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.DeleteSnapshotsFailure;
  29 import akka.persistence.DeleteSnapshotsSuccess;
  30 import akka.persistence.RecoveryCompleted;
  31 import akka.persistence.SaveSnapshotFailure;
  32 import akka.persistence.SaveSnapshotSuccess;
  33 import akka.persistence.SnapshotOffer;
  34 import akka.persistence.SnapshotSelectionCriteria;
  35 import akka.util.Timeout;
  36 import com.google.common.annotations.VisibleForTesting;
  37 import com.google.common.base.Preconditions;
  38 import java.util.ArrayList;
  39 import java.util.Collection;
  40 import java.util.Collections;
  41 import java.util.HashMap;
  42 import java.util.HashSet;
  43 import java.util.List;
  44 import java.util.Map;
  45 import java.util.Map.Entry;
  46 import java.util.Set;
  47 import java.util.concurrent.CountDownLatch;
  48 import java.util.concurrent.TimeUnit;
  49 import java.util.concurrent.TimeoutException;
  50 import java.util.function.Consumer;
  51 import java.util.function.Supplier;
  52 import org.opendaylight.controller.cluster.access.concepts.MemberName;
  53 import org.opendaylight.controller.cluster.common.actor.AbstractUntypedPersistentActorWithMetering;
  54 import org.opendaylight.controller.cluster.common.actor.Dispatchers;
  55 import org.opendaylight.controller.cluster.datastore.AbstractDataStore;
  56 import org.opendaylight.controller.cluster.datastore.ClusterWrapper;
  57 import org.opendaylight.controller.cluster.datastore.DatastoreContext;
  58 import org.opendaylight.controller.cluster.datastore.DatastoreContext.Builder;
  59 import org.opendaylight.controller.cluster.datastore.DatastoreContextFactory;
  60 import org.opendaylight.controller.cluster.datastore.Shard;
  61 import org.opendaylight.controller.cluster.datastore.config.Configuration;
  62 import org.opendaylight.controller.cluster.datastore.config.ModuleShardConfiguration;
  63 import org.opendaylight.controller.cluster.datastore.config.PrefixShardConfiguration;
  64 import org.opendaylight.controller.cluster.datastore.exceptions.AlreadyExistsException;
  65 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
  66 import org.opendaylight.controller.cluster.datastore.exceptions.NotInitializedException;
  67 import org.opendaylight.controller.cluster.datastore.exceptions.PrimaryNotFoundException;
  68 import org.opendaylight.controller.cluster.datastore.identifiers.ShardIdentifier;
  69 import org.opendaylight.controller.cluster.datastore.messages.ActorInitialized;
  70 import org.opendaylight.controller.cluster.datastore.messages.AddPrefixShardReplica;
  71 import org.opendaylight.controller.cluster.datastore.messages.AddShardReplica;
  72 import org.opendaylight.controller.cluster.datastore.messages.ChangeShardMembersVotingStatus;
  73 import org.opendaylight.controller.cluster.datastore.messages.CreateShard;
  74 import org.opendaylight.controller.cluster.datastore.messages.FindLocalShard;
  75 import org.opendaylight.controller.cluster.datastore.messages.FindPrimary;
  76 import org.opendaylight.controller.cluster.datastore.messages.FlipShardMembersVotingStatus;
  77 import org.opendaylight.controller.cluster.datastore.messages.GetShardRole;
  78 import org.opendaylight.controller.cluster.datastore.messages.GetShardRoleReply;
  79 import org.opendaylight.controller.cluster.datastore.messages.LocalPrimaryShardFound;
  80 import org.opendaylight.controller.cluster.datastore.messages.LocalShardFound;
  81 import org.opendaylight.controller.cluster.datastore.messages.LocalShardNotFound;
  82 import org.opendaylight.controller.cluster.datastore.messages.RemoteFindPrimary;
  83 import org.opendaylight.controller.cluster.datastore.messages.RemotePrimaryShardFound;
  84 import org.opendaylight.controller.cluster.datastore.messages.RemovePrefixShardReplica;
  85 import org.opendaylight.controller.cluster.datastore.messages.RemoveShardReplica;
  86 import org.opendaylight.controller.cluster.datastore.messages.ShardLeaderStateChanged;
  87 import org.opendaylight.controller.cluster.datastore.messages.UpdateSchemaContext;
  88 import org.opendaylight.controller.cluster.datastore.persisted.DatastoreSnapshot;
  89 import org.opendaylight.controller.cluster.datastore.persisted.ShardManagerSnapshot;
  90 import org.opendaylight.controller.cluster.datastore.utils.ClusterUtils;
  91 import org.opendaylight.controller.cluster.datastore.utils.CompositeOnComplete;
  92 import org.opendaylight.controller.cluster.datastore.utils.PrimaryShardInfoFutureCache;
  93 import org.opendaylight.controller.cluster.notifications.RegisterRoleChangeListener;
  94 import org.opendaylight.controller.cluster.notifications.RegisterRoleChangeListenerReply;
  95 import org.opendaylight.controller.cluster.notifications.RoleChangeNotification;
  96 import org.opendaylight.controller.cluster.raft.base.messages.FollowerInitialSyncUpStatus;
  97 import org.opendaylight.controller.cluster.raft.base.messages.SwitchBehavior;
  98 import org.opendaylight.controller.cluster.raft.client.messages.GetOnDemandRaftState;
  99 import org.opendaylight.controller.cluster.raft.client.messages.GetSnapshot;
 100 import org.opendaylight.controller.cluster.raft.client.messages.OnDemandRaftState;
 101 import org.opendaylight.controller.cluster.raft.client.messages.Shutdown;
 102 import org.opendaylight.controller.cluster.raft.messages.AddServer;
 103 import org.opendaylight.controller.cluster.raft.messages.AddServerReply;
 104 import org.opendaylight.controller.cluster.raft.messages.ChangeServersVotingStatus;
 105 import org.opendaylight.controller.cluster.raft.messages.RemoveServer;
 106 import org.opendaylight.controller.cluster.raft.messages.RemoveServerReply;
 107 import org.opendaylight.controller.cluster.raft.messages.ServerChangeReply;
 108 import org.opendaylight.controller.cluster.raft.messages.ServerChangeStatus;
 109 import org.opendaylight.controller.cluster.raft.messages.ServerRemoved;
 110 import org.opendaylight.controller.cluster.raft.policy.DisableElectionsRaftPolicy;
 111 import org.opendaylight.controller.cluster.sharding.PrefixedShardConfigUpdateHandler;
 112 import org.opendaylight.controller.cluster.sharding.messages.InitConfigListener;
 113 import org.opendaylight.controller.cluster.sharding.messages.PrefixShardCreated;
 114 import org.opendaylight.controller.cluster.sharding.messages.PrefixShardRemoved;
 115 import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeChangeListener;
 116 import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
 117 import org.opendaylight.yangtools.concepts.ListenerRegistration;
 118 import org.opendaylight.yangtools.concepts.Registration;
 119 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
 120 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
 121 import org.slf4j.Logger;
 122 import org.slf4j.LoggerFactory;
 123 import scala.concurrent.ExecutionContext;
 124 import scala.concurrent.Future;
 125 import scala.concurrent.duration.Duration;
 126 import scala.concurrent.duration.FiniteDuration;
 127
 128 /**
 129  * Manages the shards for a data store. The ShardManager has the following jobs:
 130  * <ul>
 131  * <li> Create all the local shard replicas that belong on this cluster member
 132  * <li> Find the address of the local shard
 133  * <li> Find the primary replica for any given shard
 134  * <li> Monitor the cluster members and store their addresses
 135  * </ul>
 136  */
 137 class ShardManager extends AbstractUntypedPersistentActorWithMetering {
 138     private static final Logger LOG = LoggerFactory.getLogger(ShardManager.class);
 139
 140     // Stores a mapping between a shard name and it's corresponding information
 141     // Shard names look like inventory, topology etc and are as specified in
 142     // configuration
 143     private final Map<String, ShardInformation> localShards = new HashMap<>();
 144
 145     // The type of a ShardManager reflects the type of the datastore itself
 146     // A data store could be of type config/operational
 147     private final String type;
 148
 149     private final ClusterWrapper cluster;
 150
 151     private final Configuration configuration;
 152
 153     private final String shardDispatcherPath;
 154
 155     private final ShardManagerInfo shardManagerMBean;
 156
 157     private DatastoreContextFactory datastoreContextFactory;
 158
 159     private final CountDownLatch waitTillReadyCountdownLatch;
 160
 161     private final PrimaryShardInfoFutureCache primaryShardInfoCache;
 162
 163     private final ShardPeerAddressResolver peerAddressResolver;
 164
 165     private SchemaContext schemaContext;
 166
 167     private DatastoreSnapshot restoreFromSnapshot;
 168
 169     private ShardManagerSnapshot currentSnapshot;
 170
 171     private final Set<String> shardReplicaOperationsInProgress = new HashSet<>();
 172
 173     private final Map<String, CompositeOnComplete<Boolean>> shardActorsStopping = new HashMap<>();
 174
 175     private final Set<Consumer<String>> shardAvailabilityCallbacks = new HashSet<>();
 176
 177     private final String persistenceId;
 178     private final AbstractDataStore dataStore;
 179
 180     private ListenerRegistration<DOMDataTreeChangeListener> configListenerReg = null;
 181     private PrefixedShardConfigUpdateHandler configUpdateHandler;
 182
 183     ShardManager(final AbstractShardManagerCreator<?> builder) {
 184         this.cluster = builder.getCluster();
 185         this.configuration = builder.getConfiguration();
 186         this.datastoreContextFactory = builder.getDatastoreContextFactory();
 187         this.type = datastoreContextFactory.getBaseDatastoreContext().getDataStoreName();
 188         this.shardDispatcherPath =
 189                 new Dispatchers(context().system().dispatchers()).getDispatcherPath(Dispatchers.DispatcherType.Shard);
 190         this.waitTillReadyCountdownLatch = builder.getWaitTillReadyCountDownLatch();
 191         this.primaryShardInfoCache = builder.getPrimaryShardInfoCache();
 192         this.restoreFromSnapshot = builder.getRestoreFromSnapshot();
 193
 194         String possiblePersistenceId = datastoreContextFactory.getBaseDatastoreContext().getShardManagerPersistenceId();
 195         persistenceId = possiblePersistenceId != null ? possiblePersistenceId : "shard-manager-" + type;
 196
 197         peerAddressResolver = new ShardPeerAddressResolver(type, cluster.getCurrentMemberName());
 198
 199         // Subscribe this actor to cluster member events
 200         cluster.subscribeToMemberEvents(getSelf());
 201
 202         shardManagerMBean = new ShardManagerInfo(getSelf(), cluster.getCurrentMemberName(),
 203                 "shard-manager-" + this.type,
 204                 datastoreContextFactory.getBaseDatastoreContext().getDataStoreMXBeanType());
 205         shardManagerMBean.registerMBean();
 206
 207         dataStore = builder.getDistributedDataStore();
 208     }
 209
 210     @Override
 211     public void preStart() {
 212         LOG.info("Starting ShardManager {}", persistenceId);
 213     }
 214
 215     @Override
 216     public void postStop() {
 217         LOG.info("Stopping ShardManager {}", persistenceId());
 218
 219         shardManagerMBean.unregisterMBean();
 220
 221         if (configListenerReg != null) {
 222             configListenerReg.close();
 223             configListenerReg = null;
 224         }
 225     }
 226
 227     @Override
 228     public void handleCommand(final Object message) throws Exception {
 229         if (message  instanceof FindPrimary) {
 230             findPrimary((FindPrimary)message);
 231         } else if (message instanceof FindLocalShard) {
 232             findLocalShard((FindLocalShard) message);
 233         } else if (message instanceof UpdateSchemaContext) {
 234             updateSchemaContext(message);
 235         } else if (message instanceof ActorInitialized) {
 236             onActorInitialized(message);
 237         } else if (message instanceof ClusterEvent.MemberUp) {
 238             memberUp((ClusterEvent.MemberUp) message);
 239         } else if (message instanceof ClusterEvent.MemberWeaklyUp) {
 240             memberWeaklyUp((ClusterEvent.MemberWeaklyUp) message);
 241         } else if (message instanceof ClusterEvent.MemberExited) {
 242             memberExited((ClusterEvent.MemberExited) message);
 243         } else if (message instanceof ClusterEvent.MemberRemoved) {
 244             memberRemoved((ClusterEvent.MemberRemoved) message);
 245         } else if (message instanceof ClusterEvent.UnreachableMember) {
 246             memberUnreachable((ClusterEvent.UnreachableMember) message);
 247         } else if (message instanceof ClusterEvent.ReachableMember) {
 248             memberReachable((ClusterEvent.ReachableMember) message);
 249         } else if (message instanceof DatastoreContextFactory) {
 250             onDatastoreContextFactory((DatastoreContextFactory) message);
 251         } else if (message instanceof RoleChangeNotification) {
 252             onRoleChangeNotification((RoleChangeNotification) message);
 253         } else if (message instanceof FollowerInitialSyncUpStatus) {
 254             onFollowerInitialSyncStatus((FollowerInitialSyncUpStatus) message);
 255         } else if (message instanceof ShardNotInitializedTimeout) {
 256             onShardNotInitializedTimeout((ShardNotInitializedTimeout) message);
 257         } else if (message instanceof ShardLeaderStateChanged) {
 258             onLeaderStateChanged((ShardLeaderStateChanged) message);
 259         } else if (message instanceof SwitchShardBehavior) {
 260             onSwitchShardBehavior((SwitchShardBehavior) message);
 261         } else if (message instanceof CreateShard) {
 262             onCreateShard((CreateShard)message);
 263         } else if (message instanceof AddShardReplica) {
 264             onAddShardReplica((AddShardReplica) message);
 265         } else if (message instanceof AddPrefixShardReplica) {
 266             onAddPrefixShardReplica((AddPrefixShardReplica) message);
 267         } else if (message instanceof PrefixShardCreated) {
 268             onPrefixShardCreated((PrefixShardCreated) message);
 269         } else if (message instanceof PrefixShardRemoved) {
 270             onPrefixShardRemoved((PrefixShardRemoved) message);
 271         } else if (message instanceof InitConfigListener) {
 272             onInitConfigListener();
 273         } else if (message instanceof ForwardedAddServerReply) {
 274             ForwardedAddServerReply msg = (ForwardedAddServerReply)message;
 275             onAddServerReply(msg.shardInfo, msg.addServerReply, getSender(), msg.leaderPath,
 276                     msg.removeShardOnFailure);
 277         } else if (message instanceof ForwardedAddServerFailure) {
 278             ForwardedAddServerFailure msg = (ForwardedAddServerFailure)message;
 279             onAddServerFailure(msg.shardName, msg.failureMessage, msg.failure, getSender(), msg.removeShardOnFailure);
 280         } else if (message instanceof RemoveShardReplica) {
 281             onRemoveShardReplica((RemoveShardReplica) message);
 282         } else if (message instanceof RemovePrefixShardReplica) {
 283             onRemovePrefixShardReplica((RemovePrefixShardReplica) message);
 284         } else if (message instanceof WrappedShardResponse) {
 285             onWrappedShardResponse((WrappedShardResponse) message);
 286         } else if (message instanceof GetSnapshot) {
 287             onGetSnapshot();
 288         } else if (message instanceof ServerRemoved) {
 289             onShardReplicaRemoved((ServerRemoved) message);
 290         } else if (message instanceof ChangeShardMembersVotingStatus) {
 291             onChangeShardServersVotingStatus((ChangeShardMembersVotingStatus) message);
 292         } else if (message instanceof FlipShardMembersVotingStatus) {
 293             onFlipShardMembersVotingStatus((FlipShardMembersVotingStatus) message);
 294         } else if (message instanceof SaveSnapshotSuccess) {
 295             onSaveSnapshotSuccess((SaveSnapshotSuccess) message);
 296         } else if (message instanceof SaveSnapshotFailure) {
 297             LOG.error("{}: SaveSnapshotFailure received for saving snapshot of shards", persistenceId(),
 298                     ((SaveSnapshotFailure) message).cause());
 299         } else if (message instanceof Shutdown) {
 300             onShutDown();
 301         } else if (message instanceof GetLocalShardIds) {
 302             onGetLocalShardIds();
 303         } else if (message instanceof GetShardRole) {
 304             onGetShardRole((GetShardRole) message);
 305         } else if (message instanceof RunnableMessage) {
 306             ((RunnableMessage)message).run();
 307         } else if (message instanceof RegisterForShardAvailabilityChanges) {
 308             onRegisterForShardAvailabilityChanges((RegisterForShardAvailabilityChanges)message);
 309         } else if (message instanceof DeleteSnapshotsFailure) {
 310             LOG.warn("{}: Failed to delete prior snapshots", persistenceId(),
 311                     ((DeleteSnapshotsFailure) message).cause());
 312         } else if (message instanceof DeleteSnapshotsSuccess) {
 313             LOG.debug("{}: Successfully deleted prior snapshots", persistenceId(), message);
 314         } else if (message instanceof RegisterRoleChangeListenerReply) {
 315             LOG.trace("{}: Received RegisterRoleChangeListenerReply", persistenceId());
 316         } else if (message instanceof ClusterEvent.MemberEvent) {
 317             LOG.trace("{}: Received other ClusterEvent.MemberEvent: {}", persistenceId(), message);
 318         } else {
 319             unknownMessage(message);
 320         }
 321     }
 322
 323     private void onRegisterForShardAvailabilityChanges(RegisterForShardAvailabilityChanges message) {
 324         LOG.debug("{}: onRegisterForShardAvailabilityChanges: {}", persistenceId(), message);
 325
 326         final Consumer<String> callback = message.getCallback();
 327         shardAvailabilityCallbacks.add(callback);
 328
 329         getSender().tell(new Status.Success((Registration)
 330             () -> executeInSelf(() -> shardAvailabilityCallbacks.remove(callback))), self());
 331     }
 332
 333     private void onGetShardRole(final GetShardRole message) {
 334         LOG.debug("{}: onGetShardRole for shard: {}", persistenceId(), message.getName());
 335
 336         final String name = message.getName();
 337
 338         final ShardInformation shardInformation = localShards.get(name);
 339
 340         if (shardInformation == null) {
 341             LOG.info("{}: no shard information for {} found", persistenceId(), name);
 342             getSender().tell(new Status.Failure(
 343                     new IllegalArgumentException("Shard with name " + name + " not present.")), ActorRef.noSender());
 344             return;
 345         }
 346
 347         getSender().tell(new GetShardRoleReply(shardInformation.getRole()), ActorRef.noSender());
 348     }
 349
 350     private void onInitConfigListener() {
 351         LOG.debug("{}: Initializing config listener on {}", persistenceId(), cluster.getCurrentMemberName());
 352
 353         final org.opendaylight.mdsal.common.api.LogicalDatastoreType datastoreType =
 354                 org.opendaylight.mdsal.common.api.LogicalDatastoreType
 355                         .valueOf(datastoreContextFactory.getBaseDatastoreContext().getLogicalStoreType().name());
 356
 357         if (configUpdateHandler != null) {
 358             configUpdateHandler.close();
 359         }
 360
 361         configUpdateHandler = new PrefixedShardConfigUpdateHandler(self(), cluster.getCurrentMemberName());
 362         configUpdateHandler.initListener(dataStore, datastoreType);
 363     }
 364
 365     private void onShutDown() {
 366         List<Future<Boolean>> stopFutures = new ArrayList<>(localShards.size());
 367         for (ShardInformation info : localShards.values()) {
 368             if (info.getActor() != null) {
 369                 LOG.debug("{}: Issuing gracefulStop to shard {}", persistenceId(), info.getShardId());
 370
 371                 FiniteDuration duration = info.getDatastoreContext().getShardRaftConfig()
 372                         .getElectionTimeOutInterval().$times(2);
 373                 stopFutures.add(Patterns.gracefulStop(info.getActor(), duration, Shutdown.INSTANCE));
 374             }
 375         }
 376
 377         LOG.info("Shutting down ShardManager {} - waiting on {} shards", persistenceId(), stopFutures.size());
 378
 379         ExecutionContext dispatcher = new Dispatchers(context().system().dispatchers())
 380                 .getDispatcher(Dispatchers.DispatcherType.Client);
 381         Future<Iterable<Boolean>> combinedFutures = Futures.sequence(stopFutures, dispatcher);
 382
 383         combinedFutures.onComplete(new OnComplete<Iterable<Boolean>>() {
 384             @Override
 385             public void onComplete(final Throwable failure, final Iterable<Boolean> results) {
 386                 LOG.debug("{}: All shards shutdown - sending PoisonPill to self", persistenceId());
 387
 388                 self().tell(PoisonPill.getInstance(), self());
 389
 390                 if (failure != null) {
 391                     LOG.warn("{}: An error occurred attempting to shut down the shards", persistenceId(), failure);
 392                 } else {
 393                     int nfailed = 0;
 394                     for (Boolean result : results) {
 395                         if (!result) {
 396                             nfailed++;
 397                         }
 398                     }
 399
 400                     if (nfailed > 0) {
 401                         LOG.warn("{}: {} shards did not shut down gracefully", persistenceId(), nfailed);
 402                     }
 403                 }
 404             }
 405         }, dispatcher);
 406     }
 407
 408     private void onWrappedShardResponse(final WrappedShardResponse message) {
 409         if (message.getResponse() instanceof RemoveServerReply) {
 410             onRemoveServerReply(getSender(), message.getShardId(), (RemoveServerReply) message.getResponse(),
 411                     message.getLeaderPath());
 412         }
 413     }
 414
 415     private void onRemoveServerReply(final ActorRef originalSender, final ShardIdentifier shardId,
 416             final RemoveServerReply replyMsg, final String leaderPath) {
 417         shardReplicaOperationsInProgress.remove(shardId.getShardName());
 418
 419         LOG.debug("{}: Received {} for shard {}", persistenceId(), replyMsg, shardId.getShardName());
 420
 421         if (replyMsg.getStatus() == ServerChangeStatus.OK) {
 422             LOG.debug("{}: Leader shard successfully removed the replica shard {}", persistenceId(),
 423                     shardId.getShardName());
 424             originalSender.tell(new Status.Success(null), getSelf());
 425         } else {
 426             LOG.warn("{}: Leader failed to remove shard replica {} with status {}",
 427                     persistenceId(), shardId, replyMsg.getStatus());
 428
 429             Exception failure = getServerChangeException(RemoveServer.class, replyMsg.getStatus(), leaderPath, shardId);
 430             originalSender.tell(new Status.Failure(failure), getSelf());
 431         }
 432     }
 433
 434     private void removePrefixShardReplica(final RemovePrefixShardReplica contextMessage, final String shardName,
 435                                           final String primaryPath, final ActorRef sender) {
 436         if (isShardReplicaOperationInProgress(shardName, sender)) {
 437             return;
 438         }
 439
 440         shardReplicaOperationsInProgress.add(shardName);
 441
 442         final ShardIdentifier shardId = getShardIdentifier(contextMessage.getMemberName(), shardName);
 443
 444         final DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName).build();
 445
 446         //inform ShardLeader to remove this shard as a replica by sending an RemoveServer message
 447         LOG.debug("{}: Sending RemoveServer message to peer {} for shard {}", persistenceId(),
 448                 primaryPath, shardId);
 449
 450         Timeout removeServerTimeout = new Timeout(datastoreContext.getShardLeaderElectionTimeout().duration());
 451         Future<Object> futureObj = ask(getContext().actorSelection(primaryPath),
 452                 new RemoveServer(shardId.toString()), removeServerTimeout);
 453
 454         futureObj.onComplete(new OnComplete<Object>() {
 455             @Override
 456             public void onComplete(final Throwable failure, final Object response) {
 457                 if (failure != null) {
 458                     shardReplicaOperationsInProgress.remove(shardName);
 459                     String msg = String.format("RemoveServer request to leader %s for shard %s failed",
 460                             primaryPath, shardName);
 461
 462                     LOG.debug("{}: {}", persistenceId(), msg, failure);
 463
 464                     // FAILURE
 465                     sender.tell(new Status.Failure(new RuntimeException(msg, failure)), self());
 466                 } else {
 467                     // SUCCESS
 468                     self().tell(new WrappedShardResponse(shardId, response, primaryPath), sender);
 469                 }
 470             }
 471         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
 472     }
 473
 474     private void removeShardReplica(final RemoveShardReplica contextMessage, final String shardName,
 475             final String primaryPath, final ActorRef sender) {
 476         if (isShardReplicaOperationInProgress(shardName, sender)) {
 477             return;
 478         }
 479
 480         shardReplicaOperationsInProgress.add(shardName);
 481
 482         final ShardIdentifier shardId = getShardIdentifier(contextMessage.getMemberName(), shardName);
 483
 484         final DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName).build();
 485
 486         //inform ShardLeader to remove this shard as a replica by sending an RemoveServer message
 487         LOG.debug("{}: Sending RemoveServer message to peer {} for shard {}", persistenceId(),
 488                 primaryPath, shardId);
 489
 490         Timeout removeServerTimeout = new Timeout(datastoreContext.getShardLeaderElectionTimeout().duration());
 491         Future<Object> futureObj = ask(getContext().actorSelection(primaryPath),
 492                 new RemoveServer(shardId.toString()), removeServerTimeout);
 493
 494         futureObj.onComplete(new OnComplete<Object>() {
 495             @Override
 496             public void onComplete(final Throwable failure, final Object response) {
 497                 if (failure != null) {
 498                     shardReplicaOperationsInProgress.remove(shardName);
 499                     String msg = String.format("RemoveServer request to leader %s for shard %s failed",
 500                             primaryPath, shardName);
 501
 502                     LOG.debug("{}: {}", persistenceId(), msg, failure);
 503
 504                     // FAILURE
 505                     sender.tell(new Status.Failure(new RuntimeException(msg, failure)), self());
 506                 } else {
 507                     // SUCCESS
 508                     self().tell(new WrappedShardResponse(shardId, response, primaryPath), sender);
 509                 }
 510             }
 511         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
 512     }
 513
 514     private void onShardReplicaRemoved(final ServerRemoved message) {
 515         removeShard(new ShardIdentifier.Builder().fromShardIdString(message.getServerId()).build());
 516     }
 517
 518     @SuppressWarnings("checkstyle:IllegalCatch")
 519     private void removeShard(final ShardIdentifier shardId) {
 520         final String shardName = shardId.getShardName();
 521         final ShardInformation shardInformation = localShards.remove(shardName);
 522         if (shardInformation == null) {
 523             LOG.debug("{} : Shard replica {} is not present in list", persistenceId(), shardId.toString());
 524             return;
 525         }
 526
 527         final ActorRef shardActor = shardInformation.getActor();
 528         if (shardActor != null) {
 529             long timeoutInMS = Math.max(shardInformation.getDatastoreContext().getShardRaftConfig()
 530                     .getElectionTimeOutInterval().$times(3).toMillis(), 10000);
 531
 532             LOG.debug("{} : Sending Shutdown to Shard actor {} with {} ms timeout", persistenceId(), shardActor,
 533                     timeoutInMS);
 534
 535             final Future<Boolean> stopFuture = Patterns.gracefulStop(shardActor,
 536                     FiniteDuration.apply(timeoutInMS, TimeUnit.MILLISECONDS), Shutdown.INSTANCE);
 537
 538             final CompositeOnComplete<Boolean> onComplete = new CompositeOnComplete<Boolean>() {
 539                 @Override
 540                 public void onComplete(final Throwable failure, final Boolean result) {
 541                     if (failure == null) {
 542                         LOG.debug("{} : Successfully shut down Shard actor {}", persistenceId(), shardActor);
 543                     } else {
 544                         LOG.warn("{}: Failed to shut down Shard actor {}", persistenceId(), shardActor, failure);
 545                     }
 546
 547                     self().tell((RunnableMessage) () -> {
 548                         // At any rate, invalidate primaryShardInfo cache
 549                         primaryShardInfoCache.remove(shardName);
 550
 551                         shardActorsStopping.remove(shardName);
 552                         notifyOnCompleteTasks(failure, result);
 553                     }, ActorRef.noSender());
 554                 }
 555             };
 556
 557             shardActorsStopping.put(shardName, onComplete);
 558             stopFuture.onComplete(onComplete, new Dispatchers(context().system().dispatchers())
 559                     .getDispatcher(Dispatchers.DispatcherType.Client));
 560         }
 561
 562         LOG.debug("{} : Local Shard replica for shard {} has been removed", persistenceId(), shardName);
 563         persistShardList();
 564     }
 565
 566     private void onGetSnapshot() {
 567         LOG.debug("{}: onGetSnapshot", persistenceId());
 568
 569         List<String> notInitialized = null;
 570         for (ShardInformation shardInfo : localShards.values()) {
 571             if (!shardInfo.isShardInitialized()) {
 572                 if (notInitialized == null) {
 573                     notInitialized = new ArrayList<>();
 574                 }
 575
 576                 notInitialized.add(shardInfo.getShardName());
 577             }
 578         }
 579
 580         if (notInitialized != null) {
 581             getSender().tell(new Status.Failure(new IllegalStateException(String.format(
 582                     "%d shard(s) %s are not initialized", notInitialized.size(), notInitialized))), getSelf());
 583             return;
 584         }
 585
 586         ActorRef replyActor = getContext().actorOf(ShardManagerGetSnapshotReplyActor.props(
 587                 new ArrayList<>(localShards.keySet()), type, currentSnapshot , getSender(), persistenceId(),
 588                 datastoreContextFactory.getBaseDatastoreContext().getShardInitializationTimeout().duration()));
 589
 590         for (ShardInformation shardInfo: localShards.values()) {
 591             shardInfo.getActor().tell(GetSnapshot.INSTANCE, replyActor);
 592         }
 593     }
 594
 595     @SuppressWarnings("checkstyle:IllegalCatch")
 596     private void onCreateShard(final CreateShard createShard) {
 597         LOG.debug("{}: onCreateShard: {}", persistenceId(), createShard);
 598
 599         Object reply;
 600         try {
 601             String shardName = createShard.getModuleShardConfig().getShardName();
 602             if (localShards.containsKey(shardName)) {
 603                 LOG.debug("{}: Shard {} already exists", persistenceId(), shardName);
 604                 reply = new Status.Success(String.format("Shard with name %s already exists", shardName));
 605             } else {
 606                 doCreateShard(createShard);
 607                 reply = new Status.Success(null);
 608             }
 609         } catch (Exception e) {
 610             LOG.error("{}: onCreateShard failed", persistenceId(), e);
 611             reply = new Status.Failure(e);
 612         }
 613
 614         if (getSender() != null && !getContext().system().deadLetters().equals(getSender())) {
 615             getSender().tell(reply, getSelf());
 616         }
 617     }
 618
 619     private void onPrefixShardCreated(final PrefixShardCreated message) {
 620         LOG.debug("{}: onPrefixShardCreated: {}", persistenceId(), message);
 621
 622         final PrefixShardConfiguration config = message.getConfiguration();
 623         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(),
 624                 ClusterUtils.getCleanShardName(config.getPrefix().getRootIdentifier()));
 625         final String shardName = shardId.getShardName();
 626
 627         if (isPreviousShardActorStopInProgress(shardName, message)) {
 628             return;
 629         }
 630
 631         if (localShards.containsKey(shardName)) {
 632             LOG.debug("{}: Received create for an already existing shard {}", persistenceId(), shardName);
 633             final PrefixShardConfiguration existing =
 634                     configuration.getAllPrefixShardConfigurations().get(config.getPrefix());
 635
 636             if (existing != null && existing.equals(config)) {
 637                 // we don't have to do nothing here
 638                 return;
 639             }
 640         }
 641
 642         doCreatePrefixShard(config, shardId, shardName);
 643     }
 644
 645     private boolean isPreviousShardActorStopInProgress(final String shardName, final Object messageToDefer) {
 646         final CompositeOnComplete<Boolean> stopOnComplete = shardActorsStopping.get(shardName);
 647         if (stopOnComplete == null) {
 648             return false;
 649         }
 650
 651         LOG.debug("{} : Stop is in progress for shard {} - adding OnComplete callback to defer {}", persistenceId(),
 652                 shardName, messageToDefer);
 653         final ActorRef sender = getSender();
 654         stopOnComplete.addOnComplete(new OnComplete<Boolean>() {
 655             @Override
 656             public void onComplete(final Throwable failure, final Boolean result) {
 657                 LOG.debug("{} : Stop complete for shard {} - re-queing {}", persistenceId(), shardName, messageToDefer);
 658                 self().tell(messageToDefer, sender);
 659             }
 660         });
 661
 662         return true;
 663     }
 664
 665     private void doCreatePrefixShard(final PrefixShardConfiguration config, final ShardIdentifier shardId,
 666             final String shardName) {
 667         configuration.addPrefixShardConfiguration(config);
 668
 669         final Builder builder = newShardDatastoreContextBuilder(shardName);
 670         builder.logicalStoreType(config.getPrefix().getDatastoreType())
 671                 .storeRoot(config.getPrefix().getRootIdentifier());
 672         DatastoreContext shardDatastoreContext = builder.build();
 673
 674         final Map<String, String> peerAddresses = getPeerAddresses(shardName);
 675         final boolean isActiveMember = true;
 676
 677         LOG.debug("{} doCreatePrefixShard: shardId: {}, memberNames: {}, peerAddresses: {}, isActiveMember: {}",
 678                 persistenceId(), shardId, config.getShardMemberNames(), peerAddresses, isActiveMember);
 679
 680         final ShardInformation info = new ShardInformation(shardName, shardId, peerAddresses,
 681                 shardDatastoreContext, Shard.builder(), peerAddressResolver);
 682         info.setActiveMember(isActiveMember);
 683         localShards.put(info.getShardName(), info);
 684
 685         if (schemaContext != null) {
 686             info.setSchemaContext(schemaContext);
 687             info.setActor(newShardActor(info));
 688         }
 689     }
 690
 691     private void onPrefixShardRemoved(final PrefixShardRemoved message) {
 692         LOG.debug("{}: onPrefixShardRemoved : {}", persistenceId(), message);
 693
 694         final DOMDataTreeIdentifier prefix = message.getPrefix();
 695         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(),
 696                 ClusterUtils.getCleanShardName(prefix.getRootIdentifier()));
 697
 698         configuration.removePrefixShardConfiguration(prefix);
 699         removeShard(shardId);
 700     }
 701
 702     private void doCreateShard(final CreateShard createShard) {
 703         final ModuleShardConfiguration moduleShardConfig = createShard.getModuleShardConfig();
 704         final String shardName = moduleShardConfig.getShardName();
 705
 706         configuration.addModuleShardConfiguration(moduleShardConfig);
 707
 708         DatastoreContext shardDatastoreContext = createShard.getDatastoreContext();
 709         if (shardDatastoreContext == null) {
 710             shardDatastoreContext = newShardDatastoreContext(shardName);
 711         } else {
 712             shardDatastoreContext = DatastoreContext.newBuilderFrom(shardDatastoreContext).shardPeerAddressResolver(
 713                     peerAddressResolver).build();
 714         }
 715
 716         ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
 717
 718         boolean shardWasInRecoveredSnapshot = currentSnapshot != null
 719                 && currentSnapshot.getShardList().contains(shardName);
 720
 721         Map<String, String> peerAddresses;
 722         boolean isActiveMember;
 723         if (shardWasInRecoveredSnapshot || configuration.getMembersFromShardName(shardName)
 724                 .contains(cluster.getCurrentMemberName())) {
 725             peerAddresses = getPeerAddresses(shardName);
 726             isActiveMember = true;
 727         } else {
 728             // The local member is not in the static shard member configuration and the shard did not
 729             // previously exist (ie !shardWasInRecoveredSnapshot). In this case we'll create
 730             // the shard with no peers and with elections disabled so it stays as follower. A
 731             // subsequent AddServer request will be needed to make it an active member.
 732             isActiveMember = false;
 733             peerAddresses = Collections.emptyMap();
 734             shardDatastoreContext = DatastoreContext.newBuilderFrom(shardDatastoreContext)
 735                     .customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName()).build();
 736         }
 737
 738         LOG.debug("{} doCreateShard: shardId: {}, memberNames: {}, peerAddresses: {}, isActiveMember: {}",
 739                 persistenceId(), shardId, moduleShardConfig.getShardMemberNames(), peerAddresses,
 740                 isActiveMember);
 741
 742         ShardInformation info = new ShardInformation(shardName, shardId, peerAddresses,
 743                 shardDatastoreContext, createShard.getShardBuilder(), peerAddressResolver);
 744         info.setActiveMember(isActiveMember);
 745         localShards.put(info.getShardName(), info);
 746
 747         if (schemaContext != null) {
 748             info.setSchemaContext(schemaContext);
 749             info.setActor(newShardActor(info));
 750         }
 751     }
 752
 753     private DatastoreContext.Builder newShardDatastoreContextBuilder(final String shardName) {
 754         return DatastoreContext.newBuilderFrom(datastoreContextFactory.getShardDatastoreContext(shardName))
 755                 .shardPeerAddressResolver(peerAddressResolver);
 756     }
 757
 758     private DatastoreContext newShardDatastoreContext(final String shardName) {
 759         return newShardDatastoreContextBuilder(shardName).build();
 760     }
 761
 762     private void checkReady() {
 763         if (isReadyWithLeaderId()) {
 764             LOG.info("{}: All Shards are ready - data store {} is ready, available count is {}",
 765                     persistenceId(), type, waitTillReadyCountdownLatch.getCount());
 766
 767             waitTillReadyCountdownLatch.countDown();
 768         }
 769     }
 770
 771     private void onLeaderStateChanged(final ShardLeaderStateChanged leaderStateChanged) {
 772         LOG.info("{}: Received LeaderStateChanged message: {}", persistenceId(), leaderStateChanged);
 773
 774         ShardInformation shardInformation = findShardInformation(leaderStateChanged.getMemberId());
 775         if (shardInformation != null) {
 776             shardInformation.setLocalDataTree(leaderStateChanged.getLocalShardDataTree());
 777             shardInformation.setLeaderVersion(leaderStateChanged.getLeaderPayloadVersion());
 778             if (shardInformation.setLeaderId(leaderStateChanged.getLeaderId())) {
 779                 primaryShardInfoCache.remove(shardInformation.getShardName());
 780
 781                 notifyShardAvailabilityCallbacks(shardInformation);
 782             }
 783
 784             checkReady();
 785         } else {
 786             LOG.debug("No shard found with member Id {}", leaderStateChanged.getMemberId());
 787         }
 788     }
 789
 790     private void notifyShardAvailabilityCallbacks(ShardInformation shardInformation) {
 791         shardAvailabilityCallbacks.forEach(callback -> callback.accept(shardInformation.getShardName()));
 792     }
 793
 794     private void onShardNotInitializedTimeout(final ShardNotInitializedTimeout message) {
 795         ShardInformation shardInfo = message.getShardInfo();
 796
 797         LOG.debug("{}: Received ShardNotInitializedTimeout message for shard {}", persistenceId(),
 798                 shardInfo.getShardName());
 799
 800         shardInfo.removeOnShardInitialized(message.getOnShardInitialized());
 801
 802         if (!shardInfo.isShardInitialized()) {
 803             LOG.debug("{}: Returning NotInitializedException for shard {}", persistenceId(), shardInfo.getShardName());
 804             message.getSender().tell(createNotInitializedException(shardInfo.getShardId()), getSelf());
 805         } else {
 806             LOG.debug("{}: Returning NoShardLeaderException for shard {}", persistenceId(), shardInfo.getShardName());
 807             message.getSender().tell(createNoShardLeaderException(shardInfo.getShardId()), getSelf());
 808         }
 809     }
 810
 811     private void onFollowerInitialSyncStatus(final FollowerInitialSyncUpStatus status) {
 812         LOG.info("{} Received follower initial sync status for {} status sync done {}", persistenceId(),
 813                 status.getName(), status.isInitialSyncDone());
 814
 815         ShardInformation shardInformation = findShardInformation(status.getName());
 816
 817         if (shardInformation != null) {
 818             shardInformation.setFollowerSyncStatus(status.isInitialSyncDone());
 819
 820             shardManagerMBean.setSyncStatus(isInSync());
 821         }
 822
 823     }
 824
 825     private void onRoleChangeNotification(final RoleChangeNotification roleChanged) {
 826         LOG.info("{}: Received role changed for {} from {} to {}", persistenceId(), roleChanged.getMemberId(),
 827                 roleChanged.getOldRole(), roleChanged.getNewRole());
 828
 829         ShardInformation shardInformation = findShardInformation(roleChanged.getMemberId());
 830         if (shardInformation != null) {
 831             shardInformation.setRole(roleChanged.getNewRole());
 832             checkReady();
 833             shardManagerMBean.setSyncStatus(isInSync());
 834         }
 835     }
 836
 837
 838     private ShardInformation findShardInformation(final String memberId) {
 839         for (ShardInformation info : localShards.values()) {
 840             if (info.getShardId().toString().equals(memberId)) {
 841                 return info;
 842             }
 843         }
 844
 845         return null;
 846     }
 847
 848     private boolean isReadyWithLeaderId() {
 849         boolean isReady = true;
 850         for (ShardInformation info : localShards.values()) {
 851             if (!info.isShardReadyWithLeaderId()) {
 852                 isReady = false;
 853                 break;
 854             }
 855         }
 856         return isReady;
 857     }
 858
 859     private boolean isInSync() {
 860         for (ShardInformation info : localShards.values()) {
 861             if (!info.isInSync()) {
 862                 return false;
 863             }
 864         }
 865         return true;
 866     }
 867
 868     private void onActorInitialized(final Object message) {
 869         final ActorRef sender = getSender();
 870
 871         if (sender == null) {
 872             // why is a non-actor sending this message? Just ignore.
 873             return;
 874         }
 875
 876         String actorName = sender.path().name();
 877         //find shard name from actor name; actor name is stringified shardId
 878
 879         final ShardIdentifier shardId;
 880         try {
 881             shardId = ShardIdentifier.fromShardIdString(actorName);
 882         } catch (IllegalArgumentException e) {
 883             LOG.debug("{}: ignoring actor {}", actorName, e);
 884             return;
 885         }
 886
 887         markShardAsInitialized(shardId.getShardName());
 888     }
 889
 890     private void markShardAsInitialized(final String shardName) {
 891         LOG.debug("{}: Initializing shard [{}]", persistenceId(), shardName);
 892
 893         ShardInformation shardInformation = localShards.get(shardName);
 894         if (shardInformation != null) {
 895             shardInformation.setActorInitialized();
 896
 897             shardInformation.getActor().tell(new RegisterRoleChangeListener(), self());
 898         }
 899     }
 900
 901     @Override
 902     protected void handleRecover(final Object message) throws Exception {
 903         if (message instanceof RecoveryCompleted) {
 904             onRecoveryCompleted();
 905         } else if (message instanceof SnapshotOffer) {
 906             applyShardManagerSnapshot((ShardManagerSnapshot)((SnapshotOffer) message).snapshot());
 907         }
 908     }
 909
 910     @SuppressWarnings("checkstyle:IllegalCatch")
 911     private void onRecoveryCompleted() {
 912         LOG.info("Recovery complete : {}", persistenceId());
 913
 914         if (currentSnapshot == null && restoreFromSnapshot != null
 915                 && restoreFromSnapshot.getShardManagerSnapshot() != null) {
 916             ShardManagerSnapshot snapshot = restoreFromSnapshot.getShardManagerSnapshot();
 917
 918             LOG.debug("{}: Restoring from ShardManagerSnapshot: {}", persistenceId(), snapshot);
 919
 920             applyShardManagerSnapshot(snapshot);
 921         }
 922
 923         createLocalShards();
 924     }
 925
 926     private void sendResponse(final ShardInformation shardInformation, final boolean doWait,
 927             final boolean wantShardReady, final Supplier<Object> messageSupplier) {
 928         if (!shardInformation.isShardInitialized() || wantShardReady && !shardInformation.isShardReadyWithLeaderId()) {
 929             if (doWait) {
 930                 final ActorRef sender = getSender();
 931                 final ActorRef self = self();
 932
 933                 Runnable replyRunnable = () -> sender.tell(messageSupplier.get(), self);
 934
 935                 OnShardInitialized onShardInitialized = wantShardReady ? new OnShardReady(replyRunnable) :
 936                     new OnShardInitialized(replyRunnable);
 937
 938                 shardInformation.addOnShardInitialized(onShardInitialized);
 939
 940                 FiniteDuration timeout = shardInformation.getDatastoreContext()
 941                         .getShardInitializationTimeout().duration();
 942                 if (shardInformation.isShardInitialized()) {
 943                     // If the shard is already initialized then we'll wait enough time for the shard to
 944                     // elect a leader, ie 2 times the election timeout.
 945                     timeout = FiniteDuration.create(shardInformation.getDatastoreContext().getShardRaftConfig()
 946                             .getElectionTimeOutInterval().toMillis() * 2, TimeUnit.MILLISECONDS);
 947                 }
 948
 949                 LOG.debug("{}: Scheduling {} ms timer to wait for shard {}", persistenceId(), timeout.toMillis(),
 950                         shardInformation);
 951
 952                 Cancellable timeoutSchedule = getContext().system().scheduler().scheduleOnce(
 953                         timeout, getSelf(),
 954                         new ShardNotInitializedTimeout(shardInformation, onShardInitialized, sender),
 955                         getContext().dispatcher(), getSelf());
 956
 957                 onShardInitialized.setTimeoutSchedule(timeoutSchedule);
 958
 959             } else if (!shardInformation.isShardInitialized()) {
 960                 LOG.debug("{}: Returning NotInitializedException for shard {}", persistenceId(),
 961                         shardInformation.getShardName());
 962                 getSender().tell(createNotInitializedException(shardInformation.getShardId()), getSelf());
 963             } else {
 964                 LOG.debug("{}: Returning NoShardLeaderException for shard {}", persistenceId(),
 965                         shardInformation.getShardName());
 966                 getSender().tell(createNoShardLeaderException(shardInformation.getShardId()), getSelf());
 967             }
 968
 969             return;
 970         }
 971
 972         getSender().tell(messageSupplier.get(), getSelf());
 973     }
 974
 975     private static NoShardLeaderException createNoShardLeaderException(final ShardIdentifier shardId) {
 976         return new NoShardLeaderException(null, shardId.toString());
 977     }
 978
 979     private static NotInitializedException createNotInitializedException(final ShardIdentifier shardId) {
 980         return new NotInitializedException(String.format(
 981                 "Found primary shard %s but it's not initialized yet. Please try again later", shardId));
 982     }
 983
 984     @VisibleForTesting
 985     static MemberName memberToName(final Member member) {
 986         return MemberName.forName(member.roles().iterator().next());
 987     }
 988
 989     private void memberRemoved(final ClusterEvent.MemberRemoved message) {
 990         MemberName memberName = memberToName(message.member());
 991
 992         LOG.info("{}: Received MemberRemoved: memberName: {}, address: {}", persistenceId(), memberName,
 993                 message.member().address());
 994
 995         peerAddressResolver.removePeerAddress(memberName);
 996
 997         for (ShardInformation info : localShards.values()) {
 998             info.peerDown(memberName, getShardIdentifier(memberName, info.getShardName()).toString(), getSelf());
 999         }
1000     }
1001
1002     private void memberExited(final ClusterEvent.MemberExited message) {
1003         MemberName memberName = memberToName(message.member());
1004
1005         LOG.info("{}: Received MemberExited: memberName: {}, address: {}", persistenceId(), memberName,
1006                 message.member().address());
1007
1008         peerAddressResolver.removePeerAddress(memberName);
1009
1010         for (ShardInformation info : localShards.values()) {
1011             info.peerDown(memberName, getShardIdentifier(memberName, info.getShardName()).toString(), getSelf());
1012         }
1013     }
1014
1015     private void memberUp(final ClusterEvent.MemberUp message) {
1016         MemberName memberName = memberToName(message.member());
1017
1018         LOG.info("{}: Received MemberUp: memberName: {}, address: {}", persistenceId(), memberName,
1019                 message.member().address());
1020
1021         memberUp(memberName, message.member().address());
1022     }
1023
1024     private void memberUp(final MemberName memberName, final Address address) {
1025         addPeerAddress(memberName, address);
1026         checkReady();
1027     }
1028
1029     private void memberWeaklyUp(final MemberWeaklyUp message) {
1030         MemberName memberName = memberToName(message.member());
1031
1032         LOG.info("{}: Received MemberWeaklyUp: memberName: {}, address: {}", persistenceId(), memberName,
1033                 message.member().address());
1034
1035         memberUp(memberName, message.member().address());
1036     }
1037
1038     private void addPeerAddress(final MemberName memberName, final Address address) {
1039         peerAddressResolver.addPeerAddress(memberName, address);
1040
1041         for (ShardInformation info : localShards.values()) {
1042             String shardName = info.getShardName();
1043             String peerId = getShardIdentifier(memberName, shardName).toString();
1044             info.updatePeerAddress(peerId, peerAddressResolver.getShardActorAddress(shardName, memberName), getSelf());
1045
1046             info.peerUp(memberName, peerId, getSelf());
1047         }
1048     }
1049
1050     private void memberReachable(final ClusterEvent.ReachableMember message) {
1051         MemberName memberName = memberToName(message.member());
1052         LOG.info("Received ReachableMember: memberName {}, address: {}", memberName, message.member().address());
1053
1054         addPeerAddress(memberName, message.member().address());
1055
1056         markMemberAvailable(memberName);
1057     }
1058
1059     private void memberUnreachable(final ClusterEvent.UnreachableMember message) {
1060         MemberName memberName = memberToName(message.member());
1061         LOG.info("Received UnreachableMember: memberName {}, address: {}", memberName, message.member().address());
1062
1063         markMemberUnavailable(memberName);
1064     }
1065
1066     private void markMemberUnavailable(final MemberName memberName) {
1067         for (ShardInformation info : localShards.values()) {
1068             String leaderId = info.getLeaderId();
1069             if (leaderId != null && ShardIdentifier.fromShardIdString(leaderId).getMemberName().equals(memberName)) {
1070                 LOG.debug("Marking Leader {} as unavailable.", leaderId);
1071                 info.setLeaderAvailable(false);
1072
1073                 primaryShardInfoCache.remove(info.getShardName());
1074
1075                 notifyShardAvailabilityCallbacks(info);
1076             }
1077
1078             info.peerDown(memberName, getShardIdentifier(memberName, info.getShardName()).toString(), getSelf());
1079         }
1080     }
1081
1082     private void markMemberAvailable(final MemberName memberName) {
1083         for (ShardInformation info : localShards.values()) {
1084             String leaderId = info.getLeaderId();
1085             if (leaderId != null && ShardIdentifier.fromShardIdString(leaderId).getMemberName().equals(memberName)) {
1086                 LOG.debug("Marking Leader {} as available.", leaderId);
1087                 info.setLeaderAvailable(true);
1088             }
1089
1090             info.peerUp(memberName, getShardIdentifier(memberName, info.getShardName()).toString(), getSelf());
1091         }
1092     }
1093
1094     private void onDatastoreContextFactory(final DatastoreContextFactory factory) {
1095         datastoreContextFactory = factory;
1096         for (ShardInformation info : localShards.values()) {
1097             info.setDatastoreContext(newShardDatastoreContext(info.getShardName()), getSelf());
1098         }
1099     }
1100
1101     private void onGetLocalShardIds() {
1102         final List<String> response = new ArrayList<>(localShards.size());
1103
1104         for (ShardInformation info : localShards.values()) {
1105             response.add(info.getShardId().toString());
1106         }
1107
1108         getSender().tell(new Status.Success(response), getSelf());
1109     }
1110
1111     private void onSwitchShardBehavior(final SwitchShardBehavior message) {
1112         final ShardIdentifier identifier = message.getShardId();
1113
1114         if (identifier != null) {
1115             final ShardInformation info = localShards.get(identifier.getShardName());
1116             if (info == null) {
1117                 getSender().tell(new Status.Failure(
1118                     new IllegalArgumentException("Shard " + identifier + " is not local")), getSelf());
1119                 return;
1120             }
1121
1122             switchShardBehavior(info, new SwitchBehavior(message.getNewState(), message.getTerm()));
1123         } else {
1124             for (ShardInformation info : localShards.values()) {
1125                 switchShardBehavior(info, new SwitchBehavior(message.getNewState(), message.getTerm()));
1126             }
1127         }
1128
1129         getSender().tell(new Status.Success(null), getSelf());
1130     }
1131
1132     private void switchShardBehavior(final ShardInformation info, final SwitchBehavior switchBehavior) {
1133         final ActorRef actor = info.getActor();
1134         if (actor != null) {
1135             actor.tell(switchBehavior, getSelf());
1136         } else {
1137             LOG.warn("Could not switch the behavior of shard {} to {} - shard is not yet available",
1138                 info.getShardName(), switchBehavior.getNewState());
1139         }
1140     }
1141
1142     /**
1143      * Notifies all the local shards of a change in the schema context.
1144      *
1145      * @param message the message to send
1146      */
1147     private void updateSchemaContext(final Object message) {
1148         schemaContext = ((UpdateSchemaContext) message).getSchemaContext();
1149
1150         LOG.debug("Got updated SchemaContext: # of modules {}", schemaContext.getModules().size());
1151
1152         for (ShardInformation info : localShards.values()) {
1153             info.setSchemaContext(schemaContext);
1154
1155             if (info.getActor() == null) {
1156                 LOG.debug("Creating Shard {}", info.getShardId());
1157                 info.setActor(newShardActor(info));
1158                 // Update peer address for every existing peer memeber to avoid missing sending
1159                 // PeerAddressResolved and PeerUp to this shard while UpdateSchemaContext comes after MemberUp.
1160                 String shardName = info.getShardName();
1161                 for (MemberName memberName : peerAddressResolver.getPeerMembers()) {
1162                     String peerId = getShardIdentifier(memberName, shardName).toString() ;
1163                     String peerAddress = peerAddressResolver.getShardActorAddress(shardName, memberName);
1164                     info.updatePeerAddress(peerId, peerAddress, getSelf());
1165                     info.peerUp(memberName, peerId, getSelf());
1166                     LOG.debug("{}: updated peer {} on member {} with address {} on shard {} whose actor address is {}",
1167                             persistenceId(), peerId, memberName, peerAddress, info.getShardId(), info.getActor());
1168                 }
1169             } else {
1170                 info.getActor().tell(message, getSelf());
1171             }
1172         }
1173     }
1174
1175     @VisibleForTesting
1176     protected ClusterWrapper getCluster() {
1177         return cluster;
1178     }
1179
1180     @VisibleForTesting
1181     protected ActorRef newShardActor(final ShardInformation info) {
1182         return getContext().actorOf(info.newProps().withDispatcher(shardDispatcherPath),
1183                 info.getShardId().toString());
1184     }
1185
1186     private void findPrimary(final FindPrimary message) {
1187         LOG.debug("{}: In findPrimary: {}", persistenceId(), message);
1188
1189         final String shardName = message.getShardName();
1190         final boolean canReturnLocalShardState = !(message instanceof RemoteFindPrimary);
1191
1192         // First see if the there is a local replica for the shard
1193         final ShardInformation info = localShards.get(shardName);
1194         if (info != null && info.isActiveMember()) {
1195             sendResponse(info, message.isWaitUntilReady(), true, () -> {
1196                 String primaryPath = info.getSerializedLeaderActor();
1197                 Object found = canReturnLocalShardState && info.isLeader()
1198                         ? new LocalPrimaryShardFound(primaryPath, info.getLocalShardDataTree().get()) :
1199                             new RemotePrimaryShardFound(primaryPath, info.getLeaderVersion());
1200
1201                 LOG.debug("{}: Found primary for {}: {}", persistenceId(), shardName, found);
1202                 return found;
1203             });
1204
1205             return;
1206         }
1207
1208         final Collection<String> visitedAddresses;
1209         if (message instanceof RemoteFindPrimary) {
1210             visitedAddresses = ((RemoteFindPrimary)message).getVisitedAddresses();
1211         } else {
1212             visitedAddresses = new ArrayList<>(1);
1213         }
1214
1215         visitedAddresses.add(peerAddressResolver.getShardManagerActorPathBuilder(cluster.getSelfAddress()).toString());
1216
1217         for (String address: peerAddressResolver.getShardManagerPeerActorAddresses()) {
1218             if (visitedAddresses.contains(address)) {
1219                 continue;
1220             }
1221
1222             LOG.debug("{}: findPrimary for {} forwarding to remote ShardManager {}, visitedAddresses: {}",
1223                     persistenceId(), shardName, address, visitedAddresses);
1224
1225             getContext().actorSelection(address).forward(new RemoteFindPrimary(shardName,
1226                     message.isWaitUntilReady(), visitedAddresses), getContext());
1227             return;
1228         }
1229
1230         LOG.debug("{}: No shard found for {}", persistenceId(), shardName);
1231
1232         getSender().tell(new PrimaryNotFoundException(
1233                 String.format("No primary shard found for %s.", shardName)), getSelf());
1234     }
1235
1236     private void findPrimary(final String shardName, final FindPrimaryResponseHandler handler) {
1237         Timeout findPrimaryTimeout = new Timeout(datastoreContextFactory.getBaseDatastoreContext()
1238                 .getShardInitializationTimeout().duration().$times(2));
1239
1240         Future<Object> futureObj = ask(getSelf(), new FindPrimary(shardName, true), findPrimaryTimeout);
1241         futureObj.onComplete(new OnComplete<Object>() {
1242             @Override
1243             public void onComplete(final Throwable failure, final Object response) {
1244                 if (failure != null) {
1245                     handler.onFailure(failure);
1246                 } else {
1247                     if (response instanceof RemotePrimaryShardFound) {
1248                         handler.onRemotePrimaryShardFound((RemotePrimaryShardFound) response);
1249                     } else if (response instanceof LocalPrimaryShardFound) {
1250                         handler.onLocalPrimaryFound((LocalPrimaryShardFound) response);
1251                     } else {
1252                         handler.onUnknownResponse(response);
1253                     }
1254                 }
1255             }
1256         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1257     }
1258
1259     /**
1260      * Construct the name of the shard actor given the name of the member on
1261      * which the shard resides and the name of the shard.
1262      *
1263      * @param memberName the member name
1264      * @param shardName the shard name
1265      * @return a b
1266      */
1267     private ShardIdentifier getShardIdentifier(final MemberName memberName, final String shardName) {
1268         return peerAddressResolver.getShardIdentifier(memberName, shardName);
1269     }
1270
1271     /**
1272      * Create shards that are local to the member on which the ShardManager runs.
1273      */
1274     private void createLocalShards() {
1275         MemberName memberName = this.cluster.getCurrentMemberName();
1276         Collection<String> memberShardNames = this.configuration.getMemberShardNames(memberName);
1277
1278         Map<String, DatastoreSnapshot.ShardSnapshot> shardSnapshots = new HashMap<>();
1279         if (restoreFromSnapshot != null) {
1280             for (DatastoreSnapshot.ShardSnapshot snapshot: restoreFromSnapshot.getShardSnapshots()) {
1281                 shardSnapshots.put(snapshot.getName(), snapshot);
1282             }
1283         }
1284
1285         // null out to GC
1286         restoreFromSnapshot = null;
1287
1288         for (String shardName : memberShardNames) {
1289             ShardIdentifier shardId = getShardIdentifier(memberName, shardName);
1290
1291             LOG.debug("{}: Creating local shard: {}", persistenceId(), shardId);
1292
1293             Map<String, String> peerAddresses = getPeerAddresses(shardName);
1294             localShards.put(shardName, new ShardInformation(shardName, shardId, peerAddresses,
1295                     newShardDatastoreContext(shardName), Shard.builder().restoreFromSnapshot(
1296                         shardSnapshots.get(shardName)), peerAddressResolver));
1297         }
1298     }
1299
1300     /**
1301      * Given the name of the shard find the addresses of all it's peers.
1302      *
1303      * @param shardName the shard name
1304      */
1305     private Map<String, String> getPeerAddresses(final String shardName) {
1306         final Collection<MemberName> members = configuration.getMembersFromShardName(shardName);
1307         return getPeerAddresses(shardName, members);
1308     }
1309
1310     private Map<String, String> getPeerAddresses(final String shardName, final Collection<MemberName> members) {
1311         Map<String, String> peerAddresses = new HashMap<>();
1312         MemberName currentMemberName = this.cluster.getCurrentMemberName();
1313
1314         for (MemberName memberName : members) {
1315             if (!currentMemberName.equals(memberName)) {
1316                 ShardIdentifier shardId = getShardIdentifier(memberName, shardName);
1317                 String address = peerAddressResolver.getShardActorAddress(shardName, memberName);
1318                 peerAddresses.put(shardId.toString(), address);
1319             }
1320         }
1321         return peerAddresses;
1322     }
1323
1324     @Override
1325     public SupervisorStrategy supervisorStrategy() {
1326
1327         return new OneForOneStrategy(10, Duration.create("1 minute"),
1328                 (Function<Throwable, Directive>) t -> {
1329                     LOG.warn("Supervisor Strategy caught unexpected exception - resuming", t);
1330                     return SupervisorStrategy.resume();
1331                 });
1332     }
1333
1334     @Override
1335     public String persistenceId() {
1336         return persistenceId;
1337     }
1338
1339     @VisibleForTesting
1340     ShardManagerInfoMBean getMBean() {
1341         return shardManagerMBean;
1342     }
1343
1344     private boolean isShardReplicaOperationInProgress(final String shardName, final ActorRef sender) {
1345         if (shardReplicaOperationsInProgress.contains(shardName)) {
1346             String msg = String.format("A shard replica operation for %s is already in progress", shardName);
1347             LOG.debug("{}: {}", persistenceId(), msg);
1348             sender.tell(new Status.Failure(new IllegalStateException(msg)), getSelf());
1349             return true;
1350         }
1351
1352         return false;
1353     }
1354
1355     private void onAddPrefixShardReplica(final AddPrefixShardReplica message) {
1356         LOG.debug("{}: onAddPrefixShardReplica: {}", persistenceId(), message);
1357
1358         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(),
1359                 ClusterUtils.getCleanShardName(message.getShardPrefix()));
1360         final String shardName = shardId.getShardName();
1361
1362         // Create the localShard
1363         if (schemaContext == null) {
1364             String msg = String.format(
1365                     "No SchemaContext is available in order to create a local shard instance for %s", shardName);
1366             LOG.debug("{}: {}", persistenceId(), msg);
1367             getSender().tell(new Status.Failure(new IllegalStateException(msg)), getSelf());
1368             return;
1369         }
1370
1371         findPrimary(shardName, new AutoFindPrimaryFailureResponseHandler(getSender(), shardName, persistenceId(),
1372                 getSelf()) {
1373             @Override
1374             public void onRemotePrimaryShardFound(final RemotePrimaryShardFound response) {
1375                 final RunnableMessage runnable = (RunnableMessage) () -> addPrefixShard(getShardName(),
1376                         message.getShardPrefix(), response, getSender());
1377                 if (!isPreviousShardActorStopInProgress(getShardName(), runnable)) {
1378                     getSelf().tell(runnable, getTargetActor());
1379                 }
1380             }
1381
1382             @Override
1383             public void onLocalPrimaryFound(final LocalPrimaryShardFound message) {
1384                 sendLocalReplicaAlreadyExistsReply(getShardName(), getTargetActor());
1385             }
1386         });
1387     }
1388
1389     private void onAddShardReplica(final AddShardReplica shardReplicaMsg) {
1390         final String shardName = shardReplicaMsg.getShardName();
1391
1392         LOG.debug("{}: onAddShardReplica: {}", persistenceId(), shardReplicaMsg);
1393
1394         // verify the shard with the specified name is present in the cluster configuration
1395         if (!this.configuration.isShardConfigured(shardName)) {
1396             String msg = String.format("No module configuration exists for shard %s", shardName);
1397             LOG.debug("{}: {}", persistenceId(), msg);
1398             getSender().tell(new Status.Failure(new IllegalArgumentException(msg)), getSelf());
1399             return;
1400         }
1401
1402         // Create the localShard
1403         if (schemaContext == null) {
1404             String msg = String.format(
1405                   "No SchemaContext is available in order to create a local shard instance for %s", shardName);
1406             LOG.debug("{}: {}", persistenceId(), msg);
1407             getSender().tell(new Status.Failure(new IllegalStateException(msg)), getSelf());
1408             return;
1409         }
1410
1411         findPrimary(shardName, new AutoFindPrimaryFailureResponseHandler(getSender(), shardName, persistenceId(),
1412                 getSelf()) {
1413             @Override
1414             public void onRemotePrimaryShardFound(final RemotePrimaryShardFound response) {
1415                 final RunnableMessage runnable = (RunnableMessage) () ->
1416                     addShard(getShardName(), response, getSender());
1417                 if (!isPreviousShardActorStopInProgress(getShardName(), runnable)) {
1418                     getSelf().tell(runnable, getTargetActor());
1419                 }
1420             }
1421
1422             @Override
1423             public void onLocalPrimaryFound(final LocalPrimaryShardFound message) {
1424                 sendLocalReplicaAlreadyExistsReply(getShardName(), getTargetActor());
1425             }
1426         });
1427     }
1428
1429     private void sendLocalReplicaAlreadyExistsReply(final String shardName, final ActorRef sender) {
1430         String msg = String.format("Local shard %s already exists", shardName);
1431         LOG.debug("{}: {}", persistenceId(), msg);
1432         sender.tell(new Status.Failure(new AlreadyExistsException(msg)), getSelf());
1433     }
1434
1435     private void addPrefixShard(final String shardName, final YangInstanceIdentifier shardPrefix,
1436                                 final RemotePrimaryShardFound response, final ActorRef sender) {
1437         if (isShardReplicaOperationInProgress(shardName, sender)) {
1438             return;
1439         }
1440
1441         shardReplicaOperationsInProgress.add(shardName);
1442
1443         final ShardInformation shardInfo;
1444         final boolean removeShardOnFailure;
1445         ShardInformation existingShardInfo = localShards.get(shardName);
1446         if (existingShardInfo == null) {
1447             removeShardOnFailure = true;
1448             ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
1449
1450             final Builder builder = newShardDatastoreContextBuilder(shardName);
1451             builder.storeRoot(shardPrefix).customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName());
1452
1453             DatastoreContext datastoreContext = builder.build();
1454
1455             shardInfo = new ShardInformation(shardName, shardId, getPeerAddresses(shardName), datastoreContext,
1456                     Shard.builder(), peerAddressResolver);
1457             shardInfo.setActiveMember(false);
1458             shardInfo.setSchemaContext(schemaContext);
1459             localShards.put(shardName, shardInfo);
1460             shardInfo.setActor(newShardActor(shardInfo));
1461         } else {
1462             removeShardOnFailure = false;
1463             shardInfo = existingShardInfo;
1464         }
1465
1466         execAddShard(shardName, shardInfo, response, removeShardOnFailure, sender);
1467     }
1468
1469     private void addShard(final String shardName, final RemotePrimaryShardFound response, final ActorRef sender) {
1470         if (isShardReplicaOperationInProgress(shardName, sender)) {
1471             return;
1472         }
1473
1474         shardReplicaOperationsInProgress.add(shardName);
1475
1476         final ShardInformation shardInfo;
1477         final boolean removeShardOnFailure;
1478         ShardInformation existingShardInfo = localShards.get(shardName);
1479         if (existingShardInfo == null) {
1480             removeShardOnFailure = true;
1481             ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
1482
1483             DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName)
1484                     .customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName()).build();
1485
1486             shardInfo = new ShardInformation(shardName, shardId, getPeerAddresses(shardName), datastoreContext,
1487                     Shard.builder(), peerAddressResolver);
1488             shardInfo.setActiveMember(false);
1489             shardInfo.setSchemaContext(schemaContext);
1490             localShards.put(shardName, shardInfo);
1491             shardInfo.setActor(newShardActor(shardInfo));
1492         } else {
1493             removeShardOnFailure = false;
1494             shardInfo = existingShardInfo;
1495         }
1496
1497         execAddShard(shardName, shardInfo, response, removeShardOnFailure, sender);
1498     }
1499
1500     private void execAddShard(final String shardName,
1501                               final ShardInformation shardInfo,
1502                               final RemotePrimaryShardFound response,
1503                               final boolean removeShardOnFailure,
1504                               final ActorRef sender) {
1505
1506         final String localShardAddress =
1507                 peerAddressResolver.getShardActorAddress(shardName, cluster.getCurrentMemberName());
1508
1509         //inform ShardLeader to add this shard as a replica by sending an AddServer message
1510         LOG.debug("{}: Sending AddServer message to peer {} for shard {}", persistenceId(),
1511                 response.getPrimaryPath(), shardInfo.getShardId());
1512
1513         final Timeout addServerTimeout = new Timeout(shardInfo.getDatastoreContext()
1514                 .getShardLeaderElectionTimeout().duration());
1515         final Future<Object> futureObj = ask(getContext().actorSelection(response.getPrimaryPath()),
1516                 new AddServer(shardInfo.getShardId().toString(), localShardAddress, true), addServerTimeout);
1517
1518         futureObj.onComplete(new OnComplete<Object>() {
1519             @Override
1520             public void onComplete(final Throwable failure, final Object addServerResponse) {
1521                 if (failure != null) {
1522                     LOG.debug("{}: AddServer request to {} for {} failed", persistenceId(),
1523                             response.getPrimaryPath(), shardName, failure);
1524
1525                     final String msg = String.format("AddServer request to leader %s for shard %s failed",
1526                             response.getPrimaryPath(), shardName);
1527                     self().tell(new ForwardedAddServerFailure(shardName, msg, failure, removeShardOnFailure), sender);
1528                 } else {
1529                     self().tell(new ForwardedAddServerReply(shardInfo, (AddServerReply)addServerResponse,
1530                             response.getPrimaryPath(), removeShardOnFailure), sender);
1531                 }
1532             }
1533         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1534     }
1535
1536     private void onAddServerFailure(final String shardName, final String message, final Throwable failure,
1537             final ActorRef sender, final boolean removeShardOnFailure) {
1538         shardReplicaOperationsInProgress.remove(shardName);
1539
1540         if (removeShardOnFailure) {
1541             ShardInformation shardInfo = localShards.remove(shardName);
1542             if (shardInfo.getActor() != null) {
1543                 shardInfo.getActor().tell(PoisonPill.getInstance(), getSelf());
1544             }
1545         }
1546
1547         sender.tell(new Status.Failure(message == null ? failure :
1548             new RuntimeException(message, failure)), getSelf());
1549     }
1550
1551     private void onAddServerReply(final ShardInformation shardInfo, final AddServerReply replyMsg,
1552             final ActorRef sender, final String leaderPath, final boolean removeShardOnFailure) {
1553         String shardName = shardInfo.getShardName();
1554         shardReplicaOperationsInProgress.remove(shardName);
1555
1556         LOG.debug("{}: Received {} for shard {} from leader {}", persistenceId(), replyMsg, shardName, leaderPath);
1557
1558         if (replyMsg.getStatus() == ServerChangeStatus.OK) {
1559             LOG.debug("{}: Leader shard successfully added the replica shard {}", persistenceId(), shardName);
1560
1561             // Make the local shard voting capable
1562             shardInfo.setDatastoreContext(newShardDatastoreContext(shardName), getSelf());
1563             shardInfo.setActiveMember(true);
1564             persistShardList();
1565
1566             sender.tell(new Status.Success(null), getSelf());
1567         } else if (replyMsg.getStatus() == ServerChangeStatus.ALREADY_EXISTS) {
1568             sendLocalReplicaAlreadyExistsReply(shardName, sender);
1569         } else {
1570             LOG.warn("{}: Leader failed to add shard replica {} with status {}",
1571                     persistenceId(), shardName, replyMsg.getStatus());
1572
1573             Exception failure = getServerChangeException(AddServer.class, replyMsg.getStatus(), leaderPath,
1574                     shardInfo.getShardId());
1575
1576             onAddServerFailure(shardName, null, failure, sender, removeShardOnFailure);
1577         }
1578     }
1579
1580     private static Exception getServerChangeException(final Class<?> serverChange,
1581             final ServerChangeStatus serverChangeStatus, final String leaderPath, final ShardIdentifier shardId) {
1582         switch (serverChangeStatus) {
1583             case TIMEOUT:
1584                 return new TimeoutException(String.format(
1585                         "The shard leader %s timed out trying to replicate the initial data to the new shard %s."
1586                         + "Possible causes - there was a problem replicating the data or shard leadership changed "
1587                         + "while replicating the shard data", leaderPath, shardId.getShardName()));
1588             case NO_LEADER:
1589                 return createNoShardLeaderException(shardId);
1590             case NOT_SUPPORTED:
1591                 return new UnsupportedOperationException(String.format("%s request is not supported for shard %s",
1592                         serverChange.getSimpleName(), shardId.getShardName()));
1593             default :
1594                 return new RuntimeException(String.format("%s request to leader %s for shard %s failed with status %s",
1595                         serverChange.getSimpleName(), leaderPath, shardId.getShardName(), serverChangeStatus));
1596         }
1597     }
1598
1599     private void onRemoveShardReplica(final RemoveShardReplica shardReplicaMsg) {
1600         LOG.debug("{}: onRemoveShardReplica: {}", persistenceId(), shardReplicaMsg);
1601
1602         findPrimary(shardReplicaMsg.getShardName(), new AutoFindPrimaryFailureResponseHandler(getSender(),
1603                 shardReplicaMsg.getShardName(), persistenceId(), getSelf()) {
1604             @Override
1605             public void onRemotePrimaryShardFound(final RemotePrimaryShardFound response) {
1606                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1607             }
1608
1609             @Override
1610             public void onLocalPrimaryFound(final LocalPrimaryShardFound response) {
1611                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1612             }
1613
1614             private void doRemoveShardReplicaAsync(final String primaryPath) {
1615                 getSelf().tell((RunnableMessage) () -> removeShardReplica(shardReplicaMsg, getShardName(),
1616                         primaryPath, getSender()), getTargetActor());
1617             }
1618         });
1619     }
1620
1621     private void onRemovePrefixShardReplica(final RemovePrefixShardReplica message) {
1622         LOG.debug("{}: onRemovePrefixShardReplica: {}", persistenceId(), message);
1623
1624         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(),
1625                 ClusterUtils.getCleanShardName(message.getShardPrefix()));
1626         final String shardName = shardId.getShardName();
1627
1628         findPrimary(shardName, new AutoFindPrimaryFailureResponseHandler(getSender(),
1629                 shardName, persistenceId(), getSelf()) {
1630             @Override
1631             public void onRemotePrimaryShardFound(final RemotePrimaryShardFound response) {
1632                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1633             }
1634
1635             @Override
1636             public void onLocalPrimaryFound(final LocalPrimaryShardFound response) {
1637                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1638             }
1639
1640             private void doRemoveShardReplicaAsync(final String primaryPath) {
1641                 getSelf().tell((RunnableMessage) () -> removePrefixShardReplica(message, getShardName(),
1642                         primaryPath, getSender()), getTargetActor());
1643             }
1644         });
1645     }
1646
1647     private void persistShardList() {
1648         List<String> shardList = new ArrayList<>(localShards.keySet());
1649         for (ShardInformation shardInfo : localShards.values()) {
1650             if (!shardInfo.isActiveMember()) {
1651                 shardList.remove(shardInfo.getShardName());
1652             }
1653         }
1654         LOG.debug("{}: persisting the shard list {}", persistenceId(), shardList);
1655         saveSnapshot(updateShardManagerSnapshot(shardList, configuration.getAllPrefixShardConfigurations()));
1656     }
1657
1658     private ShardManagerSnapshot updateShardManagerSnapshot(
1659             final List<String> shardList,
1660             final Map<DOMDataTreeIdentifier, PrefixShardConfiguration> allPrefixShardConfigurations) {
1661         currentSnapshot = new ShardManagerSnapshot(shardList, allPrefixShardConfigurations);
1662         return currentSnapshot;
1663     }
1664
1665     private void applyShardManagerSnapshot(final ShardManagerSnapshot snapshot) {
1666         currentSnapshot = snapshot;
1667
1668         LOG.debug("{}: onSnapshotOffer: {}", persistenceId(), currentSnapshot);
1669
1670         final MemberName currentMember = cluster.getCurrentMemberName();
1671         Set<String> configuredShardList =
1672             new HashSet<>(configuration.getMemberShardNames(currentMember));
1673         for (String shard : currentSnapshot.getShardList()) {
1674             if (!configuredShardList.contains(shard)) {
1675                 // add the current member as a replica for the shard
1676                 LOG.debug("{}: adding shard {}", persistenceId(), shard);
1677                 configuration.addMemberReplicaForShard(shard, currentMember);
1678             } else {
1679                 configuredShardList.remove(shard);
1680             }
1681         }
1682         for (String shard : configuredShardList) {
1683             // remove the member as a replica for the shard
1684             LOG.debug("{}: removing shard {}", persistenceId(), shard);
1685             configuration.removeMemberReplicaForShard(shard, currentMember);
1686         }
1687     }
1688
1689     private void onSaveSnapshotSuccess(final SaveSnapshotSuccess successMessage) {
1690         LOG.debug("{} saved ShardManager snapshot successfully. Deleting the prev snapshot if available",
1691             persistenceId());
1692         deleteSnapshots(new SnapshotSelectionCriteria(scala.Long.MaxValue(), successMessage.metadata().timestamp() - 1,
1693             0, 0));
1694     }
1695
1696     private void onChangeShardServersVotingStatus(final ChangeShardMembersVotingStatus changeMembersVotingStatus) {
1697         LOG.debug("{}: onChangeShardServersVotingStatus: {}", persistenceId(), changeMembersVotingStatus);
1698
1699         String shardName = changeMembersVotingStatus.getShardName();
1700         Map<String, Boolean> serverVotingStatusMap = new HashMap<>();
1701         for (Entry<String, Boolean> e: changeMembersVotingStatus.getMeberVotingStatusMap().entrySet()) {
1702             serverVotingStatusMap.put(getShardIdentifier(MemberName.forName(e.getKey()), shardName).toString(),
1703                     e.getValue());
1704         }
1705
1706         ChangeServersVotingStatus changeServersVotingStatus = new ChangeServersVotingStatus(serverVotingStatusMap);
1707
1708         findLocalShard(shardName, getSender(),
1709             localShardFound -> changeShardMembersVotingStatus(changeServersVotingStatus, shardName,
1710             localShardFound.getPath(), getSender()));
1711     }
1712
1713     private void onFlipShardMembersVotingStatus(final FlipShardMembersVotingStatus flipMembersVotingStatus) {
1714         LOG.debug("{}: onFlipShardMembersVotingStatus: {}", persistenceId(), flipMembersVotingStatus);
1715
1716         ActorRef sender = getSender();
1717         final String shardName = flipMembersVotingStatus.getShardName();
1718         findLocalShard(shardName, sender, localShardFound -> {
1719             Future<Object> future = ask(localShardFound.getPath(), GetOnDemandRaftState.INSTANCE,
1720                     Timeout.apply(30, TimeUnit.SECONDS));
1721
1722             future.onComplete(new OnComplete<Object>() {
1723                 @Override
1724                 public void onComplete(final Throwable failure, final Object response) {
1725                     if (failure != null) {
1726                         sender.tell(new Status.Failure(new RuntimeException(
1727                                 String.format("Failed to access local shard %s", shardName), failure)), self());
1728                         return;
1729                     }
1730
1731                     OnDemandRaftState raftState = (OnDemandRaftState) response;
1732                     Map<String, Boolean> serverVotingStatusMap = new HashMap<>();
1733                     for (Entry<String, Boolean> e: raftState.getPeerVotingStates().entrySet()) {
1734                         serverVotingStatusMap.put(e.getKey(), !e.getValue());
1735                     }
1736
1737                     serverVotingStatusMap.put(getShardIdentifier(cluster.getCurrentMemberName(), shardName)
1738                             .toString(), !raftState.isVoting());
1739
1740                     changeShardMembersVotingStatus(new ChangeServersVotingStatus(serverVotingStatusMap),
1741                             shardName, localShardFound.getPath(), sender);
1742                 }
1743             }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1744         });
1745
1746     }
1747
1748     private void findLocalShard(final FindLocalShard message) {
1749         LOG.debug("{}: findLocalShard : {}", persistenceId(), message.getShardName());
1750
1751         final ShardInformation shardInformation = localShards.get(message.getShardName());
1752
1753         if (shardInformation == null) {
1754             LOG.debug("{}: Local shard {} not found - shards present: {}",
1755                     persistenceId(), message.getShardName(), localShards.keySet());
1756
1757             getSender().tell(new LocalShardNotFound(message.getShardName()), getSelf());
1758             return;
1759         }
1760
1761         sendResponse(shardInformation, message.isWaitUntilInitialized(), false,
1762             () -> new LocalShardFound(shardInformation.getActor()));
1763     }
1764
1765     private void findLocalShard(final String shardName, final ActorRef sender,
1766             final Consumer<LocalShardFound> onLocalShardFound) {
1767         Timeout findLocalTimeout = new Timeout(datastoreContextFactory.getBaseDatastoreContext()
1768                 .getShardInitializationTimeout().duration().$times(2));
1769
1770         Future<Object> futureObj = ask(getSelf(), new FindLocalShard(shardName, true), findLocalTimeout);
1771         futureObj.onComplete(new OnComplete<Object>() {
1772             @Override
1773             public void onComplete(final Throwable failure, final Object response) {
1774                 if (failure != null) {
1775                     LOG.debug("{}: Received failure from FindLocalShard for shard {}", persistenceId, shardName,
1776                             failure);
1777                     sender.tell(new Status.Failure(new RuntimeException(
1778                             String.format("Failed to find local shard %s", shardName), failure)), self());
1779                 } else {
1780                     if (response instanceof LocalShardFound) {
1781                         getSelf().tell((RunnableMessage) () -> onLocalShardFound.accept((LocalShardFound) response),
1782                                 sender);
1783                     } else if (response instanceof LocalShardNotFound) {
1784                         String msg = String.format("Local shard %s does not exist", shardName);
1785                         LOG.debug("{}: {}", persistenceId, msg);
1786                         sender.tell(new Status.Failure(new IllegalArgumentException(msg)), self());
1787                     } else {
1788                         String msg = String.format("Failed to find local shard %s: received response: %s",
1789                                 shardName, response);
1790                         LOG.debug("{}: {}", persistenceId, msg);
1791                         sender.tell(new Status.Failure(response instanceof Throwable ? (Throwable) response :
1792                                 new RuntimeException(msg)), self());
1793                     }
1794                 }
1795             }
1796         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1797     }
1798
1799     private void changeShardMembersVotingStatus(final ChangeServersVotingStatus changeServersVotingStatus,
1800             final String shardName, final ActorRef shardActorRef, final ActorRef sender) {
1801         if (isShardReplicaOperationInProgress(shardName, sender)) {
1802             return;
1803         }
1804
1805         shardReplicaOperationsInProgress.add(shardName);
1806
1807         DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName).build();
1808         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
1809
1810         LOG.debug("{}: Sending ChangeServersVotingStatus message {} to local shard {}", persistenceId(),
1811                 changeServersVotingStatus, shardActorRef.path());
1812
1813         Timeout timeout = new Timeout(datastoreContext.getShardLeaderElectionTimeout().duration().$times(2));
1814         Future<Object> futureObj = ask(shardActorRef, changeServersVotingStatus, timeout);
1815
1816         futureObj.onComplete(new OnComplete<Object>() {
1817             @Override
1818             public void onComplete(final Throwable failure, final Object response) {
1819                 shardReplicaOperationsInProgress.remove(shardName);
1820                 if (failure != null) {
1821                     String msg = String.format("ChangeServersVotingStatus request to local shard %s failed",
1822                             shardActorRef.path());
1823                     LOG.debug("{}: {}", persistenceId(), msg, failure);
1824                     sender.tell(new Status.Failure(new RuntimeException(msg, failure)), self());
1825                 } else {
1826                     LOG.debug("{}: Received {} from local shard {}", persistenceId(), response, shardActorRef.path());
1827
1828                     ServerChangeReply replyMsg = (ServerChangeReply) response;
1829                     if (replyMsg.getStatus() == ServerChangeStatus.OK) {
1830                         LOG.debug("{}: ChangeServersVotingStatus succeeded for shard {}", persistenceId(), shardName);
1831                         sender.tell(new Status.Success(null), getSelf());
1832                     } else if (replyMsg.getStatus() == ServerChangeStatus.INVALID_REQUEST) {
1833                         sender.tell(new Status.Failure(new IllegalArgumentException(String.format(
1834                                 "The requested voting state change for shard %s is invalid. At least one member "
1835                                 + "must be voting", shardId.getShardName()))), getSelf());
1836                     } else {
1837                         LOG.warn("{}: ChangeServersVotingStatus failed for shard {} with status {}",
1838                                 persistenceId(), shardName, replyMsg.getStatus());
1839
1840                         Exception error = getServerChangeException(ChangeServersVotingStatus.class,
1841                                 replyMsg.getStatus(), shardActorRef.path().toString(), shardId);
1842                         sender.tell(new Status.Failure(error), getSelf());
1843                     }
1844                 }
1845             }
1846         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1847     }
1848
1849     private static final class ForwardedAddServerReply {
1850         ShardInformation shardInfo;
1851         AddServerReply addServerReply;
1852         String leaderPath;
1853         boolean removeShardOnFailure;
1854
1855         ForwardedAddServerReply(final ShardInformation shardInfo, final AddServerReply addServerReply,
1856             final String leaderPath, final boolean removeShardOnFailure) {
1857             this.shardInfo = shardInfo;
1858             this.addServerReply = addServerReply;
1859             this.leaderPath = leaderPath;
1860             this.removeShardOnFailure = removeShardOnFailure;
1861         }
1862     }
1863
1864     private static final class ForwardedAddServerFailure {
1865         String shardName;
1866         String failureMessage;
1867         Throwable failure;
1868         boolean removeShardOnFailure;
1869
1870         ForwardedAddServerFailure(final String shardName, final String failureMessage, final Throwable failure,
1871                 final boolean removeShardOnFailure) {
1872             this.shardName = shardName;
1873             this.failureMessage = failureMessage;
1874             this.failure = failure;
1875             this.removeShardOnFailure = removeShardOnFailure;
1876         }
1877     }
1878
1879     static class OnShardInitialized {
1880         private final Runnable replyRunnable;
1881         private Cancellable timeoutSchedule;
1882
1883         OnShardInitialized(final Runnable replyRunnable) {
1884             this.replyRunnable = replyRunnable;
1885         }
1886
1887         Runnable getReplyRunnable() {
1888             return replyRunnable;
1889         }
1890
1891         Cancellable getTimeoutSchedule() {
1892             return timeoutSchedule;
1893         }
1894
1895         void setTimeoutSchedule(final Cancellable timeoutSchedule) {
1896             this.timeoutSchedule = timeoutSchedule;
1897         }
1898     }
1899
1900     static class OnShardReady extends OnShardInitialized {
1901         OnShardReady(final Runnable replyRunnable) {
1902             super(replyRunnable);
1903         }
1904     }
1905
1906     private interface RunnableMessage extends Runnable {
1907     }
1908
1909     /**
1910      * The FindPrimaryResponseHandler provides specific callback methods which are invoked when a response to the
1911      * a remote or local find primary message is processed.
1912      */
1913     private interface FindPrimaryResponseHandler {
1914         /**
1915          * Invoked when a Failure message is received as a response.
1916          *
1917          * @param failure the failure exception
1918          */
1919         void onFailure(Throwable failure);
1920
1921         /**
1922          * Invoked when a RemotePrimaryShardFound response is received.
1923          *
1924          * @param response the response
1925          */
1926         void onRemotePrimaryShardFound(RemotePrimaryShardFound response);
1927
1928         /**
1929          * Invoked when a LocalPrimaryShardFound response is received.
1930          *
1931          * @param response the response
1932          */
1933         void onLocalPrimaryFound(LocalPrimaryShardFound response);
1934
1935         /**
1936          * Invoked when an unknown response is received. This is another type of failure.
1937          *
1938          * @param response the response
1939          */
1940         void onUnknownResponse(Object response);
1941     }
1942
1943     /**
1944      * The AutoFindPrimaryFailureResponseHandler automatically processes Failure responses when finding a primary
1945      * replica and sends a wrapped Failure response to some targetActor.
1946      */
1947     private abstract static class AutoFindPrimaryFailureResponseHandler implements FindPrimaryResponseHandler {
1948         private final ActorRef targetActor;
1949         private final String shardName;
1950         private final String persistenceId;
1951         private final ActorRef shardManagerActor;
1952
1953         /**
1954          * Constructs an instance.
1955          *
1956          * @param targetActor The actor to whom the Failure response should be sent when a FindPrimary failure occurs
1957          * @param shardName The name of the shard for which the primary replica had to be found
1958          * @param persistenceId The persistenceId for the ShardManager
1959          * @param shardManagerActor The ShardManager actor which triggered the call to FindPrimary
1960          */
1961         protected AutoFindPrimaryFailureResponseHandler(final ActorRef targetActor, final String shardName,
1962                 final String persistenceId, final ActorRef shardManagerActor) {
1963             this.targetActor = Preconditions.checkNotNull(targetActor);
1964             this.shardName = Preconditions.checkNotNull(shardName);
1965             this.persistenceId = Preconditions.checkNotNull(persistenceId);
1966             this.shardManagerActor = Preconditions.checkNotNull(shardManagerActor);
1967         }
1968
1969         public ActorRef getTargetActor() {
1970             return targetActor;
1971         }
1972
1973         public String getShardName() {
1974             return shardName;
1975         }
1976
1977         @Override
1978         public void onFailure(final Throwable failure) {
1979             LOG.debug("{}: Received failure from FindPrimary for shard {}", persistenceId, shardName, failure);
1980             targetActor.tell(new Status.Failure(new RuntimeException(
1981                     String.format("Failed to find leader for shard %s", shardName), failure)), shardManagerActor);
1982         }
1983
1984         @Override
1985         public void onUnknownResponse(final Object response) {
1986             String msg = String.format("Failed to find leader for shard %s: received response: %s",
1987                     shardName, response);
1988             LOG.debug("{}: {}", persistenceId, msg);
1989             targetActor.tell(new Status.Failure(response instanceof Throwable ? (Throwable) response :
1990                     new RuntimeException(msg)), shardManagerActor);
1991         }
1992     }
1993
1994     /**
1995      * The WrappedShardResponse class wraps a response from a Shard.
1996      */
1997     private static final class WrappedShardResponse {
1998         private final ShardIdentifier shardId;
1999         private final Object response;
2000         private final String leaderPath;
2001
2002         WrappedShardResponse(final ShardIdentifier shardId, final Object response, final String leaderPath) {
2003             this.shardId = shardId;
2004             this.response = response;
2005             this.leaderPath = leaderPath;
2006         }
2007
2008         ShardIdentifier getShardId() {
2009             return shardId;
2010         }
2011
2012         Object getResponse() {
2013             return response;
2014         }
2015
2016         String getLeaderPath() {
2017             return leaderPath;
2018         }
2019     }
2020
2021     private static final class ShardNotInitializedTimeout {
2022         private final ActorRef sender;
2023         private final ShardInformation shardInfo;
2024         private final OnShardInitialized onShardInitialized;
2025
2026         ShardNotInitializedTimeout(final ShardInformation shardInfo, final OnShardInitialized onShardInitialized,
2027             final ActorRef sender) {
2028             this.sender = sender;
2029             this.shardInfo = shardInfo;
2030             this.onShardInitialized = onShardInitialized;
2031         }
2032
2033         ActorRef getSender() {
2034             return sender;
2035         }
2036
2037         ShardInformation getShardInfo() {
2038             return shardInfo;
2039         }
2040
2041         OnShardInitialized getOnShardInitialized() {
2042             return onShardInitialized;
2043         }
2044     }
2045 }
2046
2047
2048