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