opendaylight/md-sal/sal-distributed-datastore/src/test/java/org/opendaylight/controller/cluster/datastore/entityownership/DistributedEntityOwnershipIntegrationTest.java

   1 /*
   2  * Copyright (c) 2015 Brocade Communications 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 package org.opendaylight.controller.cluster.datastore.entityownership;
   9
  10 import static org.junit.Assert.assertEquals;
  11 import static org.junit.Assert.assertTrue;
  12 import static org.mockito.AdditionalMatchers.or;
  13 import static org.mockito.Mockito.atMost;
  14 import static org.mockito.Mockito.doNothing;
  15 import static org.mockito.Mockito.reset;
  16 import static org.mockito.Mockito.timeout;
  17 import static org.mockito.Mockito.verify;
  18 import static org.opendaylight.controller.cluster.datastore.entityownership.AbstractEntityOwnershipTest.ownershipChange;
  19 import static org.opendaylight.controller.cluster.datastore.entityownership.DistributedEntityOwnershipService.ENTITY_OWNERSHIP_SHARD_NAME;
  20 import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.CANDIDATE_NAME_NODE_ID;
  21 import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.entityPath;
  22 import akka.actor.ActorSystem;
  23 import akka.actor.Address;
  24 import akka.actor.AddressFromURIString;
  25 import akka.actor.Status.Failure;
  26 import akka.actor.Status.Success;
  27 import akka.cluster.Cluster;
  28 import akka.testkit.JavaTestKit;
  29 import com.google.common.base.Function;
  30 import com.google.common.base.Optional;
  31 import com.google.common.base.Stopwatch;
  32 import com.google.common.util.concurrent.Uninterruptibles;
  33 import com.typesafe.config.ConfigFactory;
  34 import java.util.ArrayList;
  35 import java.util.Arrays;
  36 import java.util.Collection;
  37 import java.util.concurrent.TimeUnit;
  38 import org.junit.After;
  39 import org.junit.Before;
  40 import org.junit.Test;
  41 import org.mockito.ArgumentCaptor;
  42 import org.mockito.Mock;
  43 import org.mockito.Mockito;
  44 import org.mockito.MockitoAnnotations;
  45 import org.opendaylight.controller.cluster.datastore.DatastoreContext;
  46 import org.opendaylight.controller.cluster.datastore.DistributedDataStore;
  47 import org.opendaylight.controller.cluster.datastore.IntegrationTestKit;
  48 import org.opendaylight.controller.cluster.datastore.entityownership.selectionstrategy.EntityOwnerSelectionStrategyConfig;
  49 import org.opendaylight.controller.cluster.datastore.messages.AddShardReplica;
  50 import org.opendaylight.controller.md.cluster.datastore.model.SchemaContextHelper;
  51 import org.opendaylight.controller.md.sal.common.api.clustering.CandidateAlreadyRegisteredException;
  52 import org.opendaylight.controller.md.sal.common.api.clustering.Entity;
  53 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipCandidateRegistration;
  54 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipChange;
  55 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipListener;
  56 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipState;
  57 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.controller.md.sal.clustering.entity.owners.rev150804.entity.owners.entity.type.entity.Candidate;
  58 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  59 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  60 import org.opendaylight.yangtools.yang.data.api.schema.MapNode;
  61 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  62 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  63
  64 /**
  65  * End-to-end integration tests for the entity ownership functionality.
  66  *
  67  * @author Thomas Pantelis
  68  */
  69 public class DistributedEntityOwnershipIntegrationTest {
  70     private static final Address MEMBER_1_ADDRESS = AddressFromURIString.parse("akka.tcp://cluster-test@127.0.0.1:2558");
  71     private static final String MODULE_SHARDS_CONFIG = "module-shards-default.conf";
  72     private static final String MODULE_SHARDS_MEMBER_1_CONFIG = "module-shards-default-member-1.conf";
  73     private static final String ENTITY_TYPE1 = "entityType1";
  74     private static final String ENTITY_TYPE2 = "entityType2";
  75     private static final Entity ENTITY1 = new Entity(ENTITY_TYPE1, "entity1");
  76     private static final Entity ENTITY1_2 = new Entity(ENTITY_TYPE2, "entity1");
  77     private static final Entity ENTITY2 = new Entity(ENTITY_TYPE1, "entity2");
  78     private static final Entity ENTITY3 = new Entity(ENTITY_TYPE1, "entity3");
  79     private static final Entity ENTITY4 = new Entity(ENTITY_TYPE1, "entity4");
  80     private static final SchemaContext SCHEMA_CONTEXT = SchemaContextHelper.entityOwners();
  81
  82     private ActorSystem leaderSystem;
  83     private ActorSystem follower1System;
  84     private ActorSystem follower2System;
  85
  86     private final DatastoreContext.Builder leaderDatastoreContextBuilder =
  87             DatastoreContext.newBuilder().shardHeartbeatIntervalInMillis(100).shardElectionTimeoutFactor(5);
  88
  89     private final DatastoreContext.Builder followerDatastoreContextBuilder =
  90             DatastoreContext.newBuilder().shardHeartbeatIntervalInMillis(100).shardElectionTimeoutFactor(10000);
  91
  92     private DistributedDataStore leaderDistributedDataStore;
  93     private DistributedDataStore follower1DistributedDataStore;
  94     private DistributedDataStore follower2DistributedDataStore;
  95     private DistributedEntityOwnershipService leaderEntityOwnershipService;
  96     private DistributedEntityOwnershipService follower1EntityOwnershipService;
  97     private DistributedEntityOwnershipService follower2EntityOwnershipService;
  98     private IntegrationTestKit leaderTestKit;
  99     private IntegrationTestKit follower1TestKit;
 100     private IntegrationTestKit follower2TestKit;
 101
 102     @Mock
 103     private EntityOwnershipListener leaderMockListener;
 104
 105     @Mock
 106     private EntityOwnershipListener leaderMockListener2;
 107
 108     @Mock
 109     private EntityOwnershipListener follower1MockListener;
 110
 111     @Mock
 112     private EntityOwnershipListener follower2MockListener;
 113
 114     @Before
 115     public void setUp() {
 116         MockitoAnnotations.initMocks(this);
 117     }
 118
 119     @After
 120     public void tearDown() {
 121         if(leaderSystem != null) {
 122             JavaTestKit.shutdownActorSystem(leaderSystem);
 123         }
 124
 125         if(follower1System != null) {
 126             JavaTestKit.shutdownActorSystem(follower1System);
 127         }
 128
 129         if(follower2System != null) {
 130             JavaTestKit.shutdownActorSystem(follower2System);
 131         }
 132     }
 133
 134     private void startAllSystems() {
 135         startLeaderSystem();
 136         startFollower1System();
 137         startFollower2System();
 138     }
 139
 140     private void startFollower2System() {
 141         follower2System = ActorSystem.create("cluster-test", ConfigFactory.load().getConfig("Member3"));
 142         Cluster.get(follower2System).join(MEMBER_1_ADDRESS);
 143     }
 144
 145     private void startFollower1System() {
 146         follower1System = ActorSystem.create("cluster-test", ConfigFactory.load().getConfig("Member2"));
 147         Cluster.get(follower1System).join(MEMBER_1_ADDRESS);
 148     }
 149
 150     private void startLeaderSystem() {
 151         leaderSystem = ActorSystem.create("cluster-test", ConfigFactory.load().getConfig("Member1"));
 152         Cluster.get(leaderSystem).join(MEMBER_1_ADDRESS);
 153     }
 154
 155     private void initDatastores(String type) {
 156         initLeaderDatastore(type, MODULE_SHARDS_CONFIG);
 157
 158         initFollower1Datastore(type, MODULE_SHARDS_CONFIG);
 159
 160         follower2TestKit = new IntegrationTestKit(follower2System, followerDatastoreContextBuilder);
 161         follower2DistributedDataStore = follower2TestKit.setupDistributedDataStore(
 162                 type, MODULE_SHARDS_CONFIG, false, SCHEMA_CONTEXT);
 163
 164         leaderDistributedDataStore.waitTillReady();
 165         follower1DistributedDataStore.waitTillReady();
 166         follower2DistributedDataStore.waitTillReady();
 167
 168         startLeaderService();
 169
 170         startFollower1Service();
 171
 172         follower2EntityOwnershipService = new DistributedEntityOwnershipService(follower2DistributedDataStore,
 173                 EntityOwnerSelectionStrategyConfig.newBuilder().build());
 174         follower2EntityOwnershipService.start();
 175
 176         leaderTestKit.waitUntilLeader(leaderDistributedDataStore.getActorContext(), ENTITY_OWNERSHIP_SHARD_NAME);
 177     }
 178
 179     private void startFollower1Service() {
 180         follower1EntityOwnershipService = new DistributedEntityOwnershipService(follower1DistributedDataStore,
 181                 EntityOwnerSelectionStrategyConfig.newBuilder().build());
 182         follower1EntityOwnershipService.start();
 183     }
 184
 185     private void startLeaderService() {
 186         leaderEntityOwnershipService = new DistributedEntityOwnershipService(leaderDistributedDataStore,
 187                 EntityOwnerSelectionStrategyConfig.newBuilder().build());
 188         leaderEntityOwnershipService.start();
 189     }
 190
 191     private void initFollower1Datastore(String type, String moduleConfig) {
 192         follower1TestKit = new IntegrationTestKit(follower1System, followerDatastoreContextBuilder);
 193         follower1DistributedDataStore = follower1TestKit.setupDistributedDataStore(
 194                 type, moduleConfig, false, SCHEMA_CONTEXT);
 195     }
 196
 197     private void initLeaderDatastore(String type, String moduleConfig) {
 198         leaderTestKit = new IntegrationTestKit(leaderSystem, leaderDatastoreContextBuilder);
 199         leaderDistributedDataStore = leaderTestKit.setupDistributedDataStore(
 200                 type, moduleConfig, false, SCHEMA_CONTEXT);
 201     }
 202
 203     @Test
 204     public void test() throws Exception {
 205         startAllSystems();
 206         initDatastores("test");
 207
 208         leaderEntityOwnershipService.registerListener(ENTITY_TYPE1, leaderMockListener);
 209         leaderEntityOwnershipService.registerListener(ENTITY_TYPE2, leaderMockListener2);
 210         follower1EntityOwnershipService.registerListener(ENTITY_TYPE1, follower1MockListener);
 211
 212         // Register leader candidate for entity1 and verify it becomes owner
 213
 214         leaderEntityOwnershipService.registerCandidate(ENTITY1);
 215         verify(leaderMockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY1, false, true, true));
 216         verify(follower1MockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY1, false, false, true));
 217         reset(leaderMockListener, follower1MockListener);
 218
 219         verifyGetOwnershipState(leaderEntityOwnershipService, ENTITY1, true, true);
 220         verifyGetOwnershipState(follower1EntityOwnershipService, ENTITY1, false, true);
 221
 222         // Register leader candidate for entity1_2 (same id, different type) and verify it becomes owner
 223
 224         leaderEntityOwnershipService.registerCandidate(ENTITY1_2);
 225         verify(leaderMockListener2, timeout(5000)).ownershipChanged(ownershipChange(ENTITY1_2, false, true, true));
 226         verify(leaderMockListener, timeout(300).never()).ownershipChanged(ownershipChange(ENTITY1_2));
 227         reset(leaderMockListener2);
 228
 229         // Register follower1 candidate for entity1 and verify it gets added but doesn't become owner
 230
 231         follower1EntityOwnershipService.registerCandidate(ENTITY1);
 232         verifyCandidates(leaderDistributedDataStore, ENTITY1, "member-1", "member-2");
 233         verifyOwner(leaderDistributedDataStore, ENTITY1, "member-1");
 234         verify(leaderMockListener, timeout(300).never()).ownershipChanged(ownershipChange(ENTITY1));
 235         verify(follower1MockListener, timeout(300).never()).ownershipChanged(ownershipChange(ENTITY1));
 236
 237         // Register follower1 candidate for entity2 and verify it becomes owner
 238
 239         follower1EntityOwnershipService.registerCandidate(ENTITY2);
 240         verify(follower1MockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY2, false, true, true));
 241         verify(leaderMockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY2, false, false, true));
 242         reset(leaderMockListener, follower1MockListener);
 243
 244         // Register follower2 candidate for entity2 and verify it gets added but doesn't become owner
 245
 246         follower2EntityOwnershipService.registerListener(ENTITY_TYPE1, follower2MockListener);
 247         follower2EntityOwnershipService.registerCandidate(ENTITY2);
 248         verifyCandidates(leaderDistributedDataStore, ENTITY2, "member-2", "member-3");
 249         verifyOwner(leaderDistributedDataStore, ENTITY2, "member-2");
 250
 251         // Unregister follower1 candidate for entity2 and verify follower2 becomes owner
 252
 253         follower1EntityOwnershipService.unregisterCandidate(ENTITY2);
 254         verifyCandidates(leaderDistributedDataStore, ENTITY2, "member-3");
 255         verifyOwner(leaderDistributedDataStore, ENTITY2, "member-3");
 256         verify(follower1MockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY2, true, false, true));
 257         verify(leaderMockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY2, false, false, true));
 258
 259         // Depending on timing, follower2MockListener could get ownershipChanged with "false, false, true" if
 260         // if the original ownership change with "member-2 is replicated to follower2 after the listener is
 261         // registered.
 262         Uninterruptibles.sleepUninterruptibly(500, TimeUnit.MILLISECONDS);
 263         verify(follower2MockListener, atMost(1)).ownershipChanged(ownershipChange(ENTITY2, false, false, true));
 264         verify(follower2MockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY2, false, true, true));
 265
 266         // Register follower1 candidate for entity3 and verify it becomes owner
 267
 268         follower1EntityOwnershipService.registerCandidate(ENTITY3);
 269         verifyOwner(leaderDistributedDataStore, ENTITY3, "member-2");
 270         verify(follower1MockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY3, false, true, true));
 271         verify(follower2MockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY3, false, false, true));
 272         verify(leaderMockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY3, false, false, true));
 273
 274         // Register follower2 candidate for entity4 and verify it becomes owner
 275
 276         follower2EntityOwnershipService.registerCandidate(ENTITY4);
 277         verifyOwner(leaderDistributedDataStore, ENTITY4, "member-3");
 278         verify(follower2MockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY4, false, true, true));
 279         verify(follower1MockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY4, false, false, true));
 280         verify(leaderMockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY4, false, false, true));
 281         reset(follower1MockListener, follower2MockListener);
 282
 283         // Register follower1 candidate for entity4 and verify it gets added but doesn't become owner
 284
 285         follower1EntityOwnershipService.registerCandidate(ENTITY4);
 286         verifyCandidates(leaderDistributedDataStore, ENTITY4, "member-3", "member-2");
 287         verifyOwner(leaderDistributedDataStore, ENTITY4, "member-3");
 288
 289         // Shutdown follower2 and verify it's owned entities (entity 2 & 4) get re-assigned
 290
 291         reset(leaderMockListener, follower1MockListener);
 292         JavaTestKit.shutdownActorSystem(follower2System);
 293
 294         verify(follower1MockListener, timeout(15000).times(2)).ownershipChanged(or(ownershipChange(ENTITY4, false, true, true),
 295                 ownershipChange(ENTITY2, false, false, false)));
 296         verify(leaderMockListener, timeout(15000).times(2)).ownershipChanged(or(ownershipChange(ENTITY4, false, false, true),
 297                 ownershipChange(ENTITY2, false, false, false)));
 298         verifyOwner(leaderDistributedDataStore, ENTITY2, ""); // no other candidate
 299
 300         // Register leader candidate for entity2 and verify it becomes owner
 301
 302         leaderEntityOwnershipService.registerCandidate(ENTITY2);
 303         verify(leaderMockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY2, false, true, true));
 304         verifyOwner(leaderDistributedDataStore, ENTITY2, "member-1");
 305
 306         // Unregister leader candidate for entity2 and verify the owner is cleared
 307
 308         leaderEntityOwnershipService.unregisterCandidate(ENTITY2);
 309         verifyOwner(leaderDistributedDataStore, ENTITY2, "");
 310         verify(leaderMockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY2, true, false, false));
 311         verify(follower1MockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY2, false, false, false));
 312     }
 313
 314     /**
 315      * Reproduces bug <a href="https://bugs.opendaylight.org/show_bug.cgi?id=4554">4554</a>
 316      *
 317      * @throws CandidateAlreadyRegisteredException
 318      */
 319     @Test
 320     public void testCloseCandidateRegistrationInQuickSuccession() throws CandidateAlreadyRegisteredException {
 321         startAllSystems();
 322         initDatastores("testCloseCandidateRegistrationInQuickSuccession");
 323
 324         leaderEntityOwnershipService.registerListener(ENTITY_TYPE1, leaderMockListener);
 325         follower1EntityOwnershipService.registerListener(ENTITY_TYPE1, follower1MockListener);
 326         follower2EntityOwnershipService.registerListener(ENTITY_TYPE1, follower2MockListener);
 327
 328         final EntityOwnershipCandidateRegistration candidate1 = leaderEntityOwnershipService.registerCandidate(ENTITY1);
 329         final EntityOwnershipCandidateRegistration candidate2 = follower1EntityOwnershipService.registerCandidate(ENTITY1);
 330         final EntityOwnershipCandidateRegistration candidate3 = follower2EntityOwnershipService.registerCandidate(ENTITY1);
 331
 332         verify(leaderMockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY1, false, true, true));
 333
 334         Mockito.reset(leaderMockListener);
 335
 336         candidate1.close();
 337         candidate2.close();
 338         candidate3.close();
 339
 340         ArgumentCaptor<EntityOwnershipChange> leaderChangeCaptor = ArgumentCaptor.forClass(EntityOwnershipChange.class);
 341         ArgumentCaptor<EntityOwnershipChange> follower1ChangeCaptor = ArgumentCaptor.forClass(EntityOwnershipChange.class);
 342         ArgumentCaptor<EntityOwnershipChange> follower2ChangeCaptor = ArgumentCaptor.forClass(EntityOwnershipChange.class);
 343         doNothing().when(leaderMockListener).ownershipChanged(leaderChangeCaptor.capture());
 344         doNothing().when(follower1MockListener).ownershipChanged(follower1ChangeCaptor.capture());
 345         doNothing().when(follower2MockListener).ownershipChanged(follower2ChangeCaptor.capture());
 346
 347         boolean passed = false;
 348         for(int i=0;i<100;i++) {
 349             Uninterruptibles.sleepUninterruptibly(50, TimeUnit.MILLISECONDS);
 350             if(!leaderEntityOwnershipService.getOwnershipState(ENTITY1).get().hasOwner() &&
 351                     !follower1EntityOwnershipService.getOwnershipState(ENTITY1).get().hasOwner() &&
 352                     !follower2EntityOwnershipService.getOwnershipState(ENTITY1).get().hasOwner() &&
 353                     leaderChangeCaptor.getAllValues().size() > 0 && !leaderChangeCaptor.getValue().hasOwner() &&
 354                     leaderChangeCaptor.getAllValues().size() > 0 && !follower1ChangeCaptor.getValue().hasOwner() &&
 355                     leaderChangeCaptor.getAllValues().size() > 0 && !follower2ChangeCaptor.getValue().hasOwner()) {
 356                 passed = true;
 357                 break;
 358             }
 359         }
 360
 361         assertTrue("No ownership change message was sent with hasOwner=false", passed);
 362     }
 363
 364     /**
 365      * Tests bootstrapping the entity-ownership shard when there's no shards initially configured for local
 366      * member. The entity-ownership shard is initially created as inactive (ie remains a follower), requiring
 367      * an AddShardReplica request to join it to an existing leader.
 368      */
 369     @Test
 370     public void testEntityOwnershipShardBootstrapping() throws Throwable {
 371         startLeaderSystem();
 372         startFollower1System();
 373         String type = "testEntityOwnershipShardBootstrapping";
 374         initLeaderDatastore(type, MODULE_SHARDS_MEMBER_1_CONFIG);
 375         initFollower1Datastore(type, MODULE_SHARDS_MEMBER_1_CONFIG);
 376
 377         leaderDistributedDataStore.waitTillReady();
 378         follower1DistributedDataStore.waitTillReady();
 379
 380         startLeaderService();
 381         startFollower1Service();
 382
 383         leaderTestKit.waitUntilLeader(leaderDistributedDataStore.getActorContext(), ENTITY_OWNERSHIP_SHARD_NAME);
 384
 385         leaderEntityOwnershipService.registerListener(ENTITY_TYPE1, leaderMockListener);
 386
 387         // Register a candidate for follower1 - should get queued since follower1 has no leader
 388         follower1EntityOwnershipService.registerCandidate(ENTITY1);
 389         verify(leaderMockListener, timeout(300).never()).ownershipChanged(ownershipChange(ENTITY1));
 390
 391         // Add replica in follower1
 392         AddShardReplica addReplica = new AddShardReplica(ENTITY_OWNERSHIP_SHARD_NAME);
 393         follower1DistributedDataStore.getActorContext().getShardManager().tell(addReplica , follower1TestKit.getRef());
 394         Object reply = follower1TestKit.expectMsgAnyClassOf(JavaTestKit.duration("5 sec"), Success.class, Failure.class);
 395         if(reply instanceof Failure) {
 396             throw ((Failure)reply).cause();
 397         }
 398
 399         // The queued candidate registration should proceed
 400         verify(leaderMockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY1));
 401
 402     }
 403
 404     private static void verifyGetOwnershipState(DistributedEntityOwnershipService service, Entity entity,
 405             boolean isOwner, boolean hasOwner) {
 406         Optional<EntityOwnershipState> state = service.getOwnershipState(entity);
 407         assertEquals("getOwnershipState present", true, state.isPresent());
 408         assertEquals("isOwner", isOwner, state.get().isOwner());
 409         assertEquals("hasOwner", hasOwner, state.get().hasOwner());
 410     }
 411
 412     private static void verifyCandidates(DistributedDataStore dataStore, Entity entity, String... expCandidates) throws Exception {
 413         AssertionError lastError = null;
 414         Stopwatch sw = Stopwatch.createStarted();
 415         while(sw.elapsed(TimeUnit.MILLISECONDS) <= 5000) {
 416             Optional<NormalizedNode<?, ?>> possible = dataStore.newReadOnlyTransaction().read(
 417                     entityPath(entity.getType(), entity.getId()).node(Candidate.QNAME)).get(5, TimeUnit.SECONDS);
 418             try {
 419                 assertEquals("Candidates not found for " + entity, true, possible.isPresent());
 420                 Collection<String> actual = new ArrayList<>();
 421                 for(MapEntryNode candidate: ((MapNode)possible.get()).getValue()) {
 422                     actual.add(candidate.getChild(CANDIDATE_NAME_NODE_ID).get().getValue().toString());
 423                 }
 424
 425                 assertEquals("Candidates for " + entity, Arrays.asList(expCandidates), actual);
 426                 return;
 427             } catch (AssertionError e) {
 428                 lastError = e;
 429                 Uninterruptibles.sleepUninterruptibly(300, TimeUnit.MILLISECONDS);
 430             }
 431         }
 432
 433         throw lastError;
 434     }
 435
 436     private static void verifyOwner(final DistributedDataStore dataStore, Entity entity, String expOwner) {
 437         AbstractEntityOwnershipTest.verifyOwner(expOwner, entity.getType(), entity.getId(),
 438                 new Function<YangInstanceIdentifier, NormalizedNode<?,?>>() {
 439                     @Override
 440                     public NormalizedNode<?, ?> apply(YangInstanceIdentifier path) {
 441                         try {
 442                             return dataStore.newReadOnlyTransaction().read(path).get(5, TimeUnit.SECONDS).get();
 443                         } catch (Exception e) {
 444                             return null;
 445                         }
 446                     }
 447                 });
 448     }
 449 }