opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/shardmanager/ShardManager.java

   1 /*
   2  * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.controller.cluster.datastore.shardmanager;
   9
  10 import static akka.pattern.Patterns.ask;
  11 import static java.util.Objects.requireNonNull;
  12
  13 import akka.actor.ActorRef;
  14 import akka.actor.Address;
  15 import akka.actor.Cancellable;
  16 import akka.actor.OneForOneStrategy;
  17 import akka.actor.PoisonPill;
  18 import akka.actor.Status;
  19 import akka.actor.SupervisorStrategy;
  20 import akka.actor.SupervisorStrategy.Directive;
  21 import akka.cluster.ClusterEvent;
  22 import akka.cluster.ClusterEvent.MemberWeaklyUp;
  23 import akka.cluster.Member;
  24 import akka.dispatch.Futures;
  25 import akka.dispatch.OnComplete;
  26 import akka.japi.Function;
  27 import akka.pattern.Patterns;
  28 import akka.persistence.DeleteSnapshotsFailure;
  29 import akka.persistence.DeleteSnapshotsSuccess;
  30 import akka.persistence.RecoveryCompleted;
  31 import akka.persistence.SaveSnapshotFailure;
  32 import akka.persistence.SaveSnapshotSuccess;
  33 import akka.persistence.SnapshotOffer;
  34 import akka.persistence.SnapshotSelectionCriteria;
  35 import akka.util.Timeout;
  36 import com.google.common.annotations.VisibleForTesting;
  37 import com.google.common.util.concurrent.SettableFuture;
  38 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  39 import java.util.ArrayList;
  40 import java.util.Collection;
  41 import java.util.HashMap;
  42 import java.util.HashSet;
  43 import java.util.List;
  44 import java.util.Map;
  45 import java.util.Map.Entry;
  46 import java.util.Set;
  47 import java.util.concurrent.TimeUnit;
  48 import java.util.concurrent.TimeoutException;
  49 import java.util.function.Consumer;
  50 import java.util.function.Supplier;
  51 import org.opendaylight.controller.cluster.access.concepts.MemberName;
  52 import org.opendaylight.controller.cluster.common.actor.AbstractUntypedPersistentActorWithMetering;
  53 import org.opendaylight.controller.cluster.common.actor.Dispatchers;
  54 import org.opendaylight.controller.cluster.datastore.ClusterWrapper;
  55 import org.opendaylight.controller.cluster.datastore.DatastoreContext;
  56 import org.opendaylight.controller.cluster.datastore.DatastoreContextFactory;
  57 import org.opendaylight.controller.cluster.datastore.Shard;
  58 import org.opendaylight.controller.cluster.datastore.config.Configuration;
  59 import org.opendaylight.controller.cluster.datastore.config.ModuleShardConfiguration;
  60 import org.opendaylight.controller.cluster.datastore.exceptions.AlreadyExistsException;
  61 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
  62 import org.opendaylight.controller.cluster.datastore.exceptions.NotInitializedException;
  63 import org.opendaylight.controller.cluster.datastore.exceptions.PrimaryNotFoundException;
  64 import org.opendaylight.controller.cluster.datastore.identifiers.ShardIdentifier;
  65 import org.opendaylight.controller.cluster.datastore.messages.ActorInitialized;
  66 import org.opendaylight.controller.cluster.datastore.messages.AddShardReplica;
  67 import org.opendaylight.controller.cluster.datastore.messages.ChangeShardMembersVotingStatus;
  68 import org.opendaylight.controller.cluster.datastore.messages.CreateShard;
  69 import org.opendaylight.controller.cluster.datastore.messages.FindLocalShard;
  70 import org.opendaylight.controller.cluster.datastore.messages.FindPrimary;
  71 import org.opendaylight.controller.cluster.datastore.messages.FlipShardMembersVotingStatus;
  72 import org.opendaylight.controller.cluster.datastore.messages.GetShardRole;
  73 import org.opendaylight.controller.cluster.datastore.messages.GetShardRoleReply;
  74 import org.opendaylight.controller.cluster.datastore.messages.LocalPrimaryShardFound;
  75 import org.opendaylight.controller.cluster.datastore.messages.LocalShardFound;
  76 import org.opendaylight.controller.cluster.datastore.messages.LocalShardNotFound;
  77 import org.opendaylight.controller.cluster.datastore.messages.RemoteFindPrimary;
  78 import org.opendaylight.controller.cluster.datastore.messages.RemotePrimaryShardFound;
  79 import org.opendaylight.controller.cluster.datastore.messages.RemoveShardReplica;
  80 import org.opendaylight.controller.cluster.datastore.messages.ShardLeaderStateChanged;
  81 import org.opendaylight.controller.cluster.datastore.messages.UpdateSchemaContext;
  82 import org.opendaylight.controller.cluster.datastore.persisted.DatastoreSnapshot;
  83 import org.opendaylight.controller.cluster.datastore.persisted.ShardManagerSnapshot;
  84 import org.opendaylight.controller.cluster.datastore.utils.CompositeOnComplete;
  85 import org.opendaylight.controller.cluster.datastore.utils.PrimaryShardInfoFutureCache;
  86 import org.opendaylight.controller.cluster.notifications.RegisterRoleChangeListener;
  87 import org.opendaylight.controller.cluster.notifications.RegisterRoleChangeListenerReply;
  88 import org.opendaylight.controller.cluster.notifications.RoleChangeNotification;
  89 import org.opendaylight.controller.cluster.raft.base.messages.FollowerInitialSyncUpStatus;
  90 import org.opendaylight.controller.cluster.raft.base.messages.SwitchBehavior;
  91 import org.opendaylight.controller.cluster.raft.client.messages.GetOnDemandRaftState;
  92 import org.opendaylight.controller.cluster.raft.client.messages.GetSnapshot;
  93 import org.opendaylight.controller.cluster.raft.client.messages.OnDemandRaftState;
  94 import org.opendaylight.controller.cluster.raft.client.messages.Shutdown;
  95 import org.opendaylight.controller.cluster.raft.messages.AddServer;
  96 import org.opendaylight.controller.cluster.raft.messages.AddServerReply;
  97 import org.opendaylight.controller.cluster.raft.messages.ChangeServersVotingStatus;
  98 import org.opendaylight.controller.cluster.raft.messages.RemoveServer;
  99 import org.opendaylight.controller.cluster.raft.messages.RemoveServerReply;
 100 import org.opendaylight.controller.cluster.raft.messages.ServerChangeReply;
 101 import org.opendaylight.controller.cluster.raft.messages.ServerChangeStatus;
 102 import org.opendaylight.controller.cluster.raft.messages.ServerRemoved;
 103 import org.opendaylight.controller.cluster.raft.policy.DisableElectionsRaftPolicy;
 104 import org.opendaylight.yangtools.concepts.Registration;
 105 import org.opendaylight.yangtools.yang.common.Empty;
 106 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
 107 import org.slf4j.Logger;
 108 import org.slf4j.LoggerFactory;
 109 import scala.concurrent.ExecutionContext;
 110 import scala.concurrent.Future;
 111 import scala.concurrent.duration.FiniteDuration;
 112
 113 /**
 114  * Manages the shards for a data store. The ShardManager has the following jobs:
 115  * <ul>
 116  * <li> Create all the local shard replicas that belong on this cluster member
 117  * <li> Find the address of the local shard
 118  * <li> Find the primary replica for any given shard
 119  * <li> Monitor the cluster members and store their addresses
 120  * </ul>
 121  */
 122 class ShardManager extends AbstractUntypedPersistentActorWithMetering {
 123     private static final Logger LOG = LoggerFactory.getLogger(ShardManager.class);
 124
 125     // Stores a mapping between a shard name and it's corresponding information
 126     // Shard names look like inventory, topology etc and are as specified in
 127     // configuration
 128     @VisibleForTesting
 129     final Map<String, ShardInformation> localShards = new HashMap<>();
 130
 131     // The type of a ShardManager reflects the type of the datastore itself
 132     // A data store could be of type config/operational
 133     private final String type;
 134
 135     private final ClusterWrapper cluster;
 136
 137     private final Configuration configuration;
 138
 139     @VisibleForTesting
 140     final String shardDispatcherPath;
 141
 142     private final ShardManagerInfo shardManagerMBean;
 143
 144     private DatastoreContextFactory datastoreContextFactory;
 145
 146     private final SettableFuture<Empty> readinessFuture;
 147
 148     private final PrimaryShardInfoFutureCache primaryShardInfoCache;
 149
 150     @VisibleForTesting
 151     final ShardPeerAddressResolver peerAddressResolver;
 152
 153     private EffectiveModelContext schemaContext;
 154
 155     private DatastoreSnapshot restoreFromSnapshot;
 156
 157     private ShardManagerSnapshot currentSnapshot;
 158
 159     private final Set<String> shardReplicaOperationsInProgress = new HashSet<>();
 160
 161     private final Map<String, CompositeOnComplete<Boolean>> shardActorsStopping = new HashMap<>();
 162
 163     private final Set<Consumer<String>> shardAvailabilityCallbacks = new HashSet<>();
 164
 165     private final String persistenceId;
 166
 167     @SuppressFBWarnings(value = "MC_OVERRIDABLE_METHOD_CALL_IN_CONSTRUCTOR", justification = "Akka class design")
 168     ShardManager(final AbstractShardManagerCreator<?> builder) {
 169         cluster = builder.getCluster();
 170         configuration = builder.getConfiguration();
 171         datastoreContextFactory = builder.getDatastoreContextFactory();
 172         type = datastoreContextFactory.getBaseDatastoreContext().getDataStoreName();
 173         shardDispatcherPath = new Dispatchers(context().system().dispatchers())
 174             .getDispatcherPath(Dispatchers.DispatcherType.Shard);
 175         readinessFuture = builder.getReadinessFuture();
 176         primaryShardInfoCache = builder.getPrimaryShardInfoCache();
 177         restoreFromSnapshot = builder.getRestoreFromSnapshot();
 178
 179         String possiblePersistenceId = datastoreContextFactory.getBaseDatastoreContext().getShardManagerPersistenceId();
 180         persistenceId = possiblePersistenceId != null ? possiblePersistenceId : "shard-manager-" + type;
 181
 182         peerAddressResolver = new ShardPeerAddressResolver(type, cluster.getCurrentMemberName());
 183
 184         // Subscribe this actor to cluster member events
 185         cluster.subscribeToMemberEvents(getSelf());
 186
 187         shardManagerMBean = new ShardManagerInfo(getSelf(), cluster.getCurrentMemberName(),
 188                 "shard-manager-" + type,
 189                 datastoreContextFactory.getBaseDatastoreContext().getDataStoreMXBeanType());
 190         shardManagerMBean.registerMBean();
 191     }
 192
 193     @Override
 194     public void preStart() {
 195         LOG.info("Starting ShardManager {}", persistenceId);
 196     }
 197
 198     @Override
 199     public void postStop() {
 200         LOG.info("Stopping ShardManager {}", persistenceId());
 201
 202         shardManagerMBean.unregisterMBean();
 203     }
 204
 205     @Override
 206     public void handleCommand(final Object message) throws Exception {
 207         if (message  instanceof FindPrimary) {
 208             findPrimary((FindPrimary)message);
 209         } else if (message instanceof FindLocalShard) {
 210             findLocalShard((FindLocalShard) message);
 211         } else if (message instanceof UpdateSchemaContext) {
 212             updateSchemaContext(message);
 213         } else if (message instanceof ActorInitialized) {
 214             onActorInitialized(message);
 215         } else if (message instanceof ClusterEvent.MemberUp) {
 216             memberUp((ClusterEvent.MemberUp) message);
 217         } else if (message instanceof ClusterEvent.MemberWeaklyUp) {
 218             memberWeaklyUp((ClusterEvent.MemberWeaklyUp) message);
 219         } else if (message instanceof ClusterEvent.MemberExited) {
 220             memberExited((ClusterEvent.MemberExited) message);
 221         } else if (message instanceof ClusterEvent.MemberRemoved) {
 222             memberRemoved((ClusterEvent.MemberRemoved) message);
 223         } else if (message instanceof ClusterEvent.UnreachableMember) {
 224             memberUnreachable((ClusterEvent.UnreachableMember) message);
 225         } else if (message instanceof ClusterEvent.ReachableMember) {
 226             memberReachable((ClusterEvent.ReachableMember) message);
 227         } else if (message instanceof DatastoreContextFactory) {
 228             onDatastoreContextFactory((DatastoreContextFactory) message);
 229         } else if (message instanceof RoleChangeNotification) {
 230             onRoleChangeNotification((RoleChangeNotification) message);
 231         } else if (message instanceof FollowerInitialSyncUpStatus) {
 232             onFollowerInitialSyncStatus((FollowerInitialSyncUpStatus) message);
 233         } else if (message instanceof ShardNotInitializedTimeout) {
 234             onShardNotInitializedTimeout((ShardNotInitializedTimeout) message);
 235         } else if (message instanceof ShardLeaderStateChanged) {
 236             onLeaderStateChanged((ShardLeaderStateChanged) message);
 237         } else if (message instanceof SwitchShardBehavior) {
 238             onSwitchShardBehavior((SwitchShardBehavior) message);
 239         } else if (message instanceof CreateShard) {
 240             onCreateShard((CreateShard)message);
 241         } else if (message instanceof AddShardReplica) {
 242             onAddShardReplica((AddShardReplica) message);
 243         } else if (message instanceof ForwardedAddServerReply msg) {
 244             onAddServerReply(msg.shardInfo, msg.addServerReply, getSender(), msg.leaderPath,
 245                     msg.removeShardOnFailure);
 246         } else if (message instanceof ForwardedAddServerFailure msg) {
 247             onAddServerFailure(msg.shardName, msg.failureMessage, msg.failure, getSender(), msg.removeShardOnFailure);
 248         } else if (message instanceof RemoveShardReplica) {
 249             onRemoveShardReplica((RemoveShardReplica) message);
 250         } else if (message instanceof WrappedShardResponse) {
 251             onWrappedShardResponse((WrappedShardResponse) message);
 252         } else if (message instanceof GetSnapshot) {
 253             onGetSnapshot((GetSnapshot) message);
 254         } else if (message instanceof ServerRemoved) {
 255             onShardReplicaRemoved((ServerRemoved) message);
 256         } else if (message instanceof ChangeShardMembersVotingStatus) {
 257             onChangeShardServersVotingStatus((ChangeShardMembersVotingStatus) message);
 258         } else if (message instanceof FlipShardMembersVotingStatus) {
 259             onFlipShardMembersVotingStatus((FlipShardMembersVotingStatus) message);
 260         } else if (message instanceof SaveSnapshotSuccess) {
 261             onSaveSnapshotSuccess((SaveSnapshotSuccess) message);
 262         } else if (message instanceof SaveSnapshotFailure) {
 263             LOG.error("{}: SaveSnapshotFailure received for saving snapshot of shards", persistenceId(),
 264                     ((SaveSnapshotFailure) message).cause());
 265         } else if (message instanceof Shutdown) {
 266             onShutDown();
 267         } else if (message instanceof GetLocalShardIds) {
 268             onGetLocalShardIds();
 269         } else if (message instanceof GetShardRole) {
 270             onGetShardRole((GetShardRole) message);
 271         } else if (message instanceof RunnableMessage) {
 272             ((RunnableMessage)message).run();
 273         } else if (message instanceof RegisterForShardAvailabilityChanges) {
 274             onRegisterForShardAvailabilityChanges((RegisterForShardAvailabilityChanges)message);
 275         } else if (message instanceof DeleteSnapshotsFailure) {
 276             LOG.warn("{}: Failed to delete prior snapshots", persistenceId(),
 277                     ((DeleteSnapshotsFailure) message).cause());
 278         } else if (message instanceof DeleteSnapshotsSuccess) {
 279             LOG.debug("{}: Successfully deleted prior snapshots", persistenceId());
 280         } else if (message instanceof RegisterRoleChangeListenerReply) {
 281             LOG.trace("{}: Received RegisterRoleChangeListenerReply", persistenceId());
 282         } else if (message instanceof ClusterEvent.MemberEvent) {
 283             LOG.trace("{}: Received other ClusterEvent.MemberEvent: {}", persistenceId(), message);
 284         } else {
 285             unknownMessage(message);
 286         }
 287     }
 288
 289     private void onRegisterForShardAvailabilityChanges(final RegisterForShardAvailabilityChanges message) {
 290         LOG.debug("{}: onRegisterForShardAvailabilityChanges: {}", persistenceId(), message);
 291
 292         final Consumer<String> callback = message.getCallback();
 293         shardAvailabilityCallbacks.add(callback);
 294
 295         getSender().tell(new Status.Success((Registration)
 296             () -> executeInSelf(() -> shardAvailabilityCallbacks.remove(callback))), self());
 297     }
 298
 299     private void onGetShardRole(final GetShardRole message) {
 300         LOG.debug("{}: onGetShardRole for shard: {}", persistenceId(), message.getName());
 301
 302         final String name = message.getName();
 303
 304         final ShardInformation shardInformation = localShards.get(name);
 305
 306         if (shardInformation == null) {
 307             LOG.info("{}: no shard information for {} found", persistenceId(), name);
 308             getSender().tell(new Status.Failure(
 309                     new IllegalArgumentException("Shard with name " + name + " not present.")), ActorRef.noSender());
 310             return;
 311         }
 312
 313         getSender().tell(new GetShardRoleReply(shardInformation.getRole()), ActorRef.noSender());
 314     }
 315
 316     void onShutDown() {
 317         List<Future<Boolean>> stopFutures = new ArrayList<>(localShards.size());
 318         for (ShardInformation info : localShards.values()) {
 319             if (info.getActor() != null) {
 320                 LOG.debug("{}: Issuing gracefulStop to shard {}", persistenceId(), info.getShardId());
 321
 322                 FiniteDuration duration = info.getDatastoreContext().getShardRaftConfig()
 323                         .getElectionTimeOutInterval().$times(2);
 324                 stopFutures.add(Patterns.gracefulStop(info.getActor(), duration, Shutdown.INSTANCE));
 325             }
 326         }
 327
 328         LOG.info("Shutting down ShardManager {} - waiting on {} shards", persistenceId(), stopFutures.size());
 329
 330         ExecutionContext dispatcher = new Dispatchers(context().system().dispatchers())
 331                 .getDispatcher(Dispatchers.DispatcherType.Client);
 332         Future<Iterable<Boolean>> combinedFutures = Futures.sequence(stopFutures, dispatcher);
 333
 334         combinedFutures.onComplete(new OnComplete<Iterable<Boolean>>() {
 335             @Override
 336             public void onComplete(final Throwable failure, final Iterable<Boolean> results) {
 337                 LOG.debug("{}: All shards shutdown - sending PoisonPill to self", persistenceId());
 338
 339                 self().tell(PoisonPill.getInstance(), self());
 340
 341                 if (failure != null) {
 342                     LOG.warn("{}: An error occurred attempting to shut down the shards", persistenceId(), failure);
 343                 } else {
 344                     int nfailed = 0;
 345                     for (Boolean result : results) {
 346                         if (!result) {
 347                             nfailed++;
 348                         }
 349                     }
 350
 351                     if (nfailed > 0) {
 352                         LOG.warn("{}: {} shards did not shut down gracefully", persistenceId(), nfailed);
 353                     }
 354                 }
 355             }
 356         }, dispatcher);
 357     }
 358
 359     private void onWrappedShardResponse(final WrappedShardResponse message) {
 360         if (message.getResponse() instanceof RemoveServerReply) {
 361             onRemoveServerReply(getSender(), message.getShardId(), (RemoveServerReply) message.getResponse(),
 362                     message.getLeaderPath());
 363         }
 364     }
 365
 366     private void onRemoveServerReply(final ActorRef originalSender, final ShardIdentifier shardId,
 367             final RemoveServerReply replyMsg, final String leaderPath) {
 368         shardReplicaOperationsInProgress.remove(shardId.getShardName());
 369
 370         LOG.debug("{}: Received {} for shard {}", persistenceId(), replyMsg, shardId.getShardName());
 371
 372         if (replyMsg.getStatus() == ServerChangeStatus.OK) {
 373             LOG.debug("{}: Leader shard successfully removed the replica shard {}", persistenceId(),
 374                     shardId.getShardName());
 375             originalSender.tell(new Status.Success(null), getSelf());
 376         } else {
 377             LOG.warn("{}: Leader failed to remove shard replica {} with status {}",
 378                     persistenceId(), shardId, replyMsg.getStatus());
 379
 380             Exception failure = getServerChangeException(RemoveServer.class, replyMsg.getStatus(), leaderPath, shardId);
 381             originalSender.tell(new Status.Failure(failure), getSelf());
 382         }
 383     }
 384
 385     private void removeShardReplica(final RemoveShardReplica contextMessage, final String shardName,
 386             final String primaryPath, final ActorRef sender) {
 387         if (isShardReplicaOperationInProgress(shardName, sender)) {
 388             return;
 389         }
 390
 391         shardReplicaOperationsInProgress.add(shardName);
 392
 393         final ShardIdentifier shardId = getShardIdentifier(contextMessage.getMemberName(), shardName);
 394
 395         final DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName).build();
 396
 397         //inform ShardLeader to remove this shard as a replica by sending an RemoveServer message
 398         LOG.debug("{}: Sending RemoveServer message to peer {} for shard {}", persistenceId(),
 399                 primaryPath, shardId);
 400
 401         Timeout removeServerTimeout = new Timeout(datastoreContext.getShardLeaderElectionTimeout().duration());
 402         Future<Object> futureObj = ask(getContext().actorSelection(primaryPath),
 403                 new RemoveServer(shardId.toString()), removeServerTimeout);
 404
 405         futureObj.onComplete(new OnComplete<>() {
 406             @Override
 407             public void onComplete(final Throwable failure, final Object response) {
 408                 if (failure != null) {
 409                     shardReplicaOperationsInProgress.remove(shardName);
 410                     LOG.debug("{}: RemoveServer request to leader {} for shard {} failed", persistenceId(), primaryPath,
 411                         shardName, failure);
 412
 413                     // FAILURE
 414                     sender.tell(new Status.Failure(new RuntimeException(
 415                         String.format("RemoveServer request to leader %s for shard %s failed", primaryPath, shardName),
 416                         failure)), self());
 417                 } else {
 418                     // SUCCESS
 419                     self().tell(new WrappedShardResponse(shardId, response, primaryPath), sender);
 420                 }
 421             }
 422         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
 423     }
 424
 425     private void onShardReplicaRemoved(final ServerRemoved message) {
 426         removeShard(new ShardIdentifier.Builder().fromShardIdString(message.getServerId()).build());
 427     }
 428
 429     @SuppressWarnings("checkstyle:IllegalCatch")
 430     private void removeShard(final ShardIdentifier shardId) {
 431         final String shardName = shardId.getShardName();
 432         final ShardInformation shardInformation = localShards.remove(shardName);
 433         if (shardInformation == null) {
 434             LOG.debug("{} : Shard replica {} is not present in list", persistenceId(), shardId.toString());
 435             return;
 436         }
 437
 438         final ActorRef shardActor = shardInformation.getActor();
 439         if (shardActor != null) {
 440             long timeoutInMS = Math.max(shardInformation.getDatastoreContext().getShardRaftConfig()
 441                     .getElectionTimeOutInterval().$times(3).toMillis(), 10000);
 442
 443             LOG.debug("{} : Sending Shutdown to Shard actor {} with {} ms timeout", persistenceId(), shardActor,
 444                     timeoutInMS);
 445
 446             final Future<Boolean> stopFuture = Patterns.gracefulStop(shardActor,
 447                     FiniteDuration.apply(timeoutInMS, TimeUnit.MILLISECONDS), Shutdown.INSTANCE);
 448
 449             final CompositeOnComplete<Boolean> onComplete = new CompositeOnComplete<>() {
 450                 @Override
 451                 public void onComplete(final Throwable failure, final Boolean result) {
 452                     if (failure == null) {
 453                         LOG.debug("{} : Successfully shut down Shard actor {}", persistenceId(), shardActor);
 454                     } else {
 455                         LOG.warn("{}: Failed to shut down Shard actor {}", persistenceId(), shardActor, failure);
 456                     }
 457
 458                     self().tell((RunnableMessage) () -> {
 459                         // At any rate, invalidate primaryShardInfo cache
 460                         primaryShardInfoCache.remove(shardName);
 461
 462                         shardActorsStopping.remove(shardName);
 463                         notifyOnCompleteTasks(failure, result);
 464                     }, ActorRef.noSender());
 465                 }
 466             };
 467
 468             shardActorsStopping.put(shardName, onComplete);
 469             stopFuture.onComplete(onComplete, new Dispatchers(context().system().dispatchers())
 470                     .getDispatcher(Dispatchers.DispatcherType.Client));
 471         }
 472
 473         LOG.debug("{} : Local Shard replica for shard {} has been removed", persistenceId(), shardName);
 474         persistShardList();
 475     }
 476
 477     private void onGetSnapshot(final GetSnapshot getSnapshot) {
 478         LOG.debug("{}: onGetSnapshot", persistenceId());
 479
 480         List<String> notInitialized = null;
 481         for (ShardInformation shardInfo : localShards.values()) {
 482             if (!shardInfo.isShardInitialized()) {
 483                 if (notInitialized == null) {
 484                     notInitialized = new ArrayList<>();
 485                 }
 486
 487                 notInitialized.add(shardInfo.getShardName());
 488             }
 489         }
 490
 491         if (notInitialized != null) {
 492             getSender().tell(new Status.Failure(new IllegalStateException(String.format(
 493                     "%d shard(s) %s are not initialized", notInitialized.size(), notInitialized))), getSelf());
 494             return;
 495         }
 496
 497         ActorRef replyActor = getContext().actorOf(ShardManagerGetSnapshotReplyActor.props(
 498                 new ArrayList<>(localShards.keySet()), type, currentSnapshot , getSender(), persistenceId(),
 499                 datastoreContextFactory.getBaseDatastoreContext().getShardInitializationTimeout().duration()));
 500
 501         for (ShardInformation shardInfo: localShards.values()) {
 502             shardInfo.getActor().tell(getSnapshot, replyActor);
 503         }
 504     }
 505
 506     @SuppressWarnings("checkstyle:IllegalCatch")
 507     private void onCreateShard(final CreateShard createShard) {
 508         LOG.debug("{}: onCreateShard: {}", persistenceId(), createShard);
 509
 510         Object reply;
 511         try {
 512             String shardName = createShard.getModuleShardConfig().getShardName();
 513             if (localShards.containsKey(shardName)) {
 514                 LOG.debug("{}: Shard {} already exists", persistenceId(), shardName);
 515                 reply = new Status.Success(String.format("Shard with name %s already exists", shardName));
 516             } else {
 517                 doCreateShard(createShard);
 518                 reply = new Status.Success(null);
 519             }
 520         } catch (Exception e) {
 521             LOG.error("{}: onCreateShard failed", persistenceId(), e);
 522             reply = new Status.Failure(e);
 523         }
 524
 525         if (getSender() != null && !getContext().system().deadLetters().equals(getSender())) {
 526             getSender().tell(reply, getSelf());
 527         }
 528     }
 529
 530     private boolean isPreviousShardActorStopInProgress(final String shardName, final Object messageToDefer) {
 531         final CompositeOnComplete<Boolean> stopOnComplete = shardActorsStopping.get(shardName);
 532         if (stopOnComplete == null) {
 533             return false;
 534         }
 535
 536         LOG.debug("{} : Stop is in progress for shard {} - adding OnComplete callback to defer {}", persistenceId(),
 537                 shardName, messageToDefer);
 538         final ActorRef sender = getSender();
 539         stopOnComplete.addOnComplete(new OnComplete<Boolean>() {
 540             @Override
 541             public void onComplete(final Throwable failure, final Boolean result) {
 542                 LOG.debug("{} : Stop complete for shard {} - re-queing {}", persistenceId(), shardName, messageToDefer);
 543                 self().tell(messageToDefer, sender);
 544             }
 545         });
 546
 547         return true;
 548     }
 549
 550     private void doCreateShard(final CreateShard createShard) {
 551         final ModuleShardConfiguration moduleShardConfig = createShard.getModuleShardConfig();
 552         final String shardName = moduleShardConfig.getShardName();
 553
 554         configuration.addModuleShardConfiguration(moduleShardConfig);
 555
 556         DatastoreContext shardDatastoreContext = createShard.getDatastoreContext();
 557         if (shardDatastoreContext == null) {
 558             shardDatastoreContext = newShardDatastoreContext(shardName);
 559         } else {
 560             shardDatastoreContext = DatastoreContext.newBuilderFrom(shardDatastoreContext).shardPeerAddressResolver(
 561                     peerAddressResolver).build();
 562         }
 563
 564         ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
 565
 566         boolean shardWasInRecoveredSnapshot = currentSnapshot != null
 567                 && currentSnapshot.getShardList().contains(shardName);
 568
 569         Map<String, String> peerAddresses;
 570         boolean isActiveMember;
 571         if (shardWasInRecoveredSnapshot || configuration.getMembersFromShardName(shardName)
 572                 .contains(cluster.getCurrentMemberName())) {
 573             peerAddresses = getPeerAddresses(shardName);
 574             isActiveMember = true;
 575         } else {
 576             // The local member is not in the static shard member configuration and the shard did not
 577             // previously exist (ie !shardWasInRecoveredSnapshot). In this case we'll create
 578             // the shard with no peers and with elections disabled so it stays as follower. A
 579             // subsequent AddServer request will be needed to make it an active member.
 580             isActiveMember = false;
 581             peerAddresses = Map.of();
 582             shardDatastoreContext = DatastoreContext.newBuilderFrom(shardDatastoreContext)
 583                     .customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName()).build();
 584         }
 585
 586         LOG.debug("{} doCreateShard: shardId: {}, memberNames: {}, peerAddresses: {}, isActiveMember: {}",
 587                 persistenceId(), shardId, moduleShardConfig.getShardMemberNames(), peerAddresses,
 588                 isActiveMember);
 589
 590         ShardInformation info = new ShardInformation(shardName, shardId, peerAddresses,
 591                 shardDatastoreContext, createShard.getShardBuilder(), peerAddressResolver);
 592         info.setActiveMember(isActiveMember);
 593         localShards.put(info.getShardName(), info);
 594
 595         if (schemaContext != null) {
 596             info.setSchemaContext(schemaContext);
 597             info.setActor(newShardActor(info));
 598         }
 599     }
 600
 601     private DatastoreContext.Builder newShardDatastoreContextBuilder(final String shardName) {
 602         return DatastoreContext.newBuilderFrom(datastoreContextFactory.getShardDatastoreContext(shardName))
 603                 .shardPeerAddressResolver(peerAddressResolver);
 604     }
 605
 606     private DatastoreContext newShardDatastoreContext(final String shardName) {
 607         return newShardDatastoreContextBuilder(shardName).build();
 608     }
 609
 610     private void checkReady() {
 611         if (isReadyWithLeaderId()) {
 612             LOG.info("{}: All Shards are ready - data store {} is ready", persistenceId(), type);
 613             readinessFuture.set(Empty.value());
 614         }
 615     }
 616
 617     private void onLeaderStateChanged(final ShardLeaderStateChanged leaderStateChanged) {
 618         LOG.info("{}: Received LeaderStateChanged message: {}", persistenceId(), leaderStateChanged);
 619
 620         ShardInformation shardInformation = findShardInformation(leaderStateChanged.getMemberId());
 621         if (shardInformation != null) {
 622             shardInformation.setLocalDataTree(leaderStateChanged.getLocalShardDataTree());
 623             shardInformation.setLeaderVersion(leaderStateChanged.getLeaderPayloadVersion());
 624             if (shardInformation.setLeaderId(leaderStateChanged.getLeaderId())) {
 625                 primaryShardInfoCache.remove(shardInformation.getShardName());
 626
 627                 notifyShardAvailabilityCallbacks(shardInformation);
 628             }
 629
 630             checkReady();
 631         } else {
 632             LOG.debug("No shard found with member Id {}", leaderStateChanged.getMemberId());
 633         }
 634     }
 635
 636     private void notifyShardAvailabilityCallbacks(final ShardInformation shardInformation) {
 637         shardAvailabilityCallbacks.forEach(callback -> callback.accept(shardInformation.getShardName()));
 638     }
 639
 640     private void onShardNotInitializedTimeout(final ShardNotInitializedTimeout message) {
 641         ShardInformation shardInfo = message.getShardInfo();
 642
 643         LOG.debug("{}: Received ShardNotInitializedTimeout message for shard {}", persistenceId(),
 644                 shardInfo.getShardName());
 645
 646         shardInfo.removeOnShardInitialized(message.getOnShardInitialized());
 647
 648         if (!shardInfo.isShardInitialized()) {
 649             LOG.debug("{}: Returning NotInitializedException for shard {}", persistenceId(), shardInfo.getShardName());
 650             message.getSender().tell(createNotInitializedException(shardInfo.getShardId()), getSelf());
 651         } else {
 652             LOG.debug("{}: Returning NoShardLeaderException for shard {}", persistenceId(), shardInfo.getShardName());
 653             message.getSender().tell(new NoShardLeaderException(shardInfo.getShardId()), getSelf());
 654         }
 655     }
 656
 657     private void onFollowerInitialSyncStatus(final FollowerInitialSyncUpStatus status) {
 658         LOG.info("{} Received follower initial sync status for {} status sync done {}", persistenceId(),
 659                 status.getName(), status.isInitialSyncDone());
 660
 661         ShardInformation shardInformation = findShardInformation(status.getName());
 662
 663         if (shardInformation != null) {
 664             shardInformation.setFollowerSyncStatus(status.isInitialSyncDone());
 665
 666             shardManagerMBean.setSyncStatus(isInSync());
 667         }
 668
 669     }
 670
 671     private void onRoleChangeNotification(final RoleChangeNotification roleChanged) {
 672         LOG.info("{}: Received role changed for {} from {} to {}", persistenceId(), roleChanged.getMemberId(),
 673                 roleChanged.getOldRole(), roleChanged.getNewRole());
 674
 675         ShardInformation shardInformation = findShardInformation(roleChanged.getMemberId());
 676         if (shardInformation != null) {
 677             shardInformation.setRole(roleChanged.getNewRole());
 678             checkReady();
 679             shardManagerMBean.setSyncStatus(isInSync());
 680         }
 681     }
 682
 683
 684     private ShardInformation findShardInformation(final String memberId) {
 685         for (ShardInformation info : localShards.values()) {
 686             if (info.getShardId().toString().equals(memberId)) {
 687                 return info;
 688             }
 689         }
 690
 691         return null;
 692     }
 693
 694     private boolean isReadyWithLeaderId() {
 695         boolean isReady = true;
 696         for (ShardInformation info : localShards.values()) {
 697             if (!info.isShardReadyWithLeaderId()) {
 698                 isReady = false;
 699                 break;
 700             }
 701         }
 702         return isReady;
 703     }
 704
 705     private boolean isInSync() {
 706         for (ShardInformation info : localShards.values()) {
 707             if (!info.isInSync()) {
 708                 return false;
 709             }
 710         }
 711         return true;
 712     }
 713
 714     private void onActorInitialized(final Object message) {
 715         final ActorRef sender = getSender();
 716
 717         if (sender == null) {
 718             // why is a non-actor sending this message? Just ignore.
 719             return;
 720         }
 721
 722         String actorName = sender.path().name();
 723         //find shard name from actor name; actor name is stringified shardId
 724
 725         final ShardIdentifier shardId;
 726         try {
 727             shardId = ShardIdentifier.fromShardIdString(actorName);
 728         } catch (IllegalArgumentException e) {
 729             LOG.debug("{}: ignoring actor {}", persistenceId, actorName, e);
 730             return;
 731         }
 732
 733         markShardAsInitialized(shardId.getShardName());
 734     }
 735
 736     private void markShardAsInitialized(final String shardName) {
 737         LOG.debug("{}: Initializing shard [{}]", persistenceId(), shardName);
 738
 739         ShardInformation shardInformation = localShards.get(shardName);
 740         if (shardInformation != null) {
 741             shardInformation.setActorInitialized();
 742
 743             shardInformation.getActor().tell(new RegisterRoleChangeListener(), self());
 744         }
 745     }
 746
 747     @Override
 748     protected void handleRecover(final Object message) throws Exception {
 749         if (message instanceof RecoveryCompleted) {
 750             onRecoveryCompleted();
 751         } else if (message instanceof SnapshotOffer) {
 752             applyShardManagerSnapshot((ShardManagerSnapshot)((SnapshotOffer) message).snapshot());
 753         }
 754     }
 755
 756     @SuppressWarnings("checkstyle:IllegalCatch")
 757     private void onRecoveryCompleted() {
 758         LOG.info("Recovery complete : {}", persistenceId());
 759
 760         if (currentSnapshot == null && restoreFromSnapshot != null
 761                 && restoreFromSnapshot.getShardManagerSnapshot() != null) {
 762             ShardManagerSnapshot snapshot = restoreFromSnapshot.getShardManagerSnapshot();
 763
 764             LOG.debug("{}: Restoring from ShardManagerSnapshot: {}", persistenceId(), snapshot);
 765
 766             applyShardManagerSnapshot(snapshot);
 767         }
 768
 769         createLocalShards();
 770     }
 771
 772     private void sendResponse(final ShardInformation shardInformation, final boolean doWait,
 773             final boolean wantShardReady, final Supplier<Object> messageSupplier) {
 774         if (!shardInformation.isShardInitialized() || wantShardReady && !shardInformation.isShardReadyWithLeaderId()) {
 775             if (doWait) {
 776                 final ActorRef sender = getSender();
 777                 final ActorRef self = self();
 778
 779                 Runnable replyRunnable = () -> sender.tell(messageSupplier.get(), self);
 780
 781                 OnShardInitialized onShardInitialized = wantShardReady ? new OnShardReady(replyRunnable) :
 782                     new OnShardInitialized(replyRunnable);
 783
 784                 shardInformation.addOnShardInitialized(onShardInitialized);
 785
 786                 FiniteDuration timeout = shardInformation.getDatastoreContext()
 787                         .getShardInitializationTimeout().duration();
 788                 if (shardInformation.isShardInitialized()) {
 789                     // If the shard is already initialized then we'll wait enough time for the shard to
 790                     // elect a leader, ie 2 times the election timeout.
 791                     timeout = FiniteDuration.create(shardInformation.getDatastoreContext().getShardRaftConfig()
 792                             .getElectionTimeOutInterval().toMillis() * 2, TimeUnit.MILLISECONDS);
 793                 }
 794
 795                 LOG.debug("{}: Scheduling {} ms timer to wait for shard {}", persistenceId(), timeout.toMillis(),
 796                         shardInformation);
 797
 798                 Cancellable timeoutSchedule = getContext().system().scheduler().scheduleOnce(
 799                         timeout, getSelf(),
 800                         new ShardNotInitializedTimeout(shardInformation, onShardInitialized, sender),
 801                         getContext().dispatcher(), getSelf());
 802
 803                 onShardInitialized.setTimeoutSchedule(timeoutSchedule);
 804
 805             } else if (!shardInformation.isShardInitialized()) {
 806                 LOG.debug("{}: Returning NotInitializedException for shard {}", persistenceId(),
 807                         shardInformation.getShardName());
 808                 getSender().tell(createNotInitializedException(shardInformation.getShardId()), getSelf());
 809             } else {
 810                 LOG.debug("{}: Returning NoShardLeaderException for shard {}", persistenceId(),
 811                         shardInformation.getShardName());
 812                 getSender().tell(new NoShardLeaderException(shardInformation.getShardId()), getSelf());
 813             }
 814
 815             return;
 816         }
 817
 818         getSender().tell(messageSupplier.get(), getSelf());
 819     }
 820
 821     private static NotInitializedException createNotInitializedException(final ShardIdentifier shardId) {
 822         return new NotInitializedException(String.format(
 823                 "Found primary shard %s but it's not initialized yet. Please try again later", shardId));
 824     }
 825
 826     @VisibleForTesting
 827     static MemberName memberToName(final Member member) {
 828         return MemberName.forName(member.roles().iterator().next());
 829     }
 830
 831     private void memberRemoved(final ClusterEvent.MemberRemoved message) {
 832         MemberName memberName = memberToName(message.member());
 833
 834         LOG.info("{}: Received MemberRemoved: memberName: {}, address: {}", persistenceId(), memberName,
 835                 message.member().address());
 836
 837         peerAddressResolver.removePeerAddress(memberName);
 838     }
 839
 840     private void memberExited(final ClusterEvent.MemberExited message) {
 841         MemberName memberName = memberToName(message.member());
 842
 843         LOG.info("{}: Received MemberExited: memberName: {}, address: {}", persistenceId(), memberName,
 844                 message.member().address());
 845
 846         peerAddressResolver.removePeerAddress(memberName);
 847     }
 848
 849     private void memberUp(final ClusterEvent.MemberUp message) {
 850         MemberName memberName = memberToName(message.member());
 851
 852         LOG.info("{}: Received MemberUp: memberName: {}, address: {}", persistenceId(), memberName,
 853                 message.member().address());
 854
 855         memberUp(memberName, message.member().address());
 856     }
 857
 858     private void memberUp(final MemberName memberName, final Address address) {
 859         addPeerAddress(memberName, address);
 860         checkReady();
 861     }
 862
 863     private void memberWeaklyUp(final MemberWeaklyUp message) {
 864         MemberName memberName = memberToName(message.member());
 865
 866         LOG.info("{}: Received MemberWeaklyUp: memberName: {}, address: {}", persistenceId(), memberName,
 867                 message.member().address());
 868
 869         memberUp(memberName, message.member().address());
 870     }
 871
 872     private void addPeerAddress(final MemberName memberName, final Address address) {
 873         peerAddressResolver.addPeerAddress(memberName, address);
 874
 875         for (ShardInformation info : localShards.values()) {
 876             String shardName = info.getShardName();
 877             String peerId = getShardIdentifier(memberName, shardName).toString();
 878             info.updatePeerAddress(peerId, peerAddressResolver.getShardActorAddress(shardName, memberName), getSelf());
 879         }
 880     }
 881
 882     private void memberReachable(final ClusterEvent.ReachableMember message) {
 883         MemberName memberName = memberToName(message.member());
 884         LOG.info("Received ReachableMember: memberName {}, address: {}", memberName, message.member().address());
 885
 886         addPeerAddress(memberName, message.member().address());
 887
 888         markMemberAvailable(memberName);
 889     }
 890
 891     private void memberUnreachable(final ClusterEvent.UnreachableMember message) {
 892         MemberName memberName = memberToName(message.member());
 893         LOG.info("Received UnreachableMember: memberName {}, address: {}", memberName, message.member().address());
 894
 895         markMemberUnavailable(memberName);
 896     }
 897
 898     private void markMemberUnavailable(final MemberName memberName) {
 899         for (ShardInformation info : localShards.values()) {
 900             String leaderId = info.getLeaderId();
 901             if (leaderId != null && ShardIdentifier.fromShardIdString(leaderId).getMemberName().equals(memberName)) {
 902                 LOG.debug("Marking Leader {} as unavailable.", leaderId);
 903                 info.setLeaderAvailable(false);
 904
 905                 primaryShardInfoCache.remove(info.getShardName());
 906
 907                 notifyShardAvailabilityCallbacks(info);
 908             }
 909         }
 910     }
 911
 912     private void markMemberAvailable(final MemberName memberName) {
 913         for (ShardInformation info : localShards.values()) {
 914             String leaderId = info.getLeaderId();
 915             if (leaderId != null && ShardIdentifier.fromShardIdString(leaderId).getMemberName().equals(memberName)) {
 916                 LOG.debug("Marking Leader {} as available.", leaderId);
 917                 info.setLeaderAvailable(true);
 918             }
 919         }
 920     }
 921
 922     private void onDatastoreContextFactory(final DatastoreContextFactory factory) {
 923         datastoreContextFactory = factory;
 924         for (ShardInformation info : localShards.values()) {
 925             info.setDatastoreContext(newShardDatastoreContext(info.getShardName()), getSelf());
 926         }
 927     }
 928
 929     private void onGetLocalShardIds() {
 930         final List<String> response = new ArrayList<>(localShards.size());
 931
 932         for (ShardInformation info : localShards.values()) {
 933             response.add(info.getShardId().toString());
 934         }
 935
 936         getSender().tell(new Status.Success(response), getSelf());
 937     }
 938
 939     private void onSwitchShardBehavior(final SwitchShardBehavior message) {
 940         final ShardIdentifier identifier = message.getShardId();
 941
 942         if (identifier != null) {
 943             final ShardInformation info = localShards.get(identifier.getShardName());
 944             if (info == null) {
 945                 getSender().tell(new Status.Failure(
 946                     new IllegalArgumentException("Shard " + identifier + " is not local")), getSelf());
 947                 return;
 948             }
 949
 950             switchShardBehavior(info, new SwitchBehavior(message.getNewState(), message.getTerm()));
 951         } else {
 952             for (ShardInformation info : localShards.values()) {
 953                 switchShardBehavior(info, new SwitchBehavior(message.getNewState(), message.getTerm()));
 954             }
 955         }
 956
 957         getSender().tell(new Status.Success(null), getSelf());
 958     }
 959
 960     private void switchShardBehavior(final ShardInformation info, final SwitchBehavior switchBehavior) {
 961         final ActorRef actor = info.getActor();
 962         if (actor != null) {
 963             actor.tell(switchBehavior, getSelf());
 964         } else {
 965             LOG.warn("Could not switch the behavior of shard {} to {} - shard is not yet available",
 966                 info.getShardName(), switchBehavior.getNewState());
 967         }
 968     }
 969
 970     /**
 971      * Notifies all the local shards of a change in the schema context.
 972      *
 973      * @param message the message to send
 974      */
 975     private void updateSchemaContext(final Object message) {
 976         schemaContext = ((UpdateSchemaContext) message).getEffectiveModelContext();
 977
 978         LOG.debug("Got updated SchemaContext: # of modules {}", schemaContext.getModules().size());
 979
 980         for (ShardInformation info : localShards.values()) {
 981             info.setSchemaContext(schemaContext);
 982
 983             if (info.getActor() == null) {
 984                 LOG.debug("Creating Shard {}", info.getShardId());
 985                 info.setActor(newShardActor(info));
 986                 // Update peer address for every existing peer memeber to avoid missing sending
 987                 // PeerAddressResolved and PeerUp to this shard while UpdateSchemaContext comes after MemberUp.
 988                 String shardName = info.getShardName();
 989                 for (MemberName memberName : peerAddressResolver.getPeerMembers()) {
 990                     String peerId = getShardIdentifier(memberName, shardName).toString() ;
 991                     String peerAddress = peerAddressResolver.getShardActorAddress(shardName, memberName);
 992                     info.updatePeerAddress(peerId, peerAddress, getSelf());
 993                     LOG.debug("{}: updated peer {} on member {} with address {} on shard {} whose actor address is {}",
 994                             persistenceId(), peerId, memberName, peerAddress, info.getShardId(), info.getActor());
 995                 }
 996             } else {
 997                 info.getActor().tell(message, getSelf());
 998             }
 999         }
1000     }
1001
1002     @VisibleForTesting
1003     protected ClusterWrapper getCluster() {
1004         return cluster;
1005     }
1006
1007     @VisibleForTesting
1008     protected ActorRef newShardActor(final ShardInformation info) {
1009         return getContext().actorOf(info.newProps().withDispatcher(shardDispatcherPath),
1010                 info.getShardId().toString());
1011     }
1012
1013     private void findPrimary(final FindPrimary message) {
1014         LOG.debug("{}: In findPrimary: {}", persistenceId(), message);
1015
1016         final String shardName = message.getShardName();
1017         final boolean canReturnLocalShardState = !(message instanceof RemoteFindPrimary);
1018
1019         // First see if the there is a local replica for the shard
1020         final ShardInformation info = localShards.get(shardName);
1021         if (info != null && info.isActiveMember()) {
1022             sendResponse(info, message.isWaitUntilReady(), true, () -> {
1023                 String primaryPath = info.getSerializedLeaderActor();
1024                 Object found = canReturnLocalShardState && info.isLeader()
1025                         ? new LocalPrimaryShardFound(primaryPath, info.getLocalShardDataTree().orElseThrow()) :
1026                             new RemotePrimaryShardFound(primaryPath, info.getLeaderVersion());
1027
1028                 LOG.debug("{}: Found primary for {}: {}", persistenceId(), shardName, found);
1029                 return found;
1030             });
1031
1032             return;
1033         }
1034
1035         final Collection<String> visitedAddresses;
1036         if (message instanceof RemoteFindPrimary) {
1037             visitedAddresses = ((RemoteFindPrimary)message).getVisitedAddresses();
1038         } else {
1039             visitedAddresses = new ArrayList<>(1);
1040         }
1041
1042         visitedAddresses.add(peerAddressResolver.getShardManagerActorPathBuilder(cluster.getSelfAddress()).toString());
1043
1044         for (String address: peerAddressResolver.getShardManagerPeerActorAddresses()) {
1045             if (visitedAddresses.contains(address)) {
1046                 continue;
1047             }
1048
1049             LOG.debug("{}: findPrimary for {} forwarding to remote ShardManager {}, visitedAddresses: {}",
1050                     persistenceId(), shardName, address, visitedAddresses);
1051
1052             getContext().actorSelection(address).forward(new RemoteFindPrimary(shardName,
1053                     message.isWaitUntilReady(), visitedAddresses), getContext());
1054             return;
1055         }
1056
1057         LOG.debug("{}: No shard found for {}", persistenceId(), shardName);
1058
1059         getSender().tell(new PrimaryNotFoundException(
1060                 String.format("No primary shard found for %s.", shardName)), getSelf());
1061     }
1062
1063     private void findPrimary(final String shardName, final FindPrimaryResponseHandler handler) {
1064         Timeout findPrimaryTimeout = new Timeout(datastoreContextFactory.getBaseDatastoreContext()
1065                 .getShardInitializationTimeout().duration().$times(2));
1066
1067         Future<Object> futureObj = ask(getSelf(), new FindPrimary(shardName, true), findPrimaryTimeout);
1068         futureObj.onComplete(new OnComplete<>() {
1069             @Override
1070             public void onComplete(final Throwable failure, final Object response) {
1071                 if (failure != null) {
1072                     handler.onFailure(failure);
1073                 } else {
1074                     if (response instanceof RemotePrimaryShardFound) {
1075                         handler.onRemotePrimaryShardFound((RemotePrimaryShardFound) response);
1076                     } else if (response instanceof LocalPrimaryShardFound) {
1077                         handler.onLocalPrimaryFound((LocalPrimaryShardFound) response);
1078                     } else {
1079                         handler.onUnknownResponse(response);
1080                     }
1081                 }
1082             }
1083         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1084     }
1085
1086     /**
1087      * Construct the name of the shard actor given the name of the member on
1088      * which the shard resides and the name of the shard.
1089      *
1090      * @param memberName the member name
1091      * @param shardName the shard name
1092      * @return a b
1093      */
1094     private ShardIdentifier getShardIdentifier(final MemberName memberName, final String shardName) {
1095         return peerAddressResolver.getShardIdentifier(memberName, shardName);
1096     }
1097
1098     /**
1099      * Create shards that are local to the member on which the ShardManager runs.
1100      */
1101     private void createLocalShards() {
1102         MemberName memberName = cluster.getCurrentMemberName();
1103         Collection<String> memberShardNames = configuration.getMemberShardNames(memberName);
1104
1105         Map<String, DatastoreSnapshot.ShardSnapshot> shardSnapshots = new HashMap<>();
1106         if (restoreFromSnapshot != null) {
1107             for (DatastoreSnapshot.ShardSnapshot snapshot: restoreFromSnapshot.getShardSnapshots()) {
1108                 shardSnapshots.put(snapshot.getName(), snapshot);
1109             }
1110         }
1111
1112         // null out to GC
1113         restoreFromSnapshot = null;
1114
1115         for (String shardName : memberShardNames) {
1116             ShardIdentifier shardId = getShardIdentifier(memberName, shardName);
1117
1118             LOG.debug("{}: Creating local shard: {}", persistenceId(), shardId);
1119
1120             Map<String, String> peerAddresses = getPeerAddresses(shardName);
1121             localShards.put(shardName, createShardInfoFor(shardName, shardId, peerAddresses,
1122                     newShardDatastoreContext(shardName), shardSnapshots));
1123         }
1124     }
1125
1126     @VisibleForTesting
1127     ShardInformation createShardInfoFor(final String shardName, final ShardIdentifier shardId,
1128                                         final Map<String, String> peerAddresses,
1129                                         final DatastoreContext datastoreContext,
1130                                         final Map<String, DatastoreSnapshot.ShardSnapshot> shardSnapshots) {
1131         return new ShardInformation(shardName, shardId, peerAddresses,
1132                 datastoreContext, Shard.builder().restoreFromSnapshot(shardSnapshots.get(shardName)),
1133                 peerAddressResolver);
1134     }
1135
1136     /**
1137      * Given the name of the shard find the addresses of all it's peers.
1138      *
1139      * @param shardName the shard name
1140      */
1141     Map<String, String> getPeerAddresses(final String shardName) {
1142         final Collection<MemberName> members = configuration.getMembersFromShardName(shardName);
1143         return getPeerAddresses(shardName, members);
1144     }
1145
1146     private Map<String, String> getPeerAddresses(final String shardName, final Collection<MemberName> members) {
1147         Map<String, String> peerAddresses = new HashMap<>();
1148         MemberName currentMemberName = cluster.getCurrentMemberName();
1149
1150         for (MemberName memberName : members) {
1151             if (!currentMemberName.equals(memberName)) {
1152                 ShardIdentifier shardId = getShardIdentifier(memberName, shardName);
1153                 String address = peerAddressResolver.getShardActorAddress(shardName, memberName);
1154                 peerAddresses.put(shardId.toString(), address);
1155             }
1156         }
1157         return peerAddresses;
1158     }
1159
1160     @Override
1161     public SupervisorStrategy supervisorStrategy() {
1162
1163         return new OneForOneStrategy(10, FiniteDuration.create(1, TimeUnit.MINUTES),
1164                 (Function<Throwable, Directive>) t -> {
1165                     LOG.warn("Supervisor Strategy caught unexpected exception - resuming", t);
1166                     return SupervisorStrategy.resume();
1167                 });
1168     }
1169
1170     @Override
1171     public String persistenceId() {
1172         return persistenceId;
1173     }
1174
1175     @VisibleForTesting
1176     ShardManagerInfoMBean getMBean() {
1177         return shardManagerMBean;
1178     }
1179
1180     private boolean isShardReplicaOperationInProgress(final String shardName, final ActorRef sender) {
1181         if (shardReplicaOperationsInProgress.contains(shardName)) {
1182             LOG.debug("{}: A shard replica operation for {} is already in progress", persistenceId(), shardName);
1183             sender.tell(new Status.Failure(new IllegalStateException(
1184                 String.format("A shard replica operation for %s is already in progress", shardName))), getSelf());
1185             return true;
1186         }
1187
1188         return false;
1189     }
1190
1191     private void onAddShardReplica(final AddShardReplica shardReplicaMsg) {
1192         final String shardName = shardReplicaMsg.getShardName();
1193
1194         LOG.debug("{}: onAddShardReplica: {}", persistenceId(), shardReplicaMsg);
1195
1196         // verify the shard with the specified name is present in the cluster configuration
1197         if (!configuration.isShardConfigured(shardName)) {
1198             LOG.debug("{}: No module configuration exists for shard {}", persistenceId(), shardName);
1199             getSender().tell(new Status.Failure(new IllegalArgumentException(
1200                 "No module configuration exists for shard " + shardName)), getSelf());
1201             return;
1202         }
1203
1204         // Create the localShard
1205         if (schemaContext == null) {
1206             LOG.debug("{}: No SchemaContext is available in order to create a local shard instance for {}",
1207                 persistenceId(), shardName);
1208             getSender().tell(new Status.Failure(new IllegalStateException(
1209                 "No SchemaContext is available in order to create a local shard instance for " + shardName)),
1210                 getSelf());
1211             return;
1212         }
1213
1214         findPrimary(shardName, new AutoFindPrimaryFailureResponseHandler(getSender(), shardName, persistenceId(),
1215                 getSelf()) {
1216             @Override
1217             public void onRemotePrimaryShardFound(final RemotePrimaryShardFound response) {
1218                 final RunnableMessage runnable = (RunnableMessage) () ->
1219                     addShard(getShardName(), response, getSender());
1220                 if (!isPreviousShardActorStopInProgress(getShardName(), runnable)) {
1221                     getSelf().tell(runnable, getTargetActor());
1222                 }
1223             }
1224
1225             @Override
1226             public void onLocalPrimaryFound(final LocalPrimaryShardFound message) {
1227                 sendLocalReplicaAlreadyExistsReply(getShardName(), getTargetActor());
1228             }
1229         });
1230     }
1231
1232     private void sendLocalReplicaAlreadyExistsReply(final String shardName, final ActorRef sender) {
1233         LOG.debug("{}: Local shard {} already exists", persistenceId(), shardName);
1234         sender.tell(new Status.Failure(new AlreadyExistsException(
1235             String.format("Local shard %s already exists", shardName))), getSelf());
1236     }
1237
1238     private void addShard(final String shardName, final RemotePrimaryShardFound response, final ActorRef sender) {
1239         if (isShardReplicaOperationInProgress(shardName, sender)) {
1240             return;
1241         }
1242
1243         shardReplicaOperationsInProgress.add(shardName);
1244
1245         final ShardInformation shardInfo;
1246         final boolean removeShardOnFailure;
1247         ShardInformation existingShardInfo = localShards.get(shardName);
1248         if (existingShardInfo == null) {
1249             removeShardOnFailure = true;
1250             ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
1251
1252             DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName)
1253                     .customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName()).build();
1254
1255             shardInfo = new ShardInformation(shardName, shardId, getPeerAddresses(shardName), datastoreContext,
1256                     Shard.builder(), peerAddressResolver);
1257             shardInfo.setActiveMember(false);
1258             shardInfo.setSchemaContext(schemaContext);
1259             localShards.put(shardName, shardInfo);
1260             shardInfo.setActor(newShardActor(shardInfo));
1261         } else {
1262             removeShardOnFailure = false;
1263             shardInfo = existingShardInfo;
1264         }
1265
1266         execAddShard(shardName, shardInfo, response, removeShardOnFailure, sender);
1267     }
1268
1269     private void execAddShard(final String shardName,
1270                               final ShardInformation shardInfo,
1271                               final RemotePrimaryShardFound response,
1272                               final boolean removeShardOnFailure,
1273                               final ActorRef sender) {
1274
1275         final String localShardAddress =
1276                 peerAddressResolver.getShardActorAddress(shardName, cluster.getCurrentMemberName());
1277
1278         //inform ShardLeader to add this shard as a replica by sending an AddServer message
1279         LOG.debug("{}: Sending AddServer message to peer {} for shard {}", persistenceId(),
1280                 response.getPrimaryPath(), shardInfo.getShardId());
1281
1282         final Timeout addServerTimeout = new Timeout(shardInfo.getDatastoreContext()
1283                 .getShardLeaderElectionTimeout().duration());
1284         final Future<Object> futureObj = ask(getContext().actorSelection(response.getPrimaryPath()),
1285                 new AddServer(shardInfo.getShardId().toString(), localShardAddress, true), addServerTimeout);
1286
1287         futureObj.onComplete(new OnComplete<>() {
1288             @Override
1289             public void onComplete(final Throwable failure, final Object addServerResponse) {
1290                 if (failure != null) {
1291                     LOG.debug("{}: AddServer request to {} for {} failed", persistenceId(),
1292                             response.getPrimaryPath(), shardName, failure);
1293
1294                     final String msg = String.format("AddServer request to leader %s for shard %s failed",
1295                             response.getPrimaryPath(), shardName);
1296                     self().tell(new ForwardedAddServerFailure(shardName, msg, failure, removeShardOnFailure), sender);
1297                 } else {
1298                     self().tell(new ForwardedAddServerReply(shardInfo, (AddServerReply)addServerResponse,
1299                             response.getPrimaryPath(), removeShardOnFailure), sender);
1300                 }
1301             }
1302         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1303     }
1304
1305     private void onAddServerFailure(final String shardName, final String message, final Throwable failure,
1306             final ActorRef sender, final boolean removeShardOnFailure) {
1307         shardReplicaOperationsInProgress.remove(shardName);
1308
1309         if (removeShardOnFailure) {
1310             ShardInformation shardInfo = localShards.remove(shardName);
1311             if (shardInfo.getActor() != null) {
1312                 shardInfo.getActor().tell(PoisonPill.getInstance(), getSelf());
1313             }
1314         }
1315
1316         sender.tell(new Status.Failure(message == null ? failure :
1317             new RuntimeException(message, failure)), getSelf());
1318     }
1319
1320     private void onAddServerReply(final ShardInformation shardInfo, final AddServerReply replyMsg,
1321             final ActorRef sender, final String leaderPath, final boolean removeShardOnFailure) {
1322         String shardName = shardInfo.getShardName();
1323         shardReplicaOperationsInProgress.remove(shardName);
1324
1325         LOG.debug("{}: Received {} for shard {} from leader {}", persistenceId(), replyMsg, shardName, leaderPath);
1326
1327         if (replyMsg.getStatus() == ServerChangeStatus.OK) {
1328             LOG.debug("{}: Leader shard successfully added the replica shard {}", persistenceId(), shardName);
1329
1330             // Make the local shard voting capable
1331             shardInfo.setDatastoreContext(newShardDatastoreContext(shardName), getSelf());
1332             shardInfo.setActiveMember(true);
1333             persistShardList();
1334
1335             sender.tell(new Status.Success(null), getSelf());
1336         } else if (replyMsg.getStatus() == ServerChangeStatus.ALREADY_EXISTS) {
1337             sendLocalReplicaAlreadyExistsReply(shardName, sender);
1338         } else {
1339             LOG.warn("{}: Leader failed to add shard replica {} with status {}",
1340                     persistenceId(), shardName, replyMsg.getStatus());
1341
1342             Exception failure = getServerChangeException(AddServer.class, replyMsg.getStatus(), leaderPath,
1343                     shardInfo.getShardId());
1344
1345             onAddServerFailure(shardName, null, failure, sender, removeShardOnFailure);
1346         }
1347     }
1348
1349     private static Exception getServerChangeException(final Class<?> serverChange,
1350             final ServerChangeStatus serverChangeStatus, final String leaderPath, final ShardIdentifier shardId) {
1351         switch (serverChangeStatus) {
1352             case TIMEOUT:
1353                 return new TimeoutException(String.format(
1354                         "The shard leader %s timed out trying to replicate the initial data to the new shard %s."
1355                         + "Possible causes - there was a problem replicating the data or shard leadership changed "
1356                         + "while replicating the shard data", leaderPath, shardId.getShardName()));
1357             case NO_LEADER:
1358                 return new NoShardLeaderException(shardId);
1359             case NOT_SUPPORTED:
1360                 return new UnsupportedOperationException(String.format("%s request is not supported for shard %s",
1361                         serverChange.getSimpleName(), shardId.getShardName()));
1362             default :
1363                 return new RuntimeException(String.format("%s request to leader %s for shard %s failed with status %s",
1364                         serverChange.getSimpleName(), leaderPath, shardId.getShardName(), serverChangeStatus));
1365         }
1366     }
1367
1368     private void onRemoveShardReplica(final RemoveShardReplica shardReplicaMsg) {
1369         LOG.debug("{}: onRemoveShardReplica: {}", persistenceId(), shardReplicaMsg);
1370
1371         findPrimary(shardReplicaMsg.getShardName(), new AutoFindPrimaryFailureResponseHandler(getSender(),
1372                 shardReplicaMsg.getShardName(), persistenceId(), getSelf()) {
1373             @Override
1374             public void onRemotePrimaryShardFound(final RemotePrimaryShardFound response) {
1375                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1376             }
1377
1378             @Override
1379             public void onLocalPrimaryFound(final LocalPrimaryShardFound response) {
1380                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1381             }
1382
1383             private void doRemoveShardReplicaAsync(final String primaryPath) {
1384                 getSelf().tell((RunnableMessage) () -> removeShardReplica(shardReplicaMsg, getShardName(),
1385                         primaryPath, getSender()), getTargetActor());
1386             }
1387         });
1388     }
1389
1390     private void persistShardList() {
1391         List<String> shardList = new ArrayList<>(localShards.keySet());
1392         for (ShardInformation shardInfo : localShards.values()) {
1393             if (!shardInfo.isActiveMember()) {
1394                 shardList.remove(shardInfo.getShardName());
1395             }
1396         }
1397         LOG.debug("{}: persisting the shard list {}", persistenceId(), shardList);
1398         saveSnapshot(updateShardManagerSnapshot(shardList));
1399     }
1400
1401     private ShardManagerSnapshot updateShardManagerSnapshot(final List<String> shardList) {
1402         currentSnapshot = new ShardManagerSnapshot(shardList);
1403         return currentSnapshot;
1404     }
1405
1406     private void applyShardManagerSnapshot(final ShardManagerSnapshot snapshot) {
1407         currentSnapshot = snapshot;
1408
1409         LOG.debug("{}: onSnapshotOffer: {}", persistenceId(), currentSnapshot);
1410
1411         final MemberName currentMember = cluster.getCurrentMemberName();
1412         Set<String> configuredShardList =
1413             new HashSet<>(configuration.getMemberShardNames(currentMember));
1414         for (String shard : currentSnapshot.getShardList()) {
1415             if (!configuredShardList.contains(shard)) {
1416                 // add the current member as a replica for the shard
1417                 LOG.debug("{}: adding shard {}", persistenceId(), shard);
1418                 configuration.addMemberReplicaForShard(shard, currentMember);
1419             } else {
1420                 configuredShardList.remove(shard);
1421             }
1422         }
1423         for (String shard : configuredShardList) {
1424             // remove the member as a replica for the shard
1425             LOG.debug("{}: removing shard {}", persistenceId(), shard);
1426             configuration.removeMemberReplicaForShard(shard, currentMember);
1427         }
1428     }
1429
1430     private void onSaveSnapshotSuccess(final SaveSnapshotSuccess successMessage) {
1431         LOG.debug("{} saved ShardManager snapshot successfully. Deleting the prev snapshot if available",
1432             persistenceId());
1433         deleteSnapshots(new SnapshotSelectionCriteria(scala.Long.MaxValue(), successMessage.metadata().timestamp() - 1,
1434             0, 0));
1435     }
1436
1437     private void onChangeShardServersVotingStatus(final ChangeShardMembersVotingStatus changeMembersVotingStatus) {
1438         LOG.debug("{}: onChangeShardServersVotingStatus: {}", persistenceId(), changeMembersVotingStatus);
1439
1440         String shardName = changeMembersVotingStatus.getShardName();
1441         Map<String, Boolean> serverVotingStatusMap = new HashMap<>();
1442         for (Entry<String, Boolean> e: changeMembersVotingStatus.getMeberVotingStatusMap().entrySet()) {
1443             serverVotingStatusMap.put(getShardIdentifier(MemberName.forName(e.getKey()), shardName).toString(),
1444                     e.getValue());
1445         }
1446
1447         ChangeServersVotingStatus changeServersVotingStatus = new ChangeServersVotingStatus(serverVotingStatusMap);
1448
1449         findLocalShard(shardName, getSender(),
1450             localShardFound -> changeShardMembersVotingStatus(changeServersVotingStatus, shardName,
1451             localShardFound.getPath(), getSender()));
1452     }
1453
1454     private void onFlipShardMembersVotingStatus(final FlipShardMembersVotingStatus flipMembersVotingStatus) {
1455         LOG.debug("{}: onFlipShardMembersVotingStatus: {}", persistenceId(), flipMembersVotingStatus);
1456
1457         ActorRef sender = getSender();
1458         final String shardName = flipMembersVotingStatus.getShardName();
1459         findLocalShard(shardName, sender, localShardFound -> {
1460             Future<Object> future = ask(localShardFound.getPath(), GetOnDemandRaftState.INSTANCE,
1461                     Timeout.apply(30, TimeUnit.SECONDS));
1462
1463             future.onComplete(new OnComplete<>() {
1464                 @Override
1465                 public void onComplete(final Throwable failure, final Object response) {
1466                     if (failure != null) {
1467                         sender.tell(new Status.Failure(new RuntimeException(
1468                                 String.format("Failed to access local shard %s", shardName), failure)), self());
1469                         return;
1470                     }
1471
1472                     OnDemandRaftState raftState = (OnDemandRaftState) response;
1473                     Map<String, Boolean> serverVotingStatusMap = new HashMap<>();
1474                     for (Entry<String, Boolean> e: raftState.getPeerVotingStates().entrySet()) {
1475                         serverVotingStatusMap.put(e.getKey(), !e.getValue());
1476                     }
1477
1478                     serverVotingStatusMap.put(getShardIdentifier(cluster.getCurrentMemberName(), shardName)
1479                             .toString(), !raftState.isVoting());
1480
1481                     changeShardMembersVotingStatus(new ChangeServersVotingStatus(serverVotingStatusMap),
1482                             shardName, localShardFound.getPath(), sender);
1483                 }
1484             }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1485         });
1486
1487     }
1488
1489     private void findLocalShard(final FindLocalShard message) {
1490         LOG.debug("{}: findLocalShard : {}", persistenceId(), message.getShardName());
1491
1492         final ShardInformation shardInformation = localShards.get(message.getShardName());
1493
1494         if (shardInformation == null) {
1495             LOG.debug("{}: Local shard {} not found - shards present: {}",
1496                     persistenceId(), message.getShardName(), localShards.keySet());
1497
1498             getSender().tell(new LocalShardNotFound(message.getShardName()), getSelf());
1499             return;
1500         }
1501
1502         sendResponse(shardInformation, message.isWaitUntilInitialized(), false,
1503             () -> new LocalShardFound(shardInformation.getActor()));
1504     }
1505
1506     private void findLocalShard(final String shardName, final ActorRef sender,
1507             final Consumer<LocalShardFound> onLocalShardFound) {
1508         Timeout findLocalTimeout = new Timeout(datastoreContextFactory.getBaseDatastoreContext()
1509                 .getShardInitializationTimeout().duration().$times(2));
1510
1511         Future<Object> futureObj = ask(getSelf(), new FindLocalShard(shardName, true), findLocalTimeout);
1512         futureObj.onComplete(new OnComplete<>() {
1513             @Override
1514             public void onComplete(final Throwable failure, final Object response) {
1515                 if (failure != null) {
1516                     LOG.debug("{}: Received failure from FindLocalShard for shard {}", persistenceId, shardName,
1517                             failure);
1518                     sender.tell(new Status.Failure(new RuntimeException(
1519                             String.format("Failed to find local shard %s", shardName), failure)), self());
1520                 } else {
1521                     if (response instanceof LocalShardFound) {
1522                         getSelf().tell((RunnableMessage) () -> onLocalShardFound.accept((LocalShardFound) response),
1523                                 sender);
1524                     } else if (response instanceof LocalShardNotFound) {
1525                         LOG.debug("{}: Local shard {} does not exist", persistenceId, shardName);
1526                         sender.tell(new Status.Failure(new IllegalArgumentException(
1527                             String.format("Local shard %s does not exist", shardName))), self());
1528                     } else {
1529                         LOG.debug("{}: Failed to find local shard {}: received response: {}", persistenceId, shardName,
1530                             response);
1531                         sender.tell(new Status.Failure(response instanceof Throwable ? (Throwable) response
1532                                 : new RuntimeException(
1533                                     String.format("Failed to find local shard %s: received response: %s", shardName,
1534                                         response))), self());
1535                     }
1536                 }
1537             }
1538         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1539     }
1540
1541     private void changeShardMembersVotingStatus(final ChangeServersVotingStatus changeServersVotingStatus,
1542             final String shardName, final ActorRef shardActorRef, final ActorRef sender) {
1543         if (isShardReplicaOperationInProgress(shardName, sender)) {
1544             return;
1545         }
1546
1547         shardReplicaOperationsInProgress.add(shardName);
1548
1549         DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName).build();
1550         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
1551
1552         LOG.debug("{}: Sending ChangeServersVotingStatus message {} to local shard {}", persistenceId(),
1553                 changeServersVotingStatus, shardActorRef.path());
1554
1555         Timeout timeout = new Timeout(datastoreContext.getShardLeaderElectionTimeout().duration().$times(2));
1556         Future<Object> futureObj = ask(shardActorRef, changeServersVotingStatus, timeout);
1557
1558         futureObj.onComplete(new OnComplete<>() {
1559             @Override
1560             public void onComplete(final Throwable failure, final Object response) {
1561                 shardReplicaOperationsInProgress.remove(shardName);
1562                 if (failure != null) {
1563                     LOG.debug("{}: ChangeServersVotingStatus request to local shard {} failed", persistenceId(),
1564                         shardActorRef.path(), failure);
1565                     sender.tell(new Status.Failure(new RuntimeException(
1566                         String.format("ChangeServersVotingStatus request to local shard %s failed",
1567                             shardActorRef.path()), failure)), self());
1568                 } else {
1569                     LOG.debug("{}: Received {} from local shard {}", persistenceId(), response, shardActorRef.path());
1570
1571                     ServerChangeReply replyMsg = (ServerChangeReply) response;
1572                     if (replyMsg.getStatus() == ServerChangeStatus.OK) {
1573                         LOG.debug("{}: ChangeServersVotingStatus succeeded for shard {}", persistenceId(), shardName);
1574                         sender.tell(new Status.Success(null), getSelf());
1575                     } else if (replyMsg.getStatus() == ServerChangeStatus.INVALID_REQUEST) {
1576                         sender.tell(new Status.Failure(new IllegalArgumentException(String.format(
1577                                 "The requested voting state change for shard %s is invalid. At least one member "
1578                                 + "must be voting", shardId.getShardName()))), getSelf());
1579                     } else {
1580                         LOG.warn("{}: ChangeServersVotingStatus failed for shard {} with status {}",
1581                                 persistenceId(), shardName, replyMsg.getStatus());
1582
1583                         Exception error = getServerChangeException(ChangeServersVotingStatus.class,
1584                                 replyMsg.getStatus(), shardActorRef.path().toString(), shardId);
1585                         sender.tell(new Status.Failure(error), getSelf());
1586                     }
1587                 }
1588             }
1589         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1590     }
1591
1592     private static final class ForwardedAddServerReply {
1593         ShardInformation shardInfo;
1594         AddServerReply addServerReply;
1595         String leaderPath;
1596         boolean removeShardOnFailure;
1597
1598         ForwardedAddServerReply(final ShardInformation shardInfo, final AddServerReply addServerReply,
1599             final String leaderPath, final boolean removeShardOnFailure) {
1600             this.shardInfo = shardInfo;
1601             this.addServerReply = addServerReply;
1602             this.leaderPath = leaderPath;
1603             this.removeShardOnFailure = removeShardOnFailure;
1604         }
1605     }
1606
1607     private static final class ForwardedAddServerFailure {
1608         String shardName;
1609         String failureMessage;
1610         Throwable failure;
1611         boolean removeShardOnFailure;
1612
1613         ForwardedAddServerFailure(final String shardName, final String failureMessage, final Throwable failure,
1614                 final boolean removeShardOnFailure) {
1615             this.shardName = shardName;
1616             this.failureMessage = failureMessage;
1617             this.failure = failure;
1618             this.removeShardOnFailure = removeShardOnFailure;
1619         }
1620     }
1621
1622     static class OnShardInitialized {
1623         private final Runnable replyRunnable;
1624         private Cancellable timeoutSchedule;
1625
1626         OnShardInitialized(final Runnable replyRunnable) {
1627             this.replyRunnable = replyRunnable;
1628         }
1629
1630         Runnable getReplyRunnable() {
1631             return replyRunnable;
1632         }
1633
1634         Cancellable getTimeoutSchedule() {
1635             return timeoutSchedule;
1636         }
1637
1638         void setTimeoutSchedule(final Cancellable timeoutSchedule) {
1639             this.timeoutSchedule = timeoutSchedule;
1640         }
1641     }
1642
1643     static class OnShardReady extends OnShardInitialized {
1644         OnShardReady(final Runnable replyRunnable) {
1645             super(replyRunnable);
1646         }
1647     }
1648
1649     private interface RunnableMessage extends Runnable {
1650     }
1651
1652     /**
1653      * The FindPrimaryResponseHandler provides specific callback methods which are invoked when a response to the
1654      * a remote or local find primary message is processed.
1655      */
1656     private interface FindPrimaryResponseHandler {
1657         /**
1658          * Invoked when a Failure message is received as a response.
1659          *
1660          * @param failure the failure exception
1661          */
1662         void onFailure(Throwable failure);
1663
1664         /**
1665          * Invoked when a RemotePrimaryShardFound response is received.
1666          *
1667          * @param response the response
1668          */
1669         void onRemotePrimaryShardFound(RemotePrimaryShardFound response);
1670
1671         /**
1672          * Invoked when a LocalPrimaryShardFound response is received.
1673          *
1674          * @param response the response
1675          */
1676         void onLocalPrimaryFound(LocalPrimaryShardFound response);
1677
1678         /**
1679          * Invoked when an unknown response is received. This is another type of failure.
1680          *
1681          * @param response the response
1682          */
1683         void onUnknownResponse(Object response);
1684     }
1685
1686     /**
1687      * The AutoFindPrimaryFailureResponseHandler automatically processes Failure responses when finding a primary
1688      * replica and sends a wrapped Failure response to some targetActor.
1689      */
1690     private abstract static class AutoFindPrimaryFailureResponseHandler implements FindPrimaryResponseHandler {
1691         private final ActorRef targetActor;
1692         private final String shardName;
1693         private final String persistenceId;
1694         private final ActorRef shardManagerActor;
1695
1696         /**
1697          * Constructs an instance.
1698          *
1699          * @param targetActor The actor to whom the Failure response should be sent when a FindPrimary failure occurs
1700          * @param shardName The name of the shard for which the primary replica had to be found
1701          * @param persistenceId The persistenceId for the ShardManager
1702          * @param shardManagerActor The ShardManager actor which triggered the call to FindPrimary
1703          */
1704         protected AutoFindPrimaryFailureResponseHandler(final ActorRef targetActor, final String shardName,
1705                 final String persistenceId, final ActorRef shardManagerActor) {
1706             this.targetActor = requireNonNull(targetActor);
1707             this.shardName = requireNonNull(shardName);
1708             this.persistenceId = requireNonNull(persistenceId);
1709             this.shardManagerActor = requireNonNull(shardManagerActor);
1710         }
1711
1712         public ActorRef getTargetActor() {
1713             return targetActor;
1714         }
1715
1716         public String getShardName() {
1717             return shardName;
1718         }
1719
1720         @Override
1721         public void onFailure(final Throwable failure) {
1722             LOG.debug("{}: Received failure from FindPrimary for shard {}", persistenceId, shardName, failure);
1723             targetActor.tell(new Status.Failure(new RuntimeException(
1724                     String.format("Failed to find leader for shard %s", shardName), failure)), shardManagerActor);
1725         }
1726
1727         @Override
1728         public void onUnknownResponse(final Object response) {
1729             LOG.debug("{}: Failed to find leader for shard {}: received response: {}", persistenceId, shardName,
1730                 response);
1731             targetActor.tell(new Status.Failure(response instanceof Throwable ? (Throwable) response
1732                     : new RuntimeException(String.format("Failed to find leader for shard %s: received response: %s",
1733                         shardName, response))), shardManagerActor);
1734         }
1735     }
1736
1737     /**
1738      * The WrappedShardResponse class wraps a response from a Shard.
1739      */
1740     private static final class WrappedShardResponse {
1741         private final ShardIdentifier shardId;
1742         private final Object response;
1743         private final String leaderPath;
1744
1745         WrappedShardResponse(final ShardIdentifier shardId, final Object response, final String leaderPath) {
1746             this.shardId = shardId;
1747             this.response = response;
1748             this.leaderPath = leaderPath;
1749         }
1750
1751         ShardIdentifier getShardId() {
1752             return shardId;
1753         }
1754
1755         Object getResponse() {
1756             return response;
1757         }
1758
1759         String getLeaderPath() {
1760             return leaderPath;
1761         }
1762     }
1763
1764     private static final class ShardNotInitializedTimeout {
1765         private final ActorRef sender;
1766         private final ShardInformation shardInfo;
1767         private final OnShardInitialized onShardInitialized;
1768
1769         ShardNotInitializedTimeout(final ShardInformation shardInfo, final OnShardInitialized onShardInitialized,
1770             final ActorRef sender) {
1771             this.sender = sender;
1772             this.shardInfo = shardInfo;
1773             this.onShardInitialized = onShardInitialized;
1774         }
1775
1776         ActorRef getSender() {
1777             return sender;
1778         }
1779
1780         ShardInformation getShardInfo() {
1781             return shardInfo;
1782         }
1783
1784         OnShardInitialized getOnShardInitialized() {
1785             return onShardInitialized;
1786         }
1787     }
1788 }
1789
1790
1791