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
   9 package org.opendaylight.controller.cluster.datastore.shardmanager;
  10
  11 import static akka.pattern.Patterns.ask;
  12 import static java.util.Objects.requireNonNull;
  13
  14 import akka.actor.ActorRef;
  15 import akka.actor.Address;
  16 import akka.actor.Cancellable;
  17 import akka.actor.OneForOneStrategy;
  18 import akka.actor.PoisonPill;
  19 import akka.actor.Status;
  20 import akka.actor.SupervisorStrategy;
  21 import akka.actor.SupervisorStrategy.Directive;
  22 import akka.cluster.ClusterEvent;
  23 import akka.cluster.ClusterEvent.MemberWeaklyUp;
  24 import akka.cluster.Member;
  25 import akka.dispatch.Futures;
  26 import akka.dispatch.OnComplete;
  27 import akka.japi.Function;
  28 import akka.pattern.Patterns;
  29 import akka.persistence.DeleteSnapshotsFailure;
  30 import akka.persistence.DeleteSnapshotsSuccess;
  31 import akka.persistence.RecoveryCompleted;
  32 import akka.persistence.SaveSnapshotFailure;
  33 import akka.persistence.SaveSnapshotSuccess;
  34 import akka.persistence.SnapshotOffer;
  35 import akka.persistence.SnapshotSelectionCriteria;
  36 import akka.util.Timeout;
  37 import com.google.common.annotations.VisibleForTesting;
  38 import com.google.common.util.concurrent.SettableFuture;
  39 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  40 import java.util.ArrayList;
  41 import java.util.Collection;
  42 import java.util.Collections;
  43 import java.util.HashMap;
  44 import java.util.HashSet;
  45 import java.util.List;
  46 import java.util.Map;
  47 import java.util.Map.Entry;
  48 import java.util.Set;
  49 import java.util.concurrent.TimeUnit;
  50 import java.util.concurrent.TimeoutException;
  51 import java.util.function.Consumer;
  52 import java.util.function.Supplier;
  53 import org.opendaylight.controller.cluster.access.concepts.MemberName;
  54 import org.opendaylight.controller.cluster.common.actor.AbstractUntypedPersistentActorWithMetering;
  55 import org.opendaylight.controller.cluster.common.actor.Dispatchers;
  56 import org.opendaylight.controller.cluster.datastore.ClusterWrapper;
  57 import org.opendaylight.controller.cluster.datastore.DatastoreContext;
  58 import org.opendaylight.controller.cluster.datastore.DatastoreContextFactory;
  59 import org.opendaylight.controller.cluster.datastore.Shard;
  60 import org.opendaylight.controller.cluster.datastore.config.Configuration;
  61 import org.opendaylight.controller.cluster.datastore.config.ModuleShardConfiguration;
  62 import org.opendaylight.controller.cluster.datastore.exceptions.AlreadyExistsException;
  63 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
  64 import org.opendaylight.controller.cluster.datastore.exceptions.NotInitializedException;
  65 import org.opendaylight.controller.cluster.datastore.exceptions.PrimaryNotFoundException;
  66 import org.opendaylight.controller.cluster.datastore.identifiers.ShardIdentifier;
  67 import org.opendaylight.controller.cluster.datastore.messages.ActorInitialized;
  68 import org.opendaylight.controller.cluster.datastore.messages.AddShardReplica;
  69 import org.opendaylight.controller.cluster.datastore.messages.ChangeShardMembersVotingStatus;
  70 import org.opendaylight.controller.cluster.datastore.messages.CreateShard;
  71 import org.opendaylight.controller.cluster.datastore.messages.FindLocalShard;
  72 import org.opendaylight.controller.cluster.datastore.messages.FindPrimary;
  73 import org.opendaylight.controller.cluster.datastore.messages.FlipShardMembersVotingStatus;
  74 import org.opendaylight.controller.cluster.datastore.messages.GetShardRole;
  75 import org.opendaylight.controller.cluster.datastore.messages.GetShardRoleReply;
  76 import org.opendaylight.controller.cluster.datastore.messages.LocalPrimaryShardFound;
  77 import org.opendaylight.controller.cluster.datastore.messages.LocalShardFound;
  78 import org.opendaylight.controller.cluster.datastore.messages.LocalShardNotFound;
  79 import org.opendaylight.controller.cluster.datastore.messages.RemoteFindPrimary;
  80 import org.opendaylight.controller.cluster.datastore.messages.RemotePrimaryShardFound;
  81 import org.opendaylight.controller.cluster.datastore.messages.RemoveShardReplica;
  82 import org.opendaylight.controller.cluster.datastore.messages.ShardLeaderStateChanged;
  83 import org.opendaylight.controller.cluster.datastore.messages.UpdateSchemaContext;
  84 import org.opendaylight.controller.cluster.datastore.persisted.DatastoreSnapshot;
  85 import org.opendaylight.controller.cluster.datastore.persisted.ShardManagerSnapshot;
  86 import org.opendaylight.controller.cluster.datastore.utils.CompositeOnComplete;
  87 import org.opendaylight.controller.cluster.datastore.utils.PrimaryShardInfoFutureCache;
  88 import org.opendaylight.controller.cluster.notifications.RegisterRoleChangeListener;
  89 import org.opendaylight.controller.cluster.notifications.RegisterRoleChangeListenerReply;
  90 import org.opendaylight.controller.cluster.notifications.RoleChangeNotification;
  91 import org.opendaylight.controller.cluster.raft.base.messages.FollowerInitialSyncUpStatus;
  92 import org.opendaylight.controller.cluster.raft.base.messages.SwitchBehavior;
  93 import org.opendaylight.controller.cluster.raft.client.messages.GetOnDemandRaftState;
  94 import org.opendaylight.controller.cluster.raft.client.messages.GetSnapshot;
  95 import org.opendaylight.controller.cluster.raft.client.messages.OnDemandRaftState;
  96 import org.opendaylight.controller.cluster.raft.client.messages.Shutdown;
  97 import org.opendaylight.controller.cluster.raft.messages.AddServer;
  98 import org.opendaylight.controller.cluster.raft.messages.AddServerReply;
  99 import org.opendaylight.controller.cluster.raft.messages.ChangeServersVotingStatus;
 100 import org.opendaylight.controller.cluster.raft.messages.RemoveServer;
 101 import org.opendaylight.controller.cluster.raft.messages.RemoveServerReply;
 102 import org.opendaylight.controller.cluster.raft.messages.ServerChangeReply;
 103 import org.opendaylight.controller.cluster.raft.messages.ServerChangeStatus;
 104 import org.opendaylight.controller.cluster.raft.messages.ServerRemoved;
 105 import org.opendaylight.controller.cluster.raft.policy.DisableElectionsRaftPolicy;
 106 import org.opendaylight.yangtools.concepts.Registration;
 107 import org.opendaylight.yangtools.yang.model.api.EffectiveModelContext;
 108 import org.slf4j.Logger;
 109 import org.slf4j.LoggerFactory;
 110 import scala.concurrent.ExecutionContext;
 111 import scala.concurrent.Future;
 112 import scala.concurrent.duration.FiniteDuration;
 113
 114 /**
 115  * Manages the shards for a data store. The ShardManager has the following jobs:
 116  * <ul>
 117  * <li> Create all the local shard replicas that belong on this cluster member
 118  * <li> Find the address of the local shard
 119  * <li> Find the primary replica for any given shard
 120  * <li> Monitor the cluster members and store their addresses
 121  * </ul>
 122  */
 123 class ShardManager extends AbstractUntypedPersistentActorWithMetering {
 124     private static final Logger LOG = LoggerFactory.getLogger(ShardManager.class);
 125
 126     // Stores a mapping between a shard name and it's corresponding information
 127     // Shard names look like inventory, topology etc and are as specified in
 128     // configuration
 129     @VisibleForTesting
 130     final Map<String, ShardInformation> localShards = new HashMap<>();
 131
 132     // The type of a ShardManager reflects the type of the datastore itself
 133     // A data store could be of type config/operational
 134     private final String type;
 135
 136     private final ClusterWrapper cluster;
 137
 138     private final Configuration configuration;
 139
 140     @VisibleForTesting
 141     final String shardDispatcherPath;
 142
 143     private final ShardManagerInfo shardManagerMBean;
 144
 145     private DatastoreContextFactory datastoreContextFactory;
 146
 147     private final SettableFuture<Void> readinessFuture;
 148
 149     private final PrimaryShardInfoFutureCache primaryShardInfoCache;
 150
 151     @VisibleForTesting
 152     final ShardPeerAddressResolver peerAddressResolver;
 153
 154     private EffectiveModelContext schemaContext;
 155
 156     private DatastoreSnapshot restoreFromSnapshot;
 157
 158     private ShardManagerSnapshot currentSnapshot;
 159
 160     private final Set<String> shardReplicaOperationsInProgress = new HashSet<>();
 161
 162     private final Map<String, CompositeOnComplete<Boolean>> shardActorsStopping = new HashMap<>();
 163
 164     private final Set<Consumer<String>> shardAvailabilityCallbacks = new HashSet<>();
 165
 166     private final String persistenceId;
 167
 168     ShardManager(final AbstractShardManagerCreator<?> builder) {
 169         this.cluster = builder.getCluster();
 170         this.configuration = builder.getConfiguration();
 171         this.datastoreContextFactory = builder.getDatastoreContextFactory();
 172         this.type = datastoreContextFactory.getBaseDatastoreContext().getDataStoreName();
 173         this.shardDispatcherPath =
 174                 new Dispatchers(context().system().dispatchers()).getDispatcherPath(Dispatchers.DispatcherType.Shard);
 175         this.readinessFuture = builder.getReadinessFuture();
 176         this.primaryShardInfoCache = builder.getPrimaryShardInfoCache();
 177         this.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-" + this.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) {
 244             ForwardedAddServerReply msg = (ForwardedAddServerReply)message;
 245             onAddServerReply(msg.shardInfo, msg.addServerReply, getSender(), msg.leaderPath,
 246                     msg.removeShardOnFailure);
 247         } else if (message instanceof ForwardedAddServerFailure) {
 248             ForwardedAddServerFailure msg = (ForwardedAddServerFailure)message;
 249             onAddServerFailure(msg.shardName, msg.failureMessage, msg.failure, getSender(), msg.removeShardOnFailure);
 250         } else if (message instanceof RemoveShardReplica) {
 251             onRemoveShardReplica((RemoveShardReplica) message);
 252         } else if (message instanceof WrappedShardResponse) {
 253             onWrappedShardResponse((WrappedShardResponse) message);
 254         } else if (message instanceof GetSnapshot) {
 255             onGetSnapshot((GetSnapshot) message);
 256         } else if (message instanceof ServerRemoved) {
 257             onShardReplicaRemoved((ServerRemoved) message);
 258         } else if (message instanceof ChangeShardMembersVotingStatus) {
 259             onChangeShardServersVotingStatus((ChangeShardMembersVotingStatus) message);
 260         } else if (message instanceof FlipShardMembersVotingStatus) {
 261             onFlipShardMembersVotingStatus((FlipShardMembersVotingStatus) message);
 262         } else if (message instanceof SaveSnapshotSuccess) {
 263             onSaveSnapshotSuccess((SaveSnapshotSuccess) message);
 264         } else if (message instanceof SaveSnapshotFailure) {
 265             LOG.error("{}: SaveSnapshotFailure received for saving snapshot of shards", persistenceId(),
 266                     ((SaveSnapshotFailure) message).cause());
 267         } else if (message instanceof Shutdown) {
 268             onShutDown();
 269         } else if (message instanceof GetLocalShardIds) {
 270             onGetLocalShardIds();
 271         } else if (message instanceof GetShardRole) {
 272             onGetShardRole((GetShardRole) message);
 273         } else if (message instanceof RunnableMessage) {
 274             ((RunnableMessage)message).run();
 275         } else if (message instanceof RegisterForShardAvailabilityChanges) {
 276             onRegisterForShardAvailabilityChanges((RegisterForShardAvailabilityChanges)message);
 277         } else if (message instanceof DeleteSnapshotsFailure) {
 278             LOG.warn("{}: Failed to delete prior snapshots", persistenceId(),
 279                     ((DeleteSnapshotsFailure) message).cause());
 280         } else if (message instanceof DeleteSnapshotsSuccess) {
 281             LOG.debug("{}: Successfully deleted prior snapshots", persistenceId());
 282         } else if (message instanceof RegisterRoleChangeListenerReply) {
 283             LOG.trace("{}: Received RegisterRoleChangeListenerReply", persistenceId());
 284         } else if (message instanceof ClusterEvent.MemberEvent) {
 285             LOG.trace("{}: Received other ClusterEvent.MemberEvent: {}", persistenceId(), message);
 286         } else {
 287             unknownMessage(message);
 288         }
 289     }
 290
 291     private void onRegisterForShardAvailabilityChanges(final RegisterForShardAvailabilityChanges message) {
 292         LOG.debug("{}: onRegisterForShardAvailabilityChanges: {}", persistenceId(), message);
 293
 294         final Consumer<String> callback = message.getCallback();
 295         shardAvailabilityCallbacks.add(callback);
 296
 297         getSender().tell(new Status.Success((Registration)
 298             () -> executeInSelf(() -> shardAvailabilityCallbacks.remove(callback))), self());
 299     }
 300
 301     private void onGetShardRole(final GetShardRole message) {
 302         LOG.debug("{}: onGetShardRole for shard: {}", persistenceId(), message.getName());
 303
 304         final String name = message.getName();
 305
 306         final ShardInformation shardInformation = localShards.get(name);
 307
 308         if (shardInformation == null) {
 309             LOG.info("{}: no shard information for {} found", persistenceId(), name);
 310             getSender().tell(new Status.Failure(
 311                     new IllegalArgumentException("Shard with name " + name + " not present.")), ActorRef.noSender());
 312             return;
 313         }
 314
 315         getSender().tell(new GetShardRoleReply(shardInformation.getRole()), ActorRef.noSender());
 316     }
 317
 318     void onShutDown() {
 319         List<Future<Boolean>> stopFutures = new ArrayList<>(localShards.size());
 320         for (ShardInformation info : localShards.values()) {
 321             if (info.getActor() != null) {
 322                 LOG.debug("{}: Issuing gracefulStop to shard {}", persistenceId(), info.getShardId());
 323
 324                 FiniteDuration duration = info.getDatastoreContext().getShardRaftConfig()
 325                         .getElectionTimeOutInterval().$times(2);
 326                 stopFutures.add(Patterns.gracefulStop(info.getActor(), duration, Shutdown.INSTANCE));
 327             }
 328         }
 329
 330         LOG.info("Shutting down ShardManager {} - waiting on {} shards", persistenceId(), stopFutures.size());
 331
 332         ExecutionContext dispatcher = new Dispatchers(context().system().dispatchers())
 333                 .getDispatcher(Dispatchers.DispatcherType.Client);
 334         Future<Iterable<Boolean>> combinedFutures = Futures.sequence(stopFutures, dispatcher);
 335
 336         combinedFutures.onComplete(new OnComplete<Iterable<Boolean>>() {
 337             @Override
 338             public void onComplete(final Throwable failure, final Iterable<Boolean> results) {
 339                 LOG.debug("{}: All shards shutdown - sending PoisonPill to self", persistenceId());
 340
 341                 self().tell(PoisonPill.getInstance(), self());
 342
 343                 if (failure != null) {
 344                     LOG.warn("{}: An error occurred attempting to shut down the shards", persistenceId(), failure);
 345                 } else {
 346                     int nfailed = 0;
 347                     for (Boolean result : results) {
 348                         if (!result) {
 349                             nfailed++;
 350                         }
 351                     }
 352
 353                     if (nfailed > 0) {
 354                         LOG.warn("{}: {} shards did not shut down gracefully", persistenceId(), nfailed);
 355                     }
 356                 }
 357             }
 358         }, dispatcher);
 359     }
 360
 361     private void onWrappedShardResponse(final WrappedShardResponse message) {
 362         if (message.getResponse() instanceof RemoveServerReply) {
 363             onRemoveServerReply(getSender(), message.getShardId(), (RemoveServerReply) message.getResponse(),
 364                     message.getLeaderPath());
 365         }
 366     }
 367
 368     private void onRemoveServerReply(final ActorRef originalSender, final ShardIdentifier shardId,
 369             final RemoveServerReply replyMsg, final String leaderPath) {
 370         shardReplicaOperationsInProgress.remove(shardId.getShardName());
 371
 372         LOG.debug("{}: Received {} for shard {}", persistenceId(), replyMsg, shardId.getShardName());
 373
 374         if (replyMsg.getStatus() == ServerChangeStatus.OK) {
 375             LOG.debug("{}: Leader shard successfully removed the replica shard {}", persistenceId(),
 376                     shardId.getShardName());
 377             originalSender.tell(new Status.Success(null), getSelf());
 378         } else {
 379             LOG.warn("{}: Leader failed to remove shard replica {} with status {}",
 380                     persistenceId(), shardId, replyMsg.getStatus());
 381
 382             Exception failure = getServerChangeException(RemoveServer.class, replyMsg.getStatus(), leaderPath, shardId);
 383             originalSender.tell(new Status.Failure(failure), getSelf());
 384         }
 385     }
 386
 387     @SuppressFBWarnings(value = "UPM_UNCALLED_PRIVATE_METHOD",
 388             justification = "https://github.com/spotbugs/spotbugs/issues/811")
 389     private void removeShardReplica(final RemoveShardReplica contextMessage, final String shardName,
 390             final String primaryPath, final ActorRef sender) {
 391         if (isShardReplicaOperationInProgress(shardName, sender)) {
 392             return;
 393         }
 394
 395         shardReplicaOperationsInProgress.add(shardName);
 396
 397         final ShardIdentifier shardId = getShardIdentifier(contextMessage.getMemberName(), shardName);
 398
 399         final DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName).build();
 400
 401         //inform ShardLeader to remove this shard as a replica by sending an RemoveServer message
 402         LOG.debug("{}: Sending RemoveServer message to peer {} for shard {}", persistenceId(),
 403                 primaryPath, shardId);
 404
 405         Timeout removeServerTimeout = new Timeout(datastoreContext.getShardLeaderElectionTimeout().duration());
 406         Future<Object> futureObj = ask(getContext().actorSelection(primaryPath),
 407                 new RemoveServer(shardId.toString()), removeServerTimeout);
 408
 409         futureObj.onComplete(new OnComplete<>() {
 410             @Override
 411             public void onComplete(final Throwable failure, final Object response) {
 412                 if (failure != null) {
 413                     shardReplicaOperationsInProgress.remove(shardName);
 414                     LOG.debug("{}: RemoveServer request to leader {} for shard {} failed", persistenceId(), primaryPath,
 415                         shardName, failure);
 416
 417                     // FAILURE
 418                     sender.tell(new Status.Failure(new RuntimeException(
 419                         String.format("RemoveServer request to leader %s for shard %s failed", primaryPath, shardName),
 420                         failure)), self());
 421                 } else {
 422                     // SUCCESS
 423                     self().tell(new WrappedShardResponse(shardId, response, primaryPath), sender);
 424                 }
 425             }
 426         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
 427     }
 428
 429     private void onShardReplicaRemoved(final ServerRemoved message) {
 430         removeShard(new ShardIdentifier.Builder().fromShardIdString(message.getServerId()).build());
 431     }
 432
 433     @SuppressWarnings("checkstyle:IllegalCatch")
 434     private void removeShard(final ShardIdentifier shardId) {
 435         final String shardName = shardId.getShardName();
 436         final ShardInformation shardInformation = localShards.remove(shardName);
 437         if (shardInformation == null) {
 438             LOG.debug("{} : Shard replica {} is not present in list", persistenceId(), shardId.toString());
 439             return;
 440         }
 441
 442         final ActorRef shardActor = shardInformation.getActor();
 443         if (shardActor != null) {
 444             long timeoutInMS = Math.max(shardInformation.getDatastoreContext().getShardRaftConfig()
 445                     .getElectionTimeOutInterval().$times(3).toMillis(), 10000);
 446
 447             LOG.debug("{} : Sending Shutdown to Shard actor {} with {} ms timeout", persistenceId(), shardActor,
 448                     timeoutInMS);
 449
 450             final Future<Boolean> stopFuture = Patterns.gracefulStop(shardActor,
 451                     FiniteDuration.apply(timeoutInMS, TimeUnit.MILLISECONDS), Shutdown.INSTANCE);
 452
 453             final CompositeOnComplete<Boolean> onComplete = new CompositeOnComplete<>() {
 454                 @Override
 455                 public void onComplete(final Throwable failure, final Boolean result) {
 456                     if (failure == null) {
 457                         LOG.debug("{} : Successfully shut down Shard actor {}", persistenceId(), shardActor);
 458                     } else {
 459                         LOG.warn("{}: Failed to shut down Shard actor {}", persistenceId(), shardActor, failure);
 460                     }
 461
 462                     self().tell((RunnableMessage) () -> {
 463                         // At any rate, invalidate primaryShardInfo cache
 464                         primaryShardInfoCache.remove(shardName);
 465
 466                         shardActorsStopping.remove(shardName);
 467                         notifyOnCompleteTasks(failure, result);
 468                     }, ActorRef.noSender());
 469                 }
 470             };
 471
 472             shardActorsStopping.put(shardName, onComplete);
 473             stopFuture.onComplete(onComplete, new Dispatchers(context().system().dispatchers())
 474                     .getDispatcher(Dispatchers.DispatcherType.Client));
 475         }
 476
 477         LOG.debug("{} : Local Shard replica for shard {} has been removed", persistenceId(), shardName);
 478         persistShardList();
 479     }
 480
 481     private void onGetSnapshot(final GetSnapshot getSnapshot) {
 482         LOG.debug("{}: onGetSnapshot", persistenceId());
 483
 484         List<String> notInitialized = null;
 485         for (ShardInformation shardInfo : localShards.values()) {
 486             if (!shardInfo.isShardInitialized()) {
 487                 if (notInitialized == null) {
 488                     notInitialized = new ArrayList<>();
 489                 }
 490
 491                 notInitialized.add(shardInfo.getShardName());
 492             }
 493         }
 494
 495         if (notInitialized != null) {
 496             getSender().tell(new Status.Failure(new IllegalStateException(String.format(
 497                     "%d shard(s) %s are not initialized", notInitialized.size(), notInitialized))), getSelf());
 498             return;
 499         }
 500
 501         ActorRef replyActor = getContext().actorOf(ShardManagerGetSnapshotReplyActor.props(
 502                 new ArrayList<>(localShards.keySet()), type, currentSnapshot , getSender(), persistenceId(),
 503                 datastoreContextFactory.getBaseDatastoreContext().getShardInitializationTimeout().duration()));
 504
 505         for (ShardInformation shardInfo: localShards.values()) {
 506             shardInfo.getActor().tell(getSnapshot, replyActor);
 507         }
 508     }
 509
 510     @SuppressWarnings("checkstyle:IllegalCatch")
 511     private void onCreateShard(final CreateShard createShard) {
 512         LOG.debug("{}: onCreateShard: {}", persistenceId(), createShard);
 513
 514         Object reply;
 515         try {
 516             String shardName = createShard.getModuleShardConfig().getShardName();
 517             if (localShards.containsKey(shardName)) {
 518                 LOG.debug("{}: Shard {} already exists", persistenceId(), shardName);
 519                 reply = new Status.Success(String.format("Shard with name %s already exists", shardName));
 520             } else {
 521                 doCreateShard(createShard);
 522                 reply = new Status.Success(null);
 523             }
 524         } catch (Exception e) {
 525             LOG.error("{}: onCreateShard failed", persistenceId(), e);
 526             reply = new Status.Failure(e);
 527         }
 528
 529         if (getSender() != null && !getContext().system().deadLetters().equals(getSender())) {
 530             getSender().tell(reply, getSelf());
 531         }
 532     }
 533
 534     @SuppressFBWarnings(value = "UPM_UNCALLED_PRIVATE_METHOD",
 535         justification = "https://github.com/spotbugs/spotbugs/issues/811")
 536     private boolean isPreviousShardActorStopInProgress(final String shardName, final Object messageToDefer) {
 537         final CompositeOnComplete<Boolean> stopOnComplete = shardActorsStopping.get(shardName);
 538         if (stopOnComplete == null) {
 539             return false;
 540         }
 541
 542         LOG.debug("{} : Stop is in progress for shard {} - adding OnComplete callback to defer {}", persistenceId(),
 543                 shardName, messageToDefer);
 544         final ActorRef sender = getSender();
 545         stopOnComplete.addOnComplete(new OnComplete<Boolean>() {
 546             @Override
 547             public void onComplete(final Throwable failure, final Boolean result) {
 548                 LOG.debug("{} : Stop complete for shard {} - re-queing {}", persistenceId(), shardName, messageToDefer);
 549                 self().tell(messageToDefer, sender);
 550             }
 551         });
 552
 553         return true;
 554     }
 555
 556     private void doCreateShard(final CreateShard createShard) {
 557         final ModuleShardConfiguration moduleShardConfig = createShard.getModuleShardConfig();
 558         final String shardName = moduleShardConfig.getShardName();
 559
 560         configuration.addModuleShardConfiguration(moduleShardConfig);
 561
 562         DatastoreContext shardDatastoreContext = createShard.getDatastoreContext();
 563         if (shardDatastoreContext == null) {
 564             shardDatastoreContext = newShardDatastoreContext(shardName);
 565         } else {
 566             shardDatastoreContext = DatastoreContext.newBuilderFrom(shardDatastoreContext).shardPeerAddressResolver(
 567                     peerAddressResolver).build();
 568         }
 569
 570         ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
 571
 572         boolean shardWasInRecoveredSnapshot = currentSnapshot != null
 573                 && currentSnapshot.getShardList().contains(shardName);
 574
 575         Map<String, String> peerAddresses;
 576         boolean isActiveMember;
 577         if (shardWasInRecoveredSnapshot || configuration.getMembersFromShardName(shardName)
 578                 .contains(cluster.getCurrentMemberName())) {
 579             peerAddresses = getPeerAddresses(shardName);
 580             isActiveMember = true;
 581         } else {
 582             // The local member is not in the static shard member configuration and the shard did not
 583             // previously exist (ie !shardWasInRecoveredSnapshot). In this case we'll create
 584             // the shard with no peers and with elections disabled so it stays as follower. A
 585             // subsequent AddServer request will be needed to make it an active member.
 586             isActiveMember = false;
 587             peerAddresses = Collections.emptyMap();
 588             shardDatastoreContext = DatastoreContext.newBuilderFrom(shardDatastoreContext)
 589                     .customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName()).build();
 590         }
 591
 592         LOG.debug("{} doCreateShard: shardId: {}, memberNames: {}, peerAddresses: {}, isActiveMember: {}",
 593                 persistenceId(), shardId, moduleShardConfig.getShardMemberNames(), peerAddresses,
 594                 isActiveMember);
 595
 596         ShardInformation info = new ShardInformation(shardName, shardId, peerAddresses,
 597                 shardDatastoreContext, createShard.getShardBuilder(), peerAddressResolver);
 598         info.setActiveMember(isActiveMember);
 599         localShards.put(info.getShardName(), info);
 600
 601         if (schemaContext != null) {
 602             info.setSchemaContext(schemaContext);
 603             info.setActor(newShardActor(info));
 604         }
 605     }
 606
 607     private DatastoreContext.Builder newShardDatastoreContextBuilder(final String shardName) {
 608         return DatastoreContext.newBuilderFrom(datastoreContextFactory.getShardDatastoreContext(shardName))
 609                 .shardPeerAddressResolver(peerAddressResolver);
 610     }
 611
 612     private DatastoreContext newShardDatastoreContext(final String shardName) {
 613         return newShardDatastoreContextBuilder(shardName).build();
 614     }
 615
 616     private void checkReady() {
 617         if (isReadyWithLeaderId()) {
 618             LOG.info("{}: All Shards are ready - data store {} is ready", persistenceId(), type);
 619             readinessFuture.set(null);
 620         }
 621     }
 622
 623     private void onLeaderStateChanged(final ShardLeaderStateChanged leaderStateChanged) {
 624         LOG.info("{}: Received LeaderStateChanged message: {}", persistenceId(), leaderStateChanged);
 625
 626         ShardInformation shardInformation = findShardInformation(leaderStateChanged.getMemberId());
 627         if (shardInformation != null) {
 628             shardInformation.setLocalDataTree(leaderStateChanged.getLocalShardDataTree());
 629             shardInformation.setLeaderVersion(leaderStateChanged.getLeaderPayloadVersion());
 630             if (shardInformation.setLeaderId(leaderStateChanged.getLeaderId())) {
 631                 primaryShardInfoCache.remove(shardInformation.getShardName());
 632
 633                 notifyShardAvailabilityCallbacks(shardInformation);
 634             }
 635
 636             checkReady();
 637         } else {
 638             LOG.debug("No shard found with member Id {}", leaderStateChanged.getMemberId());
 639         }
 640     }
 641
 642     private void notifyShardAvailabilityCallbacks(final ShardInformation shardInformation) {
 643         shardAvailabilityCallbacks.forEach(callback -> callback.accept(shardInformation.getShardName()));
 644     }
 645
 646     private void onShardNotInitializedTimeout(final ShardNotInitializedTimeout message) {
 647         ShardInformation shardInfo = message.getShardInfo();
 648
 649         LOG.debug("{}: Received ShardNotInitializedTimeout message for shard {}", persistenceId(),
 650                 shardInfo.getShardName());
 651
 652         shardInfo.removeOnShardInitialized(message.getOnShardInitialized());
 653
 654         if (!shardInfo.isShardInitialized()) {
 655             LOG.debug("{}: Returning NotInitializedException for shard {}", persistenceId(), shardInfo.getShardName());
 656             message.getSender().tell(createNotInitializedException(shardInfo.getShardId()), getSelf());
 657         } else {
 658             LOG.debug("{}: Returning NoShardLeaderException for shard {}", persistenceId(), shardInfo.getShardName());
 659             message.getSender().tell(new NoShardLeaderException(shardInfo.getShardId()), getSelf());
 660         }
 661     }
 662
 663     private void onFollowerInitialSyncStatus(final FollowerInitialSyncUpStatus status) {
 664         LOG.info("{} Received follower initial sync status for {} status sync done {}", persistenceId(),
 665                 status.getName(), status.isInitialSyncDone());
 666
 667         ShardInformation shardInformation = findShardInformation(status.getName());
 668
 669         if (shardInformation != null) {
 670             shardInformation.setFollowerSyncStatus(status.isInitialSyncDone());
 671
 672             shardManagerMBean.setSyncStatus(isInSync());
 673         }
 674
 675     }
 676
 677     private void onRoleChangeNotification(final RoleChangeNotification roleChanged) {
 678         LOG.info("{}: Received role changed for {} from {} to {}", persistenceId(), roleChanged.getMemberId(),
 679                 roleChanged.getOldRole(), roleChanged.getNewRole());
 680
 681         ShardInformation shardInformation = findShardInformation(roleChanged.getMemberId());
 682         if (shardInformation != null) {
 683             shardInformation.setRole(roleChanged.getNewRole());
 684             checkReady();
 685             shardManagerMBean.setSyncStatus(isInSync());
 686         }
 687     }
 688
 689
 690     private ShardInformation findShardInformation(final String memberId) {
 691         for (ShardInformation info : localShards.values()) {
 692             if (info.getShardId().toString().equals(memberId)) {
 693                 return info;
 694             }
 695         }
 696
 697         return null;
 698     }
 699
 700     private boolean isReadyWithLeaderId() {
 701         boolean isReady = true;
 702         for (ShardInformation info : localShards.values()) {
 703             if (!info.isShardReadyWithLeaderId()) {
 704                 isReady = false;
 705                 break;
 706             }
 707         }
 708         return isReady;
 709     }
 710
 711     private boolean isInSync() {
 712         for (ShardInformation info : localShards.values()) {
 713             if (!info.isInSync()) {
 714                 return false;
 715             }
 716         }
 717         return true;
 718     }
 719
 720     private void onActorInitialized(final Object message) {
 721         final ActorRef sender = getSender();
 722
 723         if (sender == null) {
 724             // why is a non-actor sending this message? Just ignore.
 725             return;
 726         }
 727
 728         String actorName = sender.path().name();
 729         //find shard name from actor name; actor name is stringified shardId
 730
 731         final ShardIdentifier shardId;
 732         try {
 733             shardId = ShardIdentifier.fromShardIdString(actorName);
 734         } catch (IllegalArgumentException e) {
 735             LOG.debug("{}: ignoring actor {}", persistenceId, actorName, e);
 736             return;
 737         }
 738
 739         markShardAsInitialized(shardId.getShardName());
 740     }
 741
 742     private void markShardAsInitialized(final String shardName) {
 743         LOG.debug("{}: Initializing shard [{}]", persistenceId(), shardName);
 744
 745         ShardInformation shardInformation = localShards.get(shardName);
 746         if (shardInformation != null) {
 747             shardInformation.setActorInitialized();
 748
 749             shardInformation.getActor().tell(new RegisterRoleChangeListener(), self());
 750         }
 751     }
 752
 753     @Override
 754     protected void handleRecover(final Object message) throws Exception {
 755         if (message instanceof RecoveryCompleted) {
 756             onRecoveryCompleted();
 757         } else if (message instanceof SnapshotOffer) {
 758             applyShardManagerSnapshot((ShardManagerSnapshot)((SnapshotOffer) message).snapshot());
 759         }
 760     }
 761
 762     @SuppressWarnings("checkstyle:IllegalCatch")
 763     private void onRecoveryCompleted() {
 764         LOG.info("Recovery complete : {}", persistenceId());
 765
 766         if (currentSnapshot == null && restoreFromSnapshot != null
 767                 && restoreFromSnapshot.getShardManagerSnapshot() != null) {
 768             ShardManagerSnapshot snapshot = restoreFromSnapshot.getShardManagerSnapshot();
 769
 770             LOG.debug("{}: Restoring from ShardManagerSnapshot: {}", persistenceId(), snapshot);
 771
 772             applyShardManagerSnapshot(snapshot);
 773         }
 774
 775         createLocalShards();
 776     }
 777
 778     private void sendResponse(final ShardInformation shardInformation, final boolean doWait,
 779             final boolean wantShardReady, final Supplier<Object> messageSupplier) {
 780         if (!shardInformation.isShardInitialized() || wantShardReady && !shardInformation.isShardReadyWithLeaderId()) {
 781             if (doWait) {
 782                 final ActorRef sender = getSender();
 783                 final ActorRef self = self();
 784
 785                 Runnable replyRunnable = () -> sender.tell(messageSupplier.get(), self);
 786
 787                 OnShardInitialized onShardInitialized = wantShardReady ? new OnShardReady(replyRunnable) :
 788                     new OnShardInitialized(replyRunnable);
 789
 790                 shardInformation.addOnShardInitialized(onShardInitialized);
 791
 792                 FiniteDuration timeout = shardInformation.getDatastoreContext()
 793                         .getShardInitializationTimeout().duration();
 794                 if (shardInformation.isShardInitialized()) {
 795                     // If the shard is already initialized then we'll wait enough time for the shard to
 796                     // elect a leader, ie 2 times the election timeout.
 797                     timeout = FiniteDuration.create(shardInformation.getDatastoreContext().getShardRaftConfig()
 798                             .getElectionTimeOutInterval().toMillis() * 2, TimeUnit.MILLISECONDS);
 799                 }
 800
 801                 LOG.debug("{}: Scheduling {} ms timer to wait for shard {}", persistenceId(), timeout.toMillis(),
 802                         shardInformation);
 803
 804                 Cancellable timeoutSchedule = getContext().system().scheduler().scheduleOnce(
 805                         timeout, getSelf(),
 806                         new ShardNotInitializedTimeout(shardInformation, onShardInitialized, sender),
 807                         getContext().dispatcher(), getSelf());
 808
 809                 onShardInitialized.setTimeoutSchedule(timeoutSchedule);
 810
 811             } else if (!shardInformation.isShardInitialized()) {
 812                 LOG.debug("{}: Returning NotInitializedException for shard {}", persistenceId(),
 813                         shardInformation.getShardName());
 814                 getSender().tell(createNotInitializedException(shardInformation.getShardId()), getSelf());
 815             } else {
 816                 LOG.debug("{}: Returning NoShardLeaderException for shard {}", persistenceId(),
 817                         shardInformation.getShardName());
 818                 getSender().tell(new NoShardLeaderException(shardInformation.getShardId()), getSelf());
 819             }
 820
 821             return;
 822         }
 823
 824         getSender().tell(messageSupplier.get(), getSelf());
 825     }
 826
 827     private static NotInitializedException createNotInitializedException(final ShardIdentifier shardId) {
 828         return new NotInitializedException(String.format(
 829                 "Found primary shard %s but it's not initialized yet. Please try again later", shardId));
 830     }
 831
 832     @VisibleForTesting
 833     static MemberName memberToName(final Member member) {
 834         return MemberName.forName(member.roles().iterator().next());
 835     }
 836
 837     private void memberRemoved(final ClusterEvent.MemberRemoved message) {
 838         MemberName memberName = memberToName(message.member());
 839
 840         LOG.info("{}: Received MemberRemoved: memberName: {}, address: {}", persistenceId(), memberName,
 841                 message.member().address());
 842
 843         peerAddressResolver.removePeerAddress(memberName);
 844     }
 845
 846     private void memberExited(final ClusterEvent.MemberExited message) {
 847         MemberName memberName = memberToName(message.member());
 848
 849         LOG.info("{}: Received MemberExited: memberName: {}, address: {}", persistenceId(), memberName,
 850                 message.member().address());
 851
 852         peerAddressResolver.removePeerAddress(memberName);
 853     }
 854
 855     private void memberUp(final ClusterEvent.MemberUp message) {
 856         MemberName memberName = memberToName(message.member());
 857
 858         LOG.info("{}: Received MemberUp: memberName: {}, address: {}", persistenceId(), memberName,
 859                 message.member().address());
 860
 861         memberUp(memberName, message.member().address());
 862     }
 863
 864     private void memberUp(final MemberName memberName, final Address address) {
 865         addPeerAddress(memberName, address);
 866         checkReady();
 867     }
 868
 869     private void memberWeaklyUp(final MemberWeaklyUp message) {
 870         MemberName memberName = memberToName(message.member());
 871
 872         LOG.info("{}: Received MemberWeaklyUp: memberName: {}, address: {}", persistenceId(), memberName,
 873                 message.member().address());
 874
 875         memberUp(memberName, message.member().address());
 876     }
 877
 878     private void addPeerAddress(final MemberName memberName, final Address address) {
 879         peerAddressResolver.addPeerAddress(memberName, address);
 880
 881         for (ShardInformation info : localShards.values()) {
 882             String shardName = info.getShardName();
 883             String peerId = getShardIdentifier(memberName, shardName).toString();
 884             info.updatePeerAddress(peerId, peerAddressResolver.getShardActorAddress(shardName, memberName), getSelf());
 885         }
 886     }
 887
 888     private void memberReachable(final ClusterEvent.ReachableMember message) {
 889         MemberName memberName = memberToName(message.member());
 890         LOG.info("Received ReachableMember: memberName {}, address: {}", memberName, message.member().address());
 891
 892         addPeerAddress(memberName, message.member().address());
 893
 894         markMemberAvailable(memberName);
 895     }
 896
 897     private void memberUnreachable(final ClusterEvent.UnreachableMember message) {
 898         MemberName memberName = memberToName(message.member());
 899         LOG.info("Received UnreachableMember: memberName {}, address: {}", memberName, message.member().address());
 900
 901         markMemberUnavailable(memberName);
 902     }
 903
 904     private void markMemberUnavailable(final MemberName memberName) {
 905         for (ShardInformation info : localShards.values()) {
 906             String leaderId = info.getLeaderId();
 907             if (leaderId != null && ShardIdentifier.fromShardIdString(leaderId).getMemberName().equals(memberName)) {
 908                 LOG.debug("Marking Leader {} as unavailable.", leaderId);
 909                 info.setLeaderAvailable(false);
 910
 911                 primaryShardInfoCache.remove(info.getShardName());
 912
 913                 notifyShardAvailabilityCallbacks(info);
 914             }
 915         }
 916     }
 917
 918     private void markMemberAvailable(final MemberName memberName) {
 919         for (ShardInformation info : localShards.values()) {
 920             String leaderId = info.getLeaderId();
 921             if (leaderId != null && ShardIdentifier.fromShardIdString(leaderId).getMemberName().equals(memberName)) {
 922                 LOG.debug("Marking Leader {} as available.", leaderId);
 923                 info.setLeaderAvailable(true);
 924             }
 925         }
 926     }
 927
 928     private void onDatastoreContextFactory(final DatastoreContextFactory factory) {
 929         datastoreContextFactory = factory;
 930         for (ShardInformation info : localShards.values()) {
 931             info.setDatastoreContext(newShardDatastoreContext(info.getShardName()), getSelf());
 932         }
 933     }
 934
 935     private void onGetLocalShardIds() {
 936         final List<String> response = new ArrayList<>(localShards.size());
 937
 938         for (ShardInformation info : localShards.values()) {
 939             response.add(info.getShardId().toString());
 940         }
 941
 942         getSender().tell(new Status.Success(response), getSelf());
 943     }
 944
 945     private void onSwitchShardBehavior(final SwitchShardBehavior message) {
 946         final ShardIdentifier identifier = message.getShardId();
 947
 948         if (identifier != null) {
 949             final ShardInformation info = localShards.get(identifier.getShardName());
 950             if (info == null) {
 951                 getSender().tell(new Status.Failure(
 952                     new IllegalArgumentException("Shard " + identifier + " is not local")), getSelf());
 953                 return;
 954             }
 955
 956             switchShardBehavior(info, new SwitchBehavior(message.getNewState(), message.getTerm()));
 957         } else {
 958             for (ShardInformation info : localShards.values()) {
 959                 switchShardBehavior(info, new SwitchBehavior(message.getNewState(), message.getTerm()));
 960             }
 961         }
 962
 963         getSender().tell(new Status.Success(null), getSelf());
 964     }
 965
 966     private void switchShardBehavior(final ShardInformation info, final SwitchBehavior switchBehavior) {
 967         final ActorRef actor = info.getActor();
 968         if (actor != null) {
 969             actor.tell(switchBehavior, getSelf());
 970         } else {
 971             LOG.warn("Could not switch the behavior of shard {} to {} - shard is not yet available",
 972                 info.getShardName(), switchBehavior.getNewState());
 973         }
 974     }
 975
 976     /**
 977      * Notifies all the local shards of a change in the schema context.
 978      *
 979      * @param message the message to send
 980      */
 981     private void updateSchemaContext(final Object message) {
 982         schemaContext = ((UpdateSchemaContext) message).getEffectiveModelContext();
 983
 984         LOG.debug("Got updated SchemaContext: # of modules {}", schemaContext.getModules().size());
 985
 986         for (ShardInformation info : localShards.values()) {
 987             info.setSchemaContext(schemaContext);
 988
 989             if (info.getActor() == null) {
 990                 LOG.debug("Creating Shard {}", info.getShardId());
 991                 info.setActor(newShardActor(info));
 992                 // Update peer address for every existing peer memeber to avoid missing sending
 993                 // PeerAddressResolved and PeerUp to this shard while UpdateSchemaContext comes after MemberUp.
 994                 String shardName = info.getShardName();
 995                 for (MemberName memberName : peerAddressResolver.getPeerMembers()) {
 996                     String peerId = getShardIdentifier(memberName, shardName).toString() ;
 997                     String peerAddress = peerAddressResolver.getShardActorAddress(shardName, memberName);
 998                     info.updatePeerAddress(peerId, peerAddress, getSelf());
 999                     LOG.debug("{}: updated peer {} on member {} with address {} on shard {} whose actor address is {}",
1000                             persistenceId(), peerId, memberName, peerAddress, info.getShardId(), info.getActor());
1001                 }
1002             } else {
1003                 info.getActor().tell(message, getSelf());
1004             }
1005         }
1006     }
1007
1008     @VisibleForTesting
1009     protected ClusterWrapper getCluster() {
1010         return cluster;
1011     }
1012
1013     @VisibleForTesting
1014     protected ActorRef newShardActor(final ShardInformation info) {
1015         return getContext().actorOf(info.newProps().withDispatcher(shardDispatcherPath),
1016                 info.getShardId().toString());
1017     }
1018
1019     private void findPrimary(final FindPrimary message) {
1020         LOG.debug("{}: In findPrimary: {}", persistenceId(), message);
1021
1022         final String shardName = message.getShardName();
1023         final boolean canReturnLocalShardState = !(message instanceof RemoteFindPrimary);
1024
1025         // First see if the there is a local replica for the shard
1026         final ShardInformation info = localShards.get(shardName);
1027         if (info != null && info.isActiveMember()) {
1028             sendResponse(info, message.isWaitUntilReady(), true, () -> {
1029                 String primaryPath = info.getSerializedLeaderActor();
1030                 Object found = canReturnLocalShardState && info.isLeader()
1031                         ? new LocalPrimaryShardFound(primaryPath, info.getLocalShardDataTree().get()) :
1032                             new RemotePrimaryShardFound(primaryPath, info.getLeaderVersion());
1033
1034                 LOG.debug("{}: Found primary for {}: {}", persistenceId(), shardName, found);
1035                 return found;
1036             });
1037
1038             return;
1039         }
1040
1041         final Collection<String> visitedAddresses;
1042         if (message instanceof RemoteFindPrimary) {
1043             visitedAddresses = ((RemoteFindPrimary)message).getVisitedAddresses();
1044         } else {
1045             visitedAddresses = new ArrayList<>(1);
1046         }
1047
1048         visitedAddresses.add(peerAddressResolver.getShardManagerActorPathBuilder(cluster.getSelfAddress()).toString());
1049
1050         for (String address: peerAddressResolver.getShardManagerPeerActorAddresses()) {
1051             if (visitedAddresses.contains(address)) {
1052                 continue;
1053             }
1054
1055             LOG.debug("{}: findPrimary for {} forwarding to remote ShardManager {}, visitedAddresses: {}",
1056                     persistenceId(), shardName, address, visitedAddresses);
1057
1058             getContext().actorSelection(address).forward(new RemoteFindPrimary(shardName,
1059                     message.isWaitUntilReady(), visitedAddresses), getContext());
1060             return;
1061         }
1062
1063         LOG.debug("{}: No shard found for {}", persistenceId(), shardName);
1064
1065         getSender().tell(new PrimaryNotFoundException(
1066                 String.format("No primary shard found for %s.", shardName)), getSelf());
1067     }
1068
1069     private void findPrimary(final String shardName, final FindPrimaryResponseHandler handler) {
1070         Timeout findPrimaryTimeout = new Timeout(datastoreContextFactory.getBaseDatastoreContext()
1071                 .getShardInitializationTimeout().duration().$times(2));
1072
1073         Future<Object> futureObj = ask(getSelf(), new FindPrimary(shardName, true), findPrimaryTimeout);
1074         futureObj.onComplete(new OnComplete<>() {
1075             @Override
1076             public void onComplete(final Throwable failure, final Object response) {
1077                 if (failure != null) {
1078                     handler.onFailure(failure);
1079                 } else {
1080                     if (response instanceof RemotePrimaryShardFound) {
1081                         handler.onRemotePrimaryShardFound((RemotePrimaryShardFound) response);
1082                     } else if (response instanceof LocalPrimaryShardFound) {
1083                         handler.onLocalPrimaryFound((LocalPrimaryShardFound) response);
1084                     } else {
1085                         handler.onUnknownResponse(response);
1086                     }
1087                 }
1088             }
1089         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1090     }
1091
1092     /**
1093      * Construct the name of the shard actor given the name of the member on
1094      * which the shard resides and the name of the shard.
1095      *
1096      * @param memberName the member name
1097      * @param shardName the shard name
1098      * @return a b
1099      */
1100     private ShardIdentifier getShardIdentifier(final MemberName memberName, final String shardName) {
1101         return peerAddressResolver.getShardIdentifier(memberName, shardName);
1102     }
1103
1104     /**
1105      * Create shards that are local to the member on which the ShardManager runs.
1106      */
1107     private void createLocalShards() {
1108         MemberName memberName = this.cluster.getCurrentMemberName();
1109         Collection<String> memberShardNames = this.configuration.getMemberShardNames(memberName);
1110
1111         Map<String, DatastoreSnapshot.ShardSnapshot> shardSnapshots = new HashMap<>();
1112         if (restoreFromSnapshot != null) {
1113             for (DatastoreSnapshot.ShardSnapshot snapshot: restoreFromSnapshot.getShardSnapshots()) {
1114                 shardSnapshots.put(snapshot.getName(), snapshot);
1115             }
1116         }
1117
1118         // null out to GC
1119         restoreFromSnapshot = null;
1120
1121         for (String shardName : memberShardNames) {
1122             ShardIdentifier shardId = getShardIdentifier(memberName, shardName);
1123
1124             LOG.debug("{}: Creating local shard: {}", persistenceId(), shardId);
1125
1126             Map<String, String> peerAddresses = getPeerAddresses(shardName);
1127             localShards.put(shardName, createShardInfoFor(shardName, shardId, peerAddresses,
1128                     newShardDatastoreContext(shardName), shardSnapshots));
1129         }
1130     }
1131
1132     @VisibleForTesting
1133     ShardInformation createShardInfoFor(final String shardName, final ShardIdentifier shardId,
1134                                         final Map<String, String> peerAddresses,
1135                                         final DatastoreContext datastoreContext,
1136                                         final Map<String, DatastoreSnapshot.ShardSnapshot> shardSnapshots) {
1137         return new ShardInformation(shardName, shardId, peerAddresses,
1138                 datastoreContext, Shard.builder().restoreFromSnapshot(shardSnapshots.get(shardName)),
1139                 peerAddressResolver);
1140     }
1141
1142     /**
1143      * Given the name of the shard find the addresses of all it's peers.
1144      *
1145      * @param shardName the shard name
1146      */
1147     Map<String, String> getPeerAddresses(final String shardName) {
1148         final Collection<MemberName> members = configuration.getMembersFromShardName(shardName);
1149         return getPeerAddresses(shardName, members);
1150     }
1151
1152     private Map<String, String> getPeerAddresses(final String shardName, final Collection<MemberName> members) {
1153         Map<String, String> peerAddresses = new HashMap<>();
1154         MemberName currentMemberName = this.cluster.getCurrentMemberName();
1155
1156         for (MemberName memberName : members) {
1157             if (!currentMemberName.equals(memberName)) {
1158                 ShardIdentifier shardId = getShardIdentifier(memberName, shardName);
1159                 String address = peerAddressResolver.getShardActorAddress(shardName, memberName);
1160                 peerAddresses.put(shardId.toString(), address);
1161             }
1162         }
1163         return peerAddresses;
1164     }
1165
1166     @Override
1167     public SupervisorStrategy supervisorStrategy() {
1168
1169         return new OneForOneStrategy(10, FiniteDuration.create(1, TimeUnit.MINUTES),
1170                 (Function<Throwable, Directive>) t -> {
1171                     LOG.warn("Supervisor Strategy caught unexpected exception - resuming", t);
1172                     return SupervisorStrategy.resume();
1173                 });
1174     }
1175
1176     @Override
1177     public String persistenceId() {
1178         return persistenceId;
1179     }
1180
1181     @VisibleForTesting
1182     ShardManagerInfoMBean getMBean() {
1183         return shardManagerMBean;
1184     }
1185
1186     private boolean isShardReplicaOperationInProgress(final String shardName, final ActorRef sender) {
1187         if (shardReplicaOperationsInProgress.contains(shardName)) {
1188             LOG.debug("{}: A shard replica operation for {} is already in progress", persistenceId(), shardName);
1189             sender.tell(new Status.Failure(new IllegalStateException(
1190                 String.format("A shard replica operation for %s is already in progress", shardName))), getSelf());
1191             return true;
1192         }
1193
1194         return false;
1195     }
1196
1197     private void onAddShardReplica(final AddShardReplica shardReplicaMsg) {
1198         final String shardName = shardReplicaMsg.getShardName();
1199
1200         LOG.debug("{}: onAddShardReplica: {}", persistenceId(), shardReplicaMsg);
1201
1202         // verify the shard with the specified name is present in the cluster configuration
1203         if (!this.configuration.isShardConfigured(shardName)) {
1204             LOG.debug("{}: No module configuration exists for shard {}", persistenceId(), shardName);
1205             getSender().tell(new Status.Failure(new IllegalArgumentException(
1206                 "No module configuration exists for shard " + shardName)), getSelf());
1207             return;
1208         }
1209
1210         // Create the localShard
1211         if (schemaContext == null) {
1212             LOG.debug("{}: No SchemaContext is available in order to create a local shard instance for {}",
1213                 persistenceId(), shardName);
1214             getSender().tell(new Status.Failure(new IllegalStateException(
1215                 "No SchemaContext is available in order to create a local shard instance for " + shardName)),
1216                 getSelf());
1217             return;
1218         }
1219
1220         findPrimary(shardName, new AutoFindPrimaryFailureResponseHandler(getSender(), shardName, persistenceId(),
1221                 getSelf()) {
1222             @Override
1223             public void onRemotePrimaryShardFound(final RemotePrimaryShardFound response) {
1224                 final RunnableMessage runnable = (RunnableMessage) () ->
1225                     addShard(getShardName(), response, getSender());
1226                 if (!isPreviousShardActorStopInProgress(getShardName(), runnable)) {
1227                     getSelf().tell(runnable, getTargetActor());
1228                 }
1229             }
1230
1231             @Override
1232             public void onLocalPrimaryFound(final LocalPrimaryShardFound message) {
1233                 sendLocalReplicaAlreadyExistsReply(getShardName(), getTargetActor());
1234             }
1235         });
1236     }
1237
1238     @SuppressFBWarnings(value = "UPM_UNCALLED_PRIVATE_METHOD",
1239             justification = "https://github.com/spotbugs/spotbugs/issues/811")
1240     private void sendLocalReplicaAlreadyExistsReply(final String shardName, final ActorRef sender) {
1241         LOG.debug("{}: Local shard {} already exists", persistenceId(), shardName);
1242         sender.tell(new Status.Failure(new AlreadyExistsException(
1243             String.format("Local shard %s already exists", shardName))), getSelf());
1244     }
1245
1246     @SuppressFBWarnings(value = "UPM_UNCALLED_PRIVATE_METHOD",
1247             justification = "https://github.com/spotbugs/spotbugs/issues/811")
1248     private void addShard(final String shardName, final RemotePrimaryShardFound response, final ActorRef sender) {
1249         if (isShardReplicaOperationInProgress(shardName, sender)) {
1250             return;
1251         }
1252
1253         shardReplicaOperationsInProgress.add(shardName);
1254
1255         final ShardInformation shardInfo;
1256         final boolean removeShardOnFailure;
1257         ShardInformation existingShardInfo = localShards.get(shardName);
1258         if (existingShardInfo == null) {
1259             removeShardOnFailure = true;
1260             ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
1261
1262             DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName)
1263                     .customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName()).build();
1264
1265             shardInfo = new ShardInformation(shardName, shardId, getPeerAddresses(shardName), datastoreContext,
1266                     Shard.builder(), peerAddressResolver);
1267             shardInfo.setActiveMember(false);
1268             shardInfo.setSchemaContext(schemaContext);
1269             localShards.put(shardName, shardInfo);
1270             shardInfo.setActor(newShardActor(shardInfo));
1271         } else {
1272             removeShardOnFailure = false;
1273             shardInfo = existingShardInfo;
1274         }
1275
1276         execAddShard(shardName, shardInfo, response, removeShardOnFailure, sender);
1277     }
1278
1279     private void execAddShard(final String shardName,
1280                               final ShardInformation shardInfo,
1281                               final RemotePrimaryShardFound response,
1282                               final boolean removeShardOnFailure,
1283                               final ActorRef sender) {
1284
1285         final String localShardAddress =
1286                 peerAddressResolver.getShardActorAddress(shardName, cluster.getCurrentMemberName());
1287
1288         //inform ShardLeader to add this shard as a replica by sending an AddServer message
1289         LOG.debug("{}: Sending AddServer message to peer {} for shard {}", persistenceId(),
1290                 response.getPrimaryPath(), shardInfo.getShardId());
1291
1292         final Timeout addServerTimeout = new Timeout(shardInfo.getDatastoreContext()
1293                 .getShardLeaderElectionTimeout().duration());
1294         final Future<Object> futureObj = ask(getContext().actorSelection(response.getPrimaryPath()),
1295                 new AddServer(shardInfo.getShardId().toString(), localShardAddress, true), addServerTimeout);
1296
1297         futureObj.onComplete(new OnComplete<>() {
1298             @Override
1299             public void onComplete(final Throwable failure, final Object addServerResponse) {
1300                 if (failure != null) {
1301                     LOG.debug("{}: AddServer request to {} for {} failed", persistenceId(),
1302                             response.getPrimaryPath(), shardName, failure);
1303
1304                     final String msg = String.format("AddServer request to leader %s for shard %s failed",
1305                             response.getPrimaryPath(), shardName);
1306                     self().tell(new ForwardedAddServerFailure(shardName, msg, failure, removeShardOnFailure), sender);
1307                 } else {
1308                     self().tell(new ForwardedAddServerReply(shardInfo, (AddServerReply)addServerResponse,
1309                             response.getPrimaryPath(), removeShardOnFailure), sender);
1310                 }
1311             }
1312         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1313     }
1314
1315     private void onAddServerFailure(final String shardName, final String message, final Throwable failure,
1316             final ActorRef sender, final boolean removeShardOnFailure) {
1317         shardReplicaOperationsInProgress.remove(shardName);
1318
1319         if (removeShardOnFailure) {
1320             ShardInformation shardInfo = localShards.remove(shardName);
1321             if (shardInfo.getActor() != null) {
1322                 shardInfo.getActor().tell(PoisonPill.getInstance(), getSelf());
1323             }
1324         }
1325
1326         sender.tell(new Status.Failure(message == null ? failure :
1327             new RuntimeException(message, failure)), getSelf());
1328     }
1329
1330     private void onAddServerReply(final ShardInformation shardInfo, final AddServerReply replyMsg,
1331             final ActorRef sender, final String leaderPath, final boolean removeShardOnFailure) {
1332         String shardName = shardInfo.getShardName();
1333         shardReplicaOperationsInProgress.remove(shardName);
1334
1335         LOG.debug("{}: Received {} for shard {} from leader {}", persistenceId(), replyMsg, shardName, leaderPath);
1336
1337         if (replyMsg.getStatus() == ServerChangeStatus.OK) {
1338             LOG.debug("{}: Leader shard successfully added the replica shard {}", persistenceId(), shardName);
1339
1340             // Make the local shard voting capable
1341             shardInfo.setDatastoreContext(newShardDatastoreContext(shardName), getSelf());
1342             shardInfo.setActiveMember(true);
1343             persistShardList();
1344
1345             sender.tell(new Status.Success(null), getSelf());
1346         } else if (replyMsg.getStatus() == ServerChangeStatus.ALREADY_EXISTS) {
1347             sendLocalReplicaAlreadyExistsReply(shardName, sender);
1348         } else {
1349             LOG.warn("{}: Leader failed to add shard replica {} with status {}",
1350                     persistenceId(), shardName, replyMsg.getStatus());
1351
1352             Exception failure = getServerChangeException(AddServer.class, replyMsg.getStatus(), leaderPath,
1353                     shardInfo.getShardId());
1354
1355             onAddServerFailure(shardName, null, failure, sender, removeShardOnFailure);
1356         }
1357     }
1358
1359     private static Exception getServerChangeException(final Class<?> serverChange,
1360             final ServerChangeStatus serverChangeStatus, final String leaderPath, final ShardIdentifier shardId) {
1361         switch (serverChangeStatus) {
1362             case TIMEOUT:
1363                 return new TimeoutException(String.format(
1364                         "The shard leader %s timed out trying to replicate the initial data to the new shard %s."
1365                         + "Possible causes - there was a problem replicating the data or shard leadership changed "
1366                         + "while replicating the shard data", leaderPath, shardId.getShardName()));
1367             case NO_LEADER:
1368                 return new NoShardLeaderException(shardId);
1369             case NOT_SUPPORTED:
1370                 return new UnsupportedOperationException(String.format("%s request is not supported for shard %s",
1371                         serverChange.getSimpleName(), shardId.getShardName()));
1372             default :
1373                 return new RuntimeException(String.format("%s request to leader %s for shard %s failed with status %s",
1374                         serverChange.getSimpleName(), leaderPath, shardId.getShardName(), serverChangeStatus));
1375         }
1376     }
1377
1378     private void onRemoveShardReplica(final RemoveShardReplica shardReplicaMsg) {
1379         LOG.debug("{}: onRemoveShardReplica: {}", persistenceId(), shardReplicaMsg);
1380
1381         findPrimary(shardReplicaMsg.getShardName(), new AutoFindPrimaryFailureResponseHandler(getSender(),
1382                 shardReplicaMsg.getShardName(), persistenceId(), getSelf()) {
1383             @Override
1384             public void onRemotePrimaryShardFound(final RemotePrimaryShardFound response) {
1385                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1386             }
1387
1388             @Override
1389             public void onLocalPrimaryFound(final LocalPrimaryShardFound response) {
1390                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1391             }
1392
1393             private void doRemoveShardReplicaAsync(final String primaryPath) {
1394                 getSelf().tell((RunnableMessage) () -> removeShardReplica(shardReplicaMsg, getShardName(),
1395                         primaryPath, getSender()), getTargetActor());
1396             }
1397         });
1398     }
1399
1400     private void persistShardList() {
1401         List<String> shardList = new ArrayList<>(localShards.keySet());
1402         for (ShardInformation shardInfo : localShards.values()) {
1403             if (!shardInfo.isActiveMember()) {
1404                 shardList.remove(shardInfo.getShardName());
1405             }
1406         }
1407         LOG.debug("{}: persisting the shard list {}", persistenceId(), shardList);
1408         saveSnapshot(updateShardManagerSnapshot(shardList));
1409     }
1410
1411     private ShardManagerSnapshot updateShardManagerSnapshot(final List<String> shardList) {
1412         currentSnapshot = new ShardManagerSnapshot(shardList);
1413         return currentSnapshot;
1414     }
1415
1416     private void applyShardManagerSnapshot(final ShardManagerSnapshot snapshot) {
1417         currentSnapshot = snapshot;
1418
1419         LOG.debug("{}: onSnapshotOffer: {}", persistenceId(), currentSnapshot);
1420
1421         final MemberName currentMember = cluster.getCurrentMemberName();
1422         Set<String> configuredShardList =
1423             new HashSet<>(configuration.getMemberShardNames(currentMember));
1424         for (String shard : currentSnapshot.getShardList()) {
1425             if (!configuredShardList.contains(shard)) {
1426                 // add the current member as a replica for the shard
1427                 LOG.debug("{}: adding shard {}", persistenceId(), shard);
1428                 configuration.addMemberReplicaForShard(shard, currentMember);
1429             } else {
1430                 configuredShardList.remove(shard);
1431             }
1432         }
1433         for (String shard : configuredShardList) {
1434             // remove the member as a replica for the shard
1435             LOG.debug("{}: removing shard {}", persistenceId(), shard);
1436             configuration.removeMemberReplicaForShard(shard, currentMember);
1437         }
1438     }
1439
1440     private void onSaveSnapshotSuccess(final SaveSnapshotSuccess successMessage) {
1441         LOG.debug("{} saved ShardManager snapshot successfully. Deleting the prev snapshot if available",
1442             persistenceId());
1443         deleteSnapshots(new SnapshotSelectionCriteria(scala.Long.MaxValue(), successMessage.metadata().timestamp() - 1,
1444             0, 0));
1445     }
1446
1447     private void onChangeShardServersVotingStatus(final ChangeShardMembersVotingStatus changeMembersVotingStatus) {
1448         LOG.debug("{}: onChangeShardServersVotingStatus: {}", persistenceId(), changeMembersVotingStatus);
1449
1450         String shardName = changeMembersVotingStatus.getShardName();
1451         Map<String, Boolean> serverVotingStatusMap = new HashMap<>();
1452         for (Entry<String, Boolean> e: changeMembersVotingStatus.getMeberVotingStatusMap().entrySet()) {
1453             serverVotingStatusMap.put(getShardIdentifier(MemberName.forName(e.getKey()), shardName).toString(),
1454                     e.getValue());
1455         }
1456
1457         ChangeServersVotingStatus changeServersVotingStatus = new ChangeServersVotingStatus(serverVotingStatusMap);
1458
1459         findLocalShard(shardName, getSender(),
1460             localShardFound -> changeShardMembersVotingStatus(changeServersVotingStatus, shardName,
1461             localShardFound.getPath(), getSender()));
1462     }
1463
1464     private void onFlipShardMembersVotingStatus(final FlipShardMembersVotingStatus flipMembersVotingStatus) {
1465         LOG.debug("{}: onFlipShardMembersVotingStatus: {}", persistenceId(), flipMembersVotingStatus);
1466
1467         ActorRef sender = getSender();
1468         final String shardName = flipMembersVotingStatus.getShardName();
1469         findLocalShard(shardName, sender, localShardFound -> {
1470             Future<Object> future = ask(localShardFound.getPath(), GetOnDemandRaftState.INSTANCE,
1471                     Timeout.apply(30, TimeUnit.SECONDS));
1472
1473             future.onComplete(new OnComplete<>() {
1474                 @Override
1475                 public void onComplete(final Throwable failure, final Object response) {
1476                     if (failure != null) {
1477                         sender.tell(new Status.Failure(new RuntimeException(
1478                                 String.format("Failed to access local shard %s", shardName), failure)), self());
1479                         return;
1480                     }
1481
1482                     OnDemandRaftState raftState = (OnDemandRaftState) response;
1483                     Map<String, Boolean> serverVotingStatusMap = new HashMap<>();
1484                     for (Entry<String, Boolean> e: raftState.getPeerVotingStates().entrySet()) {
1485                         serverVotingStatusMap.put(e.getKey(), !e.getValue());
1486                     }
1487
1488                     serverVotingStatusMap.put(getShardIdentifier(cluster.getCurrentMemberName(), shardName)
1489                             .toString(), !raftState.isVoting());
1490
1491                     changeShardMembersVotingStatus(new ChangeServersVotingStatus(serverVotingStatusMap),
1492                             shardName, localShardFound.getPath(), sender);
1493                 }
1494             }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1495         });
1496
1497     }
1498
1499     private void findLocalShard(final FindLocalShard message) {
1500         LOG.debug("{}: findLocalShard : {}", persistenceId(), message.getShardName());
1501
1502         final ShardInformation shardInformation = localShards.get(message.getShardName());
1503
1504         if (shardInformation == null) {
1505             LOG.debug("{}: Local shard {} not found - shards present: {}",
1506                     persistenceId(), message.getShardName(), localShards.keySet());
1507
1508             getSender().tell(new LocalShardNotFound(message.getShardName()), getSelf());
1509             return;
1510         }
1511
1512         sendResponse(shardInformation, message.isWaitUntilInitialized(), false,
1513             () -> new LocalShardFound(shardInformation.getActor()));
1514     }
1515
1516     private void findLocalShard(final String shardName, final ActorRef sender,
1517             final Consumer<LocalShardFound> onLocalShardFound) {
1518         Timeout findLocalTimeout = new Timeout(datastoreContextFactory.getBaseDatastoreContext()
1519                 .getShardInitializationTimeout().duration().$times(2));
1520
1521         Future<Object> futureObj = ask(getSelf(), new FindLocalShard(shardName, true), findLocalTimeout);
1522         futureObj.onComplete(new OnComplete<>() {
1523             @Override
1524             public void onComplete(final Throwable failure, final Object response) {
1525                 if (failure != null) {
1526                     LOG.debug("{}: Received failure from FindLocalShard for shard {}", persistenceId, shardName,
1527                             failure);
1528                     sender.tell(new Status.Failure(new RuntimeException(
1529                             String.format("Failed to find local shard %s", shardName), failure)), self());
1530                 } else {
1531                     if (response instanceof LocalShardFound) {
1532                         getSelf().tell((RunnableMessage) () -> onLocalShardFound.accept((LocalShardFound) response),
1533                                 sender);
1534                     } else if (response instanceof LocalShardNotFound) {
1535                         LOG.debug("{}: Local shard {} does not exist", persistenceId, shardName);
1536                         sender.tell(new Status.Failure(new IllegalArgumentException(
1537                             String.format("Local shard %s does not exist", shardName))), self());
1538                     } else {
1539                         LOG.debug("{}: Failed to find local shard {}: received response: {}", persistenceId, shardName,
1540                             response);
1541                         sender.tell(new Status.Failure(response instanceof Throwable ? (Throwable) response
1542                                 : new RuntimeException(
1543                                     String.format("Failed to find local shard %s: received response: %s", shardName,
1544                                         response))), self());
1545                     }
1546                 }
1547             }
1548         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1549     }
1550
1551     private void changeShardMembersVotingStatus(final ChangeServersVotingStatus changeServersVotingStatus,
1552             final String shardName, final ActorRef shardActorRef, final ActorRef sender) {
1553         if (isShardReplicaOperationInProgress(shardName, sender)) {
1554             return;
1555         }
1556
1557         shardReplicaOperationsInProgress.add(shardName);
1558
1559         DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName).build();
1560         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
1561
1562         LOG.debug("{}: Sending ChangeServersVotingStatus message {} to local shard {}", persistenceId(),
1563                 changeServersVotingStatus, shardActorRef.path());
1564
1565         Timeout timeout = new Timeout(datastoreContext.getShardLeaderElectionTimeout().duration().$times(2));
1566         Future<Object> futureObj = ask(shardActorRef, changeServersVotingStatus, timeout);
1567
1568         futureObj.onComplete(new OnComplete<>() {
1569             @Override
1570             public void onComplete(final Throwable failure, final Object response) {
1571                 shardReplicaOperationsInProgress.remove(shardName);
1572                 if (failure != null) {
1573                     LOG.debug("{}: ChangeServersVotingStatus request to local shard {} failed", persistenceId(),
1574                         shardActorRef.path(), failure);
1575                     sender.tell(new Status.Failure(new RuntimeException(
1576                         String.format("ChangeServersVotingStatus request to local shard %s failed",
1577                             shardActorRef.path()), failure)), self());
1578                 } else {
1579                     LOG.debug("{}: Received {} from local shard {}", persistenceId(), response, shardActorRef.path());
1580
1581                     ServerChangeReply replyMsg = (ServerChangeReply) response;
1582                     if (replyMsg.getStatus() == ServerChangeStatus.OK) {
1583                         LOG.debug("{}: ChangeServersVotingStatus succeeded for shard {}", persistenceId(), shardName);
1584                         sender.tell(new Status.Success(null), getSelf());
1585                     } else if (replyMsg.getStatus() == ServerChangeStatus.INVALID_REQUEST) {
1586                         sender.tell(new Status.Failure(new IllegalArgumentException(String.format(
1587                                 "The requested voting state change for shard %s is invalid. At least one member "
1588                                 + "must be voting", shardId.getShardName()))), getSelf());
1589                     } else {
1590                         LOG.warn("{}: ChangeServersVotingStatus failed for shard {} with status {}",
1591                                 persistenceId(), shardName, replyMsg.getStatus());
1592
1593                         Exception error = getServerChangeException(ChangeServersVotingStatus.class,
1594                                 replyMsg.getStatus(), shardActorRef.path().toString(), shardId);
1595                         sender.tell(new Status.Failure(error), getSelf());
1596                     }
1597                 }
1598             }
1599         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1600     }
1601
1602     private static final class ForwardedAddServerReply {
1603         ShardInformation shardInfo;
1604         AddServerReply addServerReply;
1605         String leaderPath;
1606         boolean removeShardOnFailure;
1607
1608         ForwardedAddServerReply(final ShardInformation shardInfo, final AddServerReply addServerReply,
1609             final String leaderPath, final boolean removeShardOnFailure) {
1610             this.shardInfo = shardInfo;
1611             this.addServerReply = addServerReply;
1612             this.leaderPath = leaderPath;
1613             this.removeShardOnFailure = removeShardOnFailure;
1614         }
1615     }
1616
1617     private static final class ForwardedAddServerFailure {
1618         String shardName;
1619         String failureMessage;
1620         Throwable failure;
1621         boolean removeShardOnFailure;
1622
1623         ForwardedAddServerFailure(final String shardName, final String failureMessage, final Throwable failure,
1624                 final boolean removeShardOnFailure) {
1625             this.shardName = shardName;
1626             this.failureMessage = failureMessage;
1627             this.failure = failure;
1628             this.removeShardOnFailure = removeShardOnFailure;
1629         }
1630     }
1631
1632     static class OnShardInitialized {
1633         private final Runnable replyRunnable;
1634         private Cancellable timeoutSchedule;
1635
1636         OnShardInitialized(final Runnable replyRunnable) {
1637             this.replyRunnable = replyRunnable;
1638         }
1639
1640         Runnable getReplyRunnable() {
1641             return replyRunnable;
1642         }
1643
1644         Cancellable getTimeoutSchedule() {
1645             return timeoutSchedule;
1646         }
1647
1648         void setTimeoutSchedule(final Cancellable timeoutSchedule) {
1649             this.timeoutSchedule = timeoutSchedule;
1650         }
1651     }
1652
1653     static class OnShardReady extends OnShardInitialized {
1654         OnShardReady(final Runnable replyRunnable) {
1655             super(replyRunnable);
1656         }
1657     }
1658
1659     private interface RunnableMessage extends Runnable {
1660     }
1661
1662     /**
1663      * The FindPrimaryResponseHandler provides specific callback methods which are invoked when a response to the
1664      * a remote or local find primary message is processed.
1665      */
1666     private interface FindPrimaryResponseHandler {
1667         /**
1668          * Invoked when a Failure message is received as a response.
1669          *
1670          * @param failure the failure exception
1671          */
1672         void onFailure(Throwable failure);
1673
1674         /**
1675          * Invoked when a RemotePrimaryShardFound response is received.
1676          *
1677          * @param response the response
1678          */
1679         void onRemotePrimaryShardFound(RemotePrimaryShardFound response);
1680
1681         /**
1682          * Invoked when a LocalPrimaryShardFound response is received.
1683          *
1684          * @param response the response
1685          */
1686         void onLocalPrimaryFound(LocalPrimaryShardFound response);
1687
1688         /**
1689          * Invoked when an unknown response is received. This is another type of failure.
1690          *
1691          * @param response the response
1692          */
1693         void onUnknownResponse(Object response);
1694     }
1695
1696     /**
1697      * The AutoFindPrimaryFailureResponseHandler automatically processes Failure responses when finding a primary
1698      * replica and sends a wrapped Failure response to some targetActor.
1699      */
1700     private abstract static class AutoFindPrimaryFailureResponseHandler implements FindPrimaryResponseHandler {
1701         private final ActorRef targetActor;
1702         private final String shardName;
1703         private final String persistenceId;
1704         private final ActorRef shardManagerActor;
1705
1706         /**
1707          * Constructs an instance.
1708          *
1709          * @param targetActor The actor to whom the Failure response should be sent when a FindPrimary failure occurs
1710          * @param shardName The name of the shard for which the primary replica had to be found
1711          * @param persistenceId The persistenceId for the ShardManager
1712          * @param shardManagerActor The ShardManager actor which triggered the call to FindPrimary
1713          */
1714         protected AutoFindPrimaryFailureResponseHandler(final ActorRef targetActor, final String shardName,
1715                 final String persistenceId, final ActorRef shardManagerActor) {
1716             this.targetActor = requireNonNull(targetActor);
1717             this.shardName = requireNonNull(shardName);
1718             this.persistenceId = requireNonNull(persistenceId);
1719             this.shardManagerActor = requireNonNull(shardManagerActor);
1720         }
1721
1722         public ActorRef getTargetActor() {
1723             return targetActor;
1724         }
1725
1726         public String getShardName() {
1727             return shardName;
1728         }
1729
1730         @Override
1731         public void onFailure(final Throwable failure) {
1732             LOG.debug("{}: Received failure from FindPrimary for shard {}", persistenceId, shardName, failure);
1733             targetActor.tell(new Status.Failure(new RuntimeException(
1734                     String.format("Failed to find leader for shard %s", shardName), failure)), shardManagerActor);
1735         }
1736
1737         @Override
1738         public void onUnknownResponse(final Object response) {
1739             LOG.debug("{}: Failed to find leader for shard {}: received response: {}", persistenceId, shardName,
1740                 response);
1741             targetActor.tell(new Status.Failure(response instanceof Throwable ? (Throwable) response
1742                     : new RuntimeException(String.format("Failed to find leader for shard %s: received response: %s",
1743                         shardName, response))), shardManagerActor);
1744         }
1745     }
1746
1747     /**
1748      * The WrappedShardResponse class wraps a response from a Shard.
1749      */
1750     private static final class WrappedShardResponse {
1751         private final ShardIdentifier shardId;
1752         private final Object response;
1753         private final String leaderPath;
1754
1755         WrappedShardResponse(final ShardIdentifier shardId, final Object response, final String leaderPath) {
1756             this.shardId = shardId;
1757             this.response = response;
1758             this.leaderPath = leaderPath;
1759         }
1760
1761         ShardIdentifier getShardId() {
1762             return shardId;
1763         }
1764
1765         Object getResponse() {
1766             return response;
1767         }
1768
1769         String getLeaderPath() {
1770             return leaderPath;
1771         }
1772     }
1773
1774     private static final class ShardNotInitializedTimeout {
1775         private final ActorRef sender;
1776         private final ShardInformation shardInfo;
1777         private final OnShardInitialized onShardInitialized;
1778
1779         ShardNotInitializedTimeout(final ShardInformation shardInfo, final OnShardInitialized onShardInitialized,
1780             final ActorRef sender) {
1781             this.sender = sender;
1782             this.shardInfo = shardInfo;
1783             this.onShardInitialized = onShardInitialized;
1784         }
1785
1786         ActorRef getSender() {
1787             return sender;
1788         }
1789
1790         ShardInformation getShardInfo() {
1791             return shardInfo;
1792         }
1793
1794         OnShardInitialized getOnShardInitialized() {
1795             return onShardInitialized;
1796         }
1797     }
1798 }
1799
1800
1801