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.assertNull;
  12 import static org.junit.Assert.assertThat;
  13 import static org.junit.Assert.assertTrue;
  14 import static org.mockito.AdditionalMatchers.or;
  15 import static org.mockito.Mockito.doNothing;
  16 import static org.mockito.Mockito.never;
  17 import static org.mockito.Mockito.reset;
  18 import static org.mockito.Mockito.timeout;
  19 import static org.mockito.Mockito.verify;
  20 import static org.opendaylight.controller.cluster.datastore.MemberNode.verifyRaftState;
  21 import static org.opendaylight.controller.cluster.datastore.entityownership.AbstractEntityOwnershipTest.ownershipChange;
  22 import static org.opendaylight.controller.cluster.datastore.entityownership.DistributedEntityOwnershipService.ENTITY_OWNERSHIP_SHARD_NAME;
  23 import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.CANDIDATE_NAME_NODE_ID;
  24 import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.entityPath;
  25
  26 import akka.actor.ActorRef;
  27 import akka.actor.Status.Failure;
  28 import akka.actor.Status.Success;
  29 import akka.cluster.Cluster;
  30 import akka.testkit.JavaTestKit;
  31 import com.google.common.base.Optional;
  32 import com.google.common.base.Stopwatch;
  33 import com.google.common.collect.Iterables;
  34 import com.google.common.collect.Lists;
  35 import com.google.common.util.concurrent.Uninterruptibles;
  36 import java.util.ArrayList;
  37 import java.util.Arrays;
  38 import java.util.Collection;
  39 import java.util.List;
  40 import java.util.concurrent.TimeUnit;
  41 import java.util.concurrent.atomic.AtomicLong;
  42 import org.junit.After;
  43 import org.junit.Before;
  44 import org.junit.Test;
  45 import org.mockito.ArgumentCaptor;
  46 import org.mockito.Mock;
  47 import org.mockito.Mockito;
  48 import org.mockito.MockitoAnnotations;
  49 import org.mockito.exceptions.base.MockitoException;
  50 import org.opendaylight.controller.cluster.datastore.AbstractDataStore;
  51 import org.opendaylight.controller.cluster.datastore.DatastoreContext;
  52 import org.opendaylight.controller.cluster.datastore.IntegrationTestKit;
  53 import org.opendaylight.controller.cluster.datastore.MemberNode;
  54 import org.opendaylight.controller.cluster.datastore.entityownership.selectionstrategy.EntityOwnerSelectionStrategyConfig;
  55 import org.opendaylight.controller.cluster.datastore.messages.AddShardReplica;
  56 import org.opendaylight.controller.cluster.raft.RaftState;
  57 import org.opendaylight.controller.cluster.raft.policy.DisableElectionsRaftPolicy;
  58 import org.opendaylight.controller.cluster.raft.utils.InMemoryJournal;
  59 import org.opendaylight.controller.cluster.raft.utils.InMemorySnapshotStore;
  60 import org.opendaylight.controller.md.cluster.datastore.model.SchemaContextHelper;
  61 import org.opendaylight.mdsal.eos.common.api.EntityOwnershipState;
  62 import org.opendaylight.mdsal.eos.dom.api.DOMEntity;
  63 import org.opendaylight.mdsal.eos.dom.api.DOMEntityOwnershipCandidateRegistration;
  64 import org.opendaylight.mdsal.eos.dom.api.DOMEntityOwnershipChange;
  65 import org.opendaylight.mdsal.eos.dom.api.DOMEntityOwnershipListener;
  66 import org.opendaylight.mdsal.eos.dom.api.DOMEntityOwnershipService;
  67 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;
  68 import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
  69 import org.opendaylight.yangtools.yang.data.api.schema.MapNode;
  70 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  71 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  72
  73 /**
  74  * End-to-end integration tests for the entity ownership functionality.
  75  *
  76  * @author Thomas Pantelis
  77  */
  78 public class DistributedEntityOwnershipIntegrationTest {
  79     private static final String MODULE_SHARDS_CONFIG = "module-shards-default.conf";
  80     private static final String MODULE_SHARDS_5_NODE_CONFIG = "module-shards-default-5-node.conf";
  81     private static final String MODULE_SHARDS_MEMBER_1_CONFIG = "module-shards-default-member-1.conf";
  82     private static final String ENTITY_TYPE1 = "entityType1";
  83     private static final String ENTITY_TYPE2 = "entityType2";
  84     private static final DOMEntity ENTITY1 = new DOMEntity(ENTITY_TYPE1, "entity1");
  85     private static final DOMEntity ENTITY1_2 = new DOMEntity(ENTITY_TYPE2, "entity1");
  86     private static final DOMEntity ENTITY2 = new DOMEntity(ENTITY_TYPE1, "entity2");
  87     private static final DOMEntity ENTITY3 = new DOMEntity(ENTITY_TYPE1, "entity3");
  88     private static final DOMEntity ENTITY4 = new DOMEntity(ENTITY_TYPE1, "entity4");
  89     private static final SchemaContext SCHEMA_CONTEXT = SchemaContextHelper.entityOwners();
  90
  91     private final DatastoreContext.Builder leaderDatastoreContextBuilder =
  92             DatastoreContext.newBuilder().shardHeartbeatIntervalInMillis(100).shardElectionTimeoutFactor(5)
  93                     .shardIsolatedLeaderCheckIntervalInMillis(1000000);
  94
  95     private final DatastoreContext.Builder followerDatastoreContextBuilder =
  96             DatastoreContext.newBuilder().shardHeartbeatIntervalInMillis(100).shardElectionTimeoutFactor(10000);
  97
  98     private final List<MemberNode> memberNodes = new ArrayList<>();
  99
 100     @Mock
 101     private DOMEntityOwnershipListener leaderMockListener;
 102
 103     @Mock
 104     private DOMEntityOwnershipListener leaderMockListener2;
 105
 106     @Mock
 107     private DOMEntityOwnershipListener follower1MockListener;
 108
 109     @Mock
 110     private DOMEntityOwnershipListener follower2MockListener;
 111
 112     @Before
 113     public void setUp() {
 114         MockitoAnnotations.initMocks(this);
 115         InMemoryJournal.clear();
 116         InMemorySnapshotStore.clear();
 117     }
 118
 119     @After
 120     public void tearDown() {
 121         for (MemberNode m : Lists.reverse(memberNodes)) {
 122             m.cleanup();
 123         }
 124         memberNodes.clear();
 125     }
 126
 127     private static DistributedEntityOwnershipService newOwnershipService(final AbstractDataStore datastore) {
 128         return DistributedEntityOwnershipService.start(datastore.getActorContext(),
 129                 EntityOwnerSelectionStrategyConfig.newBuilder().build());
 130     }
 131
 132     @Test
 133     public void testFunctionalityWithThreeNodes() throws Exception {
 134         String name = "testFunctionalityWithThreeNodes";
 135         MemberNode leaderNode = MemberNode.builder(memberNodes).akkaConfig("Member1").testName(name)
 136                 .moduleShardsConfig(MODULE_SHARDS_CONFIG).schemaContext(SCHEMA_CONTEXT).createOperDatastore(false)
 137                 .datastoreContextBuilder(leaderDatastoreContextBuilder).build();
 138
 139         MemberNode follower1Node = MemberNode.builder(memberNodes).akkaConfig("Member2").testName(name)
 140                 .moduleShardsConfig(MODULE_SHARDS_CONFIG).schemaContext(SCHEMA_CONTEXT).createOperDatastore(false)
 141                 .datastoreContextBuilder(followerDatastoreContextBuilder).build();
 142
 143         MemberNode follower2Node = MemberNode.builder(memberNodes).akkaConfig("Member3").testName(name)
 144                 .moduleShardsConfig(MODULE_SHARDS_CONFIG).schemaContext(SCHEMA_CONTEXT).createOperDatastore(false)
 145                 .datastoreContextBuilder(followerDatastoreContextBuilder).build();
 146
 147         AbstractDataStore leaderDistributedDataStore = leaderNode.configDataStore();
 148
 149         leaderDistributedDataStore.waitTillReady();
 150         follower1Node.configDataStore().waitTillReady();
 151         follower2Node.configDataStore().waitTillReady();
 152
 153         final DOMEntityOwnershipService leaderEntityOwnershipService = newOwnershipService(leaderDistributedDataStore);
 154         final DOMEntityOwnershipService follower1EntityOwnershipService =
 155                 newOwnershipService(follower1Node.configDataStore());
 156         final DOMEntityOwnershipService follower2EntityOwnershipService =
 157                 newOwnershipService(follower2Node.configDataStore());
 158
 159         leaderNode.kit().waitUntilLeader(leaderNode.configDataStore().getActorContext(), ENTITY_OWNERSHIP_SHARD_NAME);
 160
 161         leaderEntityOwnershipService.registerListener(ENTITY_TYPE1, leaderMockListener);
 162         leaderEntityOwnershipService.registerListener(ENTITY_TYPE2, leaderMockListener2);
 163         follower1EntityOwnershipService.registerListener(ENTITY_TYPE1, follower1MockListener);
 164
 165         // Register leader candidate for entity1 and verify it becomes owner
 166
 167         leaderEntityOwnershipService.registerCandidate(ENTITY1);
 168         verify(leaderMockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY1, false, true, true));
 169         verify(follower1MockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY1, false, false, true));
 170         reset(leaderMockListener, follower1MockListener);
 171
 172         verifyGetOwnershipState(leaderEntityOwnershipService, ENTITY1, EntityOwnershipState.IS_OWNER);
 173         verifyGetOwnershipState(follower1EntityOwnershipService, ENTITY1, EntityOwnershipState.OWNED_BY_OTHER);
 174
 175         // Register leader candidate for entity1_2 (same id, different type) and verify it becomes owner
 176
 177         leaderEntityOwnershipService.registerCandidate(ENTITY1_2);
 178         verify(leaderMockListener2, timeout(5000)).ownershipChanged(ownershipChange(ENTITY1_2, false, true, true));
 179         Uninterruptibles.sleepUninterruptibly(300, TimeUnit.MILLISECONDS);
 180         verify(leaderMockListener, never()).ownershipChanged(ownershipChange(ENTITY1_2));
 181         reset(leaderMockListener2);
 182
 183         // Register follower1 candidate for entity1 and verify it gets added but doesn't become owner
 184
 185         follower1EntityOwnershipService.registerCandidate(ENTITY1);
 186         verifyCandidates(leaderDistributedDataStore, ENTITY1, "member-1", "member-2");
 187         verifyOwner(leaderDistributedDataStore, ENTITY1, "member-1");
 188         verifyOwner(follower2Node.configDataStore(), ENTITY1, "member-1");
 189         Uninterruptibles.sleepUninterruptibly(300, TimeUnit.MILLISECONDS);
 190         verify(leaderMockListener, never()).ownershipChanged(ownershipChange(ENTITY1));
 191         verify(follower1MockListener, never()).ownershipChanged(ownershipChange(ENTITY1));
 192
 193         // Register follower1 candidate for entity2 and verify it becomes owner
 194
 195         final DOMEntityOwnershipCandidateRegistration follower1Entity2Reg =
 196                 follower1EntityOwnershipService.registerCandidate(ENTITY2);
 197         verify(follower1MockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY2, false, true, true));
 198         verify(leaderMockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY2, false, false, true));
 199         verifyOwner(follower2Node.configDataStore(), ENTITY2, "member-2");
 200         reset(leaderMockListener, follower1MockListener);
 201
 202         // Register follower2 candidate for entity2 and verify it gets added but doesn't become owner
 203
 204         follower2EntityOwnershipService.registerListener(ENTITY_TYPE1, follower2MockListener);
 205         verify(follower2MockListener, timeout(5000).times(2)).ownershipChanged(or(
 206                 ownershipChange(ENTITY1, false, false, true), ownershipChange(ENTITY2, false, false, true)));
 207
 208         follower2EntityOwnershipService.registerCandidate(ENTITY2);
 209         verifyCandidates(leaderDistributedDataStore, ENTITY2, "member-2", "member-3");
 210         verifyOwner(leaderDistributedDataStore, ENTITY2, "member-2");
 211
 212         // Unregister follower1 candidate for entity2 and verify follower2 becomes owner
 213
 214         follower1Entity2Reg.close();
 215         verifyCandidates(leaderDistributedDataStore, ENTITY2, "member-3");
 216         verifyOwner(leaderDistributedDataStore, ENTITY2, "member-3");
 217         verify(follower1MockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY2, true, false, true));
 218         verify(leaderMockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY2, false, false, true));
 219
 220         // Depending on timing, follower2MockListener could get ownershipChanged with "false, false, true" if
 221         // if the original ownership change with "member-2 is replicated to follower2 after the listener is
 222         // registered.
 223         Uninterruptibles.sleepUninterruptibly(500, TimeUnit.MILLISECONDS);
 224         verify(follower2MockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY2, false, true, true));
 225
 226         // Register follower1 candidate for entity3 and verify it becomes owner
 227
 228         follower1EntityOwnershipService.registerCandidate(ENTITY3);
 229         verifyOwner(leaderDistributedDataStore, ENTITY3, "member-2");
 230         verify(follower1MockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY3, false, true, true));
 231         verify(follower2MockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY3, false, false, true));
 232         verify(leaderMockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY3, false, false, true));
 233
 234         // Register follower2 candidate for entity4 and verify it becomes owner
 235
 236         follower2EntityOwnershipService.registerCandidate(ENTITY4);
 237         verifyOwner(leaderDistributedDataStore, ENTITY4, "member-3");
 238         verify(follower2MockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY4, false, true, true));
 239         verify(follower1MockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY4, false, false, true));
 240         verify(leaderMockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY4, false, false, true));
 241         reset(follower1MockListener, follower2MockListener);
 242
 243         // Register follower1 candidate for entity4 and verify it gets added but doesn't become owner
 244
 245         follower1EntityOwnershipService.registerCandidate(ENTITY4);
 246         verifyCandidates(leaderDistributedDataStore, ENTITY4, "member-3", "member-2");
 247         verifyOwner(leaderDistributedDataStore, ENTITY4, "member-3");
 248
 249         // Shutdown follower2 and verify it's owned entities (entity 4) get re-assigned
 250
 251         reset(leaderMockListener, follower1MockListener);
 252         follower2Node.cleanup();
 253
 254         verify(follower1MockListener, timeout(15000)).ownershipChanged(ownershipChange(ENTITY4, false, true, true));
 255         verify(leaderMockListener, timeout(15000)).ownershipChanged(ownershipChange(ENTITY4, false, false, true));
 256
 257         // Register leader candidate for entity2 and verify it becomes owner
 258
 259         DOMEntityOwnershipCandidateRegistration leaderEntity2Reg =
 260                 leaderEntityOwnershipService.registerCandidate(ENTITY2);
 261         verifyOwner(leaderDistributedDataStore, ENTITY2, "member-1");
 262         verify(leaderMockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY2, false, true, true));
 263
 264         // Unregister leader candidate for entity2 and verify the owner is cleared
 265
 266         leaderEntity2Reg.close();
 267         verifyOwner(leaderDistributedDataStore, ENTITY2, "");
 268         verify(leaderMockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY2, true, false, false));
 269         verify(follower1MockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY2, false, false, false));
 270     }
 271
 272     @Test
 273     public void testLeaderEntityOwnersReassignedAfterShutdown() throws Exception {
 274         followerDatastoreContextBuilder.shardElectionTimeoutFactor(5)
 275                     .customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName());
 276
 277         String name = "testLeaderEntityOwnersReassignedAfterShutdown";
 278         MemberNode leaderNode = MemberNode.builder(memberNodes).akkaConfig("Member1").testName(name)
 279                 .moduleShardsConfig(MODULE_SHARDS_CONFIG).schemaContext(SCHEMA_CONTEXT).createOperDatastore(false)
 280                 .datastoreContextBuilder(leaderDatastoreContextBuilder).build();
 281
 282         MemberNode follower1Node = MemberNode.builder(memberNodes).akkaConfig("Member2").testName(name)
 283                 .moduleShardsConfig(MODULE_SHARDS_CONFIG).schemaContext(SCHEMA_CONTEXT).createOperDatastore(false)
 284                 .datastoreContextBuilder(followerDatastoreContextBuilder).build();
 285
 286         MemberNode follower2Node = MemberNode.builder(memberNodes).akkaConfig("Member3").testName(name)
 287                 .moduleShardsConfig(MODULE_SHARDS_CONFIG).schemaContext(SCHEMA_CONTEXT).createOperDatastore(false)
 288                 .datastoreContextBuilder(followerDatastoreContextBuilder).build();
 289
 290         AbstractDataStore leaderDistributedDataStore = leaderNode.configDataStore();
 291
 292         leaderDistributedDataStore.waitTillReady();
 293         follower1Node.configDataStore().waitTillReady();
 294         follower2Node.configDataStore().waitTillReady();
 295
 296         follower1Node.waitForMembersUp("member-1", "member-3");
 297
 298         final DOMEntityOwnershipService leaderEntityOwnershipService = newOwnershipService(leaderDistributedDataStore);
 299         final DOMEntityOwnershipService follower1EntityOwnershipService =
 300                 newOwnershipService(follower1Node.configDataStore());
 301         final DOMEntityOwnershipService follower2EntityOwnershipService =
 302                 newOwnershipService(follower2Node.configDataStore());
 303
 304         leaderNode.kit().waitUntilLeader(leaderNode.configDataStore().getActorContext(), ENTITY_OWNERSHIP_SHARD_NAME);
 305
 306         // Register follower1 candidate for entity1 and verify it becomes owner
 307
 308         follower1EntityOwnershipService.registerCandidate(ENTITY1);
 309         verifyOwner(leaderDistributedDataStore, ENTITY1, "member-2");
 310
 311         // Register leader candidate for entity1
 312
 313         leaderEntityOwnershipService.registerCandidate(ENTITY1);
 314         verifyCandidates(leaderDistributedDataStore, ENTITY1, "member-2", "member-1");
 315         verifyOwner(leaderDistributedDataStore, ENTITY1, "member-2");
 316
 317         // Register leader candidate for entity2 and verify it becomes owner
 318
 319         leaderEntityOwnershipService.registerCandidate(ENTITY2);
 320         verifyOwner(leaderDistributedDataStore, ENTITY2, "member-1");
 321
 322         // Register follower2 candidate for entity2
 323
 324         follower2EntityOwnershipService.registerCandidate(ENTITY2);
 325         verifyCandidates(leaderDistributedDataStore, ENTITY2, "member-1", "member-3");
 326         verifyOwner(leaderDistributedDataStore, ENTITY2, "member-1");
 327
 328         // Get the leader's lastIndex and verify followers are fully synced before shutting down the leader
 329
 330         AtomicLong leaderLastIndex = new AtomicLong();
 331         MemberNode.verifyRaftState(leaderDistributedDataStore, ENTITY_OWNERSHIP_SHARD_NAME,
 332             raftState -> leaderLastIndex.set(raftState.getLastIndex()));
 333
 334         MemberNode.verifyRaftState(follower1Node.configDataStore(), ENTITY_OWNERSHIP_SHARD_NAME,
 335             raftState -> assertEquals("Last index", leaderLastIndex.get(), raftState.getLastIndex()));
 336
 337         MemberNode.verifyRaftState(follower2Node.configDataStore(), ENTITY_OWNERSHIP_SHARD_NAME,
 338             raftState -> assertEquals("Last index", leaderLastIndex.get(), raftState.getLastIndex()));
 339
 340         // Shutdown the leader and verify its removed from the candidate list
 341
 342         leaderNode.cleanup();
 343         follower1Node.waitForMemberDown("member-1");
 344
 345         // Re-enable elections on follower1 so it becomes the leader
 346
 347         ActorRef follower1Shard = IntegrationTestKit.findLocalShard(follower1Node.configDataStore().getActorContext(),
 348                 ENTITY_OWNERSHIP_SHARD_NAME);
 349         follower1Shard.tell(DatastoreContext.newBuilderFrom(followerDatastoreContextBuilder.build())
 350                 .customRaftPolicyImplementation(null).build(), ActorRef.noSender());
 351
 352         MemberNode.verifyRaftState(follower1Node.configDataStore(), ENTITY_OWNERSHIP_SHARD_NAME,
 353             raftState -> assertEquals("Raft state", RaftState.Leader.toString(), raftState.getRaftState()));
 354
 355         // Verify the prior leader's entity owners are re-assigned.
 356
 357         verifyCandidates(follower1Node.configDataStore(), ENTITY1, "member-2", "member-1");
 358         verifyCandidates(follower1Node.configDataStore(), ENTITY2, "member-1", "member-3");
 359         verifyOwner(follower1Node.configDataStore(), ENTITY1, "member-2");
 360         verifyOwner(follower1Node.configDataStore(), ENTITY2, "member-3");
 361     }
 362
 363     @Test
 364     public void testLeaderAndFollowerEntityOwnersReassignedAfterShutdown() throws Exception {
 365         followerDatastoreContextBuilder.shardElectionTimeoutFactor(5)
 366                 .customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName());
 367
 368         String name = "testLeaderAndFollowerEntityOwnersReassignedAfterShutdown";
 369         final MemberNode leaderNode = MemberNode.builder(memberNodes).akkaConfig("Member1")
 370                 .useAkkaArtery(false).testName(name)
 371                 .moduleShardsConfig(MODULE_SHARDS_5_NODE_CONFIG).schemaContext(SCHEMA_CONTEXT)
 372                 .createOperDatastore(false).datastoreContextBuilder(leaderDatastoreContextBuilder).build();
 373
 374         final MemberNode follower1Node = MemberNode.builder(memberNodes).akkaConfig("Member2")
 375                 .useAkkaArtery(false).testName(name)
 376                 .moduleShardsConfig(MODULE_SHARDS_5_NODE_CONFIG).schemaContext(SCHEMA_CONTEXT)
 377                 .createOperDatastore(false).datastoreContextBuilder(followerDatastoreContextBuilder).build();
 378
 379         final MemberNode follower2Node = MemberNode.builder(memberNodes).akkaConfig("Member3")
 380                 .useAkkaArtery(false).testName(name)
 381                 .moduleShardsConfig(MODULE_SHARDS_5_NODE_CONFIG).schemaContext(SCHEMA_CONTEXT)
 382                 .createOperDatastore(false).datastoreContextBuilder(followerDatastoreContextBuilder).build();
 383
 384         final MemberNode follower3Node = MemberNode.builder(memberNodes).akkaConfig("Member4")
 385                 .useAkkaArtery(false).testName(name)
 386                 .moduleShardsConfig(MODULE_SHARDS_5_NODE_CONFIG).schemaContext(SCHEMA_CONTEXT)
 387                 .createOperDatastore(false).datastoreContextBuilder(followerDatastoreContextBuilder).build();
 388
 389         final MemberNode follower4Node = MemberNode.builder(memberNodes).akkaConfig("Member5")
 390                 .useAkkaArtery(false).testName(name)
 391                 .moduleShardsConfig(MODULE_SHARDS_5_NODE_CONFIG).schemaContext(SCHEMA_CONTEXT)
 392                 .createOperDatastore(false).datastoreContextBuilder(followerDatastoreContextBuilder).build();
 393
 394         AbstractDataStore leaderDistributedDataStore = leaderNode.configDataStore();
 395
 396         leaderDistributedDataStore.waitTillReady();
 397         follower1Node.configDataStore().waitTillReady();
 398         follower2Node.configDataStore().waitTillReady();
 399         follower3Node.configDataStore().waitTillReady();
 400         follower4Node.configDataStore().waitTillReady();
 401
 402         leaderNode.waitForMembersUp("member-2", "member-3", "member-4", "member-5");
 403         follower1Node.waitForMembersUp("member-1", "member-3", "member-4", "member-5");
 404
 405         final DOMEntityOwnershipService leaderEntityOwnershipService = newOwnershipService(leaderDistributedDataStore);
 406         final DOMEntityOwnershipService follower1EntityOwnershipService =
 407                 newOwnershipService(follower1Node.configDataStore());
 408         final DOMEntityOwnershipService follower2EntityOwnershipService =
 409                 newOwnershipService(follower2Node.configDataStore());
 410         final DOMEntityOwnershipService follower3EntityOwnershipService =
 411                 newOwnershipService(follower3Node.configDataStore());
 412         newOwnershipService(follower4Node.configDataStore());
 413
 414         leaderNode.kit().waitUntilLeader(leaderNode.configDataStore().getActorContext(), ENTITY_OWNERSHIP_SHARD_NAME);
 415
 416         // Register follower1 candidate for entity1 and verify it becomes owner
 417
 418         follower1EntityOwnershipService.registerCandidate(ENTITY1);
 419         verifyOwner(leaderDistributedDataStore, ENTITY1, "member-2");
 420
 421         // Register leader candidate for entity1
 422
 423         leaderEntityOwnershipService.registerCandidate(ENTITY1);
 424         verifyCandidates(leaderDistributedDataStore, ENTITY1, "member-2", "member-1");
 425         verifyOwner(leaderDistributedDataStore, ENTITY1, "member-2");
 426
 427         // Register leader candidate for entity2 and verify it becomes owner
 428
 429         leaderEntityOwnershipService.registerCandidate(ENTITY2);
 430         verifyOwner(leaderDistributedDataStore, ENTITY2, "member-1");
 431
 432         // Register follower2 candidate for entity2
 433
 434         follower2EntityOwnershipService.registerCandidate(ENTITY2);
 435         verifyCandidates(leaderDistributedDataStore, ENTITY2, "member-1", "member-3");
 436         verifyOwner(leaderDistributedDataStore, ENTITY2, "member-1");
 437
 438         // Register follower3 as a candidate for entity2 as well
 439
 440         follower3EntityOwnershipService.registerCandidate(ENTITY2);
 441         verifyCandidates(leaderDistributedDataStore, ENTITY2, "member-1", "member-3", "member-4");
 442         verifyOwner(leaderDistributedDataStore, ENTITY2, "member-1");
 443
 444         // Get the leader's lastIndex and verify followers are fully synced before shutting down the leader
 445         AtomicLong leaderLastIndex = new AtomicLong();
 446         MemberNode.verifyRaftState(leaderDistributedDataStore, ENTITY_OWNERSHIP_SHARD_NAME,
 447             raftState -> leaderLastIndex.set(raftState.getLastIndex()));
 448
 449         MemberNode.verifyRaftState(follower1Node.configDataStore(), ENTITY_OWNERSHIP_SHARD_NAME,
 450             raftState -> assertEquals("Last index", leaderLastIndex.get(), raftState.getLastIndex()));
 451
 452         MemberNode.verifyRaftState(follower2Node.configDataStore(), ENTITY_OWNERSHIP_SHARD_NAME,
 453             raftState -> assertEquals("Last index", leaderLastIndex.get(), raftState.getLastIndex()));
 454
 455         MemberNode.verifyRaftState(follower4Node.configDataStore(), ENTITY_OWNERSHIP_SHARD_NAME,
 456             raftState -> assertEquals("Last index", leaderLastIndex.get(), raftState.getLastIndex()));
 457
 458         // Shutdown the leader and follower3
 459
 460         leaderNode.cleanup();
 461         follower3Node.cleanup();
 462
 463         follower1Node.waitForMemberDown("member-1");
 464         follower1Node.waitForMemberDown("member-4");
 465
 466         // Re-enable elections on follower1 so it becomes the leader
 467
 468         ActorRef follower1Shard = IntegrationTestKit.findLocalShard(follower1Node.configDataStore().getActorContext(),
 469                 ENTITY_OWNERSHIP_SHARD_NAME);
 470         follower1Shard.tell(DatastoreContext.newBuilderFrom(followerDatastoreContextBuilder.build())
 471                 .customRaftPolicyImplementation(null).build(), ActorRef.noSender());
 472
 473         MemberNode.verifyRaftState(follower1Node.configDataStore(), ENTITY_OWNERSHIP_SHARD_NAME,
 474             raftState -> assertEquals("Raft state", RaftState.Leader.toString(), raftState.getRaftState()));
 475
 476         // Verify the prior leader's and follower3 entity owners are re-assigned.
 477
 478         verifyCandidates(follower1Node.configDataStore(), ENTITY1, "member-2", "member-1");
 479         verifyCandidates(follower1Node.configDataStore(), ENTITY2, "member-1", "member-3", "member-4");
 480         verifyOwner(follower1Node.configDataStore(), ENTITY1, "member-2");
 481         verifyOwner(follower1Node.configDataStore(), ENTITY2, "member-3");
 482     }
 483
 484     /**
 485      * Reproduces bug <a href="https://bugs.opendaylight.org/show_bug.cgi?id=4554">4554</a>.
 486      */
 487     @Test
 488     public void testCloseCandidateRegistrationInQuickSuccession() throws Exception {
 489         String name = "testCloseCandidateRegistrationInQuickSuccession";
 490         MemberNode leaderNode = MemberNode.builder(memberNodes).akkaConfig("Member1").testName(name)
 491                 .moduleShardsConfig(MODULE_SHARDS_CONFIG).schemaContext(SCHEMA_CONTEXT).createOperDatastore(false)
 492                 .datastoreContextBuilder(leaderDatastoreContextBuilder).build();
 493
 494         MemberNode follower1Node = MemberNode.builder(memberNodes).akkaConfig("Member2").testName(name)
 495                 .moduleShardsConfig(MODULE_SHARDS_CONFIG).schemaContext(SCHEMA_CONTEXT).createOperDatastore(false)
 496                 .datastoreContextBuilder(followerDatastoreContextBuilder).build();
 497
 498         MemberNode follower2Node = MemberNode.builder(memberNodes).akkaConfig("Member3").testName(name)
 499                 .moduleShardsConfig(MODULE_SHARDS_CONFIG).schemaContext(SCHEMA_CONTEXT).createOperDatastore(false)
 500                 .datastoreContextBuilder(followerDatastoreContextBuilder).build();
 501
 502         AbstractDataStore leaderDistributedDataStore = leaderNode.configDataStore();
 503
 504         leaderDistributedDataStore.waitTillReady();
 505         follower1Node.configDataStore().waitTillReady();
 506         follower2Node.configDataStore().waitTillReady();
 507
 508         final DOMEntityOwnershipService leaderEntityOwnershipService = newOwnershipService(leaderDistributedDataStore);
 509         final DOMEntityOwnershipService follower1EntityOwnershipService =
 510                 newOwnershipService(follower1Node.configDataStore());
 511         final DOMEntityOwnershipService follower2EntityOwnershipService =
 512                 newOwnershipService(follower2Node.configDataStore());
 513
 514         leaderNode.kit().waitUntilLeader(leaderNode.configDataStore().getActorContext(), ENTITY_OWNERSHIP_SHARD_NAME);
 515
 516         leaderEntityOwnershipService.registerListener(ENTITY_TYPE1, leaderMockListener);
 517         follower1EntityOwnershipService.registerListener(ENTITY_TYPE1, follower1MockListener);
 518         follower2EntityOwnershipService.registerListener(ENTITY_TYPE1, follower2MockListener);
 519
 520         final DOMEntityOwnershipCandidateRegistration candidate1 =
 521                 leaderEntityOwnershipService.registerCandidate(ENTITY1);
 522         verify(leaderMockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY1, false, true, true));
 523
 524         final DOMEntityOwnershipCandidateRegistration candidate2 =
 525                 follower1EntityOwnershipService.registerCandidate(ENTITY1);
 526         verify(follower1MockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY1, false, false, true));
 527
 528         final DOMEntityOwnershipCandidateRegistration candidate3 =
 529                 follower2EntityOwnershipService.registerCandidate(ENTITY1);
 530         verify(follower2MockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY1, false, false, true));
 531
 532         Mockito.reset(leaderMockListener, follower1MockListener, follower2MockListener);
 533
 534         ArgumentCaptor<DOMEntityOwnershipChange> leaderChangeCaptor =
 535                 ArgumentCaptor.forClass(DOMEntityOwnershipChange.class);
 536         ArgumentCaptor<DOMEntityOwnershipChange> follower1ChangeCaptor =
 537                 ArgumentCaptor.forClass(DOMEntityOwnershipChange.class);
 538         ArgumentCaptor<DOMEntityOwnershipChange> follower2ChangeCaptor =
 539                 ArgumentCaptor.forClass(DOMEntityOwnershipChange.class);
 540         doNothing().when(leaderMockListener).ownershipChanged(leaderChangeCaptor.capture());
 541         doNothing().when(follower1MockListener).ownershipChanged(follower1ChangeCaptor.capture());
 542         doNothing().when(follower2MockListener).ownershipChanged(follower2ChangeCaptor.capture());
 543
 544         candidate1.close();
 545         candidate2.close();
 546         candidate3.close();
 547
 548         boolean passed = false;
 549         for (int i = 0; i < 100; i++) {
 550             Uninterruptibles.sleepUninterruptibly(50, TimeUnit.MILLISECONDS);
 551             final Optional<EntityOwnershipState> leaderState = leaderEntityOwnershipService.getOwnershipState(ENTITY1);
 552             final Optional<EntityOwnershipState> follower1State =
 553                     follower1EntityOwnershipService.getOwnershipState(ENTITY1);
 554             final Optional<EntityOwnershipState> follower2State =
 555                     follower2EntityOwnershipService.getOwnershipState(ENTITY1);
 556             final Optional<DOMEntityOwnershipChange> leaderChange = getValueSafely(leaderChangeCaptor);
 557             final Optional<DOMEntityOwnershipChange> follower1Change = getValueSafely(follower1ChangeCaptor);
 558             final Optional<DOMEntityOwnershipChange> follower2Change = getValueSafely(follower2ChangeCaptor);
 559             if (!leaderState.isPresent() || leaderState.get() == EntityOwnershipState.NO_OWNER
 560                     && follower1State.isPresent() && follower1State.get() == EntityOwnershipState.NO_OWNER
 561                     && follower2State.isPresent() && follower2State.get() == EntityOwnershipState.NO_OWNER
 562                     && leaderChange.isPresent() && !leaderChange.get().getState().hasOwner()
 563                     && follower1Change.isPresent() && !follower1Change.get().getState().hasOwner()
 564                     && follower2Change.isPresent() && !follower2Change.get().getState().hasOwner()) {
 565                 passed = true;
 566                 break;
 567             }
 568         }
 569
 570         assertTrue("No ownership change message was sent with hasOwner=false", passed);
 571     }
 572
 573     private static Optional<DOMEntityOwnershipChange> getValueSafely(ArgumentCaptor<DOMEntityOwnershipChange> captor) {
 574         try {
 575             return Optional.fromNullable(captor.getValue());
 576         } catch (MockitoException e) {
 577             // No value was captured
 578             return Optional.absent();
 579         }
 580     }
 581
 582     /**
 583      * Tests bootstrapping the entity-ownership shard when there's no shards initially configured for local
 584      * member. The entity-ownership shard is initially created as inactive (ie remains a follower), requiring
 585      * an AddShardReplica request to join it to an existing leader.
 586      */
 587     @Test
 588     public void testEntityOwnershipShardBootstrapping() throws Exception {
 589         String name = "testEntityOwnershipShardBootstrapping";
 590         String moduleShardsConfig = MODULE_SHARDS_MEMBER_1_CONFIG;
 591         MemberNode leaderNode = MemberNode.builder(memberNodes).akkaConfig("Member1").testName(name)
 592                 .moduleShardsConfig(moduleShardsConfig).schemaContext(SCHEMA_CONTEXT).createOperDatastore(false)
 593                 .datastoreContextBuilder(leaderDatastoreContextBuilder).build();
 594
 595         AbstractDataStore leaderDistributedDataStore = leaderNode.configDataStore();
 596         final DOMEntityOwnershipService leaderEntityOwnershipService = newOwnershipService(leaderDistributedDataStore);
 597
 598         leaderNode.kit().waitUntilLeader(leaderNode.configDataStore().getActorContext(), ENTITY_OWNERSHIP_SHARD_NAME);
 599
 600         MemberNode follower1Node = MemberNode.builder(memberNodes).akkaConfig("Member2").testName(name)
 601                 .moduleShardsConfig(moduleShardsConfig).schemaContext(SCHEMA_CONTEXT).createOperDatastore(false)
 602                 .datastoreContextBuilder(followerDatastoreContextBuilder).build();
 603
 604         AbstractDataStore follower1DistributedDataStore = follower1Node.configDataStore();
 605         follower1DistributedDataStore.waitTillReady();
 606
 607         leaderNode.waitForMembersUp("member-2");
 608         follower1Node.waitForMembersUp("member-1");
 609
 610         DOMEntityOwnershipService follower1EntityOwnershipService = newOwnershipService(follower1DistributedDataStore);
 611
 612         leaderEntityOwnershipService.registerListener(ENTITY_TYPE1, leaderMockListener);
 613
 614         // Register a candidate for follower1 - should get queued since follower1 has no leader
 615         final DOMEntityOwnershipCandidateRegistration candidateReg =
 616                 follower1EntityOwnershipService.registerCandidate(ENTITY1);
 617         Uninterruptibles.sleepUninterruptibly(300, TimeUnit.MILLISECONDS);
 618         verify(leaderMockListener, never()).ownershipChanged(ownershipChange(ENTITY1));
 619
 620         // Add replica in follower1
 621         AddShardReplica addReplica = new AddShardReplica(ENTITY_OWNERSHIP_SHARD_NAME);
 622         follower1DistributedDataStore.getActorContext().getShardManager().tell(addReplica,
 623                 follower1Node.kit().getRef());
 624         Object reply = follower1Node.kit().expectMsgAnyClassOf(JavaTestKit.duration("5 sec"),
 625                 Success.class, Failure.class);
 626         if (reply instanceof Failure) {
 627             throw new AssertionError("AddShardReplica failed", ((Failure)reply).cause());
 628         }
 629
 630         // The queued candidate registration should proceed
 631         verify(leaderMockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY1, false, false, true));
 632         reset(leaderMockListener);
 633
 634         candidateReg.close();
 635         verify(leaderMockListener, timeout(5000)).ownershipChanged(ownershipChange(ENTITY1, false, false, false));
 636         reset(leaderMockListener);
 637
 638         // Restart follower1 and verify the entity ownership shard is re-instated by registering.
 639         Cluster.get(leaderNode.kit().getSystem()).down(Cluster.get(follower1Node.kit().getSystem()).selfAddress());
 640         follower1Node.cleanup();
 641
 642         follower1Node = MemberNode.builder(memberNodes).akkaConfig("Member2").testName(name)
 643                 .moduleShardsConfig(moduleShardsConfig).schemaContext(SCHEMA_CONTEXT).createOperDatastore(false)
 644                 .datastoreContextBuilder(followerDatastoreContextBuilder).build();
 645         follower1EntityOwnershipService = newOwnershipService(follower1Node.configDataStore());
 646
 647         follower1EntityOwnershipService.registerCandidate(ENTITY1);
 648         verify(leaderMockListener, timeout(20000)).ownershipChanged(ownershipChange(ENTITY1, false, false, true));
 649
 650         verifyRaftState(follower1Node.configDataStore(), ENTITY_OWNERSHIP_SHARD_NAME, raftState -> {
 651             assertNull("Custom RaftPolicy class name", raftState.getCustomRaftPolicyClassName());
 652             assertEquals("Peer count", 1, raftState.getPeerAddresses().keySet().size());
 653             assertThat("Peer Id", Iterables.<String>getLast(raftState.getPeerAddresses().keySet()),
 654                     org.hamcrest.CoreMatchers.containsString("member-1"));
 655         });
 656     }
 657
 658     @Test
 659     public void testOwnerSelectedOnRapidUnregisteringAndRegisteringOfCandidates() throws Exception {
 660         String name = "testOwnerSelectedOnRapidUnregisteringAndRegisteringOfCandidates";
 661         MemberNode leaderNode = MemberNode.builder(memberNodes).akkaConfig("Member1").testName(name)
 662                 .moduleShardsConfig(MODULE_SHARDS_CONFIG).schemaContext(SCHEMA_CONTEXT).createOperDatastore(false)
 663                 .datastoreContextBuilder(leaderDatastoreContextBuilder).build();
 664
 665         MemberNode follower1Node = MemberNode.builder(memberNodes).akkaConfig("Member2").testName(name)
 666                 .moduleShardsConfig(MODULE_SHARDS_CONFIG).schemaContext(SCHEMA_CONTEXT).createOperDatastore(false)
 667                 .datastoreContextBuilder(followerDatastoreContextBuilder).build();
 668
 669         MemberNode follower2Node = MemberNode.builder(memberNodes).akkaConfig("Member3").testName(name)
 670                 .moduleShardsConfig(MODULE_SHARDS_CONFIG).schemaContext(SCHEMA_CONTEXT).createOperDatastore(false)
 671                 .datastoreContextBuilder(followerDatastoreContextBuilder).build();
 672
 673         AbstractDataStore leaderDistributedDataStore = leaderNode.configDataStore();
 674
 675         leaderDistributedDataStore.waitTillReady();
 676         follower1Node.configDataStore().waitTillReady();
 677         follower2Node.configDataStore().waitTillReady();
 678
 679         final DOMEntityOwnershipService leaderEntityOwnershipService = newOwnershipService(leaderDistributedDataStore);
 680         final DOMEntityOwnershipService follower1EntityOwnershipService =
 681                 newOwnershipService(follower1Node.configDataStore());
 682         newOwnershipService(follower2Node.configDataStore());
 683
 684         leaderNode.kit().waitUntilLeader(leaderNode.configDataStore().getActorContext(), ENTITY_OWNERSHIP_SHARD_NAME);
 685
 686         // Register leader candidate for entity1 and verify it becomes owner
 687
 688         DOMEntityOwnershipCandidateRegistration leaderEntity1Reg =
 689                 leaderEntityOwnershipService.registerCandidate(ENTITY1);
 690
 691         verifyCandidates(leaderDistributedDataStore, ENTITY1, "member-1");
 692         verifyOwner(leaderDistributedDataStore, ENTITY1, "member-1");
 693
 694         leaderEntity1Reg.close();
 695         follower1EntityOwnershipService.registerCandidate(ENTITY1);
 696
 697         verifyCandidates(leaderDistributedDataStore, ENTITY1, "member-2");
 698         verifyOwner(leaderDistributedDataStore, ENTITY1, "member-2");
 699     }
 700
 701     @Test
 702     public void testOwnerSelectedOnRapidRegisteringAndUnregisteringOfCandidates() throws Exception {
 703         String name = "testOwnerSelectedOnRapidRegisteringAndUnregisteringOfCandidates";
 704         MemberNode leaderNode = MemberNode.builder(memberNodes).akkaConfig("Member1").testName(name)
 705                 .moduleShardsConfig(MODULE_SHARDS_CONFIG).schemaContext(SCHEMA_CONTEXT).createOperDatastore(false)
 706                 .datastoreContextBuilder(leaderDatastoreContextBuilder).build();
 707
 708         MemberNode follower1Node = MemberNode.builder(memberNodes).akkaConfig("Member2").testName(name)
 709                 .moduleShardsConfig(MODULE_SHARDS_CONFIG).schemaContext(SCHEMA_CONTEXT).createOperDatastore(false)
 710                 .datastoreContextBuilder(followerDatastoreContextBuilder).build();
 711
 712         MemberNode follower2Node = MemberNode.builder(memberNodes).akkaConfig("Member3").testName(name)
 713                 .moduleShardsConfig(MODULE_SHARDS_CONFIG).schemaContext(SCHEMA_CONTEXT).createOperDatastore(false)
 714                 .datastoreContextBuilder(followerDatastoreContextBuilder).build();
 715
 716         AbstractDataStore leaderDistributedDataStore = leaderNode.configDataStore();
 717
 718         leaderDistributedDataStore.waitTillReady();
 719         follower1Node.configDataStore().waitTillReady();
 720         follower2Node.configDataStore().waitTillReady();
 721
 722         final DOMEntityOwnershipService leaderEntityOwnershipService = newOwnershipService(leaderDistributedDataStore);
 723         final DOMEntityOwnershipService follower1EntityOwnershipService =
 724                 newOwnershipService(follower1Node.configDataStore());
 725         newOwnershipService(follower2Node.configDataStore());
 726
 727         leaderNode.kit().waitUntilLeader(leaderNode.configDataStore().getActorContext(), ENTITY_OWNERSHIP_SHARD_NAME);
 728
 729         // Register leader candidate for entity1 and verify it becomes owner
 730
 731         final DOMEntityOwnershipCandidateRegistration leaderEntity1Reg =
 732                 leaderEntityOwnershipService.registerCandidate(ENTITY1);
 733
 734         verifyCandidates(leaderDistributedDataStore, ENTITY1, "member-1");
 735         verifyOwner(leaderDistributedDataStore, ENTITY1, "member-1");
 736
 737         follower1EntityOwnershipService.registerCandidate(ENTITY1);
 738         leaderEntity1Reg.close();
 739
 740         verifyCandidates(leaderDistributedDataStore, ENTITY1, "member-2");
 741         verifyOwner(leaderDistributedDataStore, ENTITY1, "member-2");
 742     }
 743
 744     private static void verifyGetOwnershipState(final DOMEntityOwnershipService service, final DOMEntity entity,
 745             final EntityOwnershipState expState) {
 746         Optional<EntityOwnershipState> state = service.getOwnershipState(entity);
 747         assertEquals("getOwnershipState present", true, state.isPresent());
 748         assertEquals("EntityOwnershipState", expState, state.get());
 749     }
 750
 751     private static void verifyCandidates(final AbstractDataStore dataStore, final DOMEntity entity,
 752             final String... expCandidates) throws Exception {
 753         AssertionError lastError = null;
 754         Stopwatch sw = Stopwatch.createStarted();
 755         while (sw.elapsed(TimeUnit.MILLISECONDS) <= 10000) {
 756             Optional<NormalizedNode<?, ?>> possible = dataStore.newReadOnlyTransaction()
 757                     .read(entityPath(entity.getType(), entity.getIdentifier()).node(Candidate.QNAME))
 758                     .get(5, TimeUnit.SECONDS);
 759             try {
 760                 assertEquals("Candidates not found for " + entity, true, possible.isPresent());
 761                 Collection<String> actual = new ArrayList<>();
 762                 for (MapEntryNode candidate: ((MapNode)possible.get()).getValue()) {
 763                     actual.add(candidate.getChild(CANDIDATE_NAME_NODE_ID).get().getValue().toString());
 764                 }
 765
 766                 assertEquals("Candidates for " + entity, Arrays.asList(expCandidates), actual);
 767                 return;
 768             } catch (AssertionError e) {
 769                 lastError = e;
 770                 Uninterruptibles.sleepUninterruptibly(300, TimeUnit.MILLISECONDS);
 771             }
 772         }
 773
 774         throw lastError;
 775     }
 776
 777     @SuppressWarnings("checkstyle:IllegalCatch")
 778     private static void verifyOwner(final AbstractDataStore dataStore, final DOMEntity entity,
 779             final String expOwner) {
 780         AbstractEntityOwnershipTest.verifyOwner(expOwner, entity.getType(), entity.getIdentifier(), path -> {
 781             try {
 782                 return dataStore.newReadOnlyTransaction().read(path).get(5, TimeUnit.SECONDS).get();
 783             } catch (Exception e) {
 784                 return null;
 785             }
 786         });
 787     }
 788 }