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
  13 import akka.actor.ActorRef;
  14 import akka.actor.Address;
  15 import akka.actor.Cancellable;
  16 import akka.actor.OneForOneStrategy;
  17 import akka.actor.PoisonPill;
  18 import akka.actor.Status;
  19 import akka.actor.SupervisorStrategy;
  20 import akka.actor.SupervisorStrategy.Directive;
  21 import akka.cluster.ClusterEvent;
  22 import akka.cluster.ClusterEvent.MemberWeaklyUp;
  23 import akka.cluster.Member;
  24 import akka.dispatch.Futures;
  25 import akka.dispatch.OnComplete;
  26 import akka.japi.Function;
  27 import akka.pattern.Patterns;
  28 import akka.persistence.RecoveryCompleted;
  29 import akka.persistence.SaveSnapshotFailure;
  30 import akka.persistence.SaveSnapshotSuccess;
  31 import akka.persistence.SnapshotOffer;
  32 import akka.persistence.SnapshotSelectionCriteria;
  33 import akka.util.Timeout;
  34 import com.google.common.annotations.VisibleForTesting;
  35 import com.google.common.base.Preconditions;
  36 import java.util.ArrayList;
  37 import java.util.Collection;
  38 import java.util.Collections;
  39 import java.util.HashMap;
  40 import java.util.HashSet;
  41 import java.util.List;
  42 import java.util.Map;
  43 import java.util.Map.Entry;
  44 import java.util.Set;
  45 import java.util.concurrent.CountDownLatch;
  46 import java.util.concurrent.TimeUnit;
  47 import java.util.concurrent.TimeoutException;
  48 import java.util.function.Consumer;
  49 import java.util.function.Supplier;
  50 import org.opendaylight.controller.cluster.access.concepts.MemberName;
  51 import org.opendaylight.controller.cluster.common.actor.AbstractUntypedPersistentActorWithMetering;
  52 import org.opendaylight.controller.cluster.datastore.AbstractDataStore;
  53 import org.opendaylight.controller.cluster.datastore.ClusterWrapper;
  54 import org.opendaylight.controller.cluster.datastore.DatastoreContext;
  55 import org.opendaylight.controller.cluster.datastore.DatastoreContext.Builder;
  56 import org.opendaylight.controller.cluster.datastore.DatastoreContextFactory;
  57 import org.opendaylight.controller.cluster.datastore.Shard;
  58 import org.opendaylight.controller.cluster.datastore.config.Configuration;
  59 import org.opendaylight.controller.cluster.datastore.config.ModuleShardConfiguration;
  60 import org.opendaylight.controller.cluster.datastore.config.PrefixShardConfiguration;
  61 import org.opendaylight.controller.cluster.datastore.exceptions.AlreadyExistsException;
  62 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
  63 import org.opendaylight.controller.cluster.datastore.exceptions.NotInitializedException;
  64 import org.opendaylight.controller.cluster.datastore.exceptions.PrimaryNotFoundException;
  65 import org.opendaylight.controller.cluster.datastore.identifiers.ShardIdentifier;
  66 import org.opendaylight.controller.cluster.datastore.messages.ActorInitialized;
  67 import org.opendaylight.controller.cluster.datastore.messages.AddPrefixShardReplica;
  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.LocalPrimaryShardFound;
  75 import org.opendaylight.controller.cluster.datastore.messages.LocalShardFound;
  76 import org.opendaylight.controller.cluster.datastore.messages.LocalShardNotFound;
  77 import org.opendaylight.controller.cluster.datastore.messages.RemoteFindPrimary;
  78 import org.opendaylight.controller.cluster.datastore.messages.RemotePrimaryShardFound;
  79 import org.opendaylight.controller.cluster.datastore.messages.RemovePrefixShardReplica;
  80 import org.opendaylight.controller.cluster.datastore.messages.RemoveShardReplica;
  81 import org.opendaylight.controller.cluster.datastore.messages.ShardLeaderStateChanged;
  82 import org.opendaylight.controller.cluster.datastore.messages.UpdateSchemaContext;
  83 import org.opendaylight.controller.cluster.datastore.persisted.DatastoreSnapshot;
  84 import org.opendaylight.controller.cluster.datastore.persisted.ShardManagerSnapshot;
  85 import org.opendaylight.controller.cluster.datastore.utils.ClusterUtils;
  86 import org.opendaylight.controller.cluster.datastore.utils.Dispatchers;
  87 import org.opendaylight.controller.cluster.datastore.utils.PrimaryShardInfoFutureCache;
  88 import org.opendaylight.controller.cluster.notifications.RegisterRoleChangeListener;
  89 import org.opendaylight.controller.cluster.notifications.RoleChangeNotification;
  90 import org.opendaylight.controller.cluster.raft.base.messages.FollowerInitialSyncUpStatus;
  91 import org.opendaylight.controller.cluster.raft.base.messages.SwitchBehavior;
  92 import org.opendaylight.controller.cluster.raft.client.messages.GetOnDemandRaftState;
  93 import org.opendaylight.controller.cluster.raft.client.messages.GetSnapshot;
  94 import org.opendaylight.controller.cluster.raft.client.messages.OnDemandRaftState;
  95 import org.opendaylight.controller.cluster.raft.client.messages.Shutdown;
  96 import org.opendaylight.controller.cluster.raft.messages.AddServer;
  97 import org.opendaylight.controller.cluster.raft.messages.AddServerReply;
  98 import org.opendaylight.controller.cluster.raft.messages.ChangeServersVotingStatus;
  99 import org.opendaylight.controller.cluster.raft.messages.RemoveServer;
 100 import org.opendaylight.controller.cluster.raft.messages.RemoveServerReply;
 101 import org.opendaylight.controller.cluster.raft.messages.ServerChangeReply;
 102 import org.opendaylight.controller.cluster.raft.messages.ServerChangeStatus;
 103 import org.opendaylight.controller.cluster.raft.messages.ServerRemoved;
 104 import org.opendaylight.controller.cluster.raft.policy.DisableElectionsRaftPolicy;
 105 import org.opendaylight.controller.cluster.sharding.PrefixedShardConfigUpdateHandler;
 106 import org.opendaylight.controller.cluster.sharding.messages.InitConfigListener;
 107 import org.opendaylight.controller.cluster.sharding.messages.PrefixShardCreated;
 108 import org.opendaylight.controller.cluster.sharding.messages.PrefixShardRemoved;
 109 import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
 110 import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeChangeListener;
 111 import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
 112 import org.opendaylight.yangtools.concepts.ListenerRegistration;
 113 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
 114 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
 115 import org.slf4j.Logger;
 116 import org.slf4j.LoggerFactory;
 117 import scala.concurrent.ExecutionContext;
 118 import scala.concurrent.Future;
 119 import scala.concurrent.duration.Duration;
 120 import scala.concurrent.duration.FiniteDuration;
 121
 122 /**
 123  * Manages the shards for a data store. The ShardManager has the following jobs:
 124  * <ul>
 125  * <li> Create all the local shard replicas that belong on this cluster member
 126  * <li> Find the address of the local shard
 127  * <li> Find the primary replica for any given shard
 128  * <li> Monitor the cluster members and store their addresses
 129  * </ul>
 130  */
 131 class ShardManager extends AbstractUntypedPersistentActorWithMetering {
 132     private static final Logger LOG = LoggerFactory.getLogger(ShardManager.class);
 133
 134     // Stores a mapping between a shard name and it's corresponding information
 135     // Shard names look like inventory, topology etc and are as specified in
 136     // configuration
 137     private final Map<String, ShardInformation> localShards = new HashMap<>();
 138
 139     // The type of a ShardManager reflects the type of the datastore itself
 140     // A data store could be of type config/operational
 141     private final String type;
 142
 143     private final ClusterWrapper cluster;
 144
 145     private final Configuration configuration;
 146
 147     private final String shardDispatcherPath;
 148
 149     private final ShardManagerInfo shardManagerMBean;
 150
 151     private DatastoreContextFactory datastoreContextFactory;
 152
 153     private final CountDownLatch waitTillReadyCountdownLatch;
 154
 155     private final PrimaryShardInfoFutureCache primaryShardInfoCache;
 156
 157     private final ShardPeerAddressResolver peerAddressResolver;
 158
 159     private SchemaContext schemaContext;
 160
 161     private DatastoreSnapshot restoreFromSnapshot;
 162
 163     private ShardManagerSnapshot currentSnapshot;
 164
 165     private final Set<String> shardReplicaOperationsInProgress = new HashSet<>();
 166
 167     private final Map<String, Future<Boolean>> shardActorStoppingFutures = new HashMap<>();
 168
 169     private final String persistenceId;
 170     private final AbstractDataStore dataStore;
 171
 172     private ListenerRegistration<DOMDataTreeChangeListener> configListenerReg = null;
 173     private PrefixedShardConfigUpdateHandler configUpdateHandler;
 174
 175     ShardManager(AbstractShardManagerCreator<?> builder) {
 176         this.cluster = builder.getCluster();
 177         this.configuration = builder.getConfiguration();
 178         this.datastoreContextFactory = builder.getDatastoreContextFactory();
 179         this.type = datastoreContextFactory.getBaseDatastoreContext().getDataStoreName();
 180         this.shardDispatcherPath =
 181                 new Dispatchers(context().system().dispatchers()).getDispatcherPath(Dispatchers.DispatcherType.Shard);
 182         this.waitTillReadyCountdownLatch = builder.getWaitTillReadyCountDownLatch();
 183         this.primaryShardInfoCache = builder.getPrimaryShardInfoCache();
 184         this.restoreFromSnapshot = builder.getRestoreFromSnapshot();
 185
 186         String possiblePersistenceId = datastoreContextFactory.getBaseDatastoreContext().getShardManagerPersistenceId();
 187         persistenceId = possiblePersistenceId != null ? possiblePersistenceId : "shard-manager-" + type;
 188
 189         peerAddressResolver = new ShardPeerAddressResolver(type, cluster.getCurrentMemberName());
 190
 191         // Subscribe this actor to cluster member events
 192         cluster.subscribeToMemberEvents(getSelf());
 193
 194         shardManagerMBean = new ShardManagerInfo(getSelf(), cluster.getCurrentMemberName(),
 195                 "shard-manager-" + this.type,
 196                 datastoreContextFactory.getBaseDatastoreContext().getDataStoreMXBeanType());
 197         shardManagerMBean.registerMBean();
 198
 199         dataStore = builder.getDistributedDataStore();
 200     }
 201
 202     @Override
 203     public void preStart() {
 204         LOG.info("Starting ShardManager {}", persistenceId);
 205     }
 206
 207     @Override
 208     public void postStop() {
 209         LOG.info("Stopping ShardManager {}", persistenceId());
 210
 211         shardManagerMBean.unregisterMBean();
 212
 213         if (configListenerReg != null) {
 214             configListenerReg.close();
 215             configListenerReg = null;
 216         }
 217     }
 218
 219     @Override
 220     public void handleCommand(Object message) throws Exception {
 221         if (message  instanceof FindPrimary) {
 222             findPrimary((FindPrimary)message);
 223         } else if (message instanceof FindLocalShard) {
 224             findLocalShard((FindLocalShard) message);
 225         } else if (message instanceof UpdateSchemaContext) {
 226             updateSchemaContext(message);
 227         } else if (message instanceof ActorInitialized) {
 228             onActorInitialized(message);
 229         } else if (message instanceof ClusterEvent.MemberUp) {
 230             memberUp((ClusterEvent.MemberUp) message);
 231         } else if (message instanceof ClusterEvent.MemberWeaklyUp) {
 232             memberWeaklyUp((ClusterEvent.MemberWeaklyUp) message);
 233         } else if (message instanceof ClusterEvent.MemberExited) {
 234             memberExited((ClusterEvent.MemberExited) message);
 235         } else if (message instanceof ClusterEvent.MemberRemoved) {
 236             memberRemoved((ClusterEvent.MemberRemoved) message);
 237         } else if (message instanceof ClusterEvent.UnreachableMember) {
 238             memberUnreachable((ClusterEvent.UnreachableMember) message);
 239         } else if (message instanceof ClusterEvent.ReachableMember) {
 240             memberReachable((ClusterEvent.ReachableMember) message);
 241         } else if (message instanceof DatastoreContextFactory) {
 242             onDatastoreContextFactory((DatastoreContextFactory) message);
 243         } else if (message instanceof RoleChangeNotification) {
 244             onRoleChangeNotification((RoleChangeNotification) message);
 245         } else if (message instanceof FollowerInitialSyncUpStatus) {
 246             onFollowerInitialSyncStatus((FollowerInitialSyncUpStatus) message);
 247         } else if (message instanceof ShardNotInitializedTimeout) {
 248             onShardNotInitializedTimeout((ShardNotInitializedTimeout) message);
 249         } else if (message instanceof ShardLeaderStateChanged) {
 250             onLeaderStateChanged((ShardLeaderStateChanged) message);
 251         } else if (message instanceof SwitchShardBehavior) {
 252             onSwitchShardBehavior((SwitchShardBehavior) message);
 253         } else if (message instanceof CreateShard) {
 254             onCreateShard((CreateShard)message);
 255         } else if (message instanceof AddShardReplica) {
 256             onAddShardReplica((AddShardReplica) message);
 257         } else if (message instanceof AddPrefixShardReplica) {
 258             onAddPrefixShardReplica((AddPrefixShardReplica) message);
 259         } else if (message instanceof PrefixShardCreated) {
 260             onPrefixShardCreated((PrefixShardCreated) message);
 261         } else if (message instanceof PrefixShardRemoved) {
 262             onPrefixShardRemoved((PrefixShardRemoved) message);
 263         } else if (message instanceof InitConfigListener) {
 264             onInitConfigListener();
 265         } else if (message instanceof ForwardedAddServerReply) {
 266             ForwardedAddServerReply msg = (ForwardedAddServerReply)message;
 267             onAddServerReply(msg.shardInfo, msg.addServerReply, getSender(), msg.leaderPath,
 268                     msg.removeShardOnFailure);
 269         } else if (message instanceof ForwardedAddServerFailure) {
 270             ForwardedAddServerFailure msg = (ForwardedAddServerFailure)message;
 271             onAddServerFailure(msg.shardName, msg.failureMessage, msg.failure, getSender(), msg.removeShardOnFailure);
 272         } else if (message instanceof RemoveShardReplica) {
 273             onRemoveShardReplica((RemoveShardReplica) message);
 274         } else if (message instanceof RemovePrefixShardReplica) {
 275             onRemovePrefixShardReplica((RemovePrefixShardReplica) message);
 276         } else if (message instanceof WrappedShardResponse) {
 277             onWrappedShardResponse((WrappedShardResponse) message);
 278         } else if (message instanceof GetSnapshot) {
 279             onGetSnapshot();
 280         } else if (message instanceof ServerRemoved) {
 281             onShardReplicaRemoved((ServerRemoved) message);
 282         } else if (message instanceof ChangeShardMembersVotingStatus) {
 283             onChangeShardServersVotingStatus((ChangeShardMembersVotingStatus) message);
 284         } else if (message instanceof FlipShardMembersVotingStatus) {
 285             onFlipShardMembersVotingStatus((FlipShardMembersVotingStatus) message);
 286         } else if (message instanceof SaveSnapshotSuccess) {
 287             onSaveSnapshotSuccess((SaveSnapshotSuccess) message);
 288         } else if (message instanceof SaveSnapshotFailure) {
 289             LOG.error("{}: SaveSnapshotFailure received for saving snapshot of shards", persistenceId(),
 290                     ((SaveSnapshotFailure) message).cause());
 291         } else if (message instanceof Shutdown) {
 292             onShutDown();
 293         } else if (message instanceof GetLocalShardIds) {
 294             onGetLocalShardIds();
 295         } else if (message instanceof RunnableMessage) {
 296             ((RunnableMessage)message).run();
 297         } else {
 298             unknownMessage(message);
 299         }
 300     }
 301
 302     private void onInitConfigListener() {
 303         LOG.debug("{}: Initializing config listener on {}", persistenceId(), cluster.getCurrentMemberName());
 304
 305         final org.opendaylight.mdsal.common.api.LogicalDatastoreType type =
 306                 org.opendaylight.mdsal.common.api.LogicalDatastoreType
 307                         .valueOf(datastoreContextFactory.getBaseDatastoreContext().getLogicalStoreType().name());
 308
 309         if (configUpdateHandler != null) {
 310             configUpdateHandler.close();
 311         }
 312
 313         configUpdateHandler = new PrefixedShardConfigUpdateHandler(self(), cluster.getCurrentMemberName());
 314         configUpdateHandler.initListener(dataStore, type);
 315     }
 316
 317     private void onShutDown() {
 318         List<Future<Boolean>> stopFutures = new ArrayList<>(localShards.size());
 319         for (ShardInformation info : localShards.values()) {
 320             if (info.getActor() != null) {
 321                 LOG.debug("{}: Issuing gracefulStop to shard {}", persistenceId(), info.getShardId());
 322
 323                 FiniteDuration duration = info.getDatastoreContext().getShardRaftConfig()
 324                         .getElectionTimeOutInterval().$times(2);
 325                 stopFutures.add(Patterns.gracefulStop(info.getActor(), duration, Shutdown.INSTANCE));
 326             }
 327         }
 328
 329         LOG.info("Shutting down ShardManager {} - waiting on {} shards", persistenceId(), stopFutures.size());
 330
 331         ExecutionContext dispatcher = new Dispatchers(context().system().dispatchers())
 332                 .getDispatcher(Dispatchers.DispatcherType.Client);
 333         Future<Iterable<Boolean>> combinedFutures = Futures.sequence(stopFutures, dispatcher);
 334
 335         combinedFutures.onComplete(new OnComplete<Iterable<Boolean>>() {
 336             @Override
 337             public void onComplete(Throwable failure, Iterable<Boolean> results) {
 338                 LOG.debug("{}: All shards shutdown - sending PoisonPill to self", persistenceId());
 339
 340                 self().tell(PoisonPill.getInstance(), self());
 341
 342                 if (failure != null) {
 343                     LOG.warn("{}: An error occurred attempting to shut down the shards", persistenceId(), failure);
 344                 } else {
 345                     int nfailed = 0;
 346                     for (Boolean result : results) {
 347                         if (!result) {
 348                             nfailed++;
 349                         }
 350                     }
 351
 352                     if (nfailed > 0) {
 353                         LOG.warn("{}: {} shards did not shut down gracefully", persistenceId(), nfailed);
 354                     }
 355                 }
 356             }
 357         }, dispatcher);
 358     }
 359
 360     private void onWrappedShardResponse(WrappedShardResponse message) {
 361         if (message.getResponse() instanceof RemoveServerReply) {
 362             onRemoveServerReply(getSender(), message.getShardId(), (RemoveServerReply) message.getResponse(),
 363                     message.getLeaderPath());
 364         }
 365     }
 366
 367     private void onRemoveServerReply(ActorRef originalSender, ShardIdentifier shardId, RemoveServerReply replyMsg,
 368             String leaderPath) {
 369         shardReplicaOperationsInProgress.remove(shardId.getShardName());
 370
 371         LOG.debug("{}: Received {} for shard {}", persistenceId(), replyMsg, shardId.getShardName());
 372
 373         if (replyMsg.getStatus() == ServerChangeStatus.OK) {
 374             LOG.debug("{}: Leader shard successfully removed the replica shard {}", persistenceId(),
 375                     shardId.getShardName());
 376             originalSender.tell(new Status.Success(null), getSelf());
 377         } else {
 378             LOG.warn("{}: Leader failed to remove shard replica {} with status {}",
 379                     persistenceId(), shardId, replyMsg.getStatus());
 380
 381             Exception failure = getServerChangeException(RemoveServer.class, replyMsg.getStatus(), leaderPath, shardId);
 382             originalSender.tell(new Status.Failure(failure), getSelf());
 383         }
 384     }
 385
 386     private void removePrefixShardReplica(final RemovePrefixShardReplica contextMessage, final String shardName,
 387                                           final String primaryPath, final ActorRef sender) {
 388         if (isShardReplicaOperationInProgress(shardName, sender)) {
 389             return;
 390         }
 391
 392         shardReplicaOperationsInProgress.add(shardName);
 393
 394         final ShardIdentifier shardId = getShardIdentifier(contextMessage.getMemberName(), shardName);
 395
 396         final DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName).build();
 397
 398         //inform ShardLeader to remove this shard as a replica by sending an RemoveServer message
 399         LOG.debug("{}: Sending RemoveServer message to peer {} for shard {}", persistenceId(),
 400                 primaryPath, shardId);
 401
 402         Timeout removeServerTimeout = new Timeout(datastoreContext.getShardLeaderElectionTimeout().duration());
 403         Future<Object> futureObj = ask(getContext().actorSelection(primaryPath),
 404                 new RemoveServer(shardId.toString()), removeServerTimeout);
 405
 406         futureObj.onComplete(new OnComplete<Object>() {
 407             @Override
 408             public void onComplete(Throwable failure, Object response) {
 409                 if (failure != null) {
 410                     shardReplicaOperationsInProgress.remove(shardName);
 411                     String msg = String.format("RemoveServer request to leader %s for shard %s failed",
 412                             primaryPath, shardName);
 413
 414                     LOG.debug("{}: {}", persistenceId(), msg, failure);
 415
 416                     // FAILURE
 417                     sender.tell(new Status.Failure(new RuntimeException(msg, failure)), self());
 418                 } else {
 419                     // SUCCESS
 420                     self().tell(new WrappedShardResponse(shardId, response, primaryPath), sender);
 421                 }
 422             }
 423         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
 424     }
 425
 426     private void removeShardReplica(RemoveShardReplica contextMessage, final String shardName, final String primaryPath,
 427             final ActorRef sender) {
 428         if (isShardReplicaOperationInProgress(shardName, sender)) {
 429             return;
 430         }
 431
 432         shardReplicaOperationsInProgress.add(shardName);
 433
 434         final ShardIdentifier shardId = getShardIdentifier(contextMessage.getMemberName(), shardName);
 435
 436         final DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName).build();
 437
 438         //inform ShardLeader to remove this shard as a replica by sending an RemoveServer message
 439         LOG.debug("{}: Sending RemoveServer message to peer {} for shard {}", persistenceId(),
 440                 primaryPath, shardId);
 441
 442         Timeout removeServerTimeout = new Timeout(datastoreContext.getShardLeaderElectionTimeout().duration());
 443         Future<Object> futureObj = ask(getContext().actorSelection(primaryPath),
 444                 new RemoveServer(shardId.toString()), removeServerTimeout);
 445
 446         futureObj.onComplete(new OnComplete<Object>() {
 447             @Override
 448             public void onComplete(Throwable failure, Object response) {
 449                 if (failure != null) {
 450                     shardReplicaOperationsInProgress.remove(shardName);
 451                     String msg = String.format("RemoveServer request to leader %s for shard %s failed",
 452                             primaryPath, shardName);
 453
 454                     LOG.debug("{}: {}", persistenceId(), msg, failure);
 455
 456                     // FAILURE
 457                     sender.tell(new Status.Failure(new RuntimeException(msg, failure)), self());
 458                 } else {
 459                     // SUCCESS
 460                     self().tell(new WrappedShardResponse(shardId, response, primaryPath), sender);
 461                 }
 462             }
 463         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
 464     }
 465
 466     private void onShardReplicaRemoved(ServerRemoved message) {
 467         removeShard(new ShardIdentifier.Builder().fromShardIdString(message.getServerId()).build());
 468     }
 469
 470     @SuppressWarnings("checkstyle:IllegalCatch")
 471     private void removeShard(final ShardIdentifier shardId) {
 472         final String shardName = shardId.getShardName();
 473         final ShardInformation shardInformation = localShards.remove(shardName);
 474         if (shardInformation == null) {
 475             LOG.debug("{} : Shard replica {} is not present in list", persistenceId(), shardId.toString());
 476             return;
 477         }
 478
 479         final ActorRef shardActor = shardInformation.getActor();
 480         if (shardActor != null) {
 481             LOG.debug("{} : Sending Shutdown to Shard actor {}", persistenceId(), shardActor);
 482             FiniteDuration duration = shardInformation.getDatastoreContext().getShardRaftConfig()
 483                     .getElectionTimeOutInterval().$times(3);
 484             final Future<Boolean> stopFuture = Patterns.gracefulStop(shardActor, duration, Shutdown.INSTANCE);
 485             shardActorStoppingFutures.put(shardName, stopFuture);
 486             stopFuture.onComplete(new OnComplete<Boolean>() {
 487                 @Override
 488                 public void onComplete(Throwable failure, Boolean result) {
 489                     if (failure == null) {
 490                         LOG.debug("{} : Successfully shut down Shard actor {}", persistenceId(), shardActor);
 491                     } else {
 492                         LOG.warn("{}: Failed to shut down Shard actor {}", persistenceId(), shardActor, failure);
 493                     }
 494
 495                     self().tell((RunnableMessage) () -> shardActorStoppingFutures.remove(shardName),
 496                             ActorRef.noSender());
 497                 }
 498             }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
 499         }
 500
 501         LOG.debug("{} : Local Shard replica for shard {} has been removed", persistenceId(), shardName);
 502         persistShardList();
 503     }
 504
 505     private void onGetSnapshot() {
 506         LOG.debug("{}: onGetSnapshot", persistenceId());
 507
 508         List<String> notInitialized = null;
 509         for (ShardInformation shardInfo : localShards.values()) {
 510             if (!shardInfo.isShardInitialized()) {
 511                 if (notInitialized == null) {
 512                     notInitialized = new ArrayList<>();
 513                 }
 514
 515                 notInitialized.add(shardInfo.getShardName());
 516             }
 517         }
 518
 519         if (notInitialized != null) {
 520             getSender().tell(new Status.Failure(new IllegalStateException(String.format(
 521                     "%d shard(s) %s are not initialized", notInitialized.size(), notInitialized))), getSelf());
 522             return;
 523         }
 524
 525         ActorRef replyActor = getContext().actorOf(ShardManagerGetSnapshotReplyActor.props(
 526                 new ArrayList<>(localShards.keySet()), type, currentSnapshot , getSender(), persistenceId(),
 527                 datastoreContextFactory.getBaseDatastoreContext().getShardInitializationTimeout().duration()));
 528
 529         for (ShardInformation shardInfo: localShards.values()) {
 530             shardInfo.getActor().tell(GetSnapshot.INSTANCE, replyActor);
 531         }
 532     }
 533
 534     @SuppressWarnings("checkstyle:IllegalCatch")
 535     private void onCreateShard(CreateShard createShard) {
 536         LOG.debug("{}: onCreateShard: {}", persistenceId(), createShard);
 537
 538         Object reply;
 539         try {
 540             String shardName = createShard.getModuleShardConfig().getShardName();
 541             if (localShards.containsKey(shardName)) {
 542                 LOG.debug("{}: Shard {} already exists", persistenceId(), shardName);
 543                 reply = new Status.Success(String.format("Shard with name %s already exists", shardName));
 544             } else {
 545                 doCreateShard(createShard);
 546                 reply = new Status.Success(null);
 547             }
 548         } catch (Exception e) {
 549             LOG.error("{}: onCreateShard failed", persistenceId(), e);
 550             reply = new Status.Failure(e);
 551         }
 552
 553         if (getSender() != null && !getContext().system().deadLetters().equals(getSender())) {
 554             getSender().tell(reply, getSelf());
 555         }
 556     }
 557
 558     private void onPrefixShardCreated(final PrefixShardCreated message) {
 559         LOG.debug("{}: onPrefixShardCreated: {}", persistenceId(), message);
 560
 561         final PrefixShardConfiguration config = message.getConfiguration();
 562         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(),
 563                 ClusterUtils.getCleanShardName(config.getPrefix().getRootIdentifier()));
 564         final String shardName = shardId.getShardName();
 565
 566         if (isPreviousShardActorStopInProgress(shardName, message)) {
 567             return;
 568         }
 569
 570         if (localShards.containsKey(shardName)) {
 571             LOG.debug("{}: Received create for an already existing shard {}", persistenceId(), shardName);
 572             final PrefixShardConfiguration existing =
 573                     configuration.getAllPrefixShardConfigurations().get(config.getPrefix());
 574
 575             if (existing != null && existing.equals(config)) {
 576                 // we don't have to do nothing here
 577                 return;
 578             }
 579         }
 580
 581         doCreatePrefixShard(config, shardId, shardName);
 582     }
 583
 584     private boolean isPreviousShardActorStopInProgress(final String shardName, final Object messageToDefer) {
 585         final Future<Boolean> stopFuture = shardActorStoppingFutures.get(shardName);
 586         if (stopFuture == null) {
 587             return false;
 588         }
 589
 590         LOG.debug("{} : Stop is in progress for shard {} - adding Future callback to defer {}", persistenceId(),
 591                 shardName, messageToDefer);
 592         final ActorRef sender = getSender();
 593         stopFuture.onComplete(new OnComplete<Boolean>() {
 594             @Override
 595             public void onComplete(Throwable failure, Boolean result) {
 596                 LOG.debug("{} : Stop complete for shard {} - re-queing {}", persistenceId(), shardName, messageToDefer);
 597                 self().tell(messageToDefer, sender);
 598             }
 599         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
 600
 601         return true;
 602     }
 603
 604     private void doCreatePrefixShard(PrefixShardConfiguration config, ShardIdentifier shardId, String shardName) {
 605         configuration.addPrefixShardConfiguration(config);
 606
 607         final Builder builder = newShardDatastoreContextBuilder(shardName);
 608         builder.logicalStoreType(LogicalDatastoreType.valueOf(config.getPrefix().getDatastoreType().name()))
 609                 .storeRoot(config.getPrefix().getRootIdentifier());
 610         DatastoreContext shardDatastoreContext = builder.build();
 611
 612         final Map<String, String> peerAddresses = getPeerAddresses(shardName);
 613         final boolean isActiveMember = true;
 614
 615         LOG.debug("{} doCreatePrefixShard: shardId: {}, memberNames: {}, peerAddresses: {}, isActiveMember: {}",
 616                 persistenceId(), shardId, config.getShardMemberNames(), peerAddresses, isActiveMember);
 617
 618         final ShardInformation info = new ShardInformation(shardName, shardId, peerAddresses,
 619                 shardDatastoreContext, Shard.builder(), peerAddressResolver);
 620         info.setActiveMember(isActiveMember);
 621         localShards.put(info.getShardName(), info);
 622
 623         if (schemaContext != null) {
 624             info.setActor(newShardActor(schemaContext, info));
 625         }
 626     }
 627
 628     private void onPrefixShardRemoved(final PrefixShardRemoved message) {
 629         LOG.debug("{}: onPrefixShardRemoved : {}", persistenceId(), message);
 630
 631         final DOMDataTreeIdentifier prefix = message.getPrefix();
 632         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(),
 633                 ClusterUtils.getCleanShardName(prefix.getRootIdentifier()));
 634
 635         configuration.removePrefixShardConfiguration(prefix);
 636         removeShard(shardId);
 637     }
 638
 639     private void doCreateShard(final CreateShard createShard) {
 640         final ModuleShardConfiguration moduleShardConfig = createShard.getModuleShardConfig();
 641         final String shardName = moduleShardConfig.getShardName();
 642
 643         configuration.addModuleShardConfiguration(moduleShardConfig);
 644
 645         DatastoreContext shardDatastoreContext = createShard.getDatastoreContext();
 646         if (shardDatastoreContext == null) {
 647             shardDatastoreContext = newShardDatastoreContext(shardName);
 648         } else {
 649             shardDatastoreContext = DatastoreContext.newBuilderFrom(shardDatastoreContext).shardPeerAddressResolver(
 650                     peerAddressResolver).build();
 651         }
 652
 653         ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
 654
 655         boolean shardWasInRecoveredSnapshot = currentSnapshot != null
 656                 && currentSnapshot.getShardList().contains(shardName);
 657
 658         Map<String, String> peerAddresses;
 659         boolean isActiveMember;
 660         if (shardWasInRecoveredSnapshot || configuration.getMembersFromShardName(shardName)
 661                 .contains(cluster.getCurrentMemberName())) {
 662             peerAddresses = getPeerAddresses(shardName);
 663             isActiveMember = true;
 664         } else {
 665             // The local member is not in the static shard member configuration and the shard did not
 666             // previously exist (ie !shardWasInRecoveredSnapshot). In this case we'll create
 667             // the shard with no peers and with elections disabled so it stays as follower. A
 668             // subsequent AddServer request will be needed to make it an active member.
 669             isActiveMember = false;
 670             peerAddresses = Collections.emptyMap();
 671             shardDatastoreContext = DatastoreContext.newBuilderFrom(shardDatastoreContext)
 672                     .customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName()).build();
 673         }
 674
 675         LOG.debug("{} doCreateShard: shardId: {}, memberNames: {}, peerAddresses: {}, isActiveMember: {}",
 676                 persistenceId(), shardId, moduleShardConfig.getShardMemberNames(), peerAddresses,
 677                 isActiveMember);
 678
 679         ShardInformation info = new ShardInformation(shardName, shardId, peerAddresses,
 680                 shardDatastoreContext, createShard.getShardBuilder(), peerAddressResolver);
 681         info.setActiveMember(isActiveMember);
 682         localShards.put(info.getShardName(), info);
 683
 684         if (schemaContext != null) {
 685             info.setActor(newShardActor(schemaContext, info));
 686         }
 687     }
 688
 689     private DatastoreContext.Builder newShardDatastoreContextBuilder(String shardName) {
 690         return DatastoreContext.newBuilderFrom(datastoreContextFactory.getShardDatastoreContext(shardName))
 691                 .shardPeerAddressResolver(peerAddressResolver);
 692     }
 693
 694     private DatastoreContext newShardDatastoreContext(String shardName) {
 695         return newShardDatastoreContextBuilder(shardName).build();
 696     }
 697
 698     private void checkReady() {
 699         if (isReadyWithLeaderId()) {
 700             LOG.info("{}: All Shards are ready - data store {} is ready, available count is {}",
 701                     persistenceId(), type, waitTillReadyCountdownLatch.getCount());
 702
 703             waitTillReadyCountdownLatch.countDown();
 704         }
 705     }
 706
 707     private void onLeaderStateChanged(ShardLeaderStateChanged leaderStateChanged) {
 708         LOG.info("{}: Received LeaderStateChanged message: {}", persistenceId(), leaderStateChanged);
 709
 710         ShardInformation shardInformation = findShardInformation(leaderStateChanged.getMemberId());
 711         if (shardInformation != null) {
 712             shardInformation.setLocalDataTree(leaderStateChanged.getLocalShardDataTree());
 713             shardInformation.setLeaderVersion(leaderStateChanged.getLeaderPayloadVersion());
 714             if (shardInformation.setLeaderId(leaderStateChanged.getLeaderId())) {
 715                 primaryShardInfoCache.remove(shardInformation.getShardName());
 716             }
 717
 718             checkReady();
 719         } else {
 720             LOG.debug("No shard found with member Id {}", leaderStateChanged.getMemberId());
 721         }
 722     }
 723
 724     private void onShardNotInitializedTimeout(ShardNotInitializedTimeout message) {
 725         ShardInformation shardInfo = message.getShardInfo();
 726
 727         LOG.debug("{}: Received ShardNotInitializedTimeout message for shard {}", persistenceId(),
 728                 shardInfo.getShardName());
 729
 730         shardInfo.removeOnShardInitialized(message.getOnShardInitialized());
 731
 732         if (!shardInfo.isShardInitialized()) {
 733             LOG.debug("{}: Returning NotInitializedException for shard {}", persistenceId(), shardInfo.getShardName());
 734             message.getSender().tell(createNotInitializedException(shardInfo.getShardId()), getSelf());
 735         } else {
 736             LOG.debug("{}: Returning NoShardLeaderException for shard {}", persistenceId(), shardInfo.getShardName());
 737             message.getSender().tell(createNoShardLeaderException(shardInfo.getShardId()), getSelf());
 738         }
 739     }
 740
 741     private void onFollowerInitialSyncStatus(FollowerInitialSyncUpStatus status) {
 742         LOG.info("{} Received follower initial sync status for {} status sync done {}", persistenceId(),
 743                 status.getName(), status.isInitialSyncDone());
 744
 745         ShardInformation shardInformation = findShardInformation(status.getName());
 746
 747         if (shardInformation != null) {
 748             shardInformation.setFollowerSyncStatus(status.isInitialSyncDone());
 749
 750             shardManagerMBean.setSyncStatus(isInSync());
 751         }
 752
 753     }
 754
 755     private void onRoleChangeNotification(RoleChangeNotification roleChanged) {
 756         LOG.info("{}: Received role changed for {} from {} to {}", persistenceId(), roleChanged.getMemberId(),
 757                 roleChanged.getOldRole(), roleChanged.getNewRole());
 758
 759         ShardInformation shardInformation = findShardInformation(roleChanged.getMemberId());
 760         if (shardInformation != null) {
 761             shardInformation.setRole(roleChanged.getNewRole());
 762             checkReady();
 763             shardManagerMBean.setSyncStatus(isInSync());
 764         }
 765     }
 766
 767
 768     private ShardInformation findShardInformation(String memberId) {
 769         for (ShardInformation info : localShards.values()) {
 770             if (info.getShardId().toString().equals(memberId)) {
 771                 return info;
 772             }
 773         }
 774
 775         return null;
 776     }
 777
 778     private boolean isReadyWithLeaderId() {
 779         boolean isReady = true;
 780         for (ShardInformation info : localShards.values()) {
 781             if (!info.isShardReadyWithLeaderId()) {
 782                 isReady = false;
 783                 break;
 784             }
 785         }
 786         return isReady;
 787     }
 788
 789     private boolean isInSync() {
 790         for (ShardInformation info : localShards.values()) {
 791             if (!info.isInSync()) {
 792                 return false;
 793             }
 794         }
 795         return true;
 796     }
 797
 798     private void onActorInitialized(Object message) {
 799         final ActorRef sender = getSender();
 800
 801         if (sender == null) {
 802             return; //why is a non-actor sending this message? Just ignore.
 803         }
 804
 805         String actorName = sender.path().name();
 806         //find shard name from actor name; actor name is stringified shardId
 807
 808         final ShardIdentifier shardId;
 809         try {
 810             shardId = ShardIdentifier.fromShardIdString(actorName);
 811         } catch (IllegalArgumentException e) {
 812             LOG.debug("{}: ignoring actor {}", actorName, e);
 813             return;
 814         }
 815
 816         markShardAsInitialized(shardId.getShardName());
 817     }
 818
 819     private void markShardAsInitialized(String shardName) {
 820         LOG.debug("{}: Initializing shard [{}]", persistenceId(), shardName);
 821
 822         ShardInformation shardInformation = localShards.get(shardName);
 823         if (shardInformation != null) {
 824             shardInformation.setActorInitialized();
 825
 826             shardInformation.getActor().tell(new RegisterRoleChangeListener(), self());
 827         }
 828     }
 829
 830     @Override
 831     protected void handleRecover(Object message) throws Exception {
 832         if (message instanceof RecoveryCompleted) {
 833             onRecoveryCompleted();
 834         } else if (message instanceof SnapshotOffer) {
 835             applyShardManagerSnapshot((ShardManagerSnapshot)((SnapshotOffer) message).snapshot());
 836         }
 837     }
 838
 839     @SuppressWarnings("checkstyle:IllegalCatch")
 840     private void onRecoveryCompleted() {
 841         LOG.info("Recovery complete : {}", persistenceId());
 842
 843         // We no longer persist SchemaContext modules so delete all the prior messages from the akka
 844         // journal on upgrade from Helium.
 845         deleteMessages(lastSequenceNr());
 846
 847         if (currentSnapshot == null && restoreFromSnapshot != null
 848                 && restoreFromSnapshot.getShardManagerSnapshot() != null) {
 849             ShardManagerSnapshot snapshot = restoreFromSnapshot.getShardManagerSnapshot();
 850
 851             LOG.debug("{}: Restoring from ShardManagerSnapshot: {}", persistenceId(), snapshot);
 852
 853             applyShardManagerSnapshot(snapshot);
 854         }
 855
 856         createLocalShards();
 857     }
 858
 859     private void sendResponse(ShardInformation shardInformation, boolean doWait,
 860             boolean wantShardReady, final Supplier<Object> messageSupplier) {
 861         if (!shardInformation.isShardInitialized() || wantShardReady && !shardInformation.isShardReadyWithLeaderId()) {
 862             if (doWait) {
 863                 final ActorRef sender = getSender();
 864                 final ActorRef self = self();
 865
 866                 Runnable replyRunnable = () -> sender.tell(messageSupplier.get(), self);
 867
 868                 OnShardInitialized onShardInitialized = wantShardReady ? new OnShardReady(replyRunnable) :
 869                     new OnShardInitialized(replyRunnable);
 870
 871                 shardInformation.addOnShardInitialized(onShardInitialized);
 872
 873                 FiniteDuration timeout = shardInformation.getDatastoreContext()
 874                         .getShardInitializationTimeout().duration();
 875                 if (shardInformation.isShardInitialized()) {
 876                     // If the shard is already initialized then we'll wait enough time for the shard to
 877                     // elect a leader, ie 2 times the election timeout.
 878                     timeout = FiniteDuration.create(shardInformation.getDatastoreContext().getShardRaftConfig()
 879                             .getElectionTimeOutInterval().toMillis() * 2, TimeUnit.MILLISECONDS);
 880                 }
 881
 882                 LOG.debug("{}: Scheduling {} ms timer to wait for shard {}", persistenceId(), timeout.toMillis(),
 883                         shardInformation.getShardName());
 884
 885                 Cancellable timeoutSchedule = getContext().system().scheduler().scheduleOnce(
 886                         timeout, getSelf(),
 887                         new ShardNotInitializedTimeout(shardInformation, onShardInitialized, sender),
 888                         getContext().dispatcher(), getSelf());
 889
 890                 onShardInitialized.setTimeoutSchedule(timeoutSchedule);
 891
 892             } else if (!shardInformation.isShardInitialized()) {
 893                 LOG.debug("{}: Returning NotInitializedException for shard {}", persistenceId(),
 894                         shardInformation.getShardName());
 895                 getSender().tell(createNotInitializedException(shardInformation.getShardId()), getSelf());
 896             } else {
 897                 LOG.debug("{}: Returning NoShardLeaderException for shard {}", persistenceId(),
 898                         shardInformation.getShardName());
 899                 getSender().tell(createNoShardLeaderException(shardInformation.getShardId()), getSelf());
 900             }
 901
 902             return;
 903         }
 904
 905         getSender().tell(messageSupplier.get(), getSelf());
 906     }
 907
 908     private static NoShardLeaderException createNoShardLeaderException(ShardIdentifier shardId) {
 909         return new NoShardLeaderException(null, shardId.toString());
 910     }
 911
 912     private static NotInitializedException createNotInitializedException(ShardIdentifier shardId) {
 913         return new NotInitializedException(String.format(
 914                 "Found primary shard %s but it's not initialized yet. Please try again later", shardId));
 915     }
 916
 917     @VisibleForTesting
 918     static MemberName memberToName(final Member member) {
 919         return MemberName.forName(member.roles().iterator().next());
 920     }
 921
 922     private void memberRemoved(ClusterEvent.MemberRemoved message) {
 923         MemberName memberName = memberToName(message.member());
 924
 925         LOG.info("{}: Received MemberRemoved: memberName: {}, address: {}", persistenceId(), memberName,
 926                 message.member().address());
 927
 928         peerAddressResolver.removePeerAddress(memberName);
 929
 930         for (ShardInformation info : localShards.values()) {
 931             info.peerDown(memberName, getShardIdentifier(memberName, info.getShardName()).toString(), getSelf());
 932         }
 933     }
 934
 935     private void memberExited(ClusterEvent.MemberExited message) {
 936         MemberName memberName = memberToName(message.member());
 937
 938         LOG.info("{}: Received MemberExited: memberName: {}, address: {}", persistenceId(), memberName,
 939                 message.member().address());
 940
 941         peerAddressResolver.removePeerAddress(memberName);
 942
 943         for (ShardInformation info : localShards.values()) {
 944             info.peerDown(memberName, getShardIdentifier(memberName, info.getShardName()).toString(), getSelf());
 945         }
 946     }
 947
 948     private void memberUp(ClusterEvent.MemberUp message) {
 949         MemberName memberName = memberToName(message.member());
 950
 951         LOG.info("{}: Received MemberUp: memberName: {}, address: {}", persistenceId(), memberName,
 952                 message.member().address());
 953
 954         memberUp(memberName, message.member().address());
 955     }
 956
 957     private void memberUp(MemberName memberName, Address address) {
 958         addPeerAddress(memberName, address);
 959         checkReady();
 960     }
 961
 962     private void memberWeaklyUp(MemberWeaklyUp message) {
 963         MemberName memberName = memberToName(message.member());
 964
 965         LOG.info("{}: Received MemberWeaklyUp: memberName: {}, address: {}", persistenceId(), memberName,
 966                 message.member().address());
 967
 968         memberUp(memberName, message.member().address());
 969     }
 970
 971     private void addPeerAddress(MemberName memberName, Address address) {
 972         peerAddressResolver.addPeerAddress(memberName, address);
 973
 974         for (ShardInformation info : localShards.values()) {
 975             String shardName = info.getShardName();
 976             String peerId = getShardIdentifier(memberName, shardName).toString();
 977             info.updatePeerAddress(peerId, peerAddressResolver.getShardActorAddress(shardName, memberName), getSelf());
 978
 979             info.peerUp(memberName, peerId, getSelf());
 980         }
 981     }
 982
 983     private void memberReachable(ClusterEvent.ReachableMember message) {
 984         MemberName memberName = memberToName(message.member());
 985         LOG.info("Received ReachableMember: memberName {}, address: {}", memberName, message.member().address());
 986
 987         addPeerAddress(memberName, message.member().address());
 988
 989         markMemberAvailable(memberName);
 990     }
 991
 992     private void memberUnreachable(ClusterEvent.UnreachableMember message) {
 993         MemberName memberName = memberToName(message.member());
 994         LOG.info("Received UnreachableMember: memberName {}, address: {}", memberName, message.member().address());
 995
 996         markMemberUnavailable(memberName);
 997     }
 998
 999     private void markMemberUnavailable(final MemberName memberName) {
1000         final String memberStr = memberName.getName();
1001         for (ShardInformation info : localShards.values()) {
1002             String leaderId = info.getLeaderId();
1003             // XXX: why are we using String#contains() here?
1004             if (leaderId != null && leaderId.contains(memberStr)) {
1005                 LOG.debug("Marking Leader {} as unavailable.", leaderId);
1006                 info.setLeaderAvailable(false);
1007
1008                 primaryShardInfoCache.remove(info.getShardName());
1009             }
1010
1011             info.peerDown(memberName, getShardIdentifier(memberName, info.getShardName()).toString(), getSelf());
1012         }
1013     }
1014
1015     private void markMemberAvailable(final MemberName memberName) {
1016         final String memberStr = memberName.getName();
1017         for (ShardInformation info : localShards.values()) {
1018             String leaderId = info.getLeaderId();
1019             // XXX: why are we using String#contains() here?
1020             if (leaderId != null && leaderId.contains(memberStr)) {
1021                 LOG.debug("Marking Leader {} as available.", leaderId);
1022                 info.setLeaderAvailable(true);
1023             }
1024
1025             info.peerUp(memberName, getShardIdentifier(memberName, info.getShardName()).toString(), getSelf());
1026         }
1027     }
1028
1029     private void onDatastoreContextFactory(DatastoreContextFactory factory) {
1030         datastoreContextFactory = factory;
1031         for (ShardInformation info : localShards.values()) {
1032             info.setDatastoreContext(newShardDatastoreContext(info.getShardName()), getSelf());
1033         }
1034     }
1035
1036     private void onGetLocalShardIds() {
1037         final List<String> response = new ArrayList<>(localShards.size());
1038
1039         for (ShardInformation info : localShards.values()) {
1040             response.add(info.getShardId().toString());
1041         }
1042
1043         getSender().tell(new Status.Success(response), getSelf());
1044     }
1045
1046     private void onSwitchShardBehavior(final SwitchShardBehavior message) {
1047         final ShardIdentifier identifier = message.getShardId();
1048
1049         if (identifier != null) {
1050             final ShardInformation info = localShards.get(identifier.getShardName());
1051             if (info == null) {
1052                 getSender().tell(new Status.Failure(
1053                     new IllegalArgumentException("Shard " + identifier + " is not local")), getSelf());
1054                 return;
1055             }
1056
1057             switchShardBehavior(info, new SwitchBehavior(message.getNewState(), message.getTerm()));
1058         } else {
1059             for (ShardInformation info : localShards.values()) {
1060                 switchShardBehavior(info, new SwitchBehavior(message.getNewState(), message.getTerm()));
1061             }
1062         }
1063
1064         getSender().tell(new Status.Success(null), getSelf());
1065     }
1066
1067     private void switchShardBehavior(final ShardInformation info, final SwitchBehavior switchBehavior) {
1068         final ActorRef actor = info.getActor();
1069         if (actor != null) {
1070             actor.tell(switchBehavior, getSelf());
1071         } else {
1072             LOG.warn("Could not switch the behavior of shard {} to {} - shard is not yet available",
1073                 info.getShardName(), switchBehavior.getNewState());
1074         }
1075     }
1076
1077     /**
1078      * Notifies all the local shards of a change in the schema context.
1079      *
1080      * @param message the message to send
1081      */
1082     private void updateSchemaContext(final Object message) {
1083         schemaContext = ((UpdateSchemaContext) message).getSchemaContext();
1084
1085         LOG.debug("Got updated SchemaContext: # of modules {}", schemaContext.getAllModuleIdentifiers().size());
1086
1087         for (ShardInformation info : localShards.values()) {
1088             if (info.getActor() == null) {
1089                 LOG.debug("Creating Shard {}", info.getShardId());
1090                 info.setActor(newShardActor(schemaContext, info));
1091             } else {
1092                 info.getActor().tell(message, getSelf());
1093             }
1094         }
1095     }
1096
1097     @VisibleForTesting
1098     protected ClusterWrapper getCluster() {
1099         return cluster;
1100     }
1101
1102     @VisibleForTesting
1103     protected ActorRef newShardActor(final SchemaContext shardSchemaContext, final ShardInformation info) {
1104         return getContext().actorOf(info.newProps(shardSchemaContext).withDispatcher(shardDispatcherPath),
1105                 info.getShardId().toString());
1106     }
1107
1108     private void findPrimary(FindPrimary message) {
1109         LOG.debug("{}: In findPrimary: {}", persistenceId(), message);
1110
1111         final String shardName = message.getShardName();
1112         final boolean canReturnLocalShardState = !(message instanceof RemoteFindPrimary);
1113
1114         // First see if the there is a local replica for the shard
1115         final ShardInformation info = localShards.get(shardName);
1116         if (info != null && info.isActiveMember()) {
1117             sendResponse(info, message.isWaitUntilReady(), true, () -> {
1118                 String primaryPath = info.getSerializedLeaderActor();
1119                 Object found = canReturnLocalShardState && info.isLeader()
1120                         ? new LocalPrimaryShardFound(primaryPath, info.getLocalShardDataTree().get()) :
1121                             new RemotePrimaryShardFound(primaryPath, info.getLeaderVersion());
1122
1123                 LOG.debug("{}: Found primary for {}: {}", persistenceId(), shardName, found);
1124                 return found;
1125             });
1126
1127             return;
1128         }
1129
1130         final Collection<String> visitedAddresses;
1131         if (message instanceof RemoteFindPrimary) {
1132             visitedAddresses = ((RemoteFindPrimary)message).getVisitedAddresses();
1133         } else {
1134             visitedAddresses = new ArrayList<>(1);
1135         }
1136
1137         visitedAddresses.add(peerAddressResolver.getShardManagerActorPathBuilder(cluster.getSelfAddress()).toString());
1138
1139         for (String address: peerAddressResolver.getShardManagerPeerActorAddresses()) {
1140             if (visitedAddresses.contains(address)) {
1141                 continue;
1142             }
1143
1144             LOG.debug("{}: findPrimary for {} forwarding to remote ShardManager {}, visitedAddresses: {}",
1145                     persistenceId(), shardName, address, visitedAddresses);
1146
1147             getContext().actorSelection(address).forward(new RemoteFindPrimary(shardName,
1148                     message.isWaitUntilReady(), visitedAddresses), getContext());
1149             return;
1150         }
1151
1152         LOG.debug("{}: No shard found for {}", persistenceId(), shardName);
1153
1154         getSender().tell(new PrimaryNotFoundException(
1155                 String.format("No primary shard found for %s.", shardName)), getSelf());
1156     }
1157
1158     private void findPrimary(final String shardName, final FindPrimaryResponseHandler handler) {
1159         Timeout findPrimaryTimeout = new Timeout(datastoreContextFactory.getBaseDatastoreContext()
1160                 .getShardInitializationTimeout().duration().$times(2));
1161
1162         Future<Object> futureObj = ask(getSelf(), new FindPrimary(shardName, true), findPrimaryTimeout);
1163         futureObj.onComplete(new OnComplete<Object>() {
1164             @Override
1165             public void onComplete(Throwable failure, Object response) {
1166                 if (failure != null) {
1167                     handler.onFailure(failure);
1168                 } else {
1169                     if (response instanceof RemotePrimaryShardFound) {
1170                         handler.onRemotePrimaryShardFound((RemotePrimaryShardFound) response);
1171                     } else if (response instanceof LocalPrimaryShardFound) {
1172                         handler.onLocalPrimaryFound((LocalPrimaryShardFound) response);
1173                     } else {
1174                         handler.onUnknownResponse(response);
1175                     }
1176                 }
1177             }
1178         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1179     }
1180
1181     /**
1182      * Construct the name of the shard actor given the name of the member on
1183      * which the shard resides and the name of the shard.
1184      *
1185      * @param memberName the member name
1186      * @param shardName the shard name
1187      * @return a b
1188      */
1189     private ShardIdentifier getShardIdentifier(MemberName memberName, String shardName) {
1190         return peerAddressResolver.getShardIdentifier(memberName, shardName);
1191     }
1192
1193     /**
1194      * Create shards that are local to the member on which the ShardManager runs.
1195      */
1196     private void createLocalShards() {
1197         MemberName memberName = this.cluster.getCurrentMemberName();
1198         Collection<String> memberShardNames = this.configuration.getMemberShardNames(memberName);
1199
1200         Map<String, DatastoreSnapshot.ShardSnapshot> shardSnapshots = new HashMap<>();
1201         if (restoreFromSnapshot != null) {
1202             for (DatastoreSnapshot.ShardSnapshot snapshot: restoreFromSnapshot.getShardSnapshots()) {
1203                 shardSnapshots.put(snapshot.getName(), snapshot);
1204             }
1205         }
1206
1207         restoreFromSnapshot = null; // null out to GC
1208
1209         for (String shardName : memberShardNames) {
1210             ShardIdentifier shardId = getShardIdentifier(memberName, shardName);
1211
1212             LOG.debug("{}: Creating local shard: {}", persistenceId(), shardId);
1213
1214             Map<String, String> peerAddresses = getPeerAddresses(shardName);
1215             localShards.put(shardName, new ShardInformation(shardName, shardId, peerAddresses,
1216                     newShardDatastoreContext(shardName), Shard.builder().restoreFromSnapshot(
1217                         shardSnapshots.get(shardName)), peerAddressResolver));
1218         }
1219     }
1220
1221     /**
1222      * Given the name of the shard find the addresses of all it's peers.
1223      *
1224      * @param shardName the shard name
1225      */
1226     private Map<String, String> getPeerAddresses(String shardName) {
1227         final Collection<MemberName> members = configuration.getMembersFromShardName(shardName);
1228         return getPeerAddresses(shardName, members);
1229     }
1230
1231     private Map<String, String> getPeerAddresses(final String shardName, final Collection<MemberName> members) {
1232         Map<String, String> peerAddresses = new HashMap<>();
1233         MemberName currentMemberName = this.cluster.getCurrentMemberName();
1234
1235         for (MemberName memberName : members) {
1236             if (!currentMemberName.equals(memberName)) {
1237                 ShardIdentifier shardId = getShardIdentifier(memberName, shardName);
1238                 String address = peerAddressResolver.getShardActorAddress(shardName, memberName);
1239                 peerAddresses.put(shardId.toString(), address);
1240             }
1241         }
1242         return peerAddresses;
1243     }
1244
1245     @Override
1246     public SupervisorStrategy supervisorStrategy() {
1247
1248         return new OneForOneStrategy(10, Duration.create("1 minute"),
1249                 (Function<Throwable, Directive>) t -> {
1250                     LOG.warn("Supervisor Strategy caught unexpected exception - resuming", t);
1251                     return SupervisorStrategy.resume();
1252                 });
1253     }
1254
1255     @Override
1256     public String persistenceId() {
1257         return persistenceId;
1258     }
1259
1260     @VisibleForTesting
1261     ShardManagerInfoMBean getMBean() {
1262         return shardManagerMBean;
1263     }
1264
1265     private boolean isShardReplicaOperationInProgress(final String shardName, final ActorRef sender) {
1266         if (shardReplicaOperationsInProgress.contains(shardName)) {
1267             String msg = String.format("A shard replica operation for %s is already in progress", shardName);
1268             LOG.debug("{}: {}", persistenceId(), msg);
1269             sender.tell(new Status.Failure(new IllegalStateException(msg)), getSelf());
1270             return true;
1271         }
1272
1273         return false;
1274     }
1275
1276     private void onAddPrefixShardReplica(final AddPrefixShardReplica message) {
1277         LOG.debug("{}: onAddPrefixShardReplica: {}", persistenceId(), message);
1278
1279         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(),
1280                 ClusterUtils.getCleanShardName(message.getShardPrefix()));
1281         final String shardName = shardId.getShardName();
1282
1283         // Create the localShard
1284         if (schemaContext == null) {
1285             String msg = String.format(
1286                     "No SchemaContext is available in order to create a local shard instance for %s", shardName);
1287             LOG.debug("{}: {}", persistenceId(), msg);
1288             getSender().tell(new Status.Failure(new IllegalStateException(msg)), getSelf());
1289             return;
1290         }
1291
1292         findPrimary(shardName, new AutoFindPrimaryFailureResponseHandler(getSender(), shardName, persistenceId(),
1293                 getSelf()) {
1294             @Override
1295             public void onRemotePrimaryShardFound(RemotePrimaryShardFound response) {
1296                 final RunnableMessage runnable = (RunnableMessage) () -> addPrefixShard(getShardName(),
1297                         message.getShardPrefix(), response, getSender());
1298                 if (!isPreviousShardActorStopInProgress(getShardName(), runnable)) {
1299                     getSelf().tell(runnable, getTargetActor());
1300                 }
1301             }
1302
1303             @Override
1304             public void onLocalPrimaryFound(LocalPrimaryShardFound message) {
1305                 sendLocalReplicaAlreadyExistsReply(getShardName(), getTargetActor());
1306             }
1307         });
1308     }
1309
1310     private void onAddShardReplica(final AddShardReplica shardReplicaMsg) {
1311         final String shardName = shardReplicaMsg.getShardName();
1312
1313         LOG.debug("{}: onAddShardReplica: {}", persistenceId(), shardReplicaMsg);
1314
1315         // verify the shard with the specified name is present in the cluster configuration
1316         if (!this.configuration.isShardConfigured(shardName)) {
1317             String msg = String.format("No module configuration exists for shard %s", shardName);
1318             LOG.debug("{}: {}", persistenceId(), msg);
1319             getSender().tell(new Status.Failure(new IllegalArgumentException(msg)), getSelf());
1320             return;
1321         }
1322
1323         // Create the localShard
1324         if (schemaContext == null) {
1325             String msg = String.format(
1326                   "No SchemaContext is available in order to create a local shard instance for %s", shardName);
1327             LOG.debug("{}: {}", persistenceId(), msg);
1328             getSender().tell(new Status.Failure(new IllegalStateException(msg)), getSelf());
1329             return;
1330         }
1331
1332         findPrimary(shardName, new AutoFindPrimaryFailureResponseHandler(getSender(), shardName, persistenceId(),
1333                 getSelf()) {
1334             @Override
1335             public void onRemotePrimaryShardFound(RemotePrimaryShardFound response) {
1336                 final RunnableMessage runnable = (RunnableMessage) () ->
1337                     addShard(getShardName(), response, getSender());
1338                 if (!isPreviousShardActorStopInProgress(getShardName(), runnable)) {
1339                     getSelf().tell(runnable, getTargetActor());
1340                 }
1341             }
1342
1343             @Override
1344             public void onLocalPrimaryFound(LocalPrimaryShardFound message) {
1345                 sendLocalReplicaAlreadyExistsReply(getShardName(), getTargetActor());
1346             }
1347         });
1348     }
1349
1350     private void sendLocalReplicaAlreadyExistsReply(String shardName, ActorRef sender) {
1351         String msg = String.format("Local shard %s already exists", shardName);
1352         LOG.debug("{}: {}", persistenceId(), msg);
1353         sender.tell(new Status.Failure(new AlreadyExistsException(msg)), getSelf());
1354     }
1355
1356     private void addPrefixShard(final String shardName, final YangInstanceIdentifier shardPrefix,
1357                                 final RemotePrimaryShardFound response, final ActorRef sender) {
1358         if (isShardReplicaOperationInProgress(shardName, sender)) {
1359             return;
1360         }
1361
1362         shardReplicaOperationsInProgress.add(shardName);
1363
1364         final ShardInformation shardInfo;
1365         final boolean removeShardOnFailure;
1366         ShardInformation existingShardInfo = localShards.get(shardName);
1367         if (existingShardInfo == null) {
1368             removeShardOnFailure = true;
1369             ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
1370
1371             final Builder builder = newShardDatastoreContextBuilder(shardName);
1372             builder.storeRoot(shardPrefix).customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName());
1373
1374             DatastoreContext datastoreContext = builder.build();
1375
1376             shardInfo = new ShardInformation(shardName, shardId, getPeerAddresses(shardName), datastoreContext,
1377                     Shard.builder(), peerAddressResolver);
1378             shardInfo.setActiveMember(false);
1379             localShards.put(shardName, shardInfo);
1380             shardInfo.setActor(newShardActor(schemaContext, shardInfo));
1381         } else {
1382             removeShardOnFailure = false;
1383             shardInfo = existingShardInfo;
1384         }
1385
1386         execAddShard(shardName, shardInfo, response, removeShardOnFailure, sender);
1387     }
1388
1389     private void addShard(final String shardName, final RemotePrimaryShardFound response, final ActorRef sender) {
1390         if (isShardReplicaOperationInProgress(shardName, sender)) {
1391             return;
1392         }
1393
1394         shardReplicaOperationsInProgress.add(shardName);
1395
1396         final ShardInformation shardInfo;
1397         final boolean removeShardOnFailure;
1398         ShardInformation existingShardInfo = localShards.get(shardName);
1399         if (existingShardInfo == null) {
1400             removeShardOnFailure = true;
1401             ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
1402
1403             DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName)
1404                     .customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName()).build();
1405
1406             shardInfo = new ShardInformation(shardName, shardId, getPeerAddresses(shardName), datastoreContext,
1407                     Shard.builder(), peerAddressResolver);
1408             shardInfo.setActiveMember(false);
1409             localShards.put(shardName, shardInfo);
1410             shardInfo.setActor(newShardActor(schemaContext, shardInfo));
1411         } else {
1412             removeShardOnFailure = false;
1413             shardInfo = existingShardInfo;
1414         }
1415
1416         execAddShard(shardName, shardInfo, response, removeShardOnFailure, sender);
1417     }
1418
1419     private void execAddShard(final String shardName,
1420                               final ShardInformation shardInfo,
1421                               final RemotePrimaryShardFound response,
1422                               final boolean removeShardOnFailure,
1423                               final ActorRef sender) {
1424
1425         final String localShardAddress =
1426                 peerAddressResolver.getShardActorAddress(shardName, cluster.getCurrentMemberName());
1427
1428         //inform ShardLeader to add this shard as a replica by sending an AddServer message
1429         LOG.debug("{}: Sending AddServer message to peer {} for shard {}", persistenceId(),
1430                 response.getPrimaryPath(), shardInfo.getShardId());
1431
1432         final Timeout addServerTimeout = new Timeout(shardInfo.getDatastoreContext()
1433                 .getShardLeaderElectionTimeout().duration());
1434         final Future<Object> futureObj = ask(getContext().actorSelection(response.getPrimaryPath()),
1435                 new AddServer(shardInfo.getShardId().toString(), localShardAddress, true), addServerTimeout);
1436
1437         futureObj.onComplete(new OnComplete<Object>() {
1438             @Override
1439             public void onComplete(Throwable failure, Object addServerResponse) {
1440                 if (failure != null) {
1441                     LOG.debug("{}: AddServer request to {} for {} failed", persistenceId(),
1442                             response.getPrimaryPath(), shardName, failure);
1443
1444                     final String msg = String.format("AddServer request to leader %s for shard %s failed",
1445                             response.getPrimaryPath(), shardName);
1446                     self().tell(new ForwardedAddServerFailure(shardName, msg, failure, removeShardOnFailure), sender);
1447                 } else {
1448                     self().tell(new ForwardedAddServerReply(shardInfo, (AddServerReply)addServerResponse,
1449                             response.getPrimaryPath(), removeShardOnFailure), sender);
1450                 }
1451             }
1452         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1453     }
1454
1455     private void onAddServerFailure(String shardName, String message, Throwable failure, ActorRef sender,
1456             boolean removeShardOnFailure) {
1457         shardReplicaOperationsInProgress.remove(shardName);
1458
1459         if (removeShardOnFailure) {
1460             ShardInformation shardInfo = localShards.remove(shardName);
1461             if (shardInfo.getActor() != null) {
1462                 shardInfo.getActor().tell(PoisonPill.getInstance(), getSelf());
1463             }
1464         }
1465
1466         sender.tell(new Status.Failure(message == null ? failure :
1467             new RuntimeException(message, failure)), getSelf());
1468     }
1469
1470     private void onAddServerReply(ShardInformation shardInfo, AddServerReply replyMsg, ActorRef sender,
1471             String leaderPath, boolean removeShardOnFailure) {
1472         String shardName = shardInfo.getShardName();
1473         shardReplicaOperationsInProgress.remove(shardName);
1474
1475         LOG.debug("{}: Received {} for shard {} from leader {}", persistenceId(), replyMsg, shardName, leaderPath);
1476
1477         if (replyMsg.getStatus() == ServerChangeStatus.OK) {
1478             LOG.debug("{}: Leader shard successfully added the replica shard {}", persistenceId(), shardName);
1479
1480             // Make the local shard voting capable
1481             shardInfo.setDatastoreContext(newShardDatastoreContext(shardName), getSelf());
1482             shardInfo.setActiveMember(true);
1483             persistShardList();
1484
1485             sender.tell(new Status.Success(null), getSelf());
1486         } else if (replyMsg.getStatus() == ServerChangeStatus.ALREADY_EXISTS) {
1487             sendLocalReplicaAlreadyExistsReply(shardName, sender);
1488         } else {
1489             LOG.warn("{}: Leader failed to add shard replica {} with status {}",
1490                     persistenceId(), shardName, replyMsg.getStatus());
1491
1492             Exception failure = getServerChangeException(AddServer.class, replyMsg.getStatus(), leaderPath,
1493                     shardInfo.getShardId());
1494
1495             onAddServerFailure(shardName, null, failure, sender, removeShardOnFailure);
1496         }
1497     }
1498
1499     private static Exception getServerChangeException(Class<?> serverChange, ServerChangeStatus serverChangeStatus,
1500                                                String leaderPath, ShardIdentifier shardId) {
1501         Exception failure;
1502         switch (serverChangeStatus) {
1503             case TIMEOUT:
1504                 failure = new TimeoutException(String.format(
1505                         "The shard leader %s timed out trying to replicate the initial data to the new shard %s."
1506                         + "Possible causes - there was a problem replicating the data or shard leadership changed "
1507                         + "while replicating the shard data", leaderPath, shardId.getShardName()));
1508                 break;
1509             case NO_LEADER:
1510                 failure = createNoShardLeaderException(shardId);
1511                 break;
1512             case NOT_SUPPORTED:
1513                 failure = new UnsupportedOperationException(String.format("%s request is not supported for shard %s",
1514                         serverChange.getSimpleName(), shardId.getShardName()));
1515                 break;
1516             default :
1517                 failure = new RuntimeException(String.format(
1518                         "%s request to leader %s for shard %s failed with status %s",
1519                         serverChange.getSimpleName(), leaderPath, shardId.getShardName(), serverChangeStatus));
1520         }
1521         return failure;
1522     }
1523
1524     private void onRemoveShardReplica(final RemoveShardReplica shardReplicaMsg) {
1525         LOG.debug("{}: onRemoveShardReplica: {}", persistenceId(), shardReplicaMsg);
1526
1527         findPrimary(shardReplicaMsg.getShardName(), new AutoFindPrimaryFailureResponseHandler(getSender(),
1528                 shardReplicaMsg.getShardName(), persistenceId(), getSelf()) {
1529             @Override
1530             public void onRemotePrimaryShardFound(RemotePrimaryShardFound response) {
1531                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1532             }
1533
1534             @Override
1535             public void onLocalPrimaryFound(LocalPrimaryShardFound response) {
1536                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1537             }
1538
1539             private void doRemoveShardReplicaAsync(final String primaryPath) {
1540                 getSelf().tell((RunnableMessage) () -> removeShardReplica(shardReplicaMsg, getShardName(),
1541                         primaryPath, getSender()), getTargetActor());
1542             }
1543         });
1544     }
1545
1546     private void onRemovePrefixShardReplica(final RemovePrefixShardReplica message) {
1547         LOG.debug("{}: onRemovePrefixShardReplica: {}", persistenceId(), message);
1548
1549         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(),
1550                 ClusterUtils.getCleanShardName(message.getShardPrefix()));
1551         final String shardName = shardId.getShardName();
1552
1553         findPrimary(shardName, new AutoFindPrimaryFailureResponseHandler(getSender(),
1554                 shardName, persistenceId(), getSelf()) {
1555             @Override
1556             public void onRemotePrimaryShardFound(RemotePrimaryShardFound response) {
1557                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1558             }
1559
1560             @Override
1561             public void onLocalPrimaryFound(LocalPrimaryShardFound response) {
1562                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1563             }
1564
1565             private void doRemoveShardReplicaAsync(final String primaryPath) {
1566                 getSelf().tell((RunnableMessage) () -> removePrefixShardReplica(message, getShardName(),
1567                         primaryPath, getSender()), getTargetActor());
1568             }
1569         });
1570     }
1571
1572     private void persistShardList() {
1573         List<String> shardList = new ArrayList<>(localShards.keySet());
1574         for (ShardInformation shardInfo : localShards.values()) {
1575             if (!shardInfo.isActiveMember()) {
1576                 shardList.remove(shardInfo.getShardName());
1577             }
1578         }
1579         LOG.debug("{}: persisting the shard list {}", persistenceId(), shardList);
1580         saveSnapshot(updateShardManagerSnapshot(shardList, configuration.getAllPrefixShardConfigurations()));
1581     }
1582
1583     private ShardManagerSnapshot updateShardManagerSnapshot(
1584             final List<String> shardList,
1585             final Map<DOMDataTreeIdentifier, PrefixShardConfiguration> allPrefixShardConfigurations) {
1586         currentSnapshot = new ShardManagerSnapshot(shardList, allPrefixShardConfigurations);
1587         return currentSnapshot;
1588     }
1589
1590     private void applyShardManagerSnapshot(ShardManagerSnapshot snapshot) {
1591         currentSnapshot = snapshot;
1592
1593         LOG.debug("{}: onSnapshotOffer: {}", persistenceId(), currentSnapshot);
1594
1595         final MemberName currentMember = cluster.getCurrentMemberName();
1596         Set<String> configuredShardList =
1597             new HashSet<>(configuration.getMemberShardNames(currentMember));
1598         for (String shard : currentSnapshot.getShardList()) {
1599             if (!configuredShardList.contains(shard)) {
1600                 // add the current member as a replica for the shard
1601                 LOG.debug("{}: adding shard {}", persistenceId(), shard);
1602                 configuration.addMemberReplicaForShard(shard, currentMember);
1603             } else {
1604                 configuredShardList.remove(shard);
1605             }
1606         }
1607         for (String shard : configuredShardList) {
1608             // remove the member as a replica for the shard
1609             LOG.debug("{}: removing shard {}", persistenceId(), shard);
1610             configuration.removeMemberReplicaForShard(shard, currentMember);
1611         }
1612     }
1613
1614     private void onSaveSnapshotSuccess(SaveSnapshotSuccess successMessage) {
1615         LOG.debug("{} saved ShardManager snapshot successfully. Deleting the prev snapshot if available",
1616             persistenceId());
1617         deleteSnapshots(new SnapshotSelectionCriteria(scala.Long.MaxValue(), successMessage.metadata().timestamp() - 1,
1618             0, 0));
1619     }
1620
1621     private void onChangeShardServersVotingStatus(final ChangeShardMembersVotingStatus changeMembersVotingStatus) {
1622         LOG.debug("{}: onChangeShardServersVotingStatus: {}", persistenceId(), changeMembersVotingStatus);
1623
1624         String shardName = changeMembersVotingStatus.getShardName();
1625         Map<String, Boolean> serverVotingStatusMap = new HashMap<>();
1626         for (Entry<String, Boolean> e: changeMembersVotingStatus.getMeberVotingStatusMap().entrySet()) {
1627             serverVotingStatusMap.put(getShardIdentifier(MemberName.forName(e.getKey()), shardName).toString(),
1628                     e.getValue());
1629         }
1630
1631         ChangeServersVotingStatus changeServersVotingStatus = new ChangeServersVotingStatus(serverVotingStatusMap);
1632
1633         findLocalShard(shardName, getSender(),
1634             localShardFound -> changeShardMembersVotingStatus(changeServersVotingStatus, shardName,
1635             localShardFound.getPath(), getSender()));
1636     }
1637
1638     private void onFlipShardMembersVotingStatus(FlipShardMembersVotingStatus flipMembersVotingStatus) {
1639         LOG.debug("{}: onFlipShardMembersVotingStatus: {}", persistenceId(), flipMembersVotingStatus);
1640
1641         ActorRef sender = getSender();
1642         final String shardName = flipMembersVotingStatus.getShardName();
1643         findLocalShard(shardName, sender, localShardFound -> {
1644             Future<Object> future = ask(localShardFound.getPath(), GetOnDemandRaftState.INSTANCE,
1645                     Timeout.apply(30, TimeUnit.SECONDS));
1646
1647             future.onComplete(new OnComplete<Object>() {
1648                 @Override
1649                 public void onComplete(Throwable failure, Object response) {
1650                     if (failure != null) {
1651                         sender.tell(new Status.Failure(new RuntimeException(
1652                                 String.format("Failed to access local shard %s", shardName), failure)), self());
1653                         return;
1654                     }
1655
1656                     OnDemandRaftState raftState = (OnDemandRaftState) response;
1657                     Map<String, Boolean> serverVotingStatusMap = new HashMap<>();
1658                     for (Entry<String, Boolean> e: raftState.getPeerVotingStates().entrySet()) {
1659                         serverVotingStatusMap.put(e.getKey(), !e.getValue());
1660                     }
1661
1662                     serverVotingStatusMap.put(getShardIdentifier(cluster.getCurrentMemberName(), shardName)
1663                             .toString(), !raftState.isVoting());
1664
1665                     changeShardMembersVotingStatus(new ChangeServersVotingStatus(serverVotingStatusMap),
1666                             shardName, localShardFound.getPath(), sender);
1667                 }
1668             }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1669         });
1670
1671     }
1672
1673     private void findLocalShard(FindLocalShard message) {
1674         LOG.debug("{}: findLocalShard : {}", persistenceId(), message.getShardName());
1675
1676         final ShardInformation shardInformation = localShards.get(message.getShardName());
1677
1678         if (shardInformation == null) {
1679             LOG.debug("{}: Local shard {} not found - shards present: {}",
1680                     persistenceId(), message.getShardName(), localShards.keySet());
1681
1682             getSender().tell(new LocalShardNotFound(message.getShardName()), getSelf());
1683             return;
1684         }
1685
1686         sendResponse(shardInformation, message.isWaitUntilInitialized(), false,
1687             () -> new LocalShardFound(shardInformation.getActor()));
1688     }
1689
1690     private void findLocalShard(final String shardName, final ActorRef sender,
1691             final Consumer<LocalShardFound> onLocalShardFound) {
1692         Timeout findLocalTimeout = new Timeout(datastoreContextFactory.getBaseDatastoreContext()
1693                 .getShardInitializationTimeout().duration().$times(2));
1694
1695         Future<Object> futureObj = ask(getSelf(), new FindLocalShard(shardName, true), findLocalTimeout);
1696         futureObj.onComplete(new OnComplete<Object>() {
1697             @Override
1698             public void onComplete(Throwable failure, Object response) {
1699                 if (failure != null) {
1700                     LOG.debug("{}: Received failure from FindLocalShard for shard {}", persistenceId, shardName,
1701                             failure);
1702                     sender.tell(new Status.Failure(new RuntimeException(
1703                             String.format("Failed to find local shard %s", shardName), failure)), self());
1704                 } else {
1705                     if (response instanceof LocalShardFound) {
1706                         getSelf().tell((RunnableMessage) () -> onLocalShardFound.accept((LocalShardFound) response),
1707                                 sender);
1708                     } else if (response instanceof LocalShardNotFound) {
1709                         String msg = String.format("Local shard %s does not exist", shardName);
1710                         LOG.debug("{}: {}", persistenceId, msg);
1711                         sender.tell(new Status.Failure(new IllegalArgumentException(msg)), self());
1712                     } else {
1713                         String msg = String.format("Failed to find local shard %s: received response: %s",
1714                                 shardName, response);
1715                         LOG.debug("{}: {}", persistenceId, msg);
1716                         sender.tell(new Status.Failure(response instanceof Throwable ? (Throwable) response :
1717                                 new RuntimeException(msg)), self());
1718                     }
1719                 }
1720             }
1721         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1722     }
1723
1724     private void changeShardMembersVotingStatus(ChangeServersVotingStatus changeServersVotingStatus,
1725             final String shardName, final ActorRef shardActorRef, final ActorRef sender) {
1726         if (isShardReplicaOperationInProgress(shardName, sender)) {
1727             return;
1728         }
1729
1730         shardReplicaOperationsInProgress.add(shardName);
1731
1732         DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName).build();
1733         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
1734
1735         LOG.debug("{}: Sending ChangeServersVotingStatus message {} to local shard {}", persistenceId(),
1736                 changeServersVotingStatus, shardActorRef.path());
1737
1738         Timeout timeout = new Timeout(datastoreContext.getShardLeaderElectionTimeout().duration().$times(2));
1739         Future<Object> futureObj = ask(shardActorRef, changeServersVotingStatus, timeout);
1740
1741         futureObj.onComplete(new OnComplete<Object>() {
1742             @Override
1743             public void onComplete(Throwable failure, Object response) {
1744                 shardReplicaOperationsInProgress.remove(shardName);
1745                 if (failure != null) {
1746                     String msg = String.format("ChangeServersVotingStatus request to local shard %s failed",
1747                             shardActorRef.path());
1748                     LOG.debug("{}: {}", persistenceId(), msg, failure);
1749                     sender.tell(new Status.Failure(new RuntimeException(msg, failure)), self());
1750                 } else {
1751                     LOG.debug("{}: Received {} from local shard {}", persistenceId(), response, shardActorRef.path());
1752
1753                     ServerChangeReply replyMsg = (ServerChangeReply) response;
1754                     if (replyMsg.getStatus() == ServerChangeStatus.OK) {
1755                         LOG.debug("{}: ChangeServersVotingStatus succeeded for shard {}", persistenceId(), shardName);
1756                         sender.tell(new Status.Success(null), getSelf());
1757                     } else if (replyMsg.getStatus() == ServerChangeStatus.INVALID_REQUEST) {
1758                         sender.tell(new Status.Failure(new IllegalArgumentException(String.format(
1759                                 "The requested voting state change for shard %s is invalid. At least one member "
1760                                 + "must be voting", shardId.getShardName()))), getSelf());
1761                     } else {
1762                         LOG.warn("{}: ChangeServersVotingStatus failed for shard {} with status {}",
1763                                 persistenceId(), shardName, replyMsg.getStatus());
1764
1765                         Exception error = getServerChangeException(ChangeServersVotingStatus.class,
1766                                 replyMsg.getStatus(), shardActorRef.path().toString(), shardId);
1767                         sender.tell(new Status.Failure(error), getSelf());
1768                     }
1769                 }
1770             }
1771         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1772     }
1773
1774     private static final class ForwardedAddServerReply {
1775         ShardInformation shardInfo;
1776         AddServerReply addServerReply;
1777         String leaderPath;
1778         boolean removeShardOnFailure;
1779
1780         ForwardedAddServerReply(ShardInformation shardInfo, AddServerReply addServerReply, String leaderPath,
1781                 boolean removeShardOnFailure) {
1782             this.shardInfo = shardInfo;
1783             this.addServerReply = addServerReply;
1784             this.leaderPath = leaderPath;
1785             this.removeShardOnFailure = removeShardOnFailure;
1786         }
1787     }
1788
1789     private static final class ForwardedAddServerFailure {
1790         String shardName;
1791         String failureMessage;
1792         Throwable failure;
1793         boolean removeShardOnFailure;
1794
1795         ForwardedAddServerFailure(String shardName, String failureMessage, Throwable failure,
1796                 boolean removeShardOnFailure) {
1797             this.shardName = shardName;
1798             this.failureMessage = failureMessage;
1799             this.failure = failure;
1800             this.removeShardOnFailure = removeShardOnFailure;
1801         }
1802     }
1803
1804     static class OnShardInitialized {
1805         private final Runnable replyRunnable;
1806         private Cancellable timeoutSchedule;
1807
1808         OnShardInitialized(Runnable replyRunnable) {
1809             this.replyRunnable = replyRunnable;
1810         }
1811
1812         Runnable getReplyRunnable() {
1813             return replyRunnable;
1814         }
1815
1816         Cancellable getTimeoutSchedule() {
1817             return timeoutSchedule;
1818         }
1819
1820         void setTimeoutSchedule(Cancellable timeoutSchedule) {
1821             this.timeoutSchedule = timeoutSchedule;
1822         }
1823     }
1824
1825     static class OnShardReady extends OnShardInitialized {
1826         OnShardReady(Runnable replyRunnable) {
1827             super(replyRunnable);
1828         }
1829     }
1830
1831     private interface RunnableMessage extends Runnable {
1832     }
1833
1834     /**
1835      * The FindPrimaryResponseHandler provides specific callback methods which are invoked when a response to the
1836      * a remote or local find primary message is processed.
1837      */
1838     private interface FindPrimaryResponseHandler {
1839         /**
1840          * Invoked when a Failure message is received as a response.
1841          *
1842          * @param failure the failure exception
1843          */
1844         void onFailure(Throwable failure);
1845
1846         /**
1847          * Invoked when a RemotePrimaryShardFound response is received.
1848          *
1849          * @param response the response
1850          */
1851         void onRemotePrimaryShardFound(RemotePrimaryShardFound response);
1852
1853         /**
1854          * Invoked when a LocalPrimaryShardFound response is received.
1855          *
1856          * @param response the response
1857          */
1858         void onLocalPrimaryFound(LocalPrimaryShardFound response);
1859
1860         /**
1861          * Invoked when an unknown response is received. This is another type of failure.
1862          *
1863          * @param response the response
1864          */
1865         void onUnknownResponse(Object response);
1866     }
1867
1868     /**
1869      * The AutoFindPrimaryFailureResponseHandler automatically processes Failure responses when finding a primary
1870      * replica and sends a wrapped Failure response to some targetActor.
1871      */
1872     private abstract static class AutoFindPrimaryFailureResponseHandler implements FindPrimaryResponseHandler {
1873         private final ActorRef targetActor;
1874         private final String shardName;
1875         private final String persistenceId;
1876         private final ActorRef shardManagerActor;
1877
1878         /**
1879          * Constructs an instance.
1880          *
1881          * @param targetActor The actor to whom the Failure response should be sent when a FindPrimary failure occurs
1882          * @param shardName The name of the shard for which the primary replica had to be found
1883          * @param persistenceId The persistenceId for the ShardManager
1884          * @param shardManagerActor The ShardManager actor which triggered the call to FindPrimary
1885          */
1886         protected AutoFindPrimaryFailureResponseHandler(ActorRef targetActor, String shardName, String persistenceId,
1887                 ActorRef shardManagerActor) {
1888             this.targetActor = Preconditions.checkNotNull(targetActor);
1889             this.shardName = Preconditions.checkNotNull(shardName);
1890             this.persistenceId = Preconditions.checkNotNull(persistenceId);
1891             this.shardManagerActor = Preconditions.checkNotNull(shardManagerActor);
1892         }
1893
1894         public ActorRef getTargetActor() {
1895             return targetActor;
1896         }
1897
1898         public String getShardName() {
1899             return shardName;
1900         }
1901
1902         @Override
1903         public void onFailure(Throwable failure) {
1904             LOG.debug("{}: Received failure from FindPrimary for shard {}", persistenceId, shardName, failure);
1905             targetActor.tell(new Status.Failure(new RuntimeException(
1906                     String.format("Failed to find leader for shard %s", shardName), failure)), shardManagerActor);
1907         }
1908
1909         @Override
1910         public void onUnknownResponse(Object response) {
1911             String msg = String.format("Failed to find leader for shard %s: received response: %s",
1912                     shardName, response);
1913             LOG.debug("{}: {}", persistenceId, msg);
1914             targetActor.tell(new Status.Failure(response instanceof Throwable ? (Throwable) response :
1915                     new RuntimeException(msg)), shardManagerActor);
1916         }
1917     }
1918
1919     /**
1920      * The WrappedShardResponse class wraps a response from a Shard.
1921      */
1922     private static final class WrappedShardResponse {
1923         private final ShardIdentifier shardId;
1924         private final Object response;
1925         private final String leaderPath;
1926
1927         WrappedShardResponse(ShardIdentifier shardId, Object response, String leaderPath) {
1928             this.shardId = shardId;
1929             this.response = response;
1930             this.leaderPath = leaderPath;
1931         }
1932
1933         ShardIdentifier getShardId() {
1934             return shardId;
1935         }
1936
1937         Object getResponse() {
1938             return response;
1939         }
1940
1941         String getLeaderPath() {
1942             return leaderPath;
1943         }
1944     }
1945
1946     private static final class ShardNotInitializedTimeout {
1947         private final ActorRef sender;
1948         private final ShardInformation shardInfo;
1949         private final OnShardInitialized onShardInitialized;
1950
1951         ShardNotInitializedTimeout(ShardInformation shardInfo, OnShardInitialized onShardInitialized, ActorRef sender) {
1952             this.sender = sender;
1953             this.shardInfo = shardInfo;
1954             this.onShardInitialized = onShardInitialized;
1955         }
1956
1957         ActorRef getSender() {
1958             return sender;
1959         }
1960
1961         ShardInformation getShardInfo() {
1962             return shardInfo;
1963         }
1964
1965         OnShardInitialized getOnShardInitialized() {
1966             return onShardInitialized;
1967         }
1968     }
1969 }
1970
1971
1972