReceiveRecover(new UpdateElectionTerm(10, "foobar"));
 625
 626                 assertNotEquals("election term", 10, mockRaftActor.getRaftActorContext().getTermInformation().getCurrentTerm());
 627                 assertNotEquals("voted for", "foobar", mockRaftActor.getRaftActorContext().getTermInformation().getVotedFor());
 628
 629                 mockRaftActor.onReceiveRecover(mock(RecoveryCompleted.class));
 630             }};
 631     }
 632
 633
 634     @Test
 635     public void testUpdatingElectionTermCallsDataPersistence() throws Exception {
 636         new JavaTestKit(getSystem()) {
 637             {
 638                 String persistenceId = factory.generateActorId("leader-");
 639
 640                 DefaultConfigParamsImpl config = new DefaultConfigParamsImpl();
 641
 642                 config.setHeartBeatInterval(new FiniteDuration(1, TimeUnit.DAYS));
 643
 644                 CountDownLatch persistLatch = new CountDownLatch(1);
 645                 DataPersistenceProviderMonitor dataPersistenceProviderMonitor = new DataPersistenceProviderMonitor();
 646                 dataPersistenceProviderMonitor.setPersistLatch(persistLatch);
 647
 648                 TestActorRef<MockRaftActor> mockActorRef = factory.createTestActor(MockRaftActor.props(persistenceId,
 649                         Collections.<String, String>emptyMap(), Optional.<ConfigParams>of(config), dataPersistenceProviderMonitor), persistenceId);
 650
 651                 MockRaftActor mockRaftActor = mockActorRef.underlyingActor();
 652
 653                 mockRaftActor.waitForInitializeBehaviorComplete();
 654
 655                 mockRaftActor.getRaftActorContext().getTermInformation().updateAndPersist(10, "foobar");
 656
 657                 assertEquals("Persist called", true, persistLatch.await(5, TimeUnit.SECONDS));
 658             }
 659         };
 660     }
 661
 662     @Test
 663     public void testAddingReplicatedLogEntryCallsDataPersistence() throws Exception {
 664         new JavaTestKit(getSystem()) {
 665             {
 666                 String persistenceId = factory.generateActorId("leader-");
 667
 668                 DefaultConfigParamsImpl config = new DefaultConfigParamsImpl();
 669
 670                 config.setHeartBeatInterval(new FiniteDuration(1, TimeUnit.DAYS));
 671
 672                 DataPersistenceProvider dataPersistenceProvider = mock(DataPersistenceProvider.class);
 673
 674                 TestActorRef<MockRaftActor> mockActorRef = factory.createTestActor(MockRaftActor.props(persistenceId,
 675                         Collections.<String, String>emptyMap(), Optional.<ConfigParams>of(config), dataPersistenceProvider), persistenceId);
 676
 677                 MockRaftActor mockRaftActor = mockActorRef.underlyingActor();
 678
 679                 mockRaftActor.waitForInitializeBehaviorComplete();
 680
 681                 MockRaftActorContext.MockReplicatedLogEntry logEntry = new MockRaftActorContext.MockReplicatedLogEntry(10, 10, mock(Payload.class));
 682
 683                 mockRaftActor.getRaftActorContext().getReplicatedLog().appendAndPersist(logEntry);
 684
 685                 verify(dataPersistenceProvider).persist(eq(logEntry), any(Procedure.class));
 686             }
 687         };
 688     }
 689
 690     @Test
 691     public void testRemovingReplicatedLogEntryCallsDataPersistence() throws Exception {
 692         new JavaTestKit(getSystem()) {
 693             {
 694                 String persistenceId = factory.generateActorId("leader-");
 695
 696                 DefaultConfigParamsImpl config = new DefaultConfigParamsImpl();
 697
 698                 config.setHeartBeatInterval(new FiniteDuration(1, TimeUnit.DAYS));
 699
 700                 DataPersistenceProvider dataPersistenceProvider = mock(DataPersistenceProvider.class);
 701
 702                 TestActorRef<MockRaftActor> mockActorRef = factory.createTestActor(MockRaftActor.props(persistenceId,
 703                         Collections.<String, String>emptyMap(), Optional.<ConfigParams>of(config), dataPersistenceProvider), persistenceId);
 704
 705                 MockRaftActor mockRaftActor = mockActorRef.underlyingActor();
 706
 707                 mockRaftActor.waitForInitializeBehaviorComplete();
 708
 709                 mockRaftActor.waitUntilLeader();
 710
 711                 mockRaftActor.getReplicatedLog().appendAndPersist(new MockRaftActorContext.MockReplicatedLogEntry(1, 0, mock(Payload.class)));
 712
 713                 mockRaftActor.getRaftActorContext().getReplicatedLog().removeFromAndPersist(0);
 714
 715                 verify(dataPersistenceProvider, times(3)).persist(anyObject(), any(Procedure.class));
 716             }
 717         };
 718     }
 719
 720     @Test
 721     public void testApplyJournalEntriesCallsDataPersistence() throws Exception {
 722         new JavaTestKit(getSystem()) {
 723             {
 724                 String persistenceId = factory.generateActorId("leader-");
 725
 726                 DefaultConfigParamsImpl config = new DefaultConfigParamsImpl();
 727
 728                 config.setHeartBeatInterval(new FiniteDuration(1, TimeUnit.DAYS));
 729
 730                 DataPersistenceProvider dataPersistenceProvider = mock(DataPersistenceProvider.class);
 731
 732                 TestActorRef<MockRaftActor> mockActorRef = factory.createTestActor(MockRaftActor.props(persistenceId,
 733                         Collections.<String, String>emptyMap(), Optional.<ConfigParams>of(config), dataPersistenceProvider), persistenceId);
 734
 735                 MockRaftActor mockRaftActor = mockActorRef.underlyingActor();
 736
 737                 mockRaftActor.waitForInitializeBehaviorComplete();
 738
 739                 mockRaftActor.waitUntilLeader();
 740
 741                 mockRaftActor.onReceiveCommand(new ApplyJournalEntries(10));
 742
 743                 verify(dataPersistenceProvider, times(2)).persist(anyObject(), any(Procedure.class));
 744
 745             }
 746
 747         };
 748     }
 749
 750     @Test
 751     public void testCaptureSnapshotReplyCallsDataPersistence() throws Exception {
 752         new JavaTestKit(getSystem()) {
 753             {
 754                 String persistenceId = factory.generateActorId("leader-");
 755
 756                 DefaultConfigParamsImpl config = new DefaultConfigParamsImpl();
 757
 758                 config.setHeartBeatInterval(new FiniteDuration(1, TimeUnit.DAYS));
 759
 760                 DataPersistenceProvider dataPersistenceProvider = mock(DataPersistenceProvider.class);
 761
 762                 TestActorRef<MockRaftActor> mockActorRef = factory.createTestActor(
 763                         MockRaftActor.props(persistenceId, Collections.<String, String>emptyMap(),
 764                                 Optional.<ConfigParams>of(config), dataPersistenceProvider), persistenceId);
 765
 766                 MockRaftActor mockRaftActor = mockActorRef.underlyingActor();
 767
 768                 mockRaftActor.waitForInitializeBehaviorComplete();
 769
 770                 ByteString snapshotBytes = fromObject(Arrays.asList(
 771                         new MockRaftActorContext.MockPayload("A"),
 772                         new MockRaftActorContext.MockPayload("B"),
 773                         new MockRaftActorContext.MockPayload("C"),
 774                         new MockRaftActorContext.MockPayload("D")));
 775
 776                 RaftActorContext raftActorContext = mockRaftActor.getRaftActorContext();
 777
 778                 raftActorContext.getSnapshotManager().capture(
 779                         new MockRaftActorContext.MockReplicatedLogEntry(1, -1,
 780                                 new MockRaftActorContext.MockPayload("D")), -1);
 781
 782                 mockRaftActor.setCurrentBehavior(new Leader(raftActorContext));
 783
 784                 mockRaftActor.onReceiveCommand(new CaptureSnapshotReply(snapshotBytes.toByteArray()));
 785
 786                 verify(dataPersistenceProvider).saveSnapshot(anyObject());
 787
 788             }
 789         };
 790     }
 791
 792     @Test
 793     public void testSaveSnapshotSuccessCallsDataPersistence() throws Exception {
 794         new JavaTestKit(getSystem()) {
 795             {
 796                 String persistenceId = factory.generateActorId("leader-");
 797
 798                 DefaultConfigParamsImpl config = new DefaultConfigParamsImpl();
 799
 800                 config.setHeartBeatInterval(new FiniteDuration(1, TimeUnit.DAYS));
 801
 802                 DataPersistenceProvider dataPersistenceProvider = mock(DataPersistenceProvider.class);
 803
 804                 TestActorRef<MockRaftActor> mockActorRef = factory.createTestActor(MockRaftActor.props(persistenceId,
 805                         ImmutableMap.of("leader", "fake/path"), Optional.<ConfigParams>of(config), dataPersistenceProvider), persistenceId);
 806
 807                 MockRaftActor mockRaftActor = mockActorRef.underlyingActor();
 808
 809                 mockRaftActor.waitForInitializeBehaviorComplete();
 810                 MockRaftActorContext.MockReplicatedLogEntry lastEntry = new MockRaftActorContext.MockReplicatedLogEntry(1, 4, mock(Payload.class));
 811
 812                 mockRaftActor.getReplicatedLog().append(new MockRaftActorContext.MockReplicatedLogEntry(1, 0, mock(Payload.class)));
 813                 mockRaftActor.getReplicatedLog().append(new MockRaftActorContext.MockReplicatedLogEntry(1, 1, mock(Payload.class)));
 814                 mockRaftActor.getReplicatedLog().append(new MockRaftActorContext.MockReplicatedLogEntry(1, 2, mock(Payload.class)));
 815                 mockRaftActor.getReplicatedLog().append(new MockRaftActorContext.MockReplicatedLogEntry(1, 3, mock(Payload.class)));
 816                 mockRaftActor.getReplicatedLog().append(lastEntry);
 817
 818                 ByteString snapshotBytes = fromObject(Arrays.asList(
 819                         new MockRaftActorContext.MockPayload("A"),
 820                         new MockRaftActorContext.MockPayload("B"),
 821                         new MockRaftActorContext.MockPayload("C"),
 822                         new MockRaftActorContext.MockPayload("D")));
 823
 824                 RaftActorContext raftActorContext = mockRaftActor.getRaftActorContext();
 825                 mockRaftActor.setCurrentBehavior(new Follower(raftActorContext));
 826
 827                 long replicatedToAllIndex = 1;
 828
 829                 mockRaftActor.getRaftActorContext().getSnapshotManager().capture(lastEntry, replicatedToAllIndex);
 830
 831                 verify(mockRaftActor.snapshotCohortDelegate).createSnapshot(any(ActorRef.class));
 832
 833                 mockRaftActor.onReceiveCommand(new CaptureSnapshotReply(snapshotBytes.toByteArray()));
 834
 835                 mockRaftActor.onReceiveCommand(new SaveSnapshotSuccess(new SnapshotMetadata("foo", 100, 100)));
 836
 837                 verify(dataPersistenceProvider).deleteSnapshots(any(SnapshotSelectionCriteria.class));
 838
 839                 verify(dataPersistenceProvider).deleteMessages(100);
 840
 841                 assertEquals(3, mockRaftActor.getReplicatedLog().size());
 842                 assertEquals(1, mockRaftActor.getCurrentBehavior().getReplicatedToAllIndex());
 843
 844                 assertNotNull(mockRaftActor.getReplicatedLog().get(2));
 845                 assertNotNull(mockRaftActor.getReplicatedLog().get(3));
 846                 assertNotNull(mockRaftActor.getReplicatedLog().get(4));
 847
 848                 // Index 2 will not be in the log because it was removed due to snapshotting
 849                 assertNull(mockRaftActor.getReplicatedLog().get(1));
 850                 assertNull(mockRaftActor.getReplicatedLog().get(0));
 851
 852             }
 853         };
 854     }
 855
 856     @Test
 857     public void testApplyState() throws Exception {
 858
 859         new JavaTestKit(getSystem()) {
 860             {
 861                 String persistenceId = factory.generateActorId("leader-");
 862
 863                 DefaultConfigParamsImpl config = new DefaultConfigParamsImpl();
 864
 865                 config.setHeartBeatInterval(new FiniteDuration(1, TimeUnit.DAYS));
 866
 867                 DataPersistenceProvider dataPersistenceProvider = mock(DataPersistenceProvider.class);
 868
 869                 TestActorRef<MockRaftActor> mockActorRef = factory.createTestActor(MockRaftActor.props(persistenceId,
 870                         Collections.<String, String>emptyMap(), Optional.<ConfigParams>of(config), dataPersistenceProvider), persistenceId);
 871
 872                 MockRaftActor mockRaftActor = mockActorRef.underlyingActor();
 873
 874                 mockRaftActor.waitForInitializeBehaviorComplete();
 875
 876                 ReplicatedLogEntry entry = new MockRaftActorContext.MockReplicatedLogEntry(1, 5,
 877                         new MockRaftActorContext.MockPayload("F"));
 878
 879                 mockRaftActor.onReceiveCommand(new ApplyState(mockActorRef, "apply-state", entry));
 880
 881                 verify(mockRaftActor.actorDelegate).applyState(eq(mockActorRef), eq("apply-state"), anyObject());
 882
 883             }
 884         };
 885     }
 886
 887     @Test
 888     public void testApplySnapshot() throws Exception {
 889         new JavaTestKit(getSystem()) {
 890             {
 891                 String persistenceId = factory.generateActorId("leader-");
 892
 893                 DefaultConfigParamsImpl config = new DefaultConfigParamsImpl();
 894
 895                 config.setHeartBeatInterval(new FiniteDuration(1, TimeUnit.DAYS));
 896
 897                 DataPersistenceProviderMonitor dataPersistenceProviderMonitor = new DataPersistenceProviderMonitor();
 898
 899                 TestActorRef<MockRaftActor> mockActorRef = factory.createTestActor(MockRaftActor.props(persistenceId,
 900                         Collections.<String, String>emptyMap(), Optional.<ConfigParams>of(config), dataPersistenceProviderMonitor), persistenceId);
 901
 902                 MockRaftActor mockRaftActor = mockActorRef.underlyingActor();
 903
 904                 mockRaftActor.waitForInitializeBehaviorComplete();
 905
 906                 ReplicatedLog oldReplicatedLog = mockRaftActor.getReplicatedLog();
 907
 908                 oldReplicatedLog.append(new MockRaftActorContext.MockReplicatedLogEntry(1, 0, mock(Payload.class)));
 909                 oldReplicatedLog.append(new MockRaftActorContext.MockReplicatedLogEntry(1, 1, mock(Payload.class)));
 910                 oldReplicatedLog.append(
 911                         new MockRaftActorContext.MockReplicatedLogEntry(1, 2,
 912                                 mock(Payload.class)));
 913
 914                 ByteString snapshotBytes = fromObject(Arrays.asList(
 915                         new MockRaftActorContext.MockPayload("A"),
 916                         new MockRaftActorContext.MockPayload("B"),
 917                         new MockRaftActorContext.MockPayload("C"),
 918                         new MockRaftActorContext.MockPayload("D")));
 919
 920                 Snapshot snapshot = mock(Snapshot.class);
 921
 922                 doReturn(snapshotBytes.toByteArray()).when(snapshot).getState();
 923
 924                 doReturn(3L).when(snapshot).getLastAppliedIndex();
 925
 926                 mockRaftActor.onReceiveCommand(new ApplySnapshot(snapshot));
 927
 928                 verify(mockRaftActor.snapshotCohortDelegate).applySnapshot(eq(snapshot.getState()));
 929
 930                 assertTrue("The replicatedLog should have changed",
 931                         oldReplicatedLog != mockRaftActor.getReplicatedLog());
 932
 933                 assertEquals("lastApplied should be same as in the snapshot",
 934                         (Long) 3L, mockRaftActor.getLastApplied());
 935
 936                 assertEquals(0, mockRaftActor.getReplicatedLog().size());
 937
 938             }
 939         };
 940     }
 941
 942     @Test
 943     public void testSaveSnapshotFailure() throws Exception {
 944         new JavaTestKit(getSystem()) {
 945             {
 946                 String persistenceId = factory.generateActorId("leader-");
 947
 948                 DefaultConfigParamsImpl config = new DefaultConfigParamsImpl();
 949
 950                 config.setHeartBeatInterval(new FiniteDuration(1, TimeUnit.DAYS));
 951
 952                 DataPersistenceProviderMonitor dataPersistenceProviderMonitor = new DataPersistenceProviderMonitor();
 953
 954                 TestActorRef<MockRaftActor> mockActorRef = factory.createTestActor(MockRaftActor.props(persistenceId,
 955                         Collections.<String, String>emptyMap(), Optional.<ConfigParams>of(config), dataPersistenceProviderMonitor), persistenceId);
 956
 957                 MockRaftActor mockRaftActor = mockActorRef.underlyingActor();
 958
 959                 mockRaftActor.waitForInitializeBehaviorComplete();
 960
 961                 ByteString snapshotBytes = fromObject(Arrays.asList(
 962                         new MockRaftActorContext.MockPayload("A"),
 963                         new MockRaftActorContext.MockPayload("B"),
 964                         new MockRaftActorContext.MockPayload("C"),
 965                         new MockRaftActorContext.MockPayload("D")));
 966
 967                 RaftActorContext raftActorContext = mockRaftActor.getRaftActorContext();
 968
 969                 mockRaftActor.setCurrentBehavior(new Leader(raftActorContext));
 970
 971                 raftActorContext.getSnapshotManager().capture(
 972                         new MockRaftActorContext.MockReplicatedLogEntry(1, 1,
 973                                 new MockRaftActorContext.MockPayload("D")), 1);
 974
 975                 mockRaftActor.onReceiveCommand(new CaptureSnapshotReply(snapshotBytes.toByteArray()));
 976
 977                 mockRaftActor.onReceiveCommand(new SaveSnapshotFailure(new SnapshotMetadata("foobar", 10L, 1234L),
 978                         new Exception()));
 979
 980                 assertEquals("Snapshot index should not have advanced because save snapshot failed", -1,
 981                         mockRaftActor.getReplicatedLog().getSnapshotIndex());
 982
 983             }
 984         };
 985     }
 986
 987     @Test
 988     public void testRaftRoleChangeNotifierWhenRaftActorHasNoPeers() throws Exception {
 989         new JavaTestKit(getSystem()) {{
 990             TestActorRef<MessageCollectorActor> notifierActor = factory.createTestActor(
 991                     Props.create(MessageCollectorActor.class));
 992             MessageCollectorActor.waitUntilReady(notifierActor);
 993
 994             DefaultConfigParamsImpl config = new DefaultConfigParamsImpl();
 995             long heartBeatInterval = 100;
 996             config.setHeartBeatInterval(FiniteDuration.create(heartBeatInterval, TimeUnit.MILLISECONDS));
 997             config.setElectionTimeoutFactor(20);
 998
 999             String persistenceId = factory.generateActorId("notifier-");
1000
1001             TestActorRef<MockRaftActor> raftActorRef = factory.createTestActor(MockRaftActor.props(persistenceId,
1002                     Collections.<String, String>emptyMap(), Optional.<ConfigParams>of(config), notifierActor,
1003                     new NonPersistentDataProvider()), persistenceId);
1004
1005             List<RoleChanged> matches =  MessageCollectorActor.expectMatching(notifierActor, RoleChanged.class, 3);
1006
1007
1008             // check if the notifier got a role change from null to Follower
1009             RoleChanged raftRoleChanged = matches.get(0);
1010             assertEquals(persistenceId, raftRoleChanged.getMemberId());
1011             assertNull(raftRoleChanged.getOldRole());
1012             assertEquals(RaftState.Follower.name(), raftRoleChanged.getNewRole());
1013
1014             // check if the notifier got a role change from Follower to Candidate
1015             raftRoleChanged = matches.get(1);
1016             assertEquals(persistenceId, raftRoleChanged.getMemberId());
1017             assertEquals(RaftState.Follower.name(), raftRoleChanged.getOldRole());
1018             assertEquals(RaftState.Candidate.name(), raftRoleChanged.getNewRole());
1019
1020             // check if the notifier got a role change from Candidate to Leader
1021             raftRoleChanged = matches.get(2);
1022             assertEquals(persistenceId, raftRoleChanged.getMemberId());
1023             assertEquals(RaftState.Candidate.name(), raftRoleChanged.getOldRole());
1024             assertEquals(RaftState.Leader.name(), raftRoleChanged.getNewRole());
1025
1026             LeaderStateChanged leaderStateChange = MessageCollectorActor.expectFirstMatching(
1027                     notifierActor, LeaderStateChanged.class);
1028
1029             assertEquals(raftRoleChanged.getMemberId(), leaderStateChange.getLeaderId());
1030
1031             notifierActor.underlyingActor().clear();
1032
1033             MockRaftActor raftActor = raftActorRef.underlyingActor();
1034             final String newLeaderId = "new-leader";
1035             Follower follower = new Follower(raftActor.getRaftActorContext()) {
1036                 @Override
1037                 public RaftActorBehavior handleMessage(ActorRef sender, Object message) {
1038                     leaderId = newLeaderId;
1039                     return this;
1040                 }
1041             };
1042
1043             raftActor.changeCurrentBehavior(follower);
1044
1045             leaderStateChange = MessageCollectorActor.expectFirstMatching(notifierActor, LeaderStateChanged.class);
1046             assertEquals(persistenceId, leaderStateChange.getMemberId());
1047             assertEquals(null, leaderStateChange.getLeaderId());
1048
1049             raftRoleChanged = MessageCollectorActor.expectFirstMatching(notifierActor, RoleChanged.class);
1050             assertEquals(RaftState.Leader.name(), raftRoleChanged.getOldRole());
1051             assertEquals(RaftState.Follower.name(), raftRoleChanged.getNewRole());
1052
1053             notifierActor.underlyingActor().clear();
1054
1055             raftActor.handleCommand("any");
1056
1057             leaderStateChange = MessageCollectorActor.expectFirstMatching(notifierActor, LeaderStateChanged.class);
1058             assertEquals(persistenceId, leaderStateChange.getMemberId());
1059             assertEquals(newLeaderId, leaderStateChange.getLeaderId());
1060         }};
1061     }
1062
1063     @Test
1064     public void testRaftRoleChangeNotifierWhenRaftActorHasPeers() throws Exception {
1065         new JavaTestKit(getSystem()) {{
1066             ActorRef notifierActor = factory.createActor(Props.create(MessageCollectorActor.class));
1067             MessageCollectorActor.waitUntilReady(notifierActor);
1068
1069             DefaultConfigParamsImpl config = new DefaultConfigParamsImpl();
1070             long heartBeatInterval = 100;
1071             config.setHeartBeatInterval(FiniteDuration.create(heartBeatInterval, TimeUnit.MILLISECONDS));
1072             config.setElectionTimeoutFactor(1);
1073
1074             String persistenceId = factory.generateActorId("notifier-");
1075
1076             factory.createActor(MockRaftActor.props(persistenceId,
1077                     ImmutableMap.of("leader", "fake/path"), Optional.<ConfigParams>of(config), notifierActor), persistenceId);
1078
1079             List<RoleChanged> matches =  null;
1080             for(int i = 0; i < 5000 / heartBeatInterval; i++) {
1081                 matches = MessageCollectorActor.getAllMatching(notifierActor, RoleChanged.class);
1082                 assertNotNull(matches);
1083                 if(matches.size() == 3) {
1084                     break;
1085                 }
1086                 Uninterruptibles.sleepUninterruptibly(heartBeatInterval, TimeUnit.MILLISECONDS);
1087             }
1088
1089             assertEquals(2, matches.size());
1090
1091             // check if the notifier got a role change from null to Follower
1092             RoleChanged raftRoleChanged = matches.get(0);
1093             assertEquals(persistenceId, raftRoleChanged.getMemberId());
1094             assertNull(raftRoleChanged.getOldRole());
1095             assertEquals(RaftState.Follower.name(), raftRoleChanged.getNewRole());
1096
1097             // check if the notifier got a role change from Follower to Candidate
1098             raftRoleChanged = matches.get(1);
1099             assertEquals(persistenceId, raftRoleChanged.getMemberId());
1100             assertEquals(RaftState.Follower.name(), raftRoleChanged.getOldRole());
1101             assertEquals(RaftState.Candidate.name(), raftRoleChanged.getNewRole());
1102
1103         }};
1104     }
1105
1106     @Test
1107     public void testFakeSnapshotsForLeaderWithInRealSnapshots() throws Exception {
1108         new JavaTestKit(getSystem()) {
1109             {
1110                 String persistenceId = factory.generateActorId("leader-");
1111                 String follower1Id = factory.generateActorId("follower-");
1112
1113                 ActorRef followerActor1 =
1114                         factory.createActor(Props.create(MessageCollectorActor.class));
1115
1116                 DefaultConfigParamsImpl config = new DefaultConfigParamsImpl();
1117                 config.setHeartBeatInterval(new FiniteDuration(1, TimeUnit.DAYS));
1118                 config.setIsolatedLeaderCheckInterval(new FiniteDuration(1, TimeUnit.DAYS));
1119
1120                 DataPersistenceProvider dataPersistenceProvider = mock(DataPersistenceProvider.class);
1121
1122                 Map<String, String> peerAddresses = new HashMap<>();
1123                 peerAddresses.put(follower1Id, followerActor1.path().toString());
1124
1125                 TestActorRef<MockRaftActor> mockActorRef = factory.createTestActor(
1126                         MockRaftActor.props(persistenceId, peerAddresses,
1127                                 Optional.<ConfigParams>of(config), dataPersistenceProvider), persistenceId);
1128
1129                 MockRaftActor leaderActor = mockActorRef.underlyingActor();
1130
1131                 leaderActor.getRaftActorContext().setCommitIndex(4);
1132                 leaderActor.getRaftActorContext().setLastApplied(4);
1133                 leaderActor.getRaftActorContext().getTermInformation().update(1, persistenceId);
1134
1135                 leaderActor.waitForInitializeBehaviorComplete();
1136
1137                 // create 8 entries in the log - 0 to 4 are applied and will get picked up as part of the capture snapshot
1138
1139                 Leader leader = new Leader(leaderActor.getRaftActorContext());
1140                 leaderActor.setCurrentBehavior(leader);
1141                 assertEquals(RaftState.Leader, leaderActor.getCurrentBehavior().state());
1142
1143                 MockRaftActorContext.MockReplicatedLogBuilder logBuilder = new MockRaftActorContext.MockReplicatedLogBuilder();
1144                 leaderActor.getRaftActorContext().setReplicatedLog(logBuilder.createEntries(0, 8, 1).build());
1145
1146                 assertEquals(8, leaderActor.getReplicatedLog().size());
1147
1148                 leaderActor.getRaftActorContext().getSnapshotManager()
1149                         .capture(new MockRaftActorContext.MockReplicatedLogEntry(1, 6,
1150                                 new MockRaftActorContext.MockPayload("x")), 4);
1151
1152                 verify(leaderActor.snapshotCohortDelegate).createSnapshot(any(ActorRef.class));
1153
1154                 assertEquals(8, leaderActor.getReplicatedLog().size());
1155
1156                 assertEquals(RaftState.Leader, leaderActor.getCurrentBehavior().state());
1157                 //fake snapshot on index 5
1158                 leaderActor.onReceiveCommand(new AppendEntriesReply(follower1Id, 1, true, 5, 1));
1159
1160                 assertEquals(8, leaderActor.getReplicatedLog().size());
1161
1162                 //fake snapshot on index 6
1163                 assertEquals(RaftState.Leader, leaderActor.getCurrentBehavior().state());
1164                 leaderActor.onReceiveCommand(new AppendEntriesReply(follower1Id, 1, true, 6, 1));
1165                 assertEquals(8, leaderActor.getReplicatedLog().size());
1166
1167                 assertEquals(RaftState.Leader, leaderActor.getCurrentBehavior().state());
1168
1169                 assertEquals(8, leaderActor.getReplicatedLog().size());
1170
1171                 ByteString snapshotBytes = fromObject(Arrays.asList(
1172                         new MockRaftActorContext.MockPayload("foo-0"),
1173                         new MockRaftActorContext.MockPayload("foo-1"),
1174                         new MockRaftActorContext.MockPayload("foo-2"),
1175                         new MockRaftActorContext.MockPayload("foo-3"),
1176                         new MockRaftActorContext.MockPayload("foo-4")));
1177
1178                 leaderActor.getRaftActorContext().getSnapshotManager().persist(new NonPersistentDataProvider()
1179                         , snapshotBytes.toByteArray(), leader, Runtime.getRuntime().totalMemory());
1180
1181                 assertFalse(leaderActor.getRaftActorContext().getSnapshotManager().isCapturing());
1182
1183                 // The commit is needed to complete the snapshot creation process
1184                 leaderActor.getRaftActorContext().getSnapshotManager().commit(new NonPersistentDataProvider(), -1);
1185
1186                 // capture snapshot reply should remove the snapshotted entries only
1187                 assertEquals(3, leaderActor.getReplicatedLog().size());
1188                 assertEquals(7, leaderActor.getReplicatedLog().lastIndex());
1189
1190                 // add another non-replicated entry
1191                 leaderActor.getReplicatedLog().append(
1192                         new ReplicatedLogImplEntry(8, 1, new MockRaftActorContext.MockPayload("foo-8")));
1193
1194                 //fake snapshot on index 7, since lastApplied = 7 , we would keep the last applied
1195                 leaderActor.onReceiveCommand(new AppendEntriesReply(follower1Id, 1, true, 7, 1));
1196                 assertEquals(2, leaderActor.getReplicatedLog().size());
1197                 assertEquals(8, leaderActor.getReplicatedLog().lastIndex());
1198
1199             }
1200         };
1201     }
1202
1203     @Test
1204     public void testFakeSnapshotsForFollowerWithInRealSnapshots() throws Exception {
1205         new JavaTestKit(getSystem()) {
1206             {
1207                 String persistenceId = factory.generateActorId("follower-");
1208                 String leaderId = factory.generateActorId("leader-");
1209
1210
1211                 ActorRef leaderActor1 =
1212                         factory.createActor(Props.create(MessageCollectorActor.class));
1213
1214                 DefaultConfigParamsImpl config = new DefaultConfigParamsImpl();
1215                 config.setHeartBeatInterval(new FiniteDuration(1, TimeUnit.DAYS));
1216                 config.setIsolatedLeaderCheckInterval(new FiniteDuration(1, TimeUnit.DAYS));
1217
1218                 DataPersistenceProvider dataPersistenceProvider = mock(DataPersistenceProvider.class);
1219
1220                 Map<String, String> peerAddresses = new HashMap<>();
1221                 peerAddresses.put(leaderId, leaderActor1.path().toString());
1222
1223                 TestActorRef<MockRaftActor> mockActorRef = factory.createTestActor(
1224                         MockRaftActor.props(persistenceId, peerAddresses,
1225                                 Optional.<ConfigParams>of(config), dataPersistenceProvider), persistenceId);
1226
1227                 MockRaftActor followerActor = mockActorRef.underlyingActor();
1228                 followerActor.getRaftActorContext().setCommitIndex(4);
1229                 followerActor.getRaftActorContext().setLastApplied(4);
1230                 followerActor.getRaftActorContext().getTermInformation().update(1, persistenceId);
1231
1232                 followerActor.waitForInitializeBehaviorComplete();
1233
1234
1235                 Follower follower = new Follower(followerActor.getRaftActorContext());
1236                 followerActor.setCurrentBehavior(follower);
1237                 assertEquals(RaftState.Follower, followerActor.getCurrentBehavior().state());
1238
1239                 // create 6 entries in the log - 0 to 4 are applied and will get picked up as part of the capture snapshot
1240                 MockRaftActorContext.MockReplicatedLogBuilder logBuilder = new MockRaftActorContext.MockReplicatedLogBuilder();
1241                 followerActor.getRaftActorContext().setReplicatedLog(logBuilder.createEntries(0, 6, 1).build());
1242
1243                 // log has indices 0-5
1244                 assertEquals(6, followerActor.getReplicatedLog().size());
1245
1246                 //snapshot on 4
1247                 followerActor.getRaftActorContext().getSnapshotManager().capture(
1248                         new MockRaftActorContext.MockReplicatedLogEntry(1, 5,
1249                                 new MockRaftActorContext.MockPayload("D")), 4);
1250
1251                 verify(followerActor.snapshotCohortDelegate).createSnapshot(any(ActorRef.class));
1252
1253                 assertEquals(6, followerActor.getReplicatedLog().size());
1254
1255                 //fake snapshot on index 6
1256                 List<ReplicatedLogEntry> entries =
1257                         Arrays.asList(
1258                                 (ReplicatedLogEntry) new MockRaftActorContext.MockReplicatedLogEntry(1, 6,
1259                                         new MockRaftActorContext.MockPayload("foo-6"))
1260                         );
1261                 followerActor.onReceiveCommand(new AppendEntries(1, leaderId, 5, 1, entries, 5, 5));
1262                 assertEquals(7, followerActor.getReplicatedLog().size());
1263
1264                 //fake snapshot on index 7
1265                 assertEquals(RaftState.Follower, followerActor.getCurrentBehavior().state());
1266
1267                 entries =
1268                         Arrays.asList(
1269                                 (ReplicatedLogEntry) new MockRaftActorContext.MockReplicatedLogEntry(1, 7,
1270                                         new MockRaftActorContext.MockPayload("foo-7"))
1271                         );
1272                 followerActor.onReceiveCommand(new AppendEntries(1, leaderId, 6, 1, entries, 6, 6));
1273                 assertEquals(8, followerActor.getReplicatedLog().size());
1274
1275                 assertEquals(RaftState.Follower, followerActor.getCurrentBehavior().state());
1276
1277
1278                 ByteString snapshotBytes = fromObject(Arrays.asList(
1279                         new MockRaftActorContext.MockPayload("foo-0"),
1280                         new MockRaftActorContext.MockPayload("foo-1"),
1281                         new MockRaftActorContext.MockPayload("foo-2"),
1282                         new MockRaftActorContext.MockPayload("foo-3"),
1283                         new MockRaftActorContext.MockPayload("foo-4")));
1284                 followerActor.onReceiveCommand(new CaptureSnapshotReply(snapshotBytes.toByteArray()));
1285                 assertFalse(followerActor.getRaftActorContext().getSnapshotManager().isCapturing());
1286
1287                 // The commit is needed to complete the snapshot creation process
1288                 followerActor.getRaftActorContext().getSnapshotManager().commit(new NonPersistentDataProvider(), -1);
1289
1290                 // capture snapshot reply should remove the snapshotted entries only till replicatedToAllIndex
1291                 assertEquals(3, followerActor.getReplicatedLog().size()); //indexes 5,6,7 left in the log
1292                 assertEquals(7, followerActor.getReplicatedLog().lastIndex());
1293
1294                 entries =
1295                         Arrays.asList(
1296                                 (ReplicatedLogEntry) new MockRaftActorContext.MockReplicatedLogEntry(1, 8,
1297                                         new MockRaftActorContext.MockPayload("foo-7"))
1298                         );
1299                 // send an additional entry 8 with leaderCommit = 7
1300                 followerActor.onReceiveCommand(new AppendEntries(1, leaderId, 7, 1, entries, 7, 7));
1301
1302                 // 7 and 8, as lastapplied is 7
1303                 assertEquals(2, followerActor.getReplicatedLog().size());
1304
1305             }
1306         };
1307     }
1308
1309     @Test
1310     public void testFakeSnapshotsForLeaderWithInInitiateSnapshots() throws Exception {
1311         new JavaTestKit(getSystem()) {
1312             {
1313                 String persistenceId = factory.generateActorId("leader-");
1314                 String follower1Id = factory.generateActorId("follower-");
1315                 String follower2Id = factory.generateActorId("follower-");
1316
1317                 ActorRef followerActor1 =
1318                         factory.createActor(Props.create(MessageCollectorActor.class), follower1Id);
1319                 ActorRef followerActor2 =
1320                         factory.createActor(Props.create(MessageCollectorActor.class), follower2Id);
1321
1322                 DefaultConfigParamsImpl config = new DefaultConfigParamsImpl();
1323                 config.setHeartBeatInterval(new FiniteDuration(1, TimeUnit.DAYS));
1324                 config.setIsolatedLeaderCheckInterval(new FiniteDuration(1, TimeUnit.DAYS));
1325
1326                 DataPersistenceProvider dataPersistenceProvider = mock(DataPersistenceProvider.class);
1327
1328                 Map<String, String> peerAddresses = new HashMap<>();
1329                 peerAddresses.put(follower1Id, followerActor1.path().toString());
1330                 peerAddresses.put(follower2Id, followerActor2.path().toString());
1331
1332                 TestActorRef<MockRaftActor> mockActorRef = factory.createTestActor(
1333                         MockRaftActor.props(persistenceId, peerAddresses,
1334                                 Optional.<ConfigParams>of(config), dataPersistenceProvider), persistenceId);
1335
1336                 MockRaftActor leaderActor = mockActorRef.underlyingActor();
1337                 leaderActor.getRaftActorContext().setCommitIndex(9);
1338                 leaderActor.getRaftActorContext().setLastApplied(9);
1339                 leaderActor.getRaftActorContext().getTermInformation().update(1, persistenceId);
1340
1341                 leaderActor.waitForInitializeBehaviorComplete();
1342
1343                 Leader leader = new Leader(leaderActor.getRaftActorContext());
1344                 leaderActor.setCurrentBehavior(leader);
1345                 assertEquals(RaftState.Leader, leaderActor.getCurrentBehavior().state());
1346
1347                 // create 5 entries in the log
1348                 MockRaftActorContext.MockReplicatedLogBuilder logBuilder = new MockRaftActorContext.MockReplicatedLogBuilder();
1349                 leaderActor.getRaftActorContext().setReplicatedLog(logBuilder.createEntries(5, 10, 1).build());
1350
1351                 //set the snapshot index to 4 , 0 to 4 are snapshotted
1352                 leaderActor.getRaftActorContext().getReplicatedLog().setSnapshotIndex(4);
1353                 //setting replicatedToAllIndex = 9, for the log to clear
1354                 leader.setReplicatedToAllIndex(9);
1355                 assertEquals(5, leaderActor.getReplicatedLog().size());
1356                 assertEquals(RaftState.Leader, leaderActor.getCurrentBehavior().state());
1357
1358                 leaderActor.onReceiveCommand(new AppendEntriesReply(follower1Id, 1, true, 9, 1));
1359                 assertEquals(5, leaderActor.getReplicatedLog().size());
1360                 assertEquals(RaftState.Leader, leaderActor.getCurrentBehavior().state());
1361
1362                 // set the 2nd follower nextIndex to 1 which has been snapshotted
1363                 leaderActor.onReceiveCommand(new AppendEntriesReply(follower2Id, 1, true, 0, 1));
1364                 assertEquals(5, leaderActor.getReplicatedLog().size());
1365                 assertEquals(RaftState.Leader, leaderActor.getCurrentBehavior().state());
1366
1367                 // simulate a real snapshot
1368                 leaderActor.onReceiveCommand(new SendHeartBeat());
1369                 assertEquals(5, leaderActor.getReplicatedLog().size());
1370                 assertEquals(String.format("expected to be Leader but was %s. Current Leader = %s ",
1371                         leaderActor.getCurrentBehavior().state(), leaderActor.getLeaderId())
1372                         , RaftState.Leader, leaderActor.getCurrentBehavior().state());
1373
1374
1375                 //reply from a slow follower does not initiate a fake snapshot
1376                 leaderActor.onReceiveCommand(new AppendEntriesReply(follower2Id, 1, true, 9, 1));
1377                 assertEquals("Fake snapshot should not happen when Initiate is in progress", 5, leaderActor.getReplicatedLog().size());
1378
1379                 ByteString snapshotBytes = fromObject(Arrays.asList(
1380                         new MockRaftActorContext.MockPayload("foo-0"),
1381                         new MockRaftActorContext.MockPayload("foo-1"),
1382                         new MockRaftActorContext.MockPayload("foo-2"),
1383                         new MockRaftActorContext.MockPayload("foo-3"),
1384                         new MockRaftActorContext.MockPayload("foo-4")));
1385                 leaderActor.onReceiveCommand(new CaptureSnapshotReply(snapshotBytes.toByteArray()));
1386                 assertFalse(leaderActor.getRaftActorContext().getSnapshotManager().isCapturing());
1387
1388                 assertEquals("Real snapshot didn't clear the log till replicatedToAllIndex", 0, leaderActor.getReplicatedLog().size());
1389
1390                 //reply from a slow follower after should not raise errors
1391                 leaderActor.onReceiveCommand(new AppendEntriesReply(follower2Id, 1, true, 5, 1));
1392                 assertEquals(0, leaderActor.getReplicatedLog().size());
1393             }
1394         };
1395     }
1396
1397     @Test
1398     public void testRealSnapshotWhenReplicatedToAllIndexMinusOne() throws Exception {
1399         new JavaTestKit(getSystem()) {{
1400             String persistenceId = factory.generateActorId("leader-");
1401             DefaultConfigParamsImpl config = new DefaultConfigParamsImpl();
1402             config.setHeartBeatInterval(new FiniteDuration(1, TimeUnit.DAYS));
1403             config.setIsolatedLeaderCheckInterval(new FiniteDuration(1, TimeUnit.DAYS));
1404             config.setSnapshotBatchCount(5);
1405
1406             DataPersistenceProvider dataPersistenceProvider = new NonPersistentDataProvider();
1407
1408             Map<String, String> peerAddresses = new HashMap<>();
1409
1410             TestActorRef<MockRaftActor> mockActorRef = factory.createTestActor(
1411                     MockRaftActor.props(persistenceId, peerAddresses,
1412                             Optional.<ConfigParams>of(config), dataPersistenceProvider), persistenceId);
1413
1414             MockRaftActor leaderActor = mockActorRef.underlyingActor();
1415             leaderActor.getRaftActorContext().setCommitIndex(3);
1416             leaderActor.getRaftActorContext().setLastApplied(3);
1417             leaderActor.getRaftActorContext().getTermInformation().update(1, persistenceId);
1418
1419             leaderActor.waitForInitializeBehaviorComplete();
1420             for(int i=0;i< 4;i++) {
1421                 leaderActor.getReplicatedLog()
1422                         .append(new MockRaftActorContext.MockReplicatedLogEntry(1, i,
1423                                 new MockRaftActorContext.MockPayload("A")));
1424             }
1425
1426             Leader leader = new Leader(leaderActor.getRaftActorContext());
1427             leaderActor.setCurrentBehavior(leader);
1428             assertEquals(RaftState.Leader, leaderActor.getCurrentBehavior().state());
1429
1430             // Persist another entry (this will cause a CaptureSnapshot to be triggered
1431             leaderActor.persistData(mockActorRef, "x", new MockRaftActorContext.MockPayload("duh"));
1432
1433             // Now send a CaptureSnapshotReply
1434             mockActorRef.tell(new CaptureSnapshotReply(fromObject("foo").toByteArray()), mockActorRef);
1435
1436             // Trimming log in this scenario is a no-op
1437             assertEquals(-1, leaderActor.getReplicatedLog().getSnapshotIndex());
1438             assertFalse(leaderActor.getRaftActorContext().getSnapshotManager().isCapturing());
1439             assertEquals(-1, leader.getReplicatedToAllIndex());
1440
1441         }};
1442     }
1443
1444     @Test
1445     public void testRealSnapshotWhenReplicatedToAllIndexNotInReplicatedLog() throws Exception {
1446         new JavaTestKit(getSystem()) {{
1447             String persistenceId = factory.generateActorId("leader-");
1448             DefaultConfigParamsImpl config = new DefaultConfigParamsImpl();
1449             config.setHeartBeatInterval(new FiniteDuration(1, TimeUnit.DAYS));
1450             config.setIsolatedLeaderCheckInterval(new FiniteDuration(1, TimeUnit.DAYS));
1451             config.setSnapshotBatchCount(5);
1452
1453             DataPersistenceProvider dataPersistenceProvider = new NonPersistentDataProvider();
1454
1455             Map<String, String> peerAddresses = new HashMap<>();
1456
1457             TestActorRef<MockRaftActor> mockActorRef = factory.createTestActor(
1458                     MockRaftActor.props(persistenceId, peerAddresses,
1459                             Optional.<ConfigParams>of(config), dataPersistenceProvider), persistenceId);
1460
1461             MockRaftActor leaderActor = mockActorRef.underlyingActor();
1462             leaderActor.getRaftActorContext().setCommitIndex(3);
1463             leaderActor.getRaftActorContext().setLastApplied(3);
1464             leaderActor.getRaftActorContext().getTermInformation().update(1, persistenceId);
1465             leaderActor.getReplicatedLog().setSnapshotIndex(3);
1466
1467             leaderActor.waitForInitializeBehaviorComplete();
1468             Leader leader = new Leader(leaderActor.getRaftActorContext());
1469             leaderActor.setCurrentBehavior(leader);
1470             leader.setReplicatedToAllIndex(3);
1471             assertEquals(RaftState.Leader, leaderActor.getCurrentBehavior().state());
1472
1473             // Persist another entry (this will cause a CaptureSnapshot to be triggered
1474             leaderActor.persistData(mockActorRef, "x", new MockRaftActorContext.MockPayload("duh"));
1475
1476             // Now send a CaptureSnapshotReply
1477             mockActorRef.tell(new CaptureSnapshotReply(fromObject("foo").toByteArray()), mockActorRef);
1478
1479             // Trimming log in this scenario is a no-op
1480             assertEquals(3, leaderActor.getReplicatedLog().getSnapshotIndex());
1481             assertFalse(leaderActor.getRaftActorContext().getSnapshotManager().isCapturing());
1482             assertEquals(3, leader.getReplicatedToAllIndex());
1483
1484         }};
1485     }
1486
1487     private ByteString fromObject(Object snapshot) throws Exception {
1488         ByteArrayOutputStream b = null;
1489         ObjectOutputStream o = null;
1490         try {
1491             b = new ByteArrayOutputStream();
1492             o = new ObjectOutputStream(b);
1493             o.writeObject(snapshot);
1494             byte[] snapshotBytes = b.toByteArray();
1495             return ByteString.copyFrom(snapshotBytes);
1496         } finally {
1497             if (o != null) {
1498                 o.flush();
1499                 o.close();
1500             }
1501             if (b != null) {
1502                 b.close();
1503             }
1504         }
1505     }
1506
1507 }