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.FiniteDuration;
 126
 127 /**
 128  * Manages the shards for a data store. The ShardManager has the following jobs:
 129  * <ul>
 130  * <li> Create all the local shard replicas that belong on this cluster member
 131  * <li> Find the address of the local shard
 132  * <li> Find the primary replica for any given shard
 133  * <li> Monitor the cluster members and store their addresses
 134  * </ul>
 135  */
 136 class ShardManager extends AbstractUntypedPersistentActorWithMetering {
 137     private static final Logger LOG = LoggerFactory.getLogger(ShardManager.class);
 138
 139     // Stores a mapping between a shard name and it's corresponding information
 140     // Shard names look like inventory, topology etc and are as specified in
 141     // configuration
 142     private final Map<String, ShardInformation> localShards = new HashMap<>();
 143
 144     // The type of a ShardManager reflects the type of the datastore itself
 145     // A data store could be of type config/operational
 146     private final String type;
 147
 148     private final ClusterWrapper cluster;
 149
 150     private final Configuration configuration;
 151
 152     private final String shardDispatcherPath;
 153
 154     private final ShardManagerInfo shardManagerMBean;
 155
 156     private DatastoreContextFactory datastoreContextFactory;
 157
 158     private final CountDownLatch waitTillReadyCountdownLatch;
 159
 160     private final PrimaryShardInfoFutureCache primaryShardInfoCache;
 161
 162     private final ShardPeerAddressResolver peerAddressResolver;
 163
 164     private SchemaContext schemaContext;
 165
 166     private DatastoreSnapshot restoreFromSnapshot;
 167
 168     private ShardManagerSnapshot currentSnapshot;
 169
 170     private final Set<String> shardReplicaOperationsInProgress = new HashSet<>();
 171
 172     private final Map<String, CompositeOnComplete<Boolean>> shardActorsStopping = new HashMap<>();
 173
 174     private final Set<Consumer<String>> shardAvailabilityCallbacks = new HashSet<>();
 175
 176     private final String persistenceId;
 177     private final AbstractDataStore dataStore;
 178
 179     private ListenerRegistration<DOMDataTreeChangeListener> configListenerReg = null;
 180     private PrefixedShardConfigUpdateHandler configUpdateHandler;
 181
 182     ShardManager(final AbstractShardManagerCreator<?> builder) {
 183         this.cluster = builder.getCluster();
 184         this.configuration = builder.getConfiguration();
 185         this.datastoreContextFactory = builder.getDatastoreContextFactory();
 186         this.type = datastoreContextFactory.getBaseDatastoreContext().getDataStoreName();
 187         this.shardDispatcherPath =
 188                 new Dispatchers(context().system().dispatchers()).getDispatcherPath(Dispatchers.DispatcherType.Shard);
 189         this.waitTillReadyCountdownLatch = builder.getWaitTillReadyCountDownLatch();
 190         this.primaryShardInfoCache = builder.getPrimaryShardInfoCache();
 191         this.restoreFromSnapshot = builder.getRestoreFromSnapshot();
 192
 193         String possiblePersistenceId = datastoreContextFactory.getBaseDatastoreContext().getShardManagerPersistenceId();
 194         persistenceId = possiblePersistenceId != null ? possiblePersistenceId : "shard-manager-" + type;
 195
 196         peerAddressResolver = new ShardPeerAddressResolver(type, cluster.getCurrentMemberName());
 197
 198         // Subscribe this actor to cluster member events
 199         cluster.subscribeToMemberEvents(getSelf());
 200
 201         shardManagerMBean = new ShardManagerInfo(getSelf(), cluster.getCurrentMemberName(),
 202                 "shard-manager-" + this.type,
 203                 datastoreContextFactory.getBaseDatastoreContext().getDataStoreMXBeanType());
 204         shardManagerMBean.registerMBean();
 205
 206         dataStore = builder.getDistributedDataStore();
 207     }
 208
 209     @Override
 210     public void preStart() {
 211         LOG.info("Starting ShardManager {}", persistenceId);
 212     }
 213
 214     @Override
 215     public void postStop() {
 216         LOG.info("Stopping ShardManager {}", persistenceId());
 217
 218         shardManagerMBean.unregisterMBean();
 219
 220         if (configListenerReg != null) {
 221             configListenerReg.close();
 222             configListenerReg = null;
 223         }
 224     }
 225
 226     @Override
 227     public void handleCommand(final Object message) throws Exception {
 228         if (message  instanceof FindPrimary) {
 229             findPrimary((FindPrimary)message);
 230         } else if (message instanceof FindLocalShard) {
 231             findLocalShard((FindLocalShard) message);
 232         } else if (message instanceof UpdateSchemaContext) {
 233             updateSchemaContext(message);
 234         } else if (message instanceof ActorInitialized) {
 235             onActorInitialized(message);
 236         } else if (message instanceof ClusterEvent.MemberUp) {
 237             memberUp((ClusterEvent.MemberUp) message);
 238         } else if (message instanceof ClusterEvent.MemberWeaklyUp) {
 239             memberWeaklyUp((ClusterEvent.MemberWeaklyUp) message);
 240         } else if (message instanceof ClusterEvent.MemberExited) {
 241             memberExited((ClusterEvent.MemberExited) message);
 242         } else if (message instanceof ClusterEvent.MemberRemoved) {
 243             memberRemoved((ClusterEvent.MemberRemoved) message);
 244         } else if (message instanceof ClusterEvent.UnreachableMember) {
 245             memberUnreachable((ClusterEvent.UnreachableMember) message);
 246         } else if (message instanceof ClusterEvent.ReachableMember) {
 247             memberReachable((ClusterEvent.ReachableMember) message);
 248         } else if (message instanceof DatastoreContextFactory) {
 249             onDatastoreContextFactory((DatastoreContextFactory) message);
 250         } else if (message instanceof RoleChangeNotification) {
 251             onRoleChangeNotification((RoleChangeNotification) message);
 252         } else if (message instanceof FollowerInitialSyncUpStatus) {
 253             onFollowerInitialSyncStatus((FollowerInitialSyncUpStatus) message);
 254         } else if (message instanceof ShardNotInitializedTimeout) {
 255             onShardNotInitializedTimeout((ShardNotInitializedTimeout) message);
 256         } else if (message instanceof ShardLeaderStateChanged) {
 257             onLeaderStateChanged((ShardLeaderStateChanged) message);
 258         } else if (message instanceof SwitchShardBehavior) {
 259             onSwitchShardBehavior((SwitchShardBehavior) message);
 260         } else if (message instanceof CreateShard) {
 261             onCreateShard((CreateShard)message);
 262         } else if (message instanceof AddShardReplica) {
 263             onAddShardReplica((AddShardReplica) message);
 264         } else if (message instanceof AddPrefixShardReplica) {
 265             onAddPrefixShardReplica((AddPrefixShardReplica) message);
 266         } else if (message instanceof PrefixShardCreated) {
 267             onPrefixShardCreated((PrefixShardCreated) message);
 268         } else if (message instanceof PrefixShardRemoved) {
 269             onPrefixShardRemoved((PrefixShardRemoved) message);
 270         } else if (message instanceof InitConfigListener) {
 271             onInitConfigListener();
 272         } else if (message instanceof ForwardedAddServerReply) {
 273             ForwardedAddServerReply msg = (ForwardedAddServerReply)message;
 274             onAddServerReply(msg.shardInfo, msg.addServerReply, getSender(), msg.leaderPath,
 275                     msg.removeShardOnFailure);
 276         } else if (message instanceof ForwardedAddServerFailure) {
 277             ForwardedAddServerFailure msg = (ForwardedAddServerFailure)message;
 278             onAddServerFailure(msg.shardName, msg.failureMessage, msg.failure, getSender(), msg.removeShardOnFailure);
 279         } else if (message instanceof RemoveShardReplica) {
 280             onRemoveShardReplica((RemoveShardReplica) message);
 281         } else if (message instanceof RemovePrefixShardReplica) {
 282             onRemovePrefixShardReplica((RemovePrefixShardReplica) message);
 283         } else if (message instanceof WrappedShardResponse) {
 284             onWrappedShardResponse((WrappedShardResponse) message);
 285         } else if (message instanceof GetSnapshot) {
 286             onGetSnapshot();
 287         } else if (message instanceof ServerRemoved) {
 288             onShardReplicaRemoved((ServerRemoved) message);
 289         } else if (message instanceof ChangeShardMembersVotingStatus) {
 290             onChangeShardServersVotingStatus((ChangeShardMembersVotingStatus) message);
 291         } else if (message instanceof FlipShardMembersVotingStatus) {
 292             onFlipShardMembersVotingStatus((FlipShardMembersVotingStatus) message);
 293         } else if (message instanceof SaveSnapshotSuccess) {
 294             onSaveSnapshotSuccess((SaveSnapshotSuccess) message);
 295         } else if (message instanceof SaveSnapshotFailure) {
 296             LOG.error("{}: SaveSnapshotFailure received for saving snapshot of shards", persistenceId(),
 297                     ((SaveSnapshotFailure) message).cause());
 298         } else if (message instanceof Shutdown) {
 299             onShutDown();
 300         } else if (message instanceof GetLocalShardIds) {
 301             onGetLocalShardIds();
 302         } else if (message instanceof GetShardRole) {
 303             onGetShardRole((GetShardRole) message);
 304         } else if (message instanceof RunnableMessage) {
 305             ((RunnableMessage)message).run();
 306         } else if (message instanceof RegisterForShardAvailabilityChanges) {
 307             onRegisterForShardAvailabilityChanges((RegisterForShardAvailabilityChanges)message);
 308         } else if (message instanceof DeleteSnapshotsFailure) {
 309             LOG.warn("{}: Failed to delete prior snapshots", persistenceId(),
 310                     ((DeleteSnapshotsFailure) message).cause());
 311         } else if (message instanceof DeleteSnapshotsSuccess) {
 312             LOG.debug("{}: Successfully deleted prior snapshots", persistenceId());
 313         } else if (message instanceof RegisterRoleChangeListenerReply) {
 314             LOG.trace("{}: Received RegisterRoleChangeListenerReply", persistenceId());
 315         } else if (message instanceof ClusterEvent.MemberEvent) {
 316             LOG.trace("{}: Received other ClusterEvent.MemberEvent: {}", persistenceId(), message);
 317         } else {
 318             unknownMessage(message);
 319         }
 320     }
 321
 322     private void onRegisterForShardAvailabilityChanges(RegisterForShardAvailabilityChanges message) {
 323         LOG.debug("{}: onRegisterForShardAvailabilityChanges: {}", persistenceId(), message);
 324
 325         final Consumer<String> callback = message.getCallback();
 326         shardAvailabilityCallbacks.add(callback);
 327
 328         getSender().tell(new Status.Success((Registration)
 329             () -> executeInSelf(() -> shardAvailabilityCallbacks.remove(callback))), self());
 330     }
 331
 332     private void onGetShardRole(final GetShardRole message) {
 333         LOG.debug("{}: onGetShardRole for shard: {}", persistenceId(), message.getName());
 334
 335         final String name = message.getName();
 336
 337         final ShardInformation shardInformation = localShards.get(name);
 338
 339         if (shardInformation == null) {
 340             LOG.info("{}: no shard information for {} found", persistenceId(), name);
 341             getSender().tell(new Status.Failure(
 342                     new IllegalArgumentException("Shard with name " + name + " not present.")), ActorRef.noSender());
 343             return;
 344         }
 345
 346         getSender().tell(new GetShardRoleReply(shardInformation.getRole()), ActorRef.noSender());
 347     }
 348
 349     private void onInitConfigListener() {
 350         LOG.debug("{}: Initializing config listener on {}", persistenceId(), cluster.getCurrentMemberName());
 351
 352         final org.opendaylight.mdsal.common.api.LogicalDatastoreType datastoreType =
 353                 org.opendaylight.mdsal.common.api.LogicalDatastoreType
 354                         .valueOf(datastoreContextFactory.getBaseDatastoreContext().getLogicalStoreType().name());
 355
 356         if (configUpdateHandler != null) {
 357             configUpdateHandler.close();
 358         }
 359
 360         configUpdateHandler = new PrefixedShardConfigUpdateHandler(self(), cluster.getCurrentMemberName());
 361         configUpdateHandler.initListener(dataStore, datastoreType);
 362     }
 363
 364     private void onShutDown() {
 365         List<Future<Boolean>> stopFutures = new ArrayList<>(localShards.size());
 366         for (ShardInformation info : localShards.values()) {
 367             if (info.getActor() != null) {
 368                 LOG.debug("{}: Issuing gracefulStop to shard {}", persistenceId(), info.getShardId());
 369
 370                 FiniteDuration duration = info.getDatastoreContext().getShardRaftConfig()
 371                         .getElectionTimeOutInterval().$times(2);
 372                 stopFutures.add(Patterns.gracefulStop(info.getActor(), duration, Shutdown.INSTANCE));
 373             }
 374         }
 375
 376         LOG.info("Shutting down ShardManager {} - waiting on {} shards", persistenceId(), stopFutures.size());
 377
 378         ExecutionContext dispatcher = new Dispatchers(context().system().dispatchers())
 379                 .getDispatcher(Dispatchers.DispatcherType.Client);
 380         Future<Iterable<Boolean>> combinedFutures = Futures.sequence(stopFutures, dispatcher);
 381
 382         combinedFutures.onComplete(new OnComplete<Iterable<Boolean>>() {
 383             @Override
 384             public void onComplete(final Throwable failure, final Iterable<Boolean> results) {
 385                 LOG.debug("{}: All shards shutdown - sending PoisonPill to self", persistenceId());
 386
 387                 self().tell(PoisonPill.getInstance(), self());
 388
 389                 if (failure != null) {
 390                     LOG.warn("{}: An error occurred attempting to shut down the shards", persistenceId(), failure);
 391                 } else {
 392                     int nfailed = 0;
 393                     for (Boolean result : results) {
 394                         if (!result) {
 395                             nfailed++;
 396                         }
 397                     }
 398
 399                     if (nfailed > 0) {
 400                         LOG.warn("{}: {} shards did not shut down gracefully", persistenceId(), nfailed);
 401                     }
 402                 }
 403             }
 404         }, dispatcher);
 405     }
 406
 407     private void onWrappedShardResponse(final WrappedShardResponse message) {
 408         if (message.getResponse() instanceof RemoveServerReply) {
 409             onRemoveServerReply(getSender(), message.getShardId(), (RemoveServerReply) message.getResponse(),
 410                     message.getLeaderPath());
 411         }
 412     }
 413
 414     private void onRemoveServerReply(final ActorRef originalSender, final ShardIdentifier shardId,
 415             final RemoveServerReply replyMsg, final String leaderPath) {
 416         shardReplicaOperationsInProgress.remove(shardId.getShardName());
 417
 418         LOG.debug("{}: Received {} for shard {}", persistenceId(), replyMsg, shardId.getShardName());
 419
 420         if (replyMsg.getStatus() == ServerChangeStatus.OK) {
 421             LOG.debug("{}: Leader shard successfully removed the replica shard {}", persistenceId(),
 422                     shardId.getShardName());
 423             originalSender.tell(new Status.Success(null), getSelf());
 424         } else {
 425             LOG.warn("{}: Leader failed to remove shard replica {} with status {}",
 426                     persistenceId(), shardId, replyMsg.getStatus());
 427
 428             Exception failure = getServerChangeException(RemoveServer.class, replyMsg.getStatus(), leaderPath, shardId);
 429             originalSender.tell(new Status.Failure(failure), getSelf());
 430         }
 431     }
 432
 433     private void removePrefixShardReplica(final RemovePrefixShardReplica contextMessage, final String shardName,
 434                                           final String primaryPath, final ActorRef sender) {
 435         if (isShardReplicaOperationInProgress(shardName, sender)) {
 436             return;
 437         }
 438
 439         shardReplicaOperationsInProgress.add(shardName);
 440
 441         final ShardIdentifier shardId = getShardIdentifier(contextMessage.getMemberName(), shardName);
 442
 443         final DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName).build();
 444
 445         //inform ShardLeader to remove this shard as a replica by sending an RemoveServer message
 446         LOG.debug("{}: Sending RemoveServer message to peer {} for shard {}", persistenceId(),
 447                 primaryPath, shardId);
 448
 449         Timeout removeServerTimeout = new Timeout(datastoreContext.getShardLeaderElectionTimeout().duration());
 450         Future<Object> futureObj = ask(getContext().actorSelection(primaryPath),
 451                 new RemoveServer(shardId.toString()), removeServerTimeout);
 452
 453         futureObj.onComplete(new OnComplete<Object>() {
 454             @Override
 455             public void onComplete(final Throwable failure, final Object response) {
 456                 if (failure != null) {
 457                     shardReplicaOperationsInProgress.remove(shardName);
 458
 459                     LOG.debug("{}: RemoveServer request to leader {} for shard {} failed", persistenceId(), primaryPath,
 460                         shardName, failure);
 461
 462                     // FAILURE
 463                     sender.tell(new Status.Failure(new RuntimeException(
 464                         String.format("RemoveServer request to leader %s for shard %s failed", primaryPath, shardName),
 465                         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                     LOG.debug("{}: RemoveServer request to leader {} for shard {} failed", persistenceId(), primaryPath,
 500                         shardName, failure);
 501
 502                     // FAILURE
 503                     sender.tell(new Status.Failure(new RuntimeException(
 504                         String.format("RemoveServer request to leader %s for shard %s failed", primaryPath, shardName),
 505                         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 {}", persistenceId, 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, FiniteDuration.create(1, TimeUnit.MINUTES),
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             LOG.debug("{}: A shard replica operation for {} is already in progress", persistenceId(), shardName);
1347             sender.tell(new Status.Failure(new IllegalStateException(
1348                 String.format("A shard replica operation for %s is already in progress", shardName))), 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             LOG.debug("{}: No SchemaContext is available in order to create a local shard instance for {}",
1365                 persistenceId(), shardName);
1366             getSender().tell(new Status.Failure(new IllegalStateException(
1367                 "No SchemaContext is available in order to create a local shard instance for " + shardName)),
1368                 getSelf());
1369             return;
1370         }
1371
1372         findPrimary(shardName, new AutoFindPrimaryFailureResponseHandler(getSender(), shardName, persistenceId(),
1373                 getSelf()) {
1374             @Override
1375             public void onRemotePrimaryShardFound(final RemotePrimaryShardFound response) {
1376                 final RunnableMessage runnable = (RunnableMessage) () -> addPrefixShard(getShardName(),
1377                         message.getShardPrefix(), response, getSender());
1378                 if (!isPreviousShardActorStopInProgress(getShardName(), runnable)) {
1379                     getSelf().tell(runnable, getTargetActor());
1380                 }
1381             }
1382
1383             @Override
1384             public void onLocalPrimaryFound(final LocalPrimaryShardFound message) {
1385                 sendLocalReplicaAlreadyExistsReply(getShardName(), getTargetActor());
1386             }
1387         });
1388     }
1389
1390     private void onAddShardReplica(final AddShardReplica shardReplicaMsg) {
1391         final String shardName = shardReplicaMsg.getShardName();
1392
1393         LOG.debug("{}: onAddShardReplica: {}", persistenceId(), shardReplicaMsg);
1394
1395         // verify the shard with the specified name is present in the cluster configuration
1396         if (!this.configuration.isShardConfigured(shardName)) {
1397             LOG.debug("{}: No module configuration exists for shard {}", persistenceId(), shardName);
1398             getSender().tell(new Status.Failure(new IllegalArgumentException(
1399                 "No module configuration exists for shard " + shardName)), getSelf());
1400             return;
1401         }
1402
1403         // Create the localShard
1404         if (schemaContext == null) {
1405             LOG.debug("{}: No SchemaContext is available in order to create a local shard instance for {}",
1406                 persistenceId(), shardName);
1407             getSender().tell(new Status.Failure(new IllegalStateException(
1408                 "No SchemaContext is available in order to create a local shard instance for " + shardName)),
1409                 getSelf());
1410             return;
1411         }
1412
1413         findPrimary(shardName, new AutoFindPrimaryFailureResponseHandler(getSender(), shardName, persistenceId(),
1414                 getSelf()) {
1415             @Override
1416             public void onRemotePrimaryShardFound(final RemotePrimaryShardFound response) {
1417                 final RunnableMessage runnable = (RunnableMessage) () ->
1418                     addShard(getShardName(), response, getSender());
1419                 if (!isPreviousShardActorStopInProgress(getShardName(), runnable)) {
1420                     getSelf().tell(runnable, getTargetActor());
1421                 }
1422             }
1423
1424             @Override
1425             public void onLocalPrimaryFound(final LocalPrimaryShardFound message) {
1426                 sendLocalReplicaAlreadyExistsReply(getShardName(), getTargetActor());
1427             }
1428         });
1429     }
1430
1431     private void sendLocalReplicaAlreadyExistsReply(final String shardName, final ActorRef sender) {
1432         LOG.debug("{}: Local shard {} already exists", persistenceId(), shardName);
1433         sender.tell(new Status.Failure(new AlreadyExistsException(
1434             String.format("Local shard %s already exists", shardName))), getSelf());
1435     }
1436
1437     private void addPrefixShard(final String shardName, final YangInstanceIdentifier shardPrefix,
1438                                 final RemotePrimaryShardFound response, final ActorRef sender) {
1439         if (isShardReplicaOperationInProgress(shardName, sender)) {
1440             return;
1441         }
1442
1443         shardReplicaOperationsInProgress.add(shardName);
1444
1445         final ShardInformation shardInfo;
1446         final boolean removeShardOnFailure;
1447         ShardInformation existingShardInfo = localShards.get(shardName);
1448         if (existingShardInfo == null) {
1449             removeShardOnFailure = true;
1450             ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
1451
1452             final Builder builder = newShardDatastoreContextBuilder(shardName);
1453             builder.storeRoot(shardPrefix).customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName());
1454
1455             DatastoreContext datastoreContext = builder.build();
1456
1457             shardInfo = new ShardInformation(shardName, shardId, getPeerAddresses(shardName), datastoreContext,
1458                     Shard.builder(), peerAddressResolver);
1459             shardInfo.setActiveMember(false);
1460             shardInfo.setSchemaContext(schemaContext);
1461             localShards.put(shardName, shardInfo);
1462             shardInfo.setActor(newShardActor(shardInfo));
1463         } else {
1464             removeShardOnFailure = false;
1465             shardInfo = existingShardInfo;
1466         }
1467
1468         execAddShard(shardName, shardInfo, response, removeShardOnFailure, sender);
1469     }
1470
1471     private void addShard(final String shardName, final RemotePrimaryShardFound response, final ActorRef sender) {
1472         if (isShardReplicaOperationInProgress(shardName, sender)) {
1473             return;
1474         }
1475
1476         shardReplicaOperationsInProgress.add(shardName);
1477
1478         final ShardInformation shardInfo;
1479         final boolean removeShardOnFailure;
1480         ShardInformation existingShardInfo = localShards.get(shardName);
1481         if (existingShardInfo == null) {
1482             removeShardOnFailure = true;
1483             ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
1484
1485             DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName)
1486                     .customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName()).build();
1487
1488             shardInfo = new ShardInformation(shardName, shardId, getPeerAddresses(shardName), datastoreContext,
1489                     Shard.builder(), peerAddressResolver);
1490             shardInfo.setActiveMember(false);
1491             shardInfo.setSchemaContext(schemaContext);
1492             localShards.put(shardName, shardInfo);
1493             shardInfo.setActor(newShardActor(shardInfo));
1494         } else {
1495             removeShardOnFailure = false;
1496             shardInfo = existingShardInfo;
1497         }
1498
1499         execAddShard(shardName, shardInfo, response, removeShardOnFailure, sender);
1500     }
1501
1502     private void execAddShard(final String shardName,
1503                               final ShardInformation shardInfo,
1504                               final RemotePrimaryShardFound response,
1505                               final boolean removeShardOnFailure,
1506                               final ActorRef sender) {
1507
1508         final String localShardAddress =
1509                 peerAddressResolver.getShardActorAddress(shardName, cluster.getCurrentMemberName());
1510
1511         //inform ShardLeader to add this shard as a replica by sending an AddServer message
1512         LOG.debug("{}: Sending AddServer message to peer {} for shard {}", persistenceId(),
1513                 response.getPrimaryPath(), shardInfo.getShardId());
1514
1515         final Timeout addServerTimeout = new Timeout(shardInfo.getDatastoreContext()
1516                 .getShardLeaderElectionTimeout().duration());
1517         final Future<Object> futureObj = ask(getContext().actorSelection(response.getPrimaryPath()),
1518                 new AddServer(shardInfo.getShardId().toString(), localShardAddress, true), addServerTimeout);
1519
1520         futureObj.onComplete(new OnComplete<Object>() {
1521             @Override
1522             public void onComplete(final Throwable failure, final Object addServerResponse) {
1523                 if (failure != null) {
1524                     LOG.debug("{}: AddServer request to {} for {} failed", persistenceId(),
1525                             response.getPrimaryPath(), shardName, failure);
1526
1527                     final String msg = String.format("AddServer request to leader %s for shard %s failed",
1528                             response.getPrimaryPath(), shardName);
1529                     self().tell(new ForwardedAddServerFailure(shardName, msg, failure, removeShardOnFailure), sender);
1530                 } else {
1531                     self().tell(new ForwardedAddServerReply(shardInfo, (AddServerReply)addServerResponse,
1532                             response.getPrimaryPath(), removeShardOnFailure), sender);
1533                 }
1534             }
1535         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1536     }
1537
1538     private void onAddServerFailure(final String shardName, final String message, final Throwable failure,
1539             final ActorRef sender, final boolean removeShardOnFailure) {
1540         shardReplicaOperationsInProgress.remove(shardName);
1541
1542         if (removeShardOnFailure) {
1543             ShardInformation shardInfo = localShards.remove(shardName);
1544             if (shardInfo.getActor() != null) {
1545                 shardInfo.getActor().tell(PoisonPill.getInstance(), getSelf());
1546             }
1547         }
1548
1549         sender.tell(new Status.Failure(message == null ? failure :
1550             new RuntimeException(message, failure)), getSelf());
1551     }
1552
1553     private void onAddServerReply(final ShardInformation shardInfo, final AddServerReply replyMsg,
1554             final ActorRef sender, final String leaderPath, final boolean removeShardOnFailure) {
1555         String shardName = shardInfo.getShardName();
1556         shardReplicaOperationsInProgress.remove(shardName);
1557
1558         LOG.debug("{}: Received {} for shard {} from leader {}", persistenceId(), replyMsg, shardName, leaderPath);
1559
1560         if (replyMsg.getStatus() == ServerChangeStatus.OK) {
1561             LOG.debug("{}: Leader shard successfully added the replica shard {}", persistenceId(), shardName);
1562
1563             // Make the local shard voting capable
1564             shardInfo.setDatastoreContext(newShardDatastoreContext(shardName), getSelf());
1565             shardInfo.setActiveMember(true);
1566             persistShardList();
1567
1568             sender.tell(new Status.Success(null), getSelf());
1569         } else if (replyMsg.getStatus() == ServerChangeStatus.ALREADY_EXISTS) {
1570             sendLocalReplicaAlreadyExistsReply(shardName, sender);
1571         } else {
1572             LOG.warn("{}: Leader failed to add shard replica {} with status {}",
1573                     persistenceId(), shardName, replyMsg.getStatus());
1574
1575             Exception failure = getServerChangeException(AddServer.class, replyMsg.getStatus(), leaderPath,
1576                     shardInfo.getShardId());
1577
1578             onAddServerFailure(shardName, null, failure, sender, removeShardOnFailure);
1579         }
1580     }
1581
1582     private static Exception getServerChangeException(final Class<?> serverChange,
1583             final ServerChangeStatus serverChangeStatus, final String leaderPath, final ShardIdentifier shardId) {
1584         switch (serverChangeStatus) {
1585             case TIMEOUT:
1586                 return new TimeoutException(String.format(
1587                         "The shard leader %s timed out trying to replicate the initial data to the new shard %s."
1588                         + "Possible causes - there was a problem replicating the data or shard leadership changed "
1589                         + "while replicating the shard data", leaderPath, shardId.getShardName()));
1590             case NO_LEADER:
1591                 return createNoShardLeaderException(shardId);
1592             case NOT_SUPPORTED:
1593                 return new UnsupportedOperationException(String.format("%s request is not supported for shard %s",
1594                         serverChange.getSimpleName(), shardId.getShardName()));
1595             default :
1596                 return new RuntimeException(String.format("%s request to leader %s for shard %s failed with status %s",
1597                         serverChange.getSimpleName(), leaderPath, shardId.getShardName(), serverChangeStatus));
1598         }
1599     }
1600
1601     private void onRemoveShardReplica(final RemoveShardReplica shardReplicaMsg) {
1602         LOG.debug("{}: onRemoveShardReplica: {}", persistenceId(), shardReplicaMsg);
1603
1604         findPrimary(shardReplicaMsg.getShardName(), new AutoFindPrimaryFailureResponseHandler(getSender(),
1605                 shardReplicaMsg.getShardName(), persistenceId(), getSelf()) {
1606             @Override
1607             public void onRemotePrimaryShardFound(final RemotePrimaryShardFound response) {
1608                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1609             }
1610
1611             @Override
1612             public void onLocalPrimaryFound(final LocalPrimaryShardFound response) {
1613                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1614             }
1615
1616             private void doRemoveShardReplicaAsync(final String primaryPath) {
1617                 getSelf().tell((RunnableMessage) () -> removeShardReplica(shardReplicaMsg, getShardName(),
1618                         primaryPath, getSender()), getTargetActor());
1619             }
1620         });
1621     }
1622
1623     private void onRemovePrefixShardReplica(final RemovePrefixShardReplica message) {
1624         LOG.debug("{}: onRemovePrefixShardReplica: {}", persistenceId(), message);
1625
1626         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(),
1627                 ClusterUtils.getCleanShardName(message.getShardPrefix()));
1628         final String shardName = shardId.getShardName();
1629
1630         findPrimary(shardName, new AutoFindPrimaryFailureResponseHandler(getSender(),
1631                 shardName, persistenceId(), getSelf()) {
1632             @Override
1633             public void onRemotePrimaryShardFound(final RemotePrimaryShardFound response) {
1634                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1635             }
1636
1637             @Override
1638             public void onLocalPrimaryFound(final LocalPrimaryShardFound response) {
1639                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1640             }
1641
1642             private void doRemoveShardReplicaAsync(final String primaryPath) {
1643                 getSelf().tell((RunnableMessage) () -> removePrefixShardReplica(message, getShardName(),
1644                         primaryPath, getSender()), getTargetActor());
1645             }
1646         });
1647     }
1648
1649     private void persistShardList() {
1650         List<String> shardList = new ArrayList<>(localShards.keySet());
1651         for (ShardInformation shardInfo : localShards.values()) {
1652             if (!shardInfo.isActiveMember()) {
1653                 shardList.remove(shardInfo.getShardName());
1654             }
1655         }
1656         LOG.debug("{}: persisting the shard list {}", persistenceId(), shardList);
1657         saveSnapshot(updateShardManagerSnapshot(shardList, configuration.getAllPrefixShardConfigurations()));
1658     }
1659
1660     private ShardManagerSnapshot updateShardManagerSnapshot(
1661             final List<String> shardList,
1662             final Map<DOMDataTreeIdentifier, PrefixShardConfiguration> allPrefixShardConfigurations) {
1663         currentSnapshot = new ShardManagerSnapshot(shardList, allPrefixShardConfigurations);
1664         return currentSnapshot;
1665     }
1666
1667     private void applyShardManagerSnapshot(final ShardManagerSnapshot snapshot) {
1668         currentSnapshot = snapshot;
1669
1670         LOG.debug("{}: onSnapshotOffer: {}", persistenceId(), currentSnapshot);
1671
1672         final MemberName currentMember = cluster.getCurrentMemberName();
1673         Set<String> configuredShardList =
1674             new HashSet<>(configuration.getMemberShardNames(currentMember));
1675         for (String shard : currentSnapshot.getShardList()) {
1676             if (!configuredShardList.contains(shard)) {
1677                 // add the current member as a replica for the shard
1678                 LOG.debug("{}: adding shard {}", persistenceId(), shard);
1679                 configuration.addMemberReplicaForShard(shard, currentMember);
1680             } else {
1681                 configuredShardList.remove(shard);
1682             }
1683         }
1684         for (String shard : configuredShardList) {
1685             // remove the member as a replica for the shard
1686             LOG.debug("{}: removing shard {}", persistenceId(), shard);
1687             configuration.removeMemberReplicaForShard(shard, currentMember);
1688         }
1689     }
1690
1691     private void onSaveSnapshotSuccess(final SaveSnapshotSuccess successMessage) {
1692         LOG.debug("{} saved ShardManager snapshot successfully. Deleting the prev snapshot if available",
1693             persistenceId());
1694         deleteSnapshots(new SnapshotSelectionCriteria(scala.Long.MaxValue(), successMessage.metadata().timestamp() - 1,
1695             0, 0));
1696     }
1697
1698     private void onChangeShardServersVotingStatus(final ChangeShardMembersVotingStatus changeMembersVotingStatus) {
1699         LOG.debug("{}: onChangeShardServersVotingStatus: {}", persistenceId(), changeMembersVotingStatus);
1700
1701         String shardName = changeMembersVotingStatus.getShardName();
1702         Map<String, Boolean> serverVotingStatusMap = new HashMap<>();
1703         for (Entry<String, Boolean> e: changeMembersVotingStatus.getMeberVotingStatusMap().entrySet()) {
1704             serverVotingStatusMap.put(getShardIdentifier(MemberName.forName(e.getKey()), shardName).toString(),
1705                     e.getValue());
1706         }
1707
1708         ChangeServersVotingStatus changeServersVotingStatus = new ChangeServersVotingStatus(serverVotingStatusMap);
1709
1710         findLocalShard(shardName, getSender(),
1711             localShardFound -> changeShardMembersVotingStatus(changeServersVotingStatus, shardName,
1712             localShardFound.getPath(), getSender()));
1713     }
1714
1715     private void onFlipShardMembersVotingStatus(final FlipShardMembersVotingStatus flipMembersVotingStatus) {
1716         LOG.debug("{}: onFlipShardMembersVotingStatus: {}", persistenceId(), flipMembersVotingStatus);
1717
1718         ActorRef sender = getSender();
1719         final String shardName = flipMembersVotingStatus.getShardName();
1720         findLocalShard(shardName, sender, localShardFound -> {
1721             Future<Object> future = ask(localShardFound.getPath(), GetOnDemandRaftState.INSTANCE,
1722                     Timeout.apply(30, TimeUnit.SECONDS));
1723
1724             future.onComplete(new OnComplete<Object>() {
1725                 @Override
1726                 public void onComplete(final Throwable failure, final Object response) {
1727                     if (failure != null) {
1728                         sender.tell(new Status.Failure(new RuntimeException(
1729                                 String.format("Failed to access local shard %s", shardName), failure)), self());
1730                         return;
1731                     }
1732
1733                     OnDemandRaftState raftState = (OnDemandRaftState) response;
1734                     Map<String, Boolean> serverVotingStatusMap = new HashMap<>();
1735                     for (Entry<String, Boolean> e: raftState.getPeerVotingStates().entrySet()) {
1736                         serverVotingStatusMap.put(e.getKey(), !e.getValue());
1737                     }
1738
1739                     serverVotingStatusMap.put(getShardIdentifier(cluster.getCurrentMemberName(), shardName)
1740                             .toString(), !raftState.isVoting());
1741
1742                     changeShardMembersVotingStatus(new ChangeServersVotingStatus(serverVotingStatusMap),
1743                             shardName, localShardFound.getPath(), sender);
1744                 }
1745             }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1746         });
1747
1748     }
1749
1750     private void findLocalShard(final FindLocalShard message) {
1751         LOG.debug("{}: findLocalShard : {}", persistenceId(), message.getShardName());
1752
1753         final ShardInformation shardInformation = localShards.get(message.getShardName());
1754
1755         if (shardInformation == null) {
1756             LOG.debug("{}: Local shard {} not found - shards present: {}",
1757                     persistenceId(), message.getShardName(), localShards.keySet());
1758
1759             getSender().tell(new LocalShardNotFound(message.getShardName()), getSelf());
1760             return;
1761         }
1762
1763         sendResponse(shardInformation, message.isWaitUntilInitialized(), false,
1764             () -> new LocalShardFound(shardInformation.getActor()));
1765     }
1766
1767     private void findLocalShard(final String shardName, final ActorRef sender,
1768             final Consumer<LocalShardFound> onLocalShardFound) {
1769         Timeout findLocalTimeout = new Timeout(datastoreContextFactory.getBaseDatastoreContext()
1770                 .getShardInitializationTimeout().duration().$times(2));
1771
1772         Future<Object> futureObj = ask(getSelf(), new FindLocalShard(shardName, true), findLocalTimeout);
1773         futureObj.onComplete(new OnComplete<Object>() {
1774             @Override
1775             public void onComplete(final Throwable failure, final Object response) {
1776                 if (failure != null) {
1777                     LOG.debug("{}: Received failure from FindLocalShard for shard {}", persistenceId, shardName,
1778                             failure);
1779                     sender.tell(new Status.Failure(new RuntimeException(
1780                             String.format("Failed to find local shard %s", shardName), failure)), self());
1781                 } else {
1782                     if (response instanceof LocalShardFound) {
1783                         getSelf().tell((RunnableMessage) () -> onLocalShardFound.accept((LocalShardFound) response),
1784                                 sender);
1785                     } else if (response instanceof LocalShardNotFound) {
1786                         LOG.debug("{}: Local shard {} does not exist", persistenceId, shardName);
1787                         sender.tell(new Status.Failure(new IllegalArgumentException(
1788                             String.format("Local shard %s does not exist", shardName))), self());
1789                     } else {
1790                         LOG.debug("{}: Failed to find local shard {}: received response: {}", persistenceId, shardName,
1791                             response);
1792                         sender.tell(new Status.Failure(response instanceof Throwable ? (Throwable) response
1793                                 : new RuntimeException(
1794                                     String.format("Failed to find local shard %s: received response: %s", shardName,
1795                                         response))), self());
1796                     }
1797                 }
1798             }
1799         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1800     }
1801
1802     private void changeShardMembersVotingStatus(final ChangeServersVotingStatus changeServersVotingStatus,
1803             final String shardName, final ActorRef shardActorRef, final ActorRef sender) {
1804         if (isShardReplicaOperationInProgress(shardName, sender)) {
1805             return;
1806         }
1807
1808         shardReplicaOperationsInProgress.add(shardName);
1809
1810         DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName).build();
1811         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
1812
1813         LOG.debug("{}: Sending ChangeServersVotingStatus message {} to local shard {}", persistenceId(),
1814                 changeServersVotingStatus, shardActorRef.path());
1815
1816         Timeout timeout = new Timeout(datastoreContext.getShardLeaderElectionTimeout().duration().$times(2));
1817         Future<Object> futureObj = ask(shardActorRef, changeServersVotingStatus, timeout);
1818
1819         futureObj.onComplete(new OnComplete<Object>() {
1820             @Override
1821             public void onComplete(final Throwable failure, final Object response) {
1822                 shardReplicaOperationsInProgress.remove(shardName);
1823                 if (failure != null) {
1824                     LOG.debug("{}: ChangeServersVotingStatus request to local shard {} failed", persistenceId(),
1825                         shardActorRef.path(), failure);
1826                     sender.tell(new Status.Failure(new RuntimeException(
1827                         String.format("ChangeServersVotingStatus request to local shard %s failed",
1828                             shardActorRef.path()), failure)), self());
1829                 } else {
1830                     LOG.debug("{}: Received {} from local shard {}", persistenceId(), response, shardActorRef.path());
1831
1832                     ServerChangeReply replyMsg = (ServerChangeReply) response;
1833                     if (replyMsg.getStatus() == ServerChangeStatus.OK) {
1834                         LOG.debug("{}: ChangeServersVotingStatus succeeded for shard {}", persistenceId(), shardName);
1835                         sender.tell(new Status.Success(null), getSelf());
1836                     } else if (replyMsg.getStatus() == ServerChangeStatus.INVALID_REQUEST) {
1837                         sender.tell(new Status.Failure(new IllegalArgumentException(String.format(
1838                                 "The requested voting state change for shard %s is invalid. At least one member "
1839                                 + "must be voting", shardId.getShardName()))), getSelf());
1840                     } else {
1841                         LOG.warn("{}: ChangeServersVotingStatus failed for shard {} with status {}",
1842                                 persistenceId(), shardName, replyMsg.getStatus());
1843
1844                         Exception error = getServerChangeException(ChangeServersVotingStatus.class,
1845                                 replyMsg.getStatus(), shardActorRef.path().toString(), shardId);
1846                         sender.tell(new Status.Failure(error), getSelf());
1847                     }
1848                 }
1849             }
1850         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1851     }
1852
1853     private static final class ForwardedAddServerReply {
1854         ShardInformation shardInfo;
1855         AddServerReply addServerReply;
1856         String leaderPath;
1857         boolean removeShardOnFailure;
1858
1859         ForwardedAddServerReply(final ShardInformation shardInfo, final AddServerReply addServerReply,
1860             final String leaderPath, final boolean removeShardOnFailure) {
1861             this.shardInfo = shardInfo;
1862             this.addServerReply = addServerReply;
1863             this.leaderPath = leaderPath;
1864             this.removeShardOnFailure = removeShardOnFailure;
1865         }
1866     }
1867
1868     private static final class ForwardedAddServerFailure {
1869         String shardName;
1870         String failureMessage;
1871         Throwable failure;
1872         boolean removeShardOnFailure;
1873
1874         ForwardedAddServerFailure(final String shardName, final String failureMessage, final Throwable failure,
1875                 final boolean removeShardOnFailure) {
1876             this.shardName = shardName;
1877             this.failureMessage = failureMessage;
1878             this.failure = failure;
1879             this.removeShardOnFailure = removeShardOnFailure;
1880         }
1881     }
1882
1883     static class OnShardInitialized {
1884         private final Runnable replyRunnable;
1885         private Cancellable timeoutSchedule;
1886
1887         OnShardInitialized(final Runnable replyRunnable) {
1888             this.replyRunnable = replyRunnable;
1889         }
1890
1891         Runnable getReplyRunnable() {
1892             return replyRunnable;
1893         }
1894
1895         Cancellable getTimeoutSchedule() {
1896             return timeoutSchedule;
1897         }
1898
1899         void setTimeoutSchedule(final Cancellable timeoutSchedule) {
1900             this.timeoutSchedule = timeoutSchedule;
1901         }
1902     }
1903
1904     static class OnShardReady extends OnShardInitialized {
1905         OnShardReady(final Runnable replyRunnable) {
1906             super(replyRunnable);
1907         }
1908     }
1909
1910     private interface RunnableMessage extends Runnable {
1911     }
1912
1913     /**
1914      * The FindPrimaryResponseHandler provides specific callback methods which are invoked when a response to the
1915      * a remote or local find primary message is processed.
1916      */
1917     private interface FindPrimaryResponseHandler {
1918         /**
1919          * Invoked when a Failure message is received as a response.
1920          *
1921          * @param failure the failure exception
1922          */
1923         void onFailure(Throwable failure);
1924
1925         /**
1926          * Invoked when a RemotePrimaryShardFound response is received.
1927          *
1928          * @param response the response
1929          */
1930         void onRemotePrimaryShardFound(RemotePrimaryShardFound response);
1931
1932         /**
1933          * Invoked when a LocalPrimaryShardFound response is received.
1934          *
1935          * @param response the response
1936          */
1937         void onLocalPrimaryFound(LocalPrimaryShardFound response);
1938
1939         /**
1940          * Invoked when an unknown response is received. This is another type of failure.
1941          *
1942          * @param response the response
1943          */
1944         void onUnknownResponse(Object response);
1945     }
1946
1947     /**
1948      * The AutoFindPrimaryFailureResponseHandler automatically processes Failure responses when finding a primary
1949      * replica and sends a wrapped Failure response to some targetActor.
1950      */
1951     private abstract static class AutoFindPrimaryFailureResponseHandler implements FindPrimaryResponseHandler {
1952         private final ActorRef targetActor;
1953         private final String shardName;
1954         private final String persistenceId;
1955         private final ActorRef shardManagerActor;
1956
1957         /**
1958          * Constructs an instance.
1959          *
1960          * @param targetActor The actor to whom the Failure response should be sent when a FindPrimary failure occurs
1961          * @param shardName The name of the shard for which the primary replica had to be found
1962          * @param persistenceId The persistenceId for the ShardManager
1963          * @param shardManagerActor The ShardManager actor which triggered the call to FindPrimary
1964          */
1965         protected AutoFindPrimaryFailureResponseHandler(final ActorRef targetActor, final String shardName,
1966                 final String persistenceId, final ActorRef shardManagerActor) {
1967             this.targetActor = Preconditions.checkNotNull(targetActor);
1968             this.shardName = Preconditions.checkNotNull(shardName);
1969             this.persistenceId = Preconditions.checkNotNull(persistenceId);
1970             this.shardManagerActor = Preconditions.checkNotNull(shardManagerActor);
1971         }
1972
1973         public ActorRef getTargetActor() {
1974             return targetActor;
1975         }
1976
1977         public String getShardName() {
1978             return shardName;
1979         }
1980
1981         @Override
1982         public void onFailure(final Throwable failure) {
1983             LOG.debug("{}: Received failure from FindPrimary for shard {}", persistenceId, shardName, failure);
1984             targetActor.tell(new Status.Failure(new RuntimeException(
1985                     String.format("Failed to find leader for shard %s", shardName), failure)), shardManagerActor);
1986         }
1987
1988         @Override
1989         public void onUnknownResponse(final Object response) {
1990             LOG.debug("{}: Failed to find leader for shard {}: received response: {}", persistenceId, shardName,
1991                 response);
1992             targetActor.tell(new Status.Failure(response instanceof Throwable ? (Throwable) response
1993                     : new RuntimeException(String.format("Failed to find leader for shard %s: received response: %s",
1994                         shardName, response))), shardManagerActor);
1995         }
1996     }
1997
1998     /**
1999      * The WrappedShardResponse class wraps a response from a Shard.
2000      */
2001     private static final class WrappedShardResponse {
2002         private final ShardIdentifier shardId;
2003         private final Object response;
2004         private final String leaderPath;
2005
2006         WrappedShardResponse(final ShardIdentifier shardId, final Object response, final String leaderPath) {
2007             this.shardId = shardId;
2008             this.response = response;
2009             this.leaderPath = leaderPath;
2010         }
2011
2012         ShardIdentifier getShardId() {
2013             return shardId;
2014         }
2015
2016         Object getResponse() {
2017             return response;
2018         }
2019
2020         String getLeaderPath() {
2021             return leaderPath;
2022         }
2023     }
2024
2025     private static final class ShardNotInitializedTimeout {
2026         private final ActorRef sender;
2027         private final ShardInformation shardInfo;
2028         private final OnShardInitialized onShardInitialized;
2029
2030         ShardNotInitializedTimeout(final ShardInformation shardInfo, final OnShardInitialized onShardInitialized,
2031             final ActorRef sender) {
2032             this.sender = sender;
2033             this.shardInfo = shardInfo;
2034             this.onShardInitialized = onShardInitialized;
2035         }
2036
2037         ActorRef getSender() {
2038             return sender;
2039         }
2040
2041         ShardInformation getShardInfo() {
2042             return shardInfo;
2043         }
2044
2045         OnShardInitialized getOnShardInitialized() {
2046             return onShardInitialized;
2047         }
2048     }
2049 }
2050
2051
2052