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.GetShardRole;
  75 import org.opendaylight.controller.cluster.datastore.messages.GetShardRoleReply;
  76 import org.opendaylight.controller.cluster.datastore.messages.LocalPrimaryShardFound;
  77 import org.opendaylight.controller.cluster.datastore.messages.LocalShardFound;
  78 import org.opendaylight.controller.cluster.datastore.messages.LocalShardNotFound;
  79 import org.opendaylight.controller.cluster.datastore.messages.RemoteFindPrimary;
  80 import org.opendaylight.controller.cluster.datastore.messages.RemotePrimaryShardFound;
  81 import org.opendaylight.controller.cluster.datastore.messages.RemovePrefixShardReplica;
  82 import org.opendaylight.controller.cluster.datastore.messages.RemoveShardReplica;
  83 import org.opendaylight.controller.cluster.datastore.messages.ShardLeaderStateChanged;
  84 import org.opendaylight.controller.cluster.datastore.messages.UpdateSchemaContext;
  85 import org.opendaylight.controller.cluster.datastore.persisted.DatastoreSnapshot;
  86 import org.opendaylight.controller.cluster.datastore.persisted.ShardManagerSnapshot;
  87 import org.opendaylight.controller.cluster.datastore.utils.ClusterUtils;
  88 import org.opendaylight.controller.cluster.datastore.utils.CompositeOnComplete;
  89 import org.opendaylight.controller.cluster.datastore.utils.Dispatchers;
  90 import org.opendaylight.controller.cluster.datastore.utils.PrimaryShardInfoFutureCache;
  91 import org.opendaylight.controller.cluster.notifications.RegisterRoleChangeListener;
  92 import org.opendaylight.controller.cluster.notifications.RoleChangeNotification;
  93 import org.opendaylight.controller.cluster.raft.base.messages.FollowerInitialSyncUpStatus;
  94 import org.opendaylight.controller.cluster.raft.base.messages.SwitchBehavior;
  95 import org.opendaylight.controller.cluster.raft.client.messages.GetOnDemandRaftState;
  96 import org.opendaylight.controller.cluster.raft.client.messages.GetSnapshot;
  97 import org.opendaylight.controller.cluster.raft.client.messages.OnDemandRaftState;
  98 import org.opendaylight.controller.cluster.raft.client.messages.Shutdown;
  99 import org.opendaylight.controller.cluster.raft.messages.AddServer;
 100 import org.opendaylight.controller.cluster.raft.messages.AddServerReply;
 101 import org.opendaylight.controller.cluster.raft.messages.ChangeServersVotingStatus;
 102 import org.opendaylight.controller.cluster.raft.messages.RemoveServer;
 103 import org.opendaylight.controller.cluster.raft.messages.RemoveServerReply;
 104 import org.opendaylight.controller.cluster.raft.messages.ServerChangeReply;
 105 import org.opendaylight.controller.cluster.raft.messages.ServerChangeStatus;
 106 import org.opendaylight.controller.cluster.raft.messages.ServerRemoved;
 107 import org.opendaylight.controller.cluster.raft.policy.DisableElectionsRaftPolicy;
 108 import org.opendaylight.controller.cluster.sharding.PrefixedShardConfigUpdateHandler;
 109 import org.opendaylight.controller.cluster.sharding.messages.InitConfigListener;
 110 import org.opendaylight.controller.cluster.sharding.messages.PrefixShardCreated;
 111 import org.opendaylight.controller.cluster.sharding.messages.PrefixShardRemoved;
 112 import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
 113 import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeChangeListener;
 114 import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
 115 import org.opendaylight.yangtools.concepts.ListenerRegistration;
 116 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
 117 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
 118 import org.slf4j.Logger;
 119 import org.slf4j.LoggerFactory;
 120 import scala.concurrent.ExecutionContext;
 121 import scala.concurrent.Future;
 122 import scala.concurrent.duration.Duration;
 123 import scala.concurrent.duration.FiniteDuration;
 124
 125 /**
 126  * Manages the shards for a data store. The ShardManager has the following jobs:
 127  * <ul>
 128  * <li> Create all the local shard replicas that belong on this cluster member
 129  * <li> Find the address of the local shard
 130  * <li> Find the primary replica for any given shard
 131  * <li> Monitor the cluster members and store their addresses
 132  * </ul>
 133  */
 134 class ShardManager extends AbstractUntypedPersistentActorWithMetering {
 135     private static final Logger LOG = LoggerFactory.getLogger(ShardManager.class);
 136
 137     // Stores a mapping between a shard name and it's corresponding information
 138     // Shard names look like inventory, topology etc and are as specified in
 139     // configuration
 140     private final Map<String, ShardInformation> localShards = new HashMap<>();
 141
 142     // The type of a ShardManager reflects the type of the datastore itself
 143     // A data store could be of type config/operational
 144     private final String type;
 145
 146     private final ClusterWrapper cluster;
 147
 148     private final Configuration configuration;
 149
 150     private final String shardDispatcherPath;
 151
 152     private final ShardManagerInfo shardManagerMBean;
 153
 154     private DatastoreContextFactory datastoreContextFactory;
 155
 156     private final CountDownLatch waitTillReadyCountdownLatch;
 157
 158     private final PrimaryShardInfoFutureCache primaryShardInfoCache;
 159
 160     private final ShardPeerAddressResolver peerAddressResolver;
 161
 162     private SchemaContext schemaContext;
 163
 164     private DatastoreSnapshot restoreFromSnapshot;
 165
 166     private ShardManagerSnapshot currentSnapshot;
 167
 168     private final Set<String> shardReplicaOperationsInProgress = new HashSet<>();
 169
 170     private final Map<String, CompositeOnComplete<Boolean>> shardActorsStopping = new HashMap<>();
 171
 172     private final String persistenceId;
 173     private final AbstractDataStore dataStore;
 174
 175     private ListenerRegistration<DOMDataTreeChangeListener> configListenerReg = null;
 176     private PrefixedShardConfigUpdateHandler configUpdateHandler;
 177
 178     ShardManager(AbstractShardManagerCreator<?> builder) {
 179         this.cluster = builder.getCluster();
 180         this.configuration = builder.getConfiguration();
 181         this.datastoreContextFactory = builder.getDatastoreContextFactory();
 182         this.type = datastoreContextFactory.getBaseDatastoreContext().getDataStoreName();
 183         this.shardDispatcherPath =
 184                 new Dispatchers(context().system().dispatchers()).getDispatcherPath(Dispatchers.DispatcherType.Shard);
 185         this.waitTillReadyCountdownLatch = builder.getWaitTillReadyCountDownLatch();
 186         this.primaryShardInfoCache = builder.getPrimaryShardInfoCache();
 187         this.restoreFromSnapshot = builder.getRestoreFromSnapshot();
 188
 189         String possiblePersistenceId = datastoreContextFactory.getBaseDatastoreContext().getShardManagerPersistenceId();
 190         persistenceId = possiblePersistenceId != null ? possiblePersistenceId : "shard-manager-" + type;
 191
 192         peerAddressResolver = new ShardPeerAddressResolver(type, cluster.getCurrentMemberName());
 193
 194         // Subscribe this actor to cluster member events
 195         cluster.subscribeToMemberEvents(getSelf());
 196
 197         shardManagerMBean = new ShardManagerInfo(getSelf(), cluster.getCurrentMemberName(),
 198                 "shard-manager-" + this.type,
 199                 datastoreContextFactory.getBaseDatastoreContext().getDataStoreMXBeanType());
 200         shardManagerMBean.registerMBean();
 201
 202         dataStore = builder.getDistributedDataStore();
 203     }
 204
 205     @Override
 206     public void preStart() {
 207         LOG.info("Starting ShardManager {}", persistenceId);
 208     }
 209
 210     @Override
 211     public void postStop() {
 212         LOG.info("Stopping ShardManager {}", persistenceId());
 213
 214         shardManagerMBean.unregisterMBean();
 215
 216         if (configListenerReg != null) {
 217             configListenerReg.close();
 218             configListenerReg = null;
 219         }
 220     }
 221
 222     @Override
 223     public void handleCommand(Object message) throws Exception {
 224         if (message  instanceof FindPrimary) {
 225             findPrimary((FindPrimary)message);
 226         } else if (message instanceof FindLocalShard) {
 227             findLocalShard((FindLocalShard) message);
 228         } else if (message instanceof UpdateSchemaContext) {
 229             updateSchemaContext(message);
 230         } else if (message instanceof ActorInitialized) {
 231             onActorInitialized(message);
 232         } else if (message instanceof ClusterEvent.MemberUp) {
 233             memberUp((ClusterEvent.MemberUp) message);
 234         } else if (message instanceof ClusterEvent.MemberWeaklyUp) {
 235             memberWeaklyUp((ClusterEvent.MemberWeaklyUp) message);
 236         } else if (message instanceof ClusterEvent.MemberExited) {
 237             memberExited((ClusterEvent.MemberExited) message);
 238         } else if (message instanceof ClusterEvent.MemberRemoved) {
 239             memberRemoved((ClusterEvent.MemberRemoved) message);
 240         } else if (message instanceof ClusterEvent.UnreachableMember) {
 241             memberUnreachable((ClusterEvent.UnreachableMember) message);
 242         } else if (message instanceof ClusterEvent.ReachableMember) {
 243             memberReachable((ClusterEvent.ReachableMember) message);
 244         } else if (message instanceof DatastoreContextFactory) {
 245             onDatastoreContextFactory((DatastoreContextFactory) message);
 246         } else if (message instanceof RoleChangeNotification) {
 247             onRoleChangeNotification((RoleChangeNotification) message);
 248         } else if (message instanceof FollowerInitialSyncUpStatus) {
 249             onFollowerInitialSyncStatus((FollowerInitialSyncUpStatus) message);
 250         } else if (message instanceof ShardNotInitializedTimeout) {
 251             onShardNotInitializedTimeout((ShardNotInitializedTimeout) message);
 252         } else if (message instanceof ShardLeaderStateChanged) {
 253             onLeaderStateChanged((ShardLeaderStateChanged) message);
 254         } else if (message instanceof SwitchShardBehavior) {
 255             onSwitchShardBehavior((SwitchShardBehavior) message);
 256         } else if (message instanceof CreateShard) {
 257             onCreateShard((CreateShard)message);
 258         } else if (message instanceof AddShardReplica) {
 259             onAddShardReplica((AddShardReplica) message);
 260         } else if (message instanceof AddPrefixShardReplica) {
 261             onAddPrefixShardReplica((AddPrefixShardReplica) message);
 262         } else if (message instanceof PrefixShardCreated) {
 263             onPrefixShardCreated((PrefixShardCreated) message);
 264         } else if (message instanceof PrefixShardRemoved) {
 265             onPrefixShardRemoved((PrefixShardRemoved) message);
 266         } else if (message instanceof InitConfigListener) {
 267             onInitConfigListener();
 268         } else if (message instanceof ForwardedAddServerReply) {
 269             ForwardedAddServerReply msg = (ForwardedAddServerReply)message;
 270             onAddServerReply(msg.shardInfo, msg.addServerReply, getSender(), msg.leaderPath,
 271                     msg.removeShardOnFailure);
 272         } else if (message instanceof ForwardedAddServerFailure) {
 273             ForwardedAddServerFailure msg = (ForwardedAddServerFailure)message;
 274             onAddServerFailure(msg.shardName, msg.failureMessage, msg.failure, getSender(), msg.removeShardOnFailure);
 275         } else if (message instanceof RemoveShardReplica) {
 276             onRemoveShardReplica((RemoveShardReplica) message);
 277         } else if (message instanceof RemovePrefixShardReplica) {
 278             onRemovePrefixShardReplica((RemovePrefixShardReplica) message);
 279         } else if (message instanceof WrappedShardResponse) {
 280             onWrappedShardResponse((WrappedShardResponse) message);
 281         } else if (message instanceof GetSnapshot) {
 282             onGetSnapshot();
 283         } else if (message instanceof ServerRemoved) {
 284             onShardReplicaRemoved((ServerRemoved) message);
 285         } else if (message instanceof ChangeShardMembersVotingStatus) {
 286             onChangeShardServersVotingStatus((ChangeShardMembersVotingStatus) message);
 287         } else if (message instanceof FlipShardMembersVotingStatus) {
 288             onFlipShardMembersVotingStatus((FlipShardMembersVotingStatus) message);
 289         } else if (message instanceof SaveSnapshotSuccess) {
 290             onSaveSnapshotSuccess((SaveSnapshotSuccess) message);
 291         } else if (message instanceof SaveSnapshotFailure) {
 292             LOG.error("{}: SaveSnapshotFailure received for saving snapshot of shards", persistenceId(),
 293                     ((SaveSnapshotFailure) message).cause());
 294         } else if (message instanceof Shutdown) {
 295             onShutDown();
 296         } else if (message instanceof GetLocalShardIds) {
 297             onGetLocalShardIds();
 298         } else if (message instanceof GetShardRole) {
 299             onGetShardRole((GetShardRole) message);
 300         } else if (message instanceof RunnableMessage) {
 301             ((RunnableMessage)message).run();
 302         } else {
 303             unknownMessage(message);
 304         }
 305     }
 306
 307     private void onGetShardRole(final GetShardRole message) {
 308         LOG.debug("{}: onGetShardRole for shard: {}", persistenceId(), message.getName());
 309
 310         final String name = message.getName();
 311
 312         final ShardInformation shardInformation = localShards.get(name);
 313
 314         if (shardInformation == null) {
 315             LOG.info("{}: no shard information for {} found", persistenceId(), name);
 316             getSender().tell(new Status.Failure(
 317                     new IllegalArgumentException("Shard with name " + name + " not present.")), ActorRef.noSender());
 318             return;
 319         }
 320
 321         getSender().tell(new GetShardRoleReply(shardInformation.getRole()), ActorRef.noSender());
 322     }
 323
 324     private void onInitConfigListener() {
 325         LOG.debug("{}: Initializing config listener on {}", persistenceId(), cluster.getCurrentMemberName());
 326
 327         final org.opendaylight.mdsal.common.api.LogicalDatastoreType type =
 328                 org.opendaylight.mdsal.common.api.LogicalDatastoreType
 329                         .valueOf(datastoreContextFactory.getBaseDatastoreContext().getLogicalStoreType().name());
 330
 331         if (configUpdateHandler != null) {
 332             configUpdateHandler.close();
 333         }
 334
 335         configUpdateHandler = new PrefixedShardConfigUpdateHandler(self(), cluster.getCurrentMemberName());
 336         configUpdateHandler.initListener(dataStore, type);
 337     }
 338
 339     private void onShutDown() {
 340         List<Future<Boolean>> stopFutures = new ArrayList<>(localShards.size());
 341         for (ShardInformation info : localShards.values()) {
 342             if (info.getActor() != null) {
 343                 LOG.debug("{}: Issuing gracefulStop to shard {}", persistenceId(), info.getShardId());
 344
 345                 FiniteDuration duration = info.getDatastoreContext().getShardRaftConfig()
 346                         .getElectionTimeOutInterval().$times(2);
 347                 stopFutures.add(Patterns.gracefulStop(info.getActor(), duration, Shutdown.INSTANCE));
 348             }
 349         }
 350
 351         LOG.info("Shutting down ShardManager {} - waiting on {} shards", persistenceId(), stopFutures.size());
 352
 353         ExecutionContext dispatcher = new Dispatchers(context().system().dispatchers())
 354                 .getDispatcher(Dispatchers.DispatcherType.Client);
 355         Future<Iterable<Boolean>> combinedFutures = Futures.sequence(stopFutures, dispatcher);
 356
 357         combinedFutures.onComplete(new OnComplete<Iterable<Boolean>>() {
 358             @Override
 359             public void onComplete(Throwable failure, Iterable<Boolean> results) {
 360                 LOG.debug("{}: All shards shutdown - sending PoisonPill to self", persistenceId());
 361
 362                 self().tell(PoisonPill.getInstance(), self());
 363
 364                 if (failure != null) {
 365                     LOG.warn("{}: An error occurred attempting to shut down the shards", persistenceId(), failure);
 366                 } else {
 367                     int nfailed = 0;
 368                     for (Boolean result : results) {
 369                         if (!result) {
 370                             nfailed++;
 371                         }
 372                     }
 373
 374                     if (nfailed > 0) {
 375                         LOG.warn("{}: {} shards did not shut down gracefully", persistenceId(), nfailed);
 376                     }
 377                 }
 378             }
 379         }, dispatcher);
 380     }
 381
 382     private void onWrappedShardResponse(WrappedShardResponse message) {
 383         if (message.getResponse() instanceof RemoveServerReply) {
 384             onRemoveServerReply(getSender(), message.getShardId(), (RemoveServerReply) message.getResponse(),
 385                     message.getLeaderPath());
 386         }
 387     }
 388
 389     private void onRemoveServerReply(ActorRef originalSender, ShardIdentifier shardId, RemoveServerReply replyMsg,
 390             String leaderPath) {
 391         shardReplicaOperationsInProgress.remove(shardId.getShardName());
 392
 393         LOG.debug("{}: Received {} for shard {}", persistenceId(), replyMsg, shardId.getShardName());
 394
 395         if (replyMsg.getStatus() == ServerChangeStatus.OK) {
 396             LOG.debug("{}: Leader shard successfully removed the replica shard {}", persistenceId(),
 397                     shardId.getShardName());
 398             originalSender.tell(new Status.Success(null), getSelf());
 399         } else {
 400             LOG.warn("{}: Leader failed to remove shard replica {} with status {}",
 401                     persistenceId(), shardId, replyMsg.getStatus());
 402
 403             Exception failure = getServerChangeException(RemoveServer.class, replyMsg.getStatus(), leaderPath, shardId);
 404             originalSender.tell(new Status.Failure(failure), getSelf());
 405         }
 406     }
 407
 408     private void removePrefixShardReplica(final RemovePrefixShardReplica contextMessage, final String shardName,
 409                                           final String primaryPath, final ActorRef sender) {
 410         if (isShardReplicaOperationInProgress(shardName, sender)) {
 411             return;
 412         }
 413
 414         shardReplicaOperationsInProgress.add(shardName);
 415
 416         final ShardIdentifier shardId = getShardIdentifier(contextMessage.getMemberName(), shardName);
 417
 418         final DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName).build();
 419
 420         //inform ShardLeader to remove this shard as a replica by sending an RemoveServer message
 421         LOG.debug("{}: Sending RemoveServer message to peer {} for shard {}", persistenceId(),
 422                 primaryPath, shardId);
 423
 424         Timeout removeServerTimeout = new Timeout(datastoreContext.getShardLeaderElectionTimeout().duration());
 425         Future<Object> futureObj = ask(getContext().actorSelection(primaryPath),
 426                 new RemoveServer(shardId.toString()), removeServerTimeout);
 427
 428         futureObj.onComplete(new OnComplete<Object>() {
 429             @Override
 430             public void onComplete(Throwable failure, Object response) {
 431                 if (failure != null) {
 432                     shardReplicaOperationsInProgress.remove(shardName);
 433                     String msg = String.format("RemoveServer request to leader %s for shard %s failed",
 434                             primaryPath, shardName);
 435
 436                     LOG.debug("{}: {}", persistenceId(), msg, failure);
 437
 438                     // FAILURE
 439                     sender.tell(new Status.Failure(new RuntimeException(msg, failure)), self());
 440                 } else {
 441                     // SUCCESS
 442                     self().tell(new WrappedShardResponse(shardId, response, primaryPath), sender);
 443                 }
 444             }
 445         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
 446     }
 447
 448     private void removeShardReplica(RemoveShardReplica contextMessage, final String shardName, final String primaryPath,
 449             final ActorRef sender) {
 450         if (isShardReplicaOperationInProgress(shardName, sender)) {
 451             return;
 452         }
 453
 454         shardReplicaOperationsInProgress.add(shardName);
 455
 456         final ShardIdentifier shardId = getShardIdentifier(contextMessage.getMemberName(), shardName);
 457
 458         final DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName).build();
 459
 460         //inform ShardLeader to remove this shard as a replica by sending an RemoveServer message
 461         LOG.debug("{}: Sending RemoveServer message to peer {} for shard {}", persistenceId(),
 462                 primaryPath, shardId);
 463
 464         Timeout removeServerTimeout = new Timeout(datastoreContext.getShardLeaderElectionTimeout().duration());
 465         Future<Object> futureObj = ask(getContext().actorSelection(primaryPath),
 466                 new RemoveServer(shardId.toString()), removeServerTimeout);
 467
 468         futureObj.onComplete(new OnComplete<Object>() {
 469             @Override
 470             public void onComplete(Throwable failure, Object response) {
 471                 if (failure != null) {
 472                     shardReplicaOperationsInProgress.remove(shardName);
 473                     String msg = String.format("RemoveServer request to leader %s for shard %s failed",
 474                             primaryPath, shardName);
 475
 476                     LOG.debug("{}: {}", persistenceId(), msg, failure);
 477
 478                     // FAILURE
 479                     sender.tell(new Status.Failure(new RuntimeException(msg, failure)), self());
 480                 } else {
 481                     // SUCCESS
 482                     self().tell(new WrappedShardResponse(shardId, response, primaryPath), sender);
 483                 }
 484             }
 485         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
 486     }
 487
 488     private void onShardReplicaRemoved(ServerRemoved message) {
 489         removeShard(new ShardIdentifier.Builder().fromShardIdString(message.getServerId()).build());
 490     }
 491
 492     @SuppressWarnings("checkstyle:IllegalCatch")
 493     private void removeShard(final ShardIdentifier shardId) {
 494         final String shardName = shardId.getShardName();
 495         final ShardInformation shardInformation = localShards.remove(shardName);
 496         if (shardInformation == null) {
 497             LOG.debug("{} : Shard replica {} is not present in list", persistenceId(), shardId.toString());
 498             return;
 499         }
 500
 501         final ActorRef shardActor = shardInformation.getActor();
 502         if (shardActor != null) {
 503             long timeoutInMS = Math.max(shardInformation.getDatastoreContext().getShardRaftConfig()
 504                     .getElectionTimeOutInterval().$times(3).toMillis(), 10000);
 505
 506             LOG.debug("{} : Sending Shutdown to Shard actor {} with {} ms timeout", persistenceId(), shardActor,
 507                     timeoutInMS);
 508
 509             final Future<Boolean> stopFuture = Patterns.gracefulStop(shardActor,
 510                     FiniteDuration.apply(timeoutInMS, TimeUnit.MILLISECONDS), Shutdown.INSTANCE);
 511
 512             final CompositeOnComplete<Boolean> onComplete = new CompositeOnComplete<Boolean>() {
 513                 @Override
 514                 public void onComplete(final Throwable failure, final Boolean result) {
 515                     if (failure == null) {
 516                         LOG.debug("{} : Successfully shut down Shard actor {}", persistenceId(), shardActor);
 517                     } else {
 518                         LOG.warn("{}: Failed to shut down Shard actor {}", persistenceId(), shardActor, failure);
 519                     }
 520
 521                     self().tell((RunnableMessage) () -> {
 522                         shardActorsStopping.remove(shardName);
 523                         notifyOnCompleteTasks(failure, result);
 524                     }, ActorRef.noSender());
 525                 }
 526             };
 527
 528             shardActorsStopping.put(shardName, onComplete);
 529             stopFuture.onComplete(onComplete, new Dispatchers(context().system().dispatchers())
 530                     .getDispatcher(Dispatchers.DispatcherType.Client));
 531         }
 532
 533         LOG.debug("{} : Local Shard replica for shard {} has been removed", persistenceId(), shardName);
 534         persistShardList();
 535     }
 536
 537     private void onGetSnapshot() {
 538         LOG.debug("{}: onGetSnapshot", persistenceId());
 539
 540         List<String> notInitialized = null;
 541         for (ShardInformation shardInfo : localShards.values()) {
 542             if (!shardInfo.isShardInitialized()) {
 543                 if (notInitialized == null) {
 544                     notInitialized = new ArrayList<>();
 545                 }
 546
 547                 notInitialized.add(shardInfo.getShardName());
 548             }
 549         }
 550
 551         if (notInitialized != null) {
 552             getSender().tell(new Status.Failure(new IllegalStateException(String.format(
 553                     "%d shard(s) %s are not initialized", notInitialized.size(), notInitialized))), getSelf());
 554             return;
 555         }
 556
 557         ActorRef replyActor = getContext().actorOf(ShardManagerGetSnapshotReplyActor.props(
 558                 new ArrayList<>(localShards.keySet()), type, currentSnapshot , getSender(), persistenceId(),
 559                 datastoreContextFactory.getBaseDatastoreContext().getShardInitializationTimeout().duration()));
 560
 561         for (ShardInformation shardInfo: localShards.values()) {
 562             shardInfo.getActor().tell(GetSnapshot.INSTANCE, replyActor);
 563         }
 564     }
 565
 566     @SuppressWarnings("checkstyle:IllegalCatch")
 567     private void onCreateShard(CreateShard createShard) {
 568         LOG.debug("{}: onCreateShard: {}", persistenceId(), createShard);
 569
 570         Object reply;
 571         try {
 572             String shardName = createShard.getModuleShardConfig().getShardName();
 573             if (localShards.containsKey(shardName)) {
 574                 LOG.debug("{}: Shard {} already exists", persistenceId(), shardName);
 575                 reply = new Status.Success(String.format("Shard with name %s already exists", shardName));
 576             } else {
 577                 doCreateShard(createShard);
 578                 reply = new Status.Success(null);
 579             }
 580         } catch (Exception e) {
 581             LOG.error("{}: onCreateShard failed", persistenceId(), e);
 582             reply = new Status.Failure(e);
 583         }
 584
 585         if (getSender() != null && !getContext().system().deadLetters().equals(getSender())) {
 586             getSender().tell(reply, getSelf());
 587         }
 588     }
 589
 590     private void onPrefixShardCreated(final PrefixShardCreated message) {
 591         LOG.debug("{}: onPrefixShardCreated: {}", persistenceId(), message);
 592
 593         final PrefixShardConfiguration config = message.getConfiguration();
 594         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(),
 595                 ClusterUtils.getCleanShardName(config.getPrefix().getRootIdentifier()));
 596         final String shardName = shardId.getShardName();
 597
 598         if (isPreviousShardActorStopInProgress(shardName, message)) {
 599             return;
 600         }
 601
 602         if (localShards.containsKey(shardName)) {
 603             LOG.debug("{}: Received create for an already existing shard {}", persistenceId(), shardName);
 604             final PrefixShardConfiguration existing =
 605                     configuration.getAllPrefixShardConfigurations().get(config.getPrefix());
 606
 607             if (existing != null && existing.equals(config)) {
 608                 // we don't have to do nothing here
 609                 return;
 610             }
 611         }
 612
 613         doCreatePrefixShard(config, shardId, shardName);
 614     }
 615
 616     private boolean isPreviousShardActorStopInProgress(final String shardName, final Object messageToDefer) {
 617         final CompositeOnComplete<Boolean> stopOnComplete = shardActorsStopping.get(shardName);
 618         if (stopOnComplete == null) {
 619             return false;
 620         }
 621
 622         LOG.debug("{} : Stop is in progress for shard {} - adding OnComplete callback to defer {}", persistenceId(),
 623                 shardName, messageToDefer);
 624         final ActorRef sender = getSender();
 625         stopOnComplete.addOnComplete(new OnComplete<Boolean>() {
 626             @Override
 627             public void onComplete(Throwable failure, Boolean result) {
 628                 LOG.debug("{} : Stop complete for shard {} - re-queing {}", persistenceId(), shardName, messageToDefer);
 629                 self().tell(messageToDefer, sender);
 630             }
 631         });
 632
 633         return true;
 634     }
 635
 636     private void doCreatePrefixShard(PrefixShardConfiguration config, ShardIdentifier shardId, String shardName) {
 637         configuration.addPrefixShardConfiguration(config);
 638
 639         final Builder builder = newShardDatastoreContextBuilder(shardName);
 640         builder.logicalStoreType(LogicalDatastoreType.valueOf(config.getPrefix().getDatastoreType().name()))
 641                 .storeRoot(config.getPrefix().getRootIdentifier());
 642         DatastoreContext shardDatastoreContext = builder.build();
 643
 644         final Map<String, String> peerAddresses = getPeerAddresses(shardName);
 645         final boolean isActiveMember = true;
 646
 647         LOG.debug("{} doCreatePrefixShard: shardId: {}, memberNames: {}, peerAddresses: {}, isActiveMember: {}",
 648                 persistenceId(), shardId, config.getShardMemberNames(), peerAddresses, isActiveMember);
 649
 650         final ShardInformation info = new ShardInformation(shardName, shardId, peerAddresses,
 651                 shardDatastoreContext, Shard.builder(), peerAddressResolver);
 652         info.setActiveMember(isActiveMember);
 653         localShards.put(info.getShardName(), info);
 654
 655         if (schemaContext != null) {
 656             info.setActor(newShardActor(schemaContext, info));
 657         }
 658     }
 659
 660     private void onPrefixShardRemoved(final PrefixShardRemoved message) {
 661         LOG.debug("{}: onPrefixShardRemoved : {}", persistenceId(), message);
 662
 663         final DOMDataTreeIdentifier prefix = message.getPrefix();
 664         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(),
 665                 ClusterUtils.getCleanShardName(prefix.getRootIdentifier()));
 666
 667         configuration.removePrefixShardConfiguration(prefix);
 668         removeShard(shardId);
 669     }
 670
 671     private void doCreateShard(final CreateShard createShard) {
 672         final ModuleShardConfiguration moduleShardConfig = createShard.getModuleShardConfig();
 673         final String shardName = moduleShardConfig.getShardName();
 674
 675         configuration.addModuleShardConfiguration(moduleShardConfig);
 676
 677         DatastoreContext shardDatastoreContext = createShard.getDatastoreContext();
 678         if (shardDatastoreContext == null) {
 679             shardDatastoreContext = newShardDatastoreContext(shardName);
 680         } else {
 681             shardDatastoreContext = DatastoreContext.newBuilderFrom(shardDatastoreContext).shardPeerAddressResolver(
 682                     peerAddressResolver).build();
 683         }
 684
 685         ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
 686
 687         boolean shardWasInRecoveredSnapshot = currentSnapshot != null
 688                 && currentSnapshot.getShardList().contains(shardName);
 689
 690         Map<String, String> peerAddresses;
 691         boolean isActiveMember;
 692         if (shardWasInRecoveredSnapshot || configuration.getMembersFromShardName(shardName)
 693                 .contains(cluster.getCurrentMemberName())) {
 694             peerAddresses = getPeerAddresses(shardName);
 695             isActiveMember = true;
 696         } else {
 697             // The local member is not in the static shard member configuration and the shard did not
 698             // previously exist (ie !shardWasInRecoveredSnapshot). In this case we'll create
 699             // the shard with no peers and with elections disabled so it stays as follower. A
 700             // subsequent AddServer request will be needed to make it an active member.
 701             isActiveMember = false;
 702             peerAddresses = Collections.emptyMap();
 703             shardDatastoreContext = DatastoreContext.newBuilderFrom(shardDatastoreContext)
 704                     .customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName()).build();
 705         }
 706
 707         LOG.debug("{} doCreateShard: shardId: {}, memberNames: {}, peerAddresses: {}, isActiveMember: {}",
 708                 persistenceId(), shardId, moduleShardConfig.getShardMemberNames(), peerAddresses,
 709                 isActiveMember);
 710
 711         ShardInformation info = new ShardInformation(shardName, shardId, peerAddresses,
 712                 shardDatastoreContext, createShard.getShardBuilder(), peerAddressResolver);
 713         info.setActiveMember(isActiveMember);
 714         localShards.put(info.getShardName(), info);
 715
 716         if (schemaContext != null) {
 717             info.setActor(newShardActor(schemaContext, info));
 718         }
 719     }
 720
 721     private DatastoreContext.Builder newShardDatastoreContextBuilder(String shardName) {
 722         return DatastoreContext.newBuilderFrom(datastoreContextFactory.getShardDatastoreContext(shardName))
 723                 .shardPeerAddressResolver(peerAddressResolver);
 724     }
 725
 726     private DatastoreContext newShardDatastoreContext(String shardName) {
 727         return newShardDatastoreContextBuilder(shardName).build();
 728     }
 729
 730     private void checkReady() {
 731         if (isReadyWithLeaderId()) {
 732             LOG.info("{}: All Shards are ready - data store {} is ready, available count is {}",
 733                     persistenceId(), type, waitTillReadyCountdownLatch.getCount());
 734
 735             waitTillReadyCountdownLatch.countDown();
 736         }
 737     }
 738
 739     private void onLeaderStateChanged(ShardLeaderStateChanged leaderStateChanged) {
 740         LOG.info("{}: Received LeaderStateChanged message: {}", persistenceId(), leaderStateChanged);
 741
 742         ShardInformation shardInformation = findShardInformation(leaderStateChanged.getMemberId());
 743         if (shardInformation != null) {
 744             shardInformation.setLocalDataTree(leaderStateChanged.getLocalShardDataTree());
 745             shardInformation.setLeaderVersion(leaderStateChanged.getLeaderPayloadVersion());
 746             if (shardInformation.setLeaderId(leaderStateChanged.getLeaderId())) {
 747                 primaryShardInfoCache.remove(shardInformation.getShardName());
 748             }
 749
 750             checkReady();
 751         } else {
 752             LOG.debug("No shard found with member Id {}", leaderStateChanged.getMemberId());
 753         }
 754     }
 755
 756     private void onShardNotInitializedTimeout(ShardNotInitializedTimeout message) {
 757         ShardInformation shardInfo = message.getShardInfo();
 758
 759         LOG.debug("{}: Received ShardNotInitializedTimeout message for shard {}", persistenceId(),
 760                 shardInfo.getShardName());
 761
 762         shardInfo.removeOnShardInitialized(message.getOnShardInitialized());
 763
 764         if (!shardInfo.isShardInitialized()) {
 765             LOG.debug("{}: Returning NotInitializedException for shard {}", persistenceId(), shardInfo.getShardName());
 766             message.getSender().tell(createNotInitializedException(shardInfo.getShardId()), getSelf());
 767         } else {
 768             LOG.debug("{}: Returning NoShardLeaderException for shard {}", persistenceId(), shardInfo.getShardName());
 769             message.getSender().tell(createNoShardLeaderException(shardInfo.getShardId()), getSelf());
 770         }
 771     }
 772
 773     private void onFollowerInitialSyncStatus(FollowerInitialSyncUpStatus status) {
 774         LOG.info("{} Received follower initial sync status for {} status sync done {}", persistenceId(),
 775                 status.getName(), status.isInitialSyncDone());
 776
 777         ShardInformation shardInformation = findShardInformation(status.getName());
 778
 779         if (shardInformation != null) {
 780             shardInformation.setFollowerSyncStatus(status.isInitialSyncDone());
 781
 782             shardManagerMBean.setSyncStatus(isInSync());
 783         }
 784
 785     }
 786
 787     private void onRoleChangeNotification(RoleChangeNotification roleChanged) {
 788         LOG.info("{}: Received role changed for {} from {} to {}", persistenceId(), roleChanged.getMemberId(),
 789                 roleChanged.getOldRole(), roleChanged.getNewRole());
 790
 791         ShardInformation shardInformation = findShardInformation(roleChanged.getMemberId());
 792         if (shardInformation != null) {
 793             shardInformation.setRole(roleChanged.getNewRole());
 794             checkReady();
 795             shardManagerMBean.setSyncStatus(isInSync());
 796         }
 797     }
 798
 799
 800     private ShardInformation findShardInformation(String memberId) {
 801         for (ShardInformation info : localShards.values()) {
 802             if (info.getShardId().toString().equals(memberId)) {
 803                 return info;
 804             }
 805         }
 806
 807         return null;
 808     }
 809
 810     private boolean isReadyWithLeaderId() {
 811         boolean isReady = true;
 812         for (ShardInformation info : localShards.values()) {
 813             if (!info.isShardReadyWithLeaderId()) {
 814                 isReady = false;
 815                 break;
 816             }
 817         }
 818         return isReady;
 819     }
 820
 821     private boolean isInSync() {
 822         for (ShardInformation info : localShards.values()) {
 823             if (!info.isInSync()) {
 824                 return false;
 825             }
 826         }
 827         return true;
 828     }
 829
 830     private void onActorInitialized(Object message) {
 831         final ActorRef sender = getSender();
 832
 833         if (sender == null) {
 834             return; //why is a non-actor sending this message? Just ignore.
 835         }
 836
 837         String actorName = sender.path().name();
 838         //find shard name from actor name; actor name is stringified shardId
 839
 840         final ShardIdentifier shardId;
 841         try {
 842             shardId = ShardIdentifier.fromShardIdString(actorName);
 843         } catch (IllegalArgumentException e) {
 844             LOG.debug("{}: ignoring actor {}", actorName, e);
 845             return;
 846         }
 847
 848         markShardAsInitialized(shardId.getShardName());
 849     }
 850
 851     private void markShardAsInitialized(String shardName) {
 852         LOG.debug("{}: Initializing shard [{}]", persistenceId(), shardName);
 853
 854         ShardInformation shardInformation = localShards.get(shardName);
 855         if (shardInformation != null) {
 856             shardInformation.setActorInitialized();
 857
 858             shardInformation.getActor().tell(new RegisterRoleChangeListener(), self());
 859         }
 860     }
 861
 862     @Override
 863     protected void handleRecover(Object message) throws Exception {
 864         if (message instanceof RecoveryCompleted) {
 865             onRecoveryCompleted();
 866         } else if (message instanceof SnapshotOffer) {
 867             applyShardManagerSnapshot((ShardManagerSnapshot)((SnapshotOffer) message).snapshot());
 868         }
 869     }
 870
 871     @SuppressWarnings("checkstyle:IllegalCatch")
 872     private void onRecoveryCompleted() {
 873         LOG.info("Recovery complete : {}", persistenceId());
 874
 875         // We no longer persist SchemaContext modules so delete all the prior messages from the akka
 876         // journal on upgrade from Helium.
 877         deleteMessages(lastSequenceNr());
 878
 879         if (currentSnapshot == null && restoreFromSnapshot != null
 880                 && restoreFromSnapshot.getShardManagerSnapshot() != null) {
 881             ShardManagerSnapshot snapshot = restoreFromSnapshot.getShardManagerSnapshot();
 882
 883             LOG.debug("{}: Restoring from ShardManagerSnapshot: {}", persistenceId(), snapshot);
 884
 885             applyShardManagerSnapshot(snapshot);
 886         }
 887
 888         createLocalShards();
 889     }
 890
 891     private void sendResponse(ShardInformation shardInformation, boolean doWait,
 892             boolean wantShardReady, final Supplier<Object> messageSupplier) {
 893         if (!shardInformation.isShardInitialized() || wantShardReady && !shardInformation.isShardReadyWithLeaderId()) {
 894             if (doWait) {
 895                 final ActorRef sender = getSender();
 896                 final ActorRef self = self();
 897
 898                 Runnable replyRunnable = () -> sender.tell(messageSupplier.get(), self);
 899
 900                 OnShardInitialized onShardInitialized = wantShardReady ? new OnShardReady(replyRunnable) :
 901                     new OnShardInitialized(replyRunnable);
 902
 903                 shardInformation.addOnShardInitialized(onShardInitialized);
 904
 905                 FiniteDuration timeout = shardInformation.getDatastoreContext()
 906                         .getShardInitializationTimeout().duration();
 907                 if (shardInformation.isShardInitialized()) {
 908                     // If the shard is already initialized then we'll wait enough time for the shard to
 909                     // elect a leader, ie 2 times the election timeout.
 910                     timeout = FiniteDuration.create(shardInformation.getDatastoreContext().getShardRaftConfig()
 911                             .getElectionTimeOutInterval().toMillis() * 2, TimeUnit.MILLISECONDS);
 912                 }
 913
 914                 LOG.debug("{}: Scheduling {} ms timer to wait for shard {}", persistenceId(), timeout.toMillis(),
 915                         shardInformation.getShardName());
 916
 917                 Cancellable timeoutSchedule = getContext().system().scheduler().scheduleOnce(
 918                         timeout, getSelf(),
 919                         new ShardNotInitializedTimeout(shardInformation, onShardInitialized, sender),
 920                         getContext().dispatcher(), getSelf());
 921
 922                 onShardInitialized.setTimeoutSchedule(timeoutSchedule);
 923
 924             } else if (!shardInformation.isShardInitialized()) {
 925                 LOG.debug("{}: Returning NotInitializedException for shard {}", persistenceId(),
 926                         shardInformation.getShardName());
 927                 getSender().tell(createNotInitializedException(shardInformation.getShardId()), getSelf());
 928             } else {
 929                 LOG.debug("{}: Returning NoShardLeaderException for shard {}", persistenceId(),
 930                         shardInformation.getShardName());
 931                 getSender().tell(createNoShardLeaderException(shardInformation.getShardId()), getSelf());
 932             }
 933
 934             return;
 935         }
 936
 937         getSender().tell(messageSupplier.get(), getSelf());
 938     }
 939
 940     private static NoShardLeaderException createNoShardLeaderException(ShardIdentifier shardId) {
 941         return new NoShardLeaderException(null, shardId.toString());
 942     }
 943
 944     private static NotInitializedException createNotInitializedException(ShardIdentifier shardId) {
 945         return new NotInitializedException(String.format(
 946                 "Found primary shard %s but it's not initialized yet. Please try again later", shardId));
 947     }
 948
 949     @VisibleForTesting
 950     static MemberName memberToName(final Member member) {
 951         return MemberName.forName(member.roles().iterator().next());
 952     }
 953
 954     private void memberRemoved(ClusterEvent.MemberRemoved message) {
 955         MemberName memberName = memberToName(message.member());
 956
 957         LOG.info("{}: Received MemberRemoved: memberName: {}, address: {}", persistenceId(), memberName,
 958                 message.member().address());
 959
 960         peerAddressResolver.removePeerAddress(memberName);
 961
 962         for (ShardInformation info : localShards.values()) {
 963             info.peerDown(memberName, getShardIdentifier(memberName, info.getShardName()).toString(), getSelf());
 964         }
 965     }
 966
 967     private void memberExited(ClusterEvent.MemberExited message) {
 968         MemberName memberName = memberToName(message.member());
 969
 970         LOG.info("{}: Received MemberExited: memberName: {}, address: {}", persistenceId(), memberName,
 971                 message.member().address());
 972
 973         peerAddressResolver.removePeerAddress(memberName);
 974
 975         for (ShardInformation info : localShards.values()) {
 976             info.peerDown(memberName, getShardIdentifier(memberName, info.getShardName()).toString(), getSelf());
 977         }
 978     }
 979
 980     private void memberUp(ClusterEvent.MemberUp message) {
 981         MemberName memberName = memberToName(message.member());
 982
 983         LOG.info("{}: Received MemberUp: memberName: {}, address: {}", persistenceId(), memberName,
 984                 message.member().address());
 985
 986         memberUp(memberName, message.member().address());
 987     }
 988
 989     private void memberUp(MemberName memberName, Address address) {
 990         addPeerAddress(memberName, address);
 991         checkReady();
 992     }
 993
 994     private void memberWeaklyUp(MemberWeaklyUp message) {
 995         MemberName memberName = memberToName(message.member());
 996
 997         LOG.info("{}: Received MemberWeaklyUp: memberName: {}, address: {}", persistenceId(), memberName,
 998                 message.member().address());
 999
1000         memberUp(memberName, message.member().address());
1001     }
1002
1003     private void addPeerAddress(MemberName memberName, Address address) {
1004         peerAddressResolver.addPeerAddress(memberName, address);
1005
1006         for (ShardInformation info : localShards.values()) {
1007             String shardName = info.getShardName();
1008             String peerId = getShardIdentifier(memberName, shardName).toString();
1009             info.updatePeerAddress(peerId, peerAddressResolver.getShardActorAddress(shardName, memberName), getSelf());
1010
1011             info.peerUp(memberName, peerId, getSelf());
1012         }
1013     }
1014
1015     private void memberReachable(ClusterEvent.ReachableMember message) {
1016         MemberName memberName = memberToName(message.member());
1017         LOG.info("Received ReachableMember: memberName {}, address: {}", memberName, message.member().address());
1018
1019         addPeerAddress(memberName, message.member().address());
1020
1021         markMemberAvailable(memberName);
1022     }
1023
1024     private void memberUnreachable(ClusterEvent.UnreachableMember message) {
1025         MemberName memberName = memberToName(message.member());
1026         LOG.info("Received UnreachableMember: memberName {}, address: {}", memberName, message.member().address());
1027
1028         markMemberUnavailable(memberName);
1029     }
1030
1031     private void markMemberUnavailable(final MemberName memberName) {
1032         final String memberStr = memberName.getName();
1033         for (ShardInformation info : localShards.values()) {
1034             String leaderId = info.getLeaderId();
1035             // XXX: why are we using String#contains() here?
1036             if (leaderId != null && leaderId.contains(memberStr)) {
1037                 LOG.debug("Marking Leader {} as unavailable.", leaderId);
1038                 info.setLeaderAvailable(false);
1039
1040                 primaryShardInfoCache.remove(info.getShardName());
1041             }
1042
1043             info.peerDown(memberName, getShardIdentifier(memberName, info.getShardName()).toString(), getSelf());
1044         }
1045     }
1046
1047     private void markMemberAvailable(final MemberName memberName) {
1048         final String memberStr = memberName.getName();
1049         for (ShardInformation info : localShards.values()) {
1050             String leaderId = info.getLeaderId();
1051             // XXX: why are we using String#contains() here?
1052             if (leaderId != null && leaderId.contains(memberStr)) {
1053                 LOG.debug("Marking Leader {} as available.", leaderId);
1054                 info.setLeaderAvailable(true);
1055             }
1056
1057             info.peerUp(memberName, getShardIdentifier(memberName, info.getShardName()).toString(), getSelf());
1058         }
1059     }
1060
1061     private void onDatastoreContextFactory(DatastoreContextFactory factory) {
1062         datastoreContextFactory = factory;
1063         for (ShardInformation info : localShards.values()) {
1064             info.setDatastoreContext(newShardDatastoreContext(info.getShardName()), getSelf());
1065         }
1066     }
1067
1068     private void onGetLocalShardIds() {
1069         final List<String> response = new ArrayList<>(localShards.size());
1070
1071         for (ShardInformation info : localShards.values()) {
1072             response.add(info.getShardId().toString());
1073         }
1074
1075         getSender().tell(new Status.Success(response), getSelf());
1076     }
1077
1078     private void onSwitchShardBehavior(final SwitchShardBehavior message) {
1079         final ShardIdentifier identifier = message.getShardId();
1080
1081         if (identifier != null) {
1082             final ShardInformation info = localShards.get(identifier.getShardName());
1083             if (info == null) {
1084                 getSender().tell(new Status.Failure(
1085                     new IllegalArgumentException("Shard " + identifier + " is not local")), getSelf());
1086                 return;
1087             }
1088
1089             switchShardBehavior(info, new SwitchBehavior(message.getNewState(), message.getTerm()));
1090         } else {
1091             for (ShardInformation info : localShards.values()) {
1092                 switchShardBehavior(info, new SwitchBehavior(message.getNewState(), message.getTerm()));
1093             }
1094         }
1095
1096         getSender().tell(new Status.Success(null), getSelf());
1097     }
1098
1099     private void switchShardBehavior(final ShardInformation info, final SwitchBehavior switchBehavior) {
1100         final ActorRef actor = info.getActor();
1101         if (actor != null) {
1102             actor.tell(switchBehavior, getSelf());
1103         } else {
1104             LOG.warn("Could not switch the behavior of shard {} to {} - shard is not yet available",
1105                 info.getShardName(), switchBehavior.getNewState());
1106         }
1107     }
1108
1109     /**
1110      * Notifies all the local shards of a change in the schema context.
1111      *
1112      * @param message the message to send
1113      */
1114     private void updateSchemaContext(final Object message) {
1115         schemaContext = ((UpdateSchemaContext) message).getSchemaContext();
1116
1117         LOG.debug("Got updated SchemaContext: # of modules {}", schemaContext.getAllModuleIdentifiers().size());
1118
1119         for (ShardInformation info : localShards.values()) {
1120             if (info.getActor() == null) {
1121                 LOG.debug("Creating Shard {}", info.getShardId());
1122                 info.setActor(newShardActor(schemaContext, info));
1123             } else {
1124                 info.getActor().tell(message, getSelf());
1125             }
1126         }
1127     }
1128
1129     @VisibleForTesting
1130     protected ClusterWrapper getCluster() {
1131         return cluster;
1132     }
1133
1134     @VisibleForTesting
1135     protected ActorRef newShardActor(final SchemaContext shardSchemaContext, final ShardInformation info) {
1136         return getContext().actorOf(info.newProps(shardSchemaContext).withDispatcher(shardDispatcherPath),
1137                 info.getShardId().toString());
1138     }
1139
1140     private void findPrimary(FindPrimary message) {
1141         LOG.debug("{}: In findPrimary: {}", persistenceId(), message);
1142
1143         final String shardName = message.getShardName();
1144         final boolean canReturnLocalShardState = !(message instanceof RemoteFindPrimary);
1145
1146         // First see if the there is a local replica for the shard
1147         final ShardInformation info = localShards.get(shardName);
1148         if (info != null && info.isActiveMember()) {
1149             sendResponse(info, message.isWaitUntilReady(), true, () -> {
1150                 String primaryPath = info.getSerializedLeaderActor();
1151                 Object found = canReturnLocalShardState && info.isLeader()
1152                         ? new LocalPrimaryShardFound(primaryPath, info.getLocalShardDataTree().get()) :
1153                             new RemotePrimaryShardFound(primaryPath, info.getLeaderVersion());
1154
1155                 LOG.debug("{}: Found primary for {}: {}", persistenceId(), shardName, found);
1156                 return found;
1157             });
1158
1159             return;
1160         }
1161
1162         final Collection<String> visitedAddresses;
1163         if (message instanceof RemoteFindPrimary) {
1164             visitedAddresses = ((RemoteFindPrimary)message).getVisitedAddresses();
1165         } else {
1166             visitedAddresses = new ArrayList<>(1);
1167         }
1168
1169         visitedAddresses.add(peerAddressResolver.getShardManagerActorPathBuilder(cluster.getSelfAddress()).toString());
1170
1171         for (String address: peerAddressResolver.getShardManagerPeerActorAddresses()) {
1172             if (visitedAddresses.contains(address)) {
1173                 continue;
1174             }
1175
1176             LOG.debug("{}: findPrimary for {} forwarding to remote ShardManager {}, visitedAddresses: {}",
1177                     persistenceId(), shardName, address, visitedAddresses);
1178
1179             getContext().actorSelection(address).forward(new RemoteFindPrimary(shardName,
1180                     message.isWaitUntilReady(), visitedAddresses), getContext());
1181             return;
1182         }
1183
1184         LOG.debug("{}: No shard found for {}", persistenceId(), shardName);
1185
1186         getSender().tell(new PrimaryNotFoundException(
1187                 String.format("No primary shard found for %s.", shardName)), getSelf());
1188     }
1189
1190     private void findPrimary(final String shardName, final FindPrimaryResponseHandler handler) {
1191         Timeout findPrimaryTimeout = new Timeout(datastoreContextFactory.getBaseDatastoreContext()
1192                 .getShardInitializationTimeout().duration().$times(2));
1193
1194         Future<Object> futureObj = ask(getSelf(), new FindPrimary(shardName, true), findPrimaryTimeout);
1195         futureObj.onComplete(new OnComplete<Object>() {
1196             @Override
1197             public void onComplete(Throwable failure, Object response) {
1198                 if (failure != null) {
1199                     handler.onFailure(failure);
1200                 } else {
1201                     if (response instanceof RemotePrimaryShardFound) {
1202                         handler.onRemotePrimaryShardFound((RemotePrimaryShardFound) response);
1203                     } else if (response instanceof LocalPrimaryShardFound) {
1204                         handler.onLocalPrimaryFound((LocalPrimaryShardFound) response);
1205                     } else {
1206                         handler.onUnknownResponse(response);
1207                     }
1208                 }
1209             }
1210         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1211     }
1212
1213     /**
1214      * Construct the name of the shard actor given the name of the member on
1215      * which the shard resides and the name of the shard.
1216      *
1217      * @param memberName the member name
1218      * @param shardName the shard name
1219      * @return a b
1220      */
1221     private ShardIdentifier getShardIdentifier(MemberName memberName, String shardName) {
1222         return peerAddressResolver.getShardIdentifier(memberName, shardName);
1223     }
1224
1225     /**
1226      * Create shards that are local to the member on which the ShardManager runs.
1227      */
1228     private void createLocalShards() {
1229         MemberName memberName = this.cluster.getCurrentMemberName();
1230         Collection<String> memberShardNames = this.configuration.getMemberShardNames(memberName);
1231
1232         Map<String, DatastoreSnapshot.ShardSnapshot> shardSnapshots = new HashMap<>();
1233         if (restoreFromSnapshot != null) {
1234             for (DatastoreSnapshot.ShardSnapshot snapshot: restoreFromSnapshot.getShardSnapshots()) {
1235                 shardSnapshots.put(snapshot.getName(), snapshot);
1236             }
1237         }
1238
1239         restoreFromSnapshot = null; // null out to GC
1240
1241         for (String shardName : memberShardNames) {
1242             ShardIdentifier shardId = getShardIdentifier(memberName, shardName);
1243
1244             LOG.debug("{}: Creating local shard: {}", persistenceId(), shardId);
1245
1246             Map<String, String> peerAddresses = getPeerAddresses(shardName);
1247             localShards.put(shardName, new ShardInformation(shardName, shardId, peerAddresses,
1248                     newShardDatastoreContext(shardName), Shard.builder().restoreFromSnapshot(
1249                         shardSnapshots.get(shardName)), peerAddressResolver));
1250         }
1251     }
1252
1253     /**
1254      * Given the name of the shard find the addresses of all it's peers.
1255      *
1256      * @param shardName the shard name
1257      */
1258     private Map<String, String> getPeerAddresses(String shardName) {
1259         final Collection<MemberName> members = configuration.getMembersFromShardName(shardName);
1260         return getPeerAddresses(shardName, members);
1261     }
1262
1263     private Map<String, String> getPeerAddresses(final String shardName, final Collection<MemberName> members) {
1264         Map<String, String> peerAddresses = new HashMap<>();
1265         MemberName currentMemberName = this.cluster.getCurrentMemberName();
1266
1267         for (MemberName memberName : members) {
1268             if (!currentMemberName.equals(memberName)) {
1269                 ShardIdentifier shardId = getShardIdentifier(memberName, shardName);
1270                 String address = peerAddressResolver.getShardActorAddress(shardName, memberName);
1271                 peerAddresses.put(shardId.toString(), address);
1272             }
1273         }
1274         return peerAddresses;
1275     }
1276
1277     @Override
1278     public SupervisorStrategy supervisorStrategy() {
1279
1280         return new OneForOneStrategy(10, Duration.create("1 minute"),
1281                 (Function<Throwable, Directive>) t -> {
1282                     LOG.warn("Supervisor Strategy caught unexpected exception - resuming", t);
1283                     return SupervisorStrategy.resume();
1284                 });
1285     }
1286
1287     @Override
1288     public String persistenceId() {
1289         return persistenceId;
1290     }
1291
1292     @VisibleForTesting
1293     ShardManagerInfoMBean getMBean() {
1294         return shardManagerMBean;
1295     }
1296
1297     private boolean isShardReplicaOperationInProgress(final String shardName, final ActorRef sender) {
1298         if (shardReplicaOperationsInProgress.contains(shardName)) {
1299             String msg = String.format("A shard replica operation for %s is already in progress", shardName);
1300             LOG.debug("{}: {}", persistenceId(), msg);
1301             sender.tell(new Status.Failure(new IllegalStateException(msg)), getSelf());
1302             return true;
1303         }
1304
1305         return false;
1306     }
1307
1308     private void onAddPrefixShardReplica(final AddPrefixShardReplica message) {
1309         LOG.debug("{}: onAddPrefixShardReplica: {}", persistenceId(), message);
1310
1311         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(),
1312                 ClusterUtils.getCleanShardName(message.getShardPrefix()));
1313         final String shardName = shardId.getShardName();
1314
1315         // Create the localShard
1316         if (schemaContext == null) {
1317             String msg = String.format(
1318                     "No SchemaContext is available in order to create a local shard instance for %s", shardName);
1319             LOG.debug("{}: {}", persistenceId(), msg);
1320             getSender().tell(new Status.Failure(new IllegalStateException(msg)), getSelf());
1321             return;
1322         }
1323
1324         findPrimary(shardName, new AutoFindPrimaryFailureResponseHandler(getSender(), shardName, persistenceId(),
1325                 getSelf()) {
1326             @Override
1327             public void onRemotePrimaryShardFound(RemotePrimaryShardFound response) {
1328                 final RunnableMessage runnable = (RunnableMessage) () -> addPrefixShard(getShardName(),
1329                         message.getShardPrefix(), response, getSender());
1330                 if (!isPreviousShardActorStopInProgress(getShardName(), runnable)) {
1331                     getSelf().tell(runnable, getTargetActor());
1332                 }
1333             }
1334
1335             @Override
1336             public void onLocalPrimaryFound(LocalPrimaryShardFound message) {
1337                 sendLocalReplicaAlreadyExistsReply(getShardName(), getTargetActor());
1338             }
1339         });
1340     }
1341
1342     private void onAddShardReplica(final AddShardReplica shardReplicaMsg) {
1343         final String shardName = shardReplicaMsg.getShardName();
1344
1345         LOG.debug("{}: onAddShardReplica: {}", persistenceId(), shardReplicaMsg);
1346
1347         // verify the shard with the specified name is present in the cluster configuration
1348         if (!this.configuration.isShardConfigured(shardName)) {
1349             String msg = String.format("No module configuration exists for shard %s", shardName);
1350             LOG.debug("{}: {}", persistenceId(), msg);
1351             getSender().tell(new Status.Failure(new IllegalArgumentException(msg)), getSelf());
1352             return;
1353         }
1354
1355         // Create the localShard
1356         if (schemaContext == null) {
1357             String msg = String.format(
1358                   "No SchemaContext is available in order to create a local shard instance for %s", shardName);
1359             LOG.debug("{}: {}", persistenceId(), msg);
1360             getSender().tell(new Status.Failure(new IllegalStateException(msg)), getSelf());
1361             return;
1362         }
1363
1364         findPrimary(shardName, new AutoFindPrimaryFailureResponseHandler(getSender(), shardName, persistenceId(),
1365                 getSelf()) {
1366             @Override
1367             public void onRemotePrimaryShardFound(RemotePrimaryShardFound response) {
1368                 final RunnableMessage runnable = (RunnableMessage) () ->
1369                     addShard(getShardName(), response, getSender());
1370                 if (!isPreviousShardActorStopInProgress(getShardName(), runnable)) {
1371                     getSelf().tell(runnable, getTargetActor());
1372                 }
1373             }
1374
1375             @Override
1376             public void onLocalPrimaryFound(LocalPrimaryShardFound message) {
1377                 sendLocalReplicaAlreadyExistsReply(getShardName(), getTargetActor());
1378             }
1379         });
1380     }
1381
1382     private void sendLocalReplicaAlreadyExistsReply(String shardName, ActorRef sender) {
1383         String msg = String.format("Local shard %s already exists", shardName);
1384         LOG.debug("{}: {}", persistenceId(), msg);
1385         sender.tell(new Status.Failure(new AlreadyExistsException(msg)), getSelf());
1386     }
1387
1388     private void addPrefixShard(final String shardName, final YangInstanceIdentifier shardPrefix,
1389                                 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             final Builder builder = newShardDatastoreContextBuilder(shardName);
1404             builder.storeRoot(shardPrefix).customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName());
1405
1406             DatastoreContext datastoreContext = builder.build();
1407
1408             shardInfo = new ShardInformation(shardName, shardId, getPeerAddresses(shardName), datastoreContext,
1409                     Shard.builder(), peerAddressResolver);
1410             shardInfo.setActiveMember(false);
1411             localShards.put(shardName, shardInfo);
1412             shardInfo.setActor(newShardActor(schemaContext, shardInfo));
1413         } else {
1414             removeShardOnFailure = false;
1415             shardInfo = existingShardInfo;
1416         }
1417
1418         execAddShard(shardName, shardInfo, response, removeShardOnFailure, sender);
1419     }
1420
1421     private void addShard(final String shardName, final RemotePrimaryShardFound response, final ActorRef sender) {
1422         if (isShardReplicaOperationInProgress(shardName, sender)) {
1423             return;
1424         }
1425
1426         shardReplicaOperationsInProgress.add(shardName);
1427
1428         final ShardInformation shardInfo;
1429         final boolean removeShardOnFailure;
1430         ShardInformation existingShardInfo = localShards.get(shardName);
1431         if (existingShardInfo == null) {
1432             removeShardOnFailure = true;
1433             ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
1434
1435             DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName)
1436                     .customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName()).build();
1437
1438             shardInfo = new ShardInformation(shardName, shardId, getPeerAddresses(shardName), datastoreContext,
1439                     Shard.builder(), peerAddressResolver);
1440             shardInfo.setActiveMember(false);
1441             localShards.put(shardName, shardInfo);
1442             shardInfo.setActor(newShardActor(schemaContext, shardInfo));
1443         } else {
1444             removeShardOnFailure = false;
1445             shardInfo = existingShardInfo;
1446         }
1447
1448         execAddShard(shardName, shardInfo, response, removeShardOnFailure, sender);
1449     }
1450
1451     private void execAddShard(final String shardName,
1452                               final ShardInformation shardInfo,
1453                               final RemotePrimaryShardFound response,
1454                               final boolean removeShardOnFailure,
1455                               final ActorRef sender) {
1456
1457         final String localShardAddress =
1458                 peerAddressResolver.getShardActorAddress(shardName, cluster.getCurrentMemberName());
1459
1460         //inform ShardLeader to add this shard as a replica by sending an AddServer message
1461         LOG.debug("{}: Sending AddServer message to peer {} for shard {}", persistenceId(),
1462                 response.getPrimaryPath(), shardInfo.getShardId());
1463
1464         final Timeout addServerTimeout = new Timeout(shardInfo.getDatastoreContext()
1465                 .getShardLeaderElectionTimeout().duration());
1466         final Future<Object> futureObj = ask(getContext().actorSelection(response.getPrimaryPath()),
1467                 new AddServer(shardInfo.getShardId().toString(), localShardAddress, true), addServerTimeout);
1468
1469         futureObj.onComplete(new OnComplete<Object>() {
1470             @Override
1471             public void onComplete(Throwable failure, Object addServerResponse) {
1472                 if (failure != null) {
1473                     LOG.debug("{}: AddServer request to {} for {} failed", persistenceId(),
1474                             response.getPrimaryPath(), shardName, failure);
1475
1476                     final String msg = String.format("AddServer request to leader %s for shard %s failed",
1477                             response.getPrimaryPath(), shardName);
1478                     self().tell(new ForwardedAddServerFailure(shardName, msg, failure, removeShardOnFailure), sender);
1479                 } else {
1480                     self().tell(new ForwardedAddServerReply(shardInfo, (AddServerReply)addServerResponse,
1481                             response.getPrimaryPath(), removeShardOnFailure), sender);
1482                 }
1483             }
1484         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1485     }
1486
1487     private void onAddServerFailure(String shardName, String message, Throwable failure, ActorRef sender,
1488             boolean removeShardOnFailure) {
1489         shardReplicaOperationsInProgress.remove(shardName);
1490
1491         if (removeShardOnFailure) {
1492             ShardInformation shardInfo = localShards.remove(shardName);
1493             if (shardInfo.getActor() != null) {
1494                 shardInfo.getActor().tell(PoisonPill.getInstance(), getSelf());
1495             }
1496         }
1497
1498         sender.tell(new Status.Failure(message == null ? failure :
1499             new RuntimeException(message, failure)), getSelf());
1500     }
1501
1502     private void onAddServerReply(ShardInformation shardInfo, AddServerReply replyMsg, ActorRef sender,
1503             String leaderPath, boolean removeShardOnFailure) {
1504         String shardName = shardInfo.getShardName();
1505         shardReplicaOperationsInProgress.remove(shardName);
1506
1507         LOG.debug("{}: Received {} for shard {} from leader {}", persistenceId(), replyMsg, shardName, leaderPath);
1508
1509         if (replyMsg.getStatus() == ServerChangeStatus.OK) {
1510             LOG.debug("{}: Leader shard successfully added the replica shard {}", persistenceId(), shardName);
1511
1512             // Make the local shard voting capable
1513             shardInfo.setDatastoreContext(newShardDatastoreContext(shardName), getSelf());
1514             shardInfo.setActiveMember(true);
1515             persistShardList();
1516
1517             sender.tell(new Status.Success(null), getSelf());
1518         } else if (replyMsg.getStatus() == ServerChangeStatus.ALREADY_EXISTS) {
1519             sendLocalReplicaAlreadyExistsReply(shardName, sender);
1520         } else {
1521             LOG.warn("{}: Leader failed to add shard replica {} with status {}",
1522                     persistenceId(), shardName, replyMsg.getStatus());
1523
1524             Exception failure = getServerChangeException(AddServer.class, replyMsg.getStatus(), leaderPath,
1525                     shardInfo.getShardId());
1526
1527             onAddServerFailure(shardName, null, failure, sender, removeShardOnFailure);
1528         }
1529     }
1530
1531     private static Exception getServerChangeException(Class<?> serverChange, ServerChangeStatus serverChangeStatus,
1532                                                String leaderPath, ShardIdentifier shardId) {
1533         Exception failure;
1534         switch (serverChangeStatus) {
1535             case TIMEOUT:
1536                 failure = new TimeoutException(String.format(
1537                         "The shard leader %s timed out trying to replicate the initial data to the new shard %s."
1538                         + "Possible causes - there was a problem replicating the data or shard leadership changed "
1539                         + "while replicating the shard data", leaderPath, shardId.getShardName()));
1540                 break;
1541             case NO_LEADER:
1542                 failure = createNoShardLeaderException(shardId);
1543                 break;
1544             case NOT_SUPPORTED:
1545                 failure = new UnsupportedOperationException(String.format("%s request is not supported for shard %s",
1546                         serverChange.getSimpleName(), shardId.getShardName()));
1547                 break;
1548             default :
1549                 failure = new RuntimeException(String.format(
1550                         "%s request to leader %s for shard %s failed with status %s",
1551                         serverChange.getSimpleName(), leaderPath, shardId.getShardName(), serverChangeStatus));
1552         }
1553         return failure;
1554     }
1555
1556     private void onRemoveShardReplica(final RemoveShardReplica shardReplicaMsg) {
1557         LOG.debug("{}: onRemoveShardReplica: {}", persistenceId(), shardReplicaMsg);
1558
1559         findPrimary(shardReplicaMsg.getShardName(), new AutoFindPrimaryFailureResponseHandler(getSender(),
1560                 shardReplicaMsg.getShardName(), persistenceId(), getSelf()) {
1561             @Override
1562             public void onRemotePrimaryShardFound(RemotePrimaryShardFound response) {
1563                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1564             }
1565
1566             @Override
1567             public void onLocalPrimaryFound(LocalPrimaryShardFound response) {
1568                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1569             }
1570
1571             private void doRemoveShardReplicaAsync(final String primaryPath) {
1572                 getSelf().tell((RunnableMessage) () -> removeShardReplica(shardReplicaMsg, getShardName(),
1573                         primaryPath, getSender()), getTargetActor());
1574             }
1575         });
1576     }
1577
1578     private void onRemovePrefixShardReplica(final RemovePrefixShardReplica message) {
1579         LOG.debug("{}: onRemovePrefixShardReplica: {}", persistenceId(), message);
1580
1581         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(),
1582                 ClusterUtils.getCleanShardName(message.getShardPrefix()));
1583         final String shardName = shardId.getShardName();
1584
1585         findPrimary(shardName, new AutoFindPrimaryFailureResponseHandler(getSender(),
1586                 shardName, persistenceId(), getSelf()) {
1587             @Override
1588             public void onRemotePrimaryShardFound(RemotePrimaryShardFound response) {
1589                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1590             }
1591
1592             @Override
1593             public void onLocalPrimaryFound(LocalPrimaryShardFound response) {
1594                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1595             }
1596
1597             private void doRemoveShardReplicaAsync(final String primaryPath) {
1598                 getSelf().tell((RunnableMessage) () -> removePrefixShardReplica(message, getShardName(),
1599                         primaryPath, getSender()), getTargetActor());
1600             }
1601         });
1602     }
1603
1604     private void persistShardList() {
1605         List<String> shardList = new ArrayList<>(localShards.keySet());
1606         for (ShardInformation shardInfo : localShards.values()) {
1607             if (!shardInfo.isActiveMember()) {
1608                 shardList.remove(shardInfo.getShardName());
1609             }
1610         }
1611         LOG.debug("{}: persisting the shard list {}", persistenceId(), shardList);
1612         saveSnapshot(updateShardManagerSnapshot(shardList, configuration.getAllPrefixShardConfigurations()));
1613     }
1614
1615     private ShardManagerSnapshot updateShardManagerSnapshot(
1616             final List<String> shardList,
1617             final Map<DOMDataTreeIdentifier, PrefixShardConfiguration> allPrefixShardConfigurations) {
1618         currentSnapshot = new ShardManagerSnapshot(shardList, allPrefixShardConfigurations);
1619         return currentSnapshot;
1620     }
1621
1622     private void applyShardManagerSnapshot(ShardManagerSnapshot snapshot) {
1623         currentSnapshot = snapshot;
1624
1625         LOG.debug("{}: onSnapshotOffer: {}", persistenceId(), currentSnapshot);
1626
1627         final MemberName currentMember = cluster.getCurrentMemberName();
1628         Set<String> configuredShardList =
1629             new HashSet<>(configuration.getMemberShardNames(currentMember));
1630         for (String shard : currentSnapshot.getShardList()) {
1631             if (!configuredShardList.contains(shard)) {
1632                 // add the current member as a replica for the shard
1633                 LOG.debug("{}: adding shard {}", persistenceId(), shard);
1634                 configuration.addMemberReplicaForShard(shard, currentMember);
1635             } else {
1636                 configuredShardList.remove(shard);
1637             }
1638         }
1639         for (String shard : configuredShardList) {
1640             // remove the member as a replica for the shard
1641             LOG.debug("{}: removing shard {}", persistenceId(), shard);
1642             configuration.removeMemberReplicaForShard(shard, currentMember);
1643         }
1644     }
1645
1646     private void onSaveSnapshotSuccess(SaveSnapshotSuccess successMessage) {
1647         LOG.debug("{} saved ShardManager snapshot successfully. Deleting the prev snapshot if available",
1648             persistenceId());
1649         deleteSnapshots(new SnapshotSelectionCriteria(scala.Long.MaxValue(), successMessage.metadata().timestamp() - 1,
1650             0, 0));
1651     }
1652
1653     private void onChangeShardServersVotingStatus(final ChangeShardMembersVotingStatus changeMembersVotingStatus) {
1654         LOG.debug("{}: onChangeShardServersVotingStatus: {}", persistenceId(), changeMembersVotingStatus);
1655
1656         String shardName = changeMembersVotingStatus.getShardName();
1657         Map<String, Boolean> serverVotingStatusMap = new HashMap<>();
1658         for (Entry<String, Boolean> e: changeMembersVotingStatus.getMeberVotingStatusMap().entrySet()) {
1659             serverVotingStatusMap.put(getShardIdentifier(MemberName.forName(e.getKey()), shardName).toString(),
1660                     e.getValue());
1661         }
1662
1663         ChangeServersVotingStatus changeServersVotingStatus = new ChangeServersVotingStatus(serverVotingStatusMap);
1664
1665         findLocalShard(shardName, getSender(),
1666             localShardFound -> changeShardMembersVotingStatus(changeServersVotingStatus, shardName,
1667             localShardFound.getPath(), getSender()));
1668     }
1669
1670     private void onFlipShardMembersVotingStatus(FlipShardMembersVotingStatus flipMembersVotingStatus) {
1671         LOG.debug("{}: onFlipShardMembersVotingStatus: {}", persistenceId(), flipMembersVotingStatus);
1672
1673         ActorRef sender = getSender();
1674         final String shardName = flipMembersVotingStatus.getShardName();
1675         findLocalShard(shardName, sender, localShardFound -> {
1676             Future<Object> future = ask(localShardFound.getPath(), GetOnDemandRaftState.INSTANCE,
1677                     Timeout.apply(30, TimeUnit.SECONDS));
1678
1679             future.onComplete(new OnComplete<Object>() {
1680                 @Override
1681                 public void onComplete(Throwable failure, Object response) {
1682                     if (failure != null) {
1683                         sender.tell(new Status.Failure(new RuntimeException(
1684                                 String.format("Failed to access local shard %s", shardName), failure)), self());
1685                         return;
1686                     }
1687
1688                     OnDemandRaftState raftState = (OnDemandRaftState) response;
1689                     Map<String, Boolean> serverVotingStatusMap = new HashMap<>();
1690                     for (Entry<String, Boolean> e: raftState.getPeerVotingStates().entrySet()) {
1691                         serverVotingStatusMap.put(e.getKey(), !e.getValue());
1692                     }
1693
1694                     serverVotingStatusMap.put(getShardIdentifier(cluster.getCurrentMemberName(), shardName)
1695                             .toString(), !raftState.isVoting());
1696
1697                     changeShardMembersVotingStatus(new ChangeServersVotingStatus(serverVotingStatusMap),
1698                             shardName, localShardFound.getPath(), sender);
1699                 }
1700             }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1701         });
1702
1703     }
1704
1705     private void findLocalShard(FindLocalShard message) {
1706         LOG.debug("{}: findLocalShard : {}", persistenceId(), message.getShardName());
1707
1708         final ShardInformation shardInformation = localShards.get(message.getShardName());
1709
1710         if (shardInformation == null) {
1711             LOG.debug("{}: Local shard {} not found - shards present: {}",
1712                     persistenceId(), message.getShardName(), localShards.keySet());
1713
1714             getSender().tell(new LocalShardNotFound(message.getShardName()), getSelf());
1715             return;
1716         }
1717
1718         sendResponse(shardInformation, message.isWaitUntilInitialized(), false,
1719             () -> new LocalShardFound(shardInformation.getActor()));
1720     }
1721
1722     private void findLocalShard(final String shardName, final ActorRef sender,
1723             final Consumer<LocalShardFound> onLocalShardFound) {
1724         Timeout findLocalTimeout = new Timeout(datastoreContextFactory.getBaseDatastoreContext()
1725                 .getShardInitializationTimeout().duration().$times(2));
1726
1727         Future<Object> futureObj = ask(getSelf(), new FindLocalShard(shardName, true), findLocalTimeout);
1728         futureObj.onComplete(new OnComplete<Object>() {
1729             @Override
1730             public void onComplete(Throwable failure, Object response) {
1731                 if (failure != null) {
1732                     LOG.debug("{}: Received failure from FindLocalShard for shard {}", persistenceId, shardName,
1733                             failure);
1734                     sender.tell(new Status.Failure(new RuntimeException(
1735                             String.format("Failed to find local shard %s", shardName), failure)), self());
1736                 } else {
1737                     if (response instanceof LocalShardFound) {
1738                         getSelf().tell((RunnableMessage) () -> onLocalShardFound.accept((LocalShardFound) response),
1739                                 sender);
1740                     } else if (response instanceof LocalShardNotFound) {
1741                         String msg = String.format("Local shard %s does not exist", shardName);
1742                         LOG.debug("{}: {}", persistenceId, msg);
1743                         sender.tell(new Status.Failure(new IllegalArgumentException(msg)), self());
1744                     } else {
1745                         String msg = String.format("Failed to find local shard %s: received response: %s",
1746                                 shardName, response);
1747                         LOG.debug("{}: {}", persistenceId, msg);
1748                         sender.tell(new Status.Failure(response instanceof Throwable ? (Throwable) response :
1749                                 new RuntimeException(msg)), self());
1750                     }
1751                 }
1752             }
1753         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1754     }
1755
1756     private void changeShardMembersVotingStatus(ChangeServersVotingStatus changeServersVotingStatus,
1757             final String shardName, final ActorRef shardActorRef, final ActorRef sender) {
1758         if (isShardReplicaOperationInProgress(shardName, sender)) {
1759             return;
1760         }
1761
1762         shardReplicaOperationsInProgress.add(shardName);
1763
1764         DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName).build();
1765         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
1766
1767         LOG.debug("{}: Sending ChangeServersVotingStatus message {} to local shard {}", persistenceId(),
1768                 changeServersVotingStatus, shardActorRef.path());
1769
1770         Timeout timeout = new Timeout(datastoreContext.getShardLeaderElectionTimeout().duration().$times(2));
1771         Future<Object> futureObj = ask(shardActorRef, changeServersVotingStatus, timeout);
1772
1773         futureObj.onComplete(new OnComplete<Object>() {
1774             @Override
1775             public void onComplete(Throwable failure, Object response) {
1776                 shardReplicaOperationsInProgress.remove(shardName);
1777                 if (failure != null) {
1778                     String msg = String.format("ChangeServersVotingStatus request to local shard %s failed",
1779                             shardActorRef.path());
1780                     LOG.debug("{}: {}", persistenceId(), msg, failure);
1781                     sender.tell(new Status.Failure(new RuntimeException(msg, failure)), self());
1782                 } else {
1783                     LOG.debug("{}: Received {} from local shard {}", persistenceId(), response, shardActorRef.path());
1784
1785                     ServerChangeReply replyMsg = (ServerChangeReply) response;
1786                     if (replyMsg.getStatus() == ServerChangeStatus.OK) {
1787                         LOG.debug("{}: ChangeServersVotingStatus succeeded for shard {}", persistenceId(), shardName);
1788                         sender.tell(new Status.Success(null), getSelf());
1789                     } else if (replyMsg.getStatus() == ServerChangeStatus.INVALID_REQUEST) {
1790                         sender.tell(new Status.Failure(new IllegalArgumentException(String.format(
1791                                 "The requested voting state change for shard %s is invalid. At least one member "
1792                                 + "must be voting", shardId.getShardName()))), getSelf());
1793                     } else {
1794                         LOG.warn("{}: ChangeServersVotingStatus failed for shard {} with status {}",
1795                                 persistenceId(), shardName, replyMsg.getStatus());
1796
1797                         Exception error = getServerChangeException(ChangeServersVotingStatus.class,
1798                                 replyMsg.getStatus(), shardActorRef.path().toString(), shardId);
1799                         sender.tell(new Status.Failure(error), getSelf());
1800                     }
1801                 }
1802             }
1803         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1804     }
1805
1806     private static final class ForwardedAddServerReply {
1807         ShardInformation shardInfo;
1808         AddServerReply addServerReply;
1809         String leaderPath;
1810         boolean removeShardOnFailure;
1811
1812         ForwardedAddServerReply(ShardInformation shardInfo, AddServerReply addServerReply, String leaderPath,
1813                 boolean removeShardOnFailure) {
1814             this.shardInfo = shardInfo;
1815             this.addServerReply = addServerReply;
1816             this.leaderPath = leaderPath;
1817             this.removeShardOnFailure = removeShardOnFailure;
1818         }
1819     }
1820
1821     private static final class ForwardedAddServerFailure {
1822         String shardName;
1823         String failureMessage;
1824         Throwable failure;
1825         boolean removeShardOnFailure;
1826
1827         ForwardedAddServerFailure(String shardName, String failureMessage, Throwable failure,
1828                 boolean removeShardOnFailure) {
1829             this.shardName = shardName;
1830             this.failureMessage = failureMessage;
1831             this.failure = failure;
1832             this.removeShardOnFailure = removeShardOnFailure;
1833         }
1834     }
1835
1836     static class OnShardInitialized {
1837         private final Runnable replyRunnable;
1838         private Cancellable timeoutSchedule;
1839
1840         OnShardInitialized(Runnable replyRunnable) {
1841             this.replyRunnable = replyRunnable;
1842         }
1843
1844         Runnable getReplyRunnable() {
1845             return replyRunnable;
1846         }
1847
1848         Cancellable getTimeoutSchedule() {
1849             return timeoutSchedule;
1850         }
1851
1852         void setTimeoutSchedule(Cancellable timeoutSchedule) {
1853             this.timeoutSchedule = timeoutSchedule;
1854         }
1855     }
1856
1857     static class OnShardReady extends OnShardInitialized {
1858         OnShardReady(Runnable replyRunnable) {
1859             super(replyRunnable);
1860         }
1861     }
1862
1863     private interface RunnableMessage extends Runnable {
1864     }
1865
1866     /**
1867      * The FindPrimaryResponseHandler provides specific callback methods which are invoked when a response to the
1868      * a remote or local find primary message is processed.
1869      */
1870     private interface FindPrimaryResponseHandler {
1871         /**
1872          * Invoked when a Failure message is received as a response.
1873          *
1874          * @param failure the failure exception
1875          */
1876         void onFailure(Throwable failure);
1877
1878         /**
1879          * Invoked when a RemotePrimaryShardFound response is received.
1880          *
1881          * @param response the response
1882          */
1883         void onRemotePrimaryShardFound(RemotePrimaryShardFound response);
1884
1885         /**
1886          * Invoked when a LocalPrimaryShardFound response is received.
1887          *
1888          * @param response the response
1889          */
1890         void onLocalPrimaryFound(LocalPrimaryShardFound response);
1891
1892         /**
1893          * Invoked when an unknown response is received. This is another type of failure.
1894          *
1895          * @param response the response
1896          */
1897         void onUnknownResponse(Object response);
1898     }
1899
1900     /**
1901      * The AutoFindPrimaryFailureResponseHandler automatically processes Failure responses when finding a primary
1902      * replica and sends a wrapped Failure response to some targetActor.
1903      */
1904     private abstract static class AutoFindPrimaryFailureResponseHandler implements FindPrimaryResponseHandler {
1905         private final ActorRef targetActor;
1906         private final String shardName;
1907         private final String persistenceId;
1908         private final ActorRef shardManagerActor;
1909
1910         /**
1911          * Constructs an instance.
1912          *
1913          * @param targetActor The actor to whom the Failure response should be sent when a FindPrimary failure occurs
1914          * @param shardName The name of the shard for which the primary replica had to be found
1915          * @param persistenceId The persistenceId for the ShardManager
1916          * @param shardManagerActor The ShardManager actor which triggered the call to FindPrimary
1917          */
1918         protected AutoFindPrimaryFailureResponseHandler(ActorRef targetActor, String shardName, String persistenceId,
1919                 ActorRef shardManagerActor) {
1920             this.targetActor = Preconditions.checkNotNull(targetActor);
1921             this.shardName = Preconditions.checkNotNull(shardName);
1922             this.persistenceId = Preconditions.checkNotNull(persistenceId);
1923             this.shardManagerActor = Preconditions.checkNotNull(shardManagerActor);
1924         }
1925
1926         public ActorRef getTargetActor() {
1927             return targetActor;
1928         }
1929
1930         public String getShardName() {
1931             return shardName;
1932         }
1933
1934         @Override
1935         public void onFailure(Throwable failure) {
1936             LOG.debug("{}: Received failure from FindPrimary for shard {}", persistenceId, shardName, failure);
1937             targetActor.tell(new Status.Failure(new RuntimeException(
1938                     String.format("Failed to find leader for shard %s", shardName), failure)), shardManagerActor);
1939         }
1940
1941         @Override
1942         public void onUnknownResponse(Object response) {
1943             String msg = String.format("Failed to find leader for shard %s: received response: %s",
1944                     shardName, response);
1945             LOG.debug("{}: {}", persistenceId, msg);
1946             targetActor.tell(new Status.Failure(response instanceof Throwable ? (Throwable) response :
1947                     new RuntimeException(msg)), shardManagerActor);
1948         }
1949     }
1950
1951     /**
1952      * The WrappedShardResponse class wraps a response from a Shard.
1953      */
1954     private static final class WrappedShardResponse {
1955         private final ShardIdentifier shardId;
1956         private final Object response;
1957         private final String leaderPath;
1958
1959         WrappedShardResponse(ShardIdentifier shardId, Object response, String leaderPath) {
1960             this.shardId = shardId;
1961             this.response = response;
1962             this.leaderPath = leaderPath;
1963         }
1964
1965         ShardIdentifier getShardId() {
1966             return shardId;
1967         }
1968
1969         Object getResponse() {
1970             return response;
1971         }
1972
1973         String getLeaderPath() {
1974             return leaderPath;
1975         }
1976     }
1977
1978     private static final class ShardNotInitializedTimeout {
1979         private final ActorRef sender;
1980         private final ShardInformation shardInfo;
1981         private final OnShardInitialized onShardInitialized;
1982
1983         ShardNotInitializedTimeout(ShardInformation shardInfo, OnShardInitialized onShardInitialized, ActorRef sender) {
1984             this.sender = sender;
1985             this.shardInfo = shardInfo;
1986             this.onShardInitialized = onShardInitialized;
1987         }
1988
1989         ActorRef getSender() {
1990             return sender;
1991         }
1992
1993         ShardInformation getShardInfo() {
1994             return shardInfo;
1995         }
1996
1997         OnShardInitialized getOnShardInitialized() {
1998             return onShardInitialized;
1999         }
2000     }
2001 }
2002
2003
2004