opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/shardmanager/ShardManager.java

   1 /*
   2  * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8
   9 package org.opendaylight.controller.cluster.datastore.shardmanager;
  10
  11 import static akka.pattern.Patterns.ask;
  12
  13 import akka.actor.ActorRef;
  14 import akka.actor.Address;
  15 import akka.actor.Cancellable;
  16 import akka.actor.OneForOneStrategy;
  17 import akka.actor.PoisonPill;
  18 import akka.actor.Status;
  19 import akka.actor.SupervisorStrategy;
  20 import akka.actor.SupervisorStrategy.Directive;
  21 import akka.cluster.ClusterEvent;
  22 import akka.cluster.ClusterEvent.MemberWeaklyUp;
  23 import akka.cluster.Member;
  24 import akka.dispatch.Futures;
  25 import akka.dispatch.OnComplete;
  26 import akka.japi.Function;
  27 import akka.pattern.Patterns;
  28 import akka.persistence.DeleteSnapshotsFailure;
  29 import akka.persistence.DeleteSnapshotsSuccess;
  30 import akka.persistence.RecoveryCompleted;
  31 import akka.persistence.SaveSnapshotFailure;
  32 import akka.persistence.SaveSnapshotSuccess;
  33 import akka.persistence.SnapshotOffer;
  34 import akka.persistence.SnapshotSelectionCriteria;
  35 import akka.util.Timeout;
  36 import com.google.common.annotations.VisibleForTesting;
  37 import com.google.common.base.Preconditions;
  38 import java.util.ArrayList;
  39 import java.util.Collection;
  40 import java.util.Collections;
  41 import java.util.HashMap;
  42 import java.util.HashSet;
  43 import java.util.List;
  44 import java.util.Map;
  45 import java.util.Map.Entry;
  46 import java.util.Set;
  47 import java.util.concurrent.CountDownLatch;
  48 import java.util.concurrent.TimeUnit;
  49 import java.util.concurrent.TimeoutException;
  50 import java.util.function.Consumer;
  51 import java.util.function.Supplier;
  52 import org.opendaylight.controller.cluster.access.concepts.MemberName;
  53 import org.opendaylight.controller.cluster.common.actor.AbstractUntypedPersistentActorWithMetering;
  54 import org.opendaylight.controller.cluster.common.actor.Dispatchers;
  55 import org.opendaylight.controller.cluster.datastore.AbstractDataStore;
  56 import org.opendaylight.controller.cluster.datastore.ClusterWrapper;
  57 import org.opendaylight.controller.cluster.datastore.DatastoreContext;
  58 import org.opendaylight.controller.cluster.datastore.DatastoreContext.Builder;
  59 import org.opendaylight.controller.cluster.datastore.DatastoreContextFactory;
  60 import org.opendaylight.controller.cluster.datastore.Shard;
  61 import org.opendaylight.controller.cluster.datastore.config.Configuration;
  62 import org.opendaylight.controller.cluster.datastore.config.ModuleShardConfiguration;
  63 import org.opendaylight.controller.cluster.datastore.config.PrefixShardConfiguration;
  64 import org.opendaylight.controller.cluster.datastore.exceptions.AlreadyExistsException;
  65 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
  66 import org.opendaylight.controller.cluster.datastore.exceptions.NotInitializedException;
  67 import org.opendaylight.controller.cluster.datastore.exceptions.PrimaryNotFoundException;
  68 import org.opendaylight.controller.cluster.datastore.identifiers.ShardIdentifier;
  69 import org.opendaylight.controller.cluster.datastore.messages.ActorInitialized;
  70 import org.opendaylight.controller.cluster.datastore.messages.AddPrefixShardReplica;
  71 import org.opendaylight.controller.cluster.datastore.messages.AddShardReplica;
  72 import org.opendaylight.controller.cluster.datastore.messages.ChangeShardMembersVotingStatus;
  73 import org.opendaylight.controller.cluster.datastore.messages.CreateShard;
  74 import org.opendaylight.controller.cluster.datastore.messages.FindLocalShard;
  75 import org.opendaylight.controller.cluster.datastore.messages.FindPrimary;
  76 import org.opendaylight.controller.cluster.datastore.messages.FlipShardMembersVotingStatus;
  77 import org.opendaylight.controller.cluster.datastore.messages.GetShardRole;
  78 import org.opendaylight.controller.cluster.datastore.messages.GetShardRoleReply;
  79 import org.opendaylight.controller.cluster.datastore.messages.LocalPrimaryShardFound;
  80 import org.opendaylight.controller.cluster.datastore.messages.LocalShardFound;
  81 import org.opendaylight.controller.cluster.datastore.messages.LocalShardNotFound;
  82 import org.opendaylight.controller.cluster.datastore.messages.RemoteFindPrimary;
  83 import org.opendaylight.controller.cluster.datastore.messages.RemotePrimaryShardFound;
  84 import org.opendaylight.controller.cluster.datastore.messages.RemovePrefixShardReplica;
  85 import org.opendaylight.controller.cluster.datastore.messages.RemoveShardReplica;
  86 import org.opendaylight.controller.cluster.datastore.messages.ShardLeaderStateChanged;
  87 import org.opendaylight.controller.cluster.datastore.messages.UpdateSchemaContext;
  88 import org.opendaylight.controller.cluster.datastore.persisted.DatastoreSnapshot;
  89 import org.opendaylight.controller.cluster.datastore.persisted.ShardManagerSnapshot;
  90 import org.opendaylight.controller.cluster.datastore.utils.ClusterUtils;
  91 import org.opendaylight.controller.cluster.datastore.utils.CompositeOnComplete;
  92 import org.opendaylight.controller.cluster.datastore.utils.PrimaryShardInfoFutureCache;
  93 import org.opendaylight.controller.cluster.notifications.RegisterRoleChangeListener;
  94 import org.opendaylight.controller.cluster.notifications.RegisterRoleChangeListenerReply;
  95 import org.opendaylight.controller.cluster.notifications.RoleChangeNotification;
  96 import org.opendaylight.controller.cluster.raft.base.messages.FollowerInitialSyncUpStatus;
  97 import org.opendaylight.controller.cluster.raft.base.messages.SwitchBehavior;
  98 import org.opendaylight.controller.cluster.raft.client.messages.GetOnDemandRaftState;
  99 import org.opendaylight.controller.cluster.raft.client.messages.GetSnapshot;
 100 import org.opendaylight.controller.cluster.raft.client.messages.OnDemandRaftState;
 101 import org.opendaylight.controller.cluster.raft.client.messages.Shutdown;
 102 import org.opendaylight.controller.cluster.raft.messages.AddServer;
 103 import org.opendaylight.controller.cluster.raft.messages.AddServerReply;
 104 import org.opendaylight.controller.cluster.raft.messages.ChangeServersVotingStatus;
 105 import org.opendaylight.controller.cluster.raft.messages.RemoveServer;
 106 import org.opendaylight.controller.cluster.raft.messages.RemoveServerReply;
 107 import org.opendaylight.controller.cluster.raft.messages.ServerChangeReply;
 108 import org.opendaylight.controller.cluster.raft.messages.ServerChangeStatus;
 109 import org.opendaylight.controller.cluster.raft.messages.ServerRemoved;
 110 import org.opendaylight.controller.cluster.raft.policy.DisableElectionsRaftPolicy;
 111 import org.opendaylight.controller.cluster.sharding.PrefixedShardConfigUpdateHandler;
 112 import org.opendaylight.controller.cluster.sharding.messages.InitConfigListener;
 113 import org.opendaylight.controller.cluster.sharding.messages.PrefixShardCreated;
 114 import org.opendaylight.controller.cluster.sharding.messages.PrefixShardRemoved;
 115 import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
 116 import org.opendaylight.yangtools.concepts.Registration;
 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.FiniteDuration;
 124
 125 /**
 126  * Manages the shards for a data store. The ShardManager has the following jobs:
 127  * <ul>
 128  * <li> Create all the local shard replicas that belong on this cluster member
 129  * <li> Find the address of the local shard
 130  * <li> Find the primary replica for any given shard
 131  * <li> Monitor the cluster members and store their addresses
 132  * </ul>
 133  */
 134 class ShardManager extends AbstractUntypedPersistentActorWithMetering {
 135     private static final Logger LOG = LoggerFactory.getLogger(ShardManager.class);
 136
 137     // Stores a mapping between a shard name and it's corresponding information
 138     // Shard names look like inventory, topology etc and are as specified in
 139     // configuration
 140     @VisibleForTesting
 141     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     @VisibleForTesting
 152     final String shardDispatcherPath;
 153
 154     private final ShardManagerInfo shardManagerMBean;
 155
 156     private DatastoreContextFactory datastoreContextFactory;
 157
 158     private final CountDownLatch waitTillReadyCountdownLatch;
 159
 160     private final PrimaryShardInfoFutureCache primaryShardInfoCache;
 161
 162     @VisibleForTesting
 163     final ShardPeerAddressResolver peerAddressResolver;
 164
 165     private SchemaContext schemaContext;
 166
 167     private DatastoreSnapshot restoreFromSnapshot;
 168
 169     private ShardManagerSnapshot currentSnapshot;
 170
 171     private final Set<String> shardReplicaOperationsInProgress = new HashSet<>();
 172
 173     private final Map<String, CompositeOnComplete<Boolean>> shardActorsStopping = new HashMap<>();
 174
 175     private final Set<Consumer<String>> shardAvailabilityCallbacks = new HashSet<>();
 176
 177     private final String persistenceId;
 178     private final AbstractDataStore dataStore;
 179
 180     private PrefixedShardConfigUpdateHandler configUpdateHandler;
 181
 182     ShardManager(final AbstractShardManagerCreator<?> builder) {
 183         this.cluster = builder.getCluster();
 184         this.configuration = builder.getConfiguration();
 185         this.datastoreContextFactory = builder.getDatastoreContextFactory();
 186         this.type = datastoreContextFactory.getBaseDatastoreContext().getDataStoreName();
 187         this.shardDispatcherPath =
 188                 new Dispatchers(context().system().dispatchers()).getDispatcherPath(Dispatchers.DispatcherType.Shard);
 189         this.waitTillReadyCountdownLatch = builder.getWaitTillReadyCountDownLatch();
 190         this.primaryShardInfoCache = builder.getPrimaryShardInfoCache();
 191         this.restoreFromSnapshot = builder.getRestoreFromSnapshot();
 192
 193         String possiblePersistenceId = datastoreContextFactory.getBaseDatastoreContext().getShardManagerPersistenceId();
 194         persistenceId = possiblePersistenceId != null ? possiblePersistenceId : "shard-manager-" + type;
 195
 196         peerAddressResolver = new ShardPeerAddressResolver(type, cluster.getCurrentMemberName());
 197
 198         // Subscribe this actor to cluster member events
 199         cluster.subscribeToMemberEvents(getSelf());
 200
 201         shardManagerMBean = new ShardManagerInfo(getSelf(), cluster.getCurrentMemberName(),
 202                 "shard-manager-" + this.type,
 203                 datastoreContextFactory.getBaseDatastoreContext().getDataStoreMXBeanType());
 204         shardManagerMBean.registerMBean();
 205
 206         dataStore = builder.getDistributedDataStore();
 207     }
 208
 209     @Override
 210     public void preStart() {
 211         LOG.info("Starting ShardManager {}", persistenceId);
 212     }
 213
 214     @Override
 215     public void postStop() {
 216         LOG.info("Stopping ShardManager {}", persistenceId());
 217
 218         shardManagerMBean.unregisterMBean();
 219     }
 220
 221     @Override
 222     public void handleCommand(final Object message) throws Exception {
 223         if (message  instanceof FindPrimary) {
 224             findPrimary((FindPrimary)message);
 225         } else if (message instanceof FindLocalShard) {
 226             findLocalShard((FindLocalShard) message);
 227         } else if (message instanceof UpdateSchemaContext) {
 228             updateSchemaContext(message);
 229         } else if (message instanceof ActorInitialized) {
 230             onActorInitialized(message);
 231         } else if (message instanceof ClusterEvent.MemberUp) {
 232             memberUp((ClusterEvent.MemberUp) message);
 233         } else if (message instanceof ClusterEvent.MemberWeaklyUp) {
 234             memberWeaklyUp((ClusterEvent.MemberWeaklyUp) message);
 235         } else if (message instanceof ClusterEvent.MemberExited) {
 236             memberExited((ClusterEvent.MemberExited) message);
 237         } else if (message instanceof ClusterEvent.MemberRemoved) {
 238             memberRemoved((ClusterEvent.MemberRemoved) message);
 239         } else if (message instanceof ClusterEvent.UnreachableMember) {
 240             memberUnreachable((ClusterEvent.UnreachableMember) message);
 241         } else if (message instanceof ClusterEvent.ReachableMember) {
 242             memberReachable((ClusterEvent.ReachableMember) message);
 243         } else if (message instanceof DatastoreContextFactory) {
 244             onDatastoreContextFactory((DatastoreContextFactory) message);
 245         } else if (message instanceof RoleChangeNotification) {
 246             onRoleChangeNotification((RoleChangeNotification) message);
 247         } else if (message instanceof FollowerInitialSyncUpStatus) {
 248             onFollowerInitialSyncStatus((FollowerInitialSyncUpStatus) message);
 249         } else if (message instanceof ShardNotInitializedTimeout) {
 250             onShardNotInitializedTimeout((ShardNotInitializedTimeout) message);
 251         } else if (message instanceof ShardLeaderStateChanged) {
 252             onLeaderStateChanged((ShardLeaderStateChanged) message);
 253         } else if (message instanceof SwitchShardBehavior) {
 254             onSwitchShardBehavior((SwitchShardBehavior) message);
 255         } else if (message instanceof CreateShard) {
 256             onCreateShard((CreateShard)message);
 257         } else if (message instanceof AddShardReplica) {
 258             onAddShardReplica((AddShardReplica) message);
 259         } else if (message instanceof AddPrefixShardReplica) {
 260             onAddPrefixShardReplica((AddPrefixShardReplica) message);
 261         } else if (message instanceof PrefixShardCreated) {
 262             onPrefixShardCreated((PrefixShardCreated) message);
 263         } else if (message instanceof PrefixShardRemoved) {
 264             onPrefixShardRemoved((PrefixShardRemoved) message);
 265         } else if (message instanceof InitConfigListener) {
 266             onInitConfigListener();
 267         } else if (message instanceof ForwardedAddServerReply) {
 268             ForwardedAddServerReply msg = (ForwardedAddServerReply)message;
 269             onAddServerReply(msg.shardInfo, msg.addServerReply, getSender(), msg.leaderPath,
 270                     msg.removeShardOnFailure);
 271         } else if (message instanceof ForwardedAddServerFailure) {
 272             ForwardedAddServerFailure msg = (ForwardedAddServerFailure)message;
 273             onAddServerFailure(msg.shardName, msg.failureMessage, msg.failure, getSender(), msg.removeShardOnFailure);
 274         } else if (message instanceof RemoveShardReplica) {
 275             onRemoveShardReplica((RemoveShardReplica) message);
 276         } else if (message instanceof RemovePrefixShardReplica) {
 277             onRemovePrefixShardReplica((RemovePrefixShardReplica) message);
 278         } else if (message instanceof WrappedShardResponse) {
 279             onWrappedShardResponse((WrappedShardResponse) message);
 280         } else if (message instanceof GetSnapshot) {
 281             onGetSnapshot();
 282         } else if (message instanceof ServerRemoved) {
 283             onShardReplicaRemoved((ServerRemoved) message);
 284         } else if (message instanceof ChangeShardMembersVotingStatus) {
 285             onChangeShardServersVotingStatus((ChangeShardMembersVotingStatus) message);
 286         } else if (message instanceof FlipShardMembersVotingStatus) {
 287             onFlipShardMembersVotingStatus((FlipShardMembersVotingStatus) message);
 288         } else if (message instanceof SaveSnapshotSuccess) {
 289             onSaveSnapshotSuccess((SaveSnapshotSuccess) message);
 290         } else if (message instanceof SaveSnapshotFailure) {
 291             LOG.error("{}: SaveSnapshotFailure received for saving snapshot of shards", persistenceId(),
 292                     ((SaveSnapshotFailure) message).cause());
 293         } else if (message instanceof Shutdown) {
 294             onShutDown();
 295         } else if (message instanceof GetLocalShardIds) {
 296             onGetLocalShardIds();
 297         } else if (message instanceof GetShardRole) {
 298             onGetShardRole((GetShardRole) message);
 299         } else if (message instanceof RunnableMessage) {
 300             ((RunnableMessage)message).run();
 301         } else if (message instanceof RegisterForShardAvailabilityChanges) {
 302             onRegisterForShardAvailabilityChanges((RegisterForShardAvailabilityChanges)message);
 303         } else if (message instanceof DeleteSnapshotsFailure) {
 304             LOG.warn("{}: Failed to delete prior snapshots", persistenceId(),
 305                     ((DeleteSnapshotsFailure) message).cause());
 306         } else if (message instanceof DeleteSnapshotsSuccess) {
 307             LOG.debug("{}: Successfully deleted prior snapshots", persistenceId());
 308         } else if (message instanceof RegisterRoleChangeListenerReply) {
 309             LOG.trace("{}: Received RegisterRoleChangeListenerReply", persistenceId());
 310         } else if (message instanceof ClusterEvent.MemberEvent) {
 311             LOG.trace("{}: Received other ClusterEvent.MemberEvent: {}", persistenceId(), message);
 312         } else {
 313             unknownMessage(message);
 314         }
 315     }
 316
 317     private void onRegisterForShardAvailabilityChanges(final RegisterForShardAvailabilityChanges message) {
 318         LOG.debug("{}: onRegisterForShardAvailabilityChanges: {}", persistenceId(), message);
 319
 320         final Consumer<String> callback = message.getCallback();
 321         shardAvailabilityCallbacks.add(callback);
 322
 323         getSender().tell(new Status.Success((Registration)
 324             () -> executeInSelf(() -> shardAvailabilityCallbacks.remove(callback))), self());
 325     }
 326
 327     private void onGetShardRole(final GetShardRole message) {
 328         LOG.debug("{}: onGetShardRole for shard: {}", persistenceId(), message.getName());
 329
 330         final String name = message.getName();
 331
 332         final ShardInformation shardInformation = localShards.get(name);
 333
 334         if (shardInformation == null) {
 335             LOG.info("{}: no shard information for {} found", persistenceId(), name);
 336             getSender().tell(new Status.Failure(
 337                     new IllegalArgumentException("Shard with name " + name + " not present.")), ActorRef.noSender());
 338             return;
 339         }
 340
 341         getSender().tell(new GetShardRoleReply(shardInformation.getRole()), ActorRef.noSender());
 342     }
 343
 344     private void onInitConfigListener() {
 345         LOG.debug("{}: Initializing config listener on {}", persistenceId(), cluster.getCurrentMemberName());
 346
 347         final org.opendaylight.mdsal.common.api.LogicalDatastoreType datastoreType =
 348                 org.opendaylight.mdsal.common.api.LogicalDatastoreType
 349                         .valueOf(datastoreContextFactory.getBaseDatastoreContext().getLogicalStoreType().name());
 350
 351         if (configUpdateHandler != null) {
 352             configUpdateHandler.close();
 353         }
 354
 355         configUpdateHandler = new PrefixedShardConfigUpdateHandler(self(), cluster.getCurrentMemberName());
 356         configUpdateHandler.initListener(dataStore, datastoreType);
 357     }
 358
 359     private void onShutDown() {
 360         List<Future<Boolean>> stopFutures = new ArrayList<>(localShards.size());
 361         for (ShardInformation info : localShards.values()) {
 362             if (info.getActor() != null) {
 363                 LOG.debug("{}: Issuing gracefulStop to shard {}", persistenceId(), info.getShardId());
 364
 365                 FiniteDuration duration = info.getDatastoreContext().getShardRaftConfig()
 366                         .getElectionTimeOutInterval().$times(2);
 367                 stopFutures.add(Patterns.gracefulStop(info.getActor(), duration, Shutdown.INSTANCE));
 368             }
 369         }
 370
 371         LOG.info("Shutting down ShardManager {} - waiting on {} shards", persistenceId(), stopFutures.size());
 372
 373         ExecutionContext dispatcher = new Dispatchers(context().system().dispatchers())
 374                 .getDispatcher(Dispatchers.DispatcherType.Client);
 375         Future<Iterable<Boolean>> combinedFutures = Futures.sequence(stopFutures, dispatcher);
 376
 377         combinedFutures.onComplete(new OnComplete<Iterable<Boolean>>() {
 378             @Override
 379             public void onComplete(final Throwable failure, final Iterable<Boolean> results) {
 380                 LOG.debug("{}: All shards shutdown - sending PoisonPill to self", persistenceId());
 381
 382                 self().tell(PoisonPill.getInstance(), self());
 383
 384                 if (failure != null) {
 385                     LOG.warn("{}: An error occurred attempting to shut down the shards", persistenceId(), failure);
 386                 } else {
 387                     int nfailed = 0;
 388                     for (Boolean result : results) {
 389                         if (!result) {
 390                             nfailed++;
 391                         }
 392                     }
 393
 394                     if (nfailed > 0) {
 395                         LOG.warn("{}: {} shards did not shut down gracefully", persistenceId(), nfailed);
 396                     }
 397                 }
 398             }
 399         }, dispatcher);
 400     }
 401
 402     private void onWrappedShardResponse(final WrappedShardResponse message) {
 403         if (message.getResponse() instanceof RemoveServerReply) {
 404             onRemoveServerReply(getSender(), message.getShardId(), (RemoveServerReply) message.getResponse(),
 405                     message.getLeaderPath());
 406         }
 407     }
 408
 409     private void onRemoveServerReply(final ActorRef originalSender, final ShardIdentifier shardId,
 410             final RemoveServerReply replyMsg, final String leaderPath) {
 411         shardReplicaOperationsInProgress.remove(shardId.getShardName());
 412
 413         LOG.debug("{}: Received {} for shard {}", persistenceId(), replyMsg, shardId.getShardName());
 414
 415         if (replyMsg.getStatus() == ServerChangeStatus.OK) {
 416             LOG.debug("{}: Leader shard successfully removed the replica shard {}", persistenceId(),
 417                     shardId.getShardName());
 418             originalSender.tell(new Status.Success(null), getSelf());
 419         } else {
 420             LOG.warn("{}: Leader failed to remove shard replica {} with status {}",
 421                     persistenceId(), shardId, replyMsg.getStatus());
 422
 423             Exception failure = getServerChangeException(RemoveServer.class, replyMsg.getStatus(), leaderPath, shardId);
 424             originalSender.tell(new Status.Failure(failure), getSelf());
 425         }
 426     }
 427
 428     private void removePrefixShardReplica(final RemovePrefixShardReplica contextMessage, final String shardName,
 429                                           final String primaryPath, final ActorRef sender) {
 430         if (isShardReplicaOperationInProgress(shardName, sender)) {
 431             return;
 432         }
 433
 434         shardReplicaOperationsInProgress.add(shardName);
 435
 436         final ShardIdentifier shardId = getShardIdentifier(contextMessage.getMemberName(), shardName);
 437
 438         final DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName).build();
 439
 440         //inform ShardLeader to remove this shard as a replica by sending an RemoveServer message
 441         LOG.debug("{}: Sending RemoveServer message to peer {} for shard {}", persistenceId(),
 442                 primaryPath, shardId);
 443
 444         Timeout removeServerTimeout = new Timeout(datastoreContext.getShardLeaderElectionTimeout().duration());
 445         Future<Object> futureObj = ask(getContext().actorSelection(primaryPath),
 446                 new RemoveServer(shardId.toString()), removeServerTimeout);
 447
 448         futureObj.onComplete(new OnComplete<Object>() {
 449             @Override
 450             public void onComplete(final Throwable failure, final Object response) {
 451                 if (failure != null) {
 452                     shardReplicaOperationsInProgress.remove(shardName);
 453
 454                     LOG.debug("{}: RemoveServer request to leader {} for shard {} failed", persistenceId(), primaryPath,
 455                         shardName, failure);
 456
 457                     // FAILURE
 458                     sender.tell(new Status.Failure(new RuntimeException(
 459                         String.format("RemoveServer request to leader %s for shard %s failed", primaryPath, shardName),
 460                         failure)), self());
 461                 } else {
 462                     // SUCCESS
 463                     self().tell(new WrappedShardResponse(shardId, response, primaryPath), sender);
 464                 }
 465             }
 466         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
 467     }
 468
 469     private void removeShardReplica(final RemoveShardReplica contextMessage, final String shardName,
 470             final String primaryPath, final ActorRef sender) {
 471         if (isShardReplicaOperationInProgress(shardName, sender)) {
 472             return;
 473         }
 474
 475         shardReplicaOperationsInProgress.add(shardName);
 476
 477         final ShardIdentifier shardId = getShardIdentifier(contextMessage.getMemberName(), shardName);
 478
 479         final DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName).build();
 480
 481         //inform ShardLeader to remove this shard as a replica by sending an RemoveServer message
 482         LOG.debug("{}: Sending RemoveServer message to peer {} for shard {}", persistenceId(),
 483                 primaryPath, shardId);
 484
 485         Timeout removeServerTimeout = new Timeout(datastoreContext.getShardLeaderElectionTimeout().duration());
 486         Future<Object> futureObj = ask(getContext().actorSelection(primaryPath),
 487                 new RemoveServer(shardId.toString()), removeServerTimeout);
 488
 489         futureObj.onComplete(new OnComplete<Object>() {
 490             @Override
 491             public void onComplete(final Throwable failure, final Object response) {
 492                 if (failure != null) {
 493                     shardReplicaOperationsInProgress.remove(shardName);
 494                     LOG.debug("{}: RemoveServer request to leader {} for shard {} failed", persistenceId(), primaryPath,
 495                         shardName, failure);
 496
 497                     // FAILURE
 498                     sender.tell(new Status.Failure(new RuntimeException(
 499                         String.format("RemoveServer request to leader %s for shard %s failed", primaryPath, shardName),
 500                         failure)), self());
 501                 } else {
 502                     // SUCCESS
 503                     self().tell(new WrappedShardResponse(shardId, response, primaryPath), sender);
 504                 }
 505             }
 506         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
 507     }
 508
 509     private void onShardReplicaRemoved(final ServerRemoved message) {
 510         removeShard(new ShardIdentifier.Builder().fromShardIdString(message.getServerId()).build());
 511     }
 512
 513     @SuppressWarnings("checkstyle:IllegalCatch")
 514     private void removeShard(final ShardIdentifier shardId) {
 515         final String shardName = shardId.getShardName();
 516         final ShardInformation shardInformation = localShards.remove(shardName);
 517         if (shardInformation == null) {
 518             LOG.debug("{} : Shard replica {} is not present in list", persistenceId(), shardId.toString());
 519             return;
 520         }
 521
 522         final ActorRef shardActor = shardInformation.getActor();
 523         if (shardActor != null) {
 524             long timeoutInMS = Math.max(shardInformation.getDatastoreContext().getShardRaftConfig()
 525                     .getElectionTimeOutInterval().$times(3).toMillis(), 10000);
 526
 527             LOG.debug("{} : Sending Shutdown to Shard actor {} with {} ms timeout", persistenceId(), shardActor,
 528                     timeoutInMS);
 529
 530             final Future<Boolean> stopFuture = Patterns.gracefulStop(shardActor,
 531                     FiniteDuration.apply(timeoutInMS, TimeUnit.MILLISECONDS), Shutdown.INSTANCE);
 532
 533             final CompositeOnComplete<Boolean> onComplete = new CompositeOnComplete<Boolean>() {
 534                 @Override
 535                 public void onComplete(final Throwable failure, final Boolean result) {
 536                     if (failure == null) {
 537                         LOG.debug("{} : Successfully shut down Shard actor {}", persistenceId(), shardActor);
 538                     } else {
 539                         LOG.warn("{}: Failed to shut down Shard actor {}", persistenceId(), shardActor, failure);
 540                     }
 541
 542                     self().tell((RunnableMessage) () -> {
 543                         // At any rate, invalidate primaryShardInfo cache
 544                         primaryShardInfoCache.remove(shardName);
 545
 546                         shardActorsStopping.remove(shardName);
 547                         notifyOnCompleteTasks(failure, result);
 548                     }, ActorRef.noSender());
 549                 }
 550             };
 551
 552             shardActorsStopping.put(shardName, onComplete);
 553             stopFuture.onComplete(onComplete, new Dispatchers(context().system().dispatchers())
 554                     .getDispatcher(Dispatchers.DispatcherType.Client));
 555         }
 556
 557         LOG.debug("{} : Local Shard replica for shard {} has been removed", persistenceId(), shardName);
 558         persistShardList();
 559     }
 560
 561     private void onGetSnapshot() {
 562         LOG.debug("{}: onGetSnapshot", persistenceId());
 563
 564         List<String> notInitialized = null;
 565         for (ShardInformation shardInfo : localShards.values()) {
 566             if (!shardInfo.isShardInitialized()) {
 567                 if (notInitialized == null) {
 568                     notInitialized = new ArrayList<>();
 569                 }
 570
 571                 notInitialized.add(shardInfo.getShardName());
 572             }
 573         }
 574
 575         if (notInitialized != null) {
 576             getSender().tell(new Status.Failure(new IllegalStateException(String.format(
 577                     "%d shard(s) %s are not initialized", notInitialized.size(), notInitialized))), getSelf());
 578             return;
 579         }
 580
 581         ActorRef replyActor = getContext().actorOf(ShardManagerGetSnapshotReplyActor.props(
 582                 new ArrayList<>(localShards.keySet()), type, currentSnapshot , getSender(), persistenceId(),
 583                 datastoreContextFactory.getBaseDatastoreContext().getShardInitializationTimeout().duration()));
 584
 585         for (ShardInformation shardInfo: localShards.values()) {
 586             shardInfo.getActor().tell(GetSnapshot.INSTANCE, replyActor);
 587         }
 588     }
 589
 590     @SuppressWarnings("checkstyle:IllegalCatch")
 591     private void onCreateShard(final CreateShard createShard) {
 592         LOG.debug("{}: onCreateShard: {}", persistenceId(), createShard);
 593
 594         Object reply;
 595         try {
 596             String shardName = createShard.getModuleShardConfig().getShardName();
 597             if (localShards.containsKey(shardName)) {
 598                 LOG.debug("{}: Shard {} already exists", persistenceId(), shardName);
 599                 reply = new Status.Success(String.format("Shard with name %s already exists", shardName));
 600             } else {
 601                 doCreateShard(createShard);
 602                 reply = new Status.Success(null);
 603             }
 604         } catch (Exception e) {
 605             LOG.error("{}: onCreateShard failed", persistenceId(), e);
 606             reply = new Status.Failure(e);
 607         }
 608
 609         if (getSender() != null && !getContext().system().deadLetters().equals(getSender())) {
 610             getSender().tell(reply, getSelf());
 611         }
 612     }
 613
 614     private void onPrefixShardCreated(final PrefixShardCreated message) {
 615         LOG.debug("{}: onPrefixShardCreated: {}", persistenceId(), message);
 616
 617         final PrefixShardConfiguration config = message.getConfiguration();
 618         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(),
 619                 ClusterUtils.getCleanShardName(config.getPrefix().getRootIdentifier()));
 620         final String shardName = shardId.getShardName();
 621
 622         if (isPreviousShardActorStopInProgress(shardName, message)) {
 623             return;
 624         }
 625
 626         if (localShards.containsKey(shardName)) {
 627             LOG.debug("{}: Received create for an already existing shard {}", persistenceId(), shardName);
 628             final PrefixShardConfiguration existing =
 629                     configuration.getAllPrefixShardConfigurations().get(config.getPrefix());
 630
 631             if (existing != null && existing.equals(config)) {
 632                 // we don't have to do nothing here
 633                 return;
 634             }
 635         }
 636
 637         doCreatePrefixShard(config, shardId, shardName);
 638     }
 639
 640     private boolean isPreviousShardActorStopInProgress(final String shardName, final Object messageToDefer) {
 641         final CompositeOnComplete<Boolean> stopOnComplete = shardActorsStopping.get(shardName);
 642         if (stopOnComplete == null) {
 643             return false;
 644         }
 645
 646         LOG.debug("{} : Stop is in progress for shard {} - adding OnComplete callback to defer {}", persistenceId(),
 647                 shardName, messageToDefer);
 648         final ActorRef sender = getSender();
 649         stopOnComplete.addOnComplete(new OnComplete<Boolean>() {
 650             @Override
 651             public void onComplete(final Throwable failure, final Boolean result) {
 652                 LOG.debug("{} : Stop complete for shard {} - re-queing {}", persistenceId(), shardName, messageToDefer);
 653                 self().tell(messageToDefer, sender);
 654             }
 655         });
 656
 657         return true;
 658     }
 659
 660     private void doCreatePrefixShard(final PrefixShardConfiguration config, final ShardIdentifier shardId,
 661             final String shardName) {
 662         configuration.addPrefixShardConfiguration(config);
 663
 664         final Builder builder = newShardDatastoreContextBuilder(shardName);
 665         builder.logicalStoreType(config.getPrefix().getDatastoreType())
 666                 .storeRoot(config.getPrefix().getRootIdentifier());
 667         DatastoreContext shardDatastoreContext = builder.build();
 668
 669         final Map<String, String> peerAddresses = getPeerAddresses(shardName);
 670         final boolean isActiveMember = true;
 671
 672         LOG.debug("{} doCreatePrefixShard: shardId: {}, memberNames: {}, peerAddresses: {}, isActiveMember: {}",
 673                 persistenceId(), shardId, config.getShardMemberNames(), peerAddresses, isActiveMember);
 674
 675         final ShardInformation info = new ShardInformation(shardName, shardId, peerAddresses,
 676                 shardDatastoreContext, Shard.builder(), peerAddressResolver);
 677         info.setActiveMember(isActiveMember);
 678         localShards.put(info.getShardName(), info);
 679
 680         if (schemaContext != null) {
 681             info.setSchemaContext(schemaContext);
 682             info.setActor(newShardActor(info));
 683         }
 684     }
 685
 686     private void onPrefixShardRemoved(final PrefixShardRemoved message) {
 687         LOG.debug("{}: onPrefixShardRemoved : {}", persistenceId(), message);
 688
 689         final DOMDataTreeIdentifier prefix = message.getPrefix();
 690         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(),
 691                 ClusterUtils.getCleanShardName(prefix.getRootIdentifier()));
 692
 693         configuration.removePrefixShardConfiguration(prefix);
 694         removeShard(shardId);
 695     }
 696
 697     private void doCreateShard(final CreateShard createShard) {
 698         final ModuleShardConfiguration moduleShardConfig = createShard.getModuleShardConfig();
 699         final String shardName = moduleShardConfig.getShardName();
 700
 701         configuration.addModuleShardConfiguration(moduleShardConfig);
 702
 703         DatastoreContext shardDatastoreContext = createShard.getDatastoreContext();
 704         if (shardDatastoreContext == null) {
 705             shardDatastoreContext = newShardDatastoreContext(shardName);
 706         } else {
 707             shardDatastoreContext = DatastoreContext.newBuilderFrom(shardDatastoreContext).shardPeerAddressResolver(
 708                     peerAddressResolver).build();
 709         }
 710
 711         ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
 712
 713         boolean shardWasInRecoveredSnapshot = currentSnapshot != null
 714                 && currentSnapshot.getShardList().contains(shardName);
 715
 716         Map<String, String> peerAddresses;
 717         boolean isActiveMember;
 718         if (shardWasInRecoveredSnapshot || configuration.getMembersFromShardName(shardName)
 719                 .contains(cluster.getCurrentMemberName())) {
 720             peerAddresses = getPeerAddresses(shardName);
 721             isActiveMember = true;
 722         } else {
 723             // The local member is not in the static shard member configuration and the shard did not
 724             // previously exist (ie !shardWasInRecoveredSnapshot). In this case we'll create
 725             // the shard with no peers and with elections disabled so it stays as follower. A
 726             // subsequent AddServer request will be needed to make it an active member.
 727             isActiveMember = false;
 728             peerAddresses = Collections.emptyMap();
 729             shardDatastoreContext = DatastoreContext.newBuilderFrom(shardDatastoreContext)
 730                     .customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName()).build();
 731         }
 732
 733         LOG.debug("{} doCreateShard: shardId: {}, memberNames: {}, peerAddresses: {}, isActiveMember: {}",
 734                 persistenceId(), shardId, moduleShardConfig.getShardMemberNames(), peerAddresses,
 735                 isActiveMember);
 736
 737         ShardInformation info = new ShardInformation(shardName, shardId, peerAddresses,
 738                 shardDatastoreContext, createShard.getShardBuilder(), peerAddressResolver);
 739         info.setActiveMember(isActiveMember);
 740         localShards.put(info.getShardName(), info);
 741
 742         if (schemaContext != null) {
 743             info.setSchemaContext(schemaContext);
 744             info.setActor(newShardActor(info));
 745         }
 746     }
 747
 748     private DatastoreContext.Builder newShardDatastoreContextBuilder(final String shardName) {
 749         return DatastoreContext.newBuilderFrom(datastoreContextFactory.getShardDatastoreContext(shardName))
 750                 .shardPeerAddressResolver(peerAddressResolver);
 751     }
 752
 753     private DatastoreContext newShardDatastoreContext(final String shardName) {
 754         return newShardDatastoreContextBuilder(shardName).build();
 755     }
 756
 757     private void checkReady() {
 758         if (isReadyWithLeaderId()) {
 759             LOG.info("{}: All Shards are ready - data store {} is ready, available count is {}",
 760                     persistenceId(), type, waitTillReadyCountdownLatch.getCount());
 761
 762             waitTillReadyCountdownLatch.countDown();
 763         }
 764     }
 765
 766     private void onLeaderStateChanged(final ShardLeaderStateChanged leaderStateChanged) {
 767         LOG.info("{}: Received LeaderStateChanged message: {}", persistenceId(), leaderStateChanged);
 768
 769         ShardInformation shardInformation = findShardInformation(leaderStateChanged.getMemberId());
 770         if (shardInformation != null) {
 771             shardInformation.setLocalDataTree(leaderStateChanged.getLocalShardDataTree());
 772             shardInformation.setLeaderVersion(leaderStateChanged.getLeaderPayloadVersion());
 773             if (shardInformation.setLeaderId(leaderStateChanged.getLeaderId())) {
 774                 primaryShardInfoCache.remove(shardInformation.getShardName());
 775
 776                 notifyShardAvailabilityCallbacks(shardInformation);
 777             }
 778
 779             checkReady();
 780         } else {
 781             LOG.debug("No shard found with member Id {}", leaderStateChanged.getMemberId());
 782         }
 783     }
 784
 785     private void notifyShardAvailabilityCallbacks(final ShardInformation shardInformation) {
 786         shardAvailabilityCallbacks.forEach(callback -> callback.accept(shardInformation.getShardName()));
 787     }
 788
 789     private void onShardNotInitializedTimeout(final ShardNotInitializedTimeout message) {
 790         ShardInformation shardInfo = message.getShardInfo();
 791
 792         LOG.debug("{}: Received ShardNotInitializedTimeout message for shard {}", persistenceId(),
 793                 shardInfo.getShardName());
 794
 795         shardInfo.removeOnShardInitialized(message.getOnShardInitialized());
 796
 797         if (!shardInfo.isShardInitialized()) {
 798             LOG.debug("{}: Returning NotInitializedException for shard {}", persistenceId(), shardInfo.getShardName());
 799             message.getSender().tell(createNotInitializedException(shardInfo.getShardId()), getSelf());
 800         } else {
 801             LOG.debug("{}: Returning NoShardLeaderException for shard {}", persistenceId(), shardInfo.getShardName());
 802             message.getSender().tell(new NoShardLeaderException(shardInfo.getShardId()), getSelf());
 803         }
 804     }
 805
 806     private void onFollowerInitialSyncStatus(final FollowerInitialSyncUpStatus status) {
 807         LOG.info("{} Received follower initial sync status for {} status sync done {}", persistenceId(),
 808                 status.getName(), status.isInitialSyncDone());
 809
 810         ShardInformation shardInformation = findShardInformation(status.getName());
 811
 812         if (shardInformation != null) {
 813             shardInformation.setFollowerSyncStatus(status.isInitialSyncDone());
 814
 815             shardManagerMBean.setSyncStatus(isInSync());
 816         }
 817
 818     }
 819
 820     private void onRoleChangeNotification(final RoleChangeNotification roleChanged) {
 821         LOG.info("{}: Received role changed for {} from {} to {}", persistenceId(), roleChanged.getMemberId(),
 822                 roleChanged.getOldRole(), roleChanged.getNewRole());
 823
 824         ShardInformation shardInformation = findShardInformation(roleChanged.getMemberId());
 825         if (shardInformation != null) {
 826             shardInformation.setRole(roleChanged.getNewRole());
 827             checkReady();
 828             shardManagerMBean.setSyncStatus(isInSync());
 829         }
 830     }
 831
 832
 833     private ShardInformation findShardInformation(final String memberId) {
 834         for (ShardInformation info : localShards.values()) {
 835             if (info.getShardId().toString().equals(memberId)) {
 836                 return info;
 837             }
 838         }
 839
 840         return null;
 841     }
 842
 843     private boolean isReadyWithLeaderId() {
 844         boolean isReady = true;
 845         for (ShardInformation info : localShards.values()) {
 846             if (!info.isShardReadyWithLeaderId()) {
 847                 isReady = false;
 848                 break;
 849             }
 850         }
 851         return isReady;
 852     }
 853
 854     private boolean isInSync() {
 855         for (ShardInformation info : localShards.values()) {
 856             if (!info.isInSync()) {
 857                 return false;
 858             }
 859         }
 860         return true;
 861     }
 862
 863     private void onActorInitialized(final Object message) {
 864         final ActorRef sender = getSender();
 865
 866         if (sender == null) {
 867             // why is a non-actor sending this message? Just ignore.
 868             return;
 869         }
 870
 871         String actorName = sender.path().name();
 872         //find shard name from actor name; actor name is stringified shardId
 873
 874         final ShardIdentifier shardId;
 875         try {
 876             shardId = ShardIdentifier.fromShardIdString(actorName);
 877         } catch (IllegalArgumentException e) {
 878             LOG.debug("{}: ignoring actor {}", persistenceId, actorName, e);
 879             return;
 880         }
 881
 882         markShardAsInitialized(shardId.getShardName());
 883     }
 884
 885     private void markShardAsInitialized(final String shardName) {
 886         LOG.debug("{}: Initializing shard [{}]", persistenceId(), shardName);
 887
 888         ShardInformation shardInformation = localShards.get(shardName);
 889         if (shardInformation != null) {
 890             shardInformation.setActorInitialized();
 891
 892             shardInformation.getActor().tell(new RegisterRoleChangeListener(), self());
 893         }
 894     }
 895
 896     @Override
 897     protected void handleRecover(final Object message) throws Exception {
 898         if (message instanceof RecoveryCompleted) {
 899             onRecoveryCompleted();
 900         } else if (message instanceof SnapshotOffer) {
 901             applyShardManagerSnapshot((ShardManagerSnapshot)((SnapshotOffer) message).snapshot());
 902         }
 903     }
 904
 905     @SuppressWarnings("checkstyle:IllegalCatch")
 906     private void onRecoveryCompleted() {
 907         LOG.info("Recovery complete : {}", persistenceId());
 908
 909         if (currentSnapshot == null && restoreFromSnapshot != null
 910                 && restoreFromSnapshot.getShardManagerSnapshot() != null) {
 911             ShardManagerSnapshot snapshot = restoreFromSnapshot.getShardManagerSnapshot();
 912
 913             LOG.debug("{}: Restoring from ShardManagerSnapshot: {}", persistenceId(), snapshot);
 914
 915             applyShardManagerSnapshot(snapshot);
 916         }
 917
 918         createLocalShards();
 919     }
 920
 921     private void sendResponse(final ShardInformation shardInformation, final boolean doWait,
 922             final boolean wantShardReady, final Supplier<Object> messageSupplier) {
 923         if (!shardInformation.isShardInitialized() || wantShardReady && !shardInformation.isShardReadyWithLeaderId()) {
 924             if (doWait) {
 925                 final ActorRef sender = getSender();
 926                 final ActorRef self = self();
 927
 928                 Runnable replyRunnable = () -> sender.tell(messageSupplier.get(), self);
 929
 930                 OnShardInitialized onShardInitialized = wantShardReady ? new OnShardReady(replyRunnable) :
 931                     new OnShardInitialized(replyRunnable);
 932
 933                 shardInformation.addOnShardInitialized(onShardInitialized);
 934
 935                 FiniteDuration timeout = shardInformation.getDatastoreContext()
 936                         .getShardInitializationTimeout().duration();
 937                 if (shardInformation.isShardInitialized()) {
 938                     // If the shard is already initialized then we'll wait enough time for the shard to
 939                     // elect a leader, ie 2 times the election timeout.
 940                     timeout = FiniteDuration.create(shardInformation.getDatastoreContext().getShardRaftConfig()
 941                             .getElectionTimeOutInterval().toMillis() * 2, TimeUnit.MILLISECONDS);
 942                 }
 943
 944                 LOG.debug("{}: Scheduling {} ms timer to wait for shard {}", persistenceId(), timeout.toMillis(),
 945                         shardInformation);
 946
 947                 Cancellable timeoutSchedule = getContext().system().scheduler().scheduleOnce(
 948                         timeout, getSelf(),
 949                         new ShardNotInitializedTimeout(shardInformation, onShardInitialized, sender),
 950                         getContext().dispatcher(), getSelf());
 951
 952                 onShardInitialized.setTimeoutSchedule(timeoutSchedule);
 953
 954             } else if (!shardInformation.isShardInitialized()) {
 955                 LOG.debug("{}: Returning NotInitializedException for shard {}", persistenceId(),
 956                         shardInformation.getShardName());
 957                 getSender().tell(createNotInitializedException(shardInformation.getShardId()), getSelf());
 958             } else {
 959                 LOG.debug("{}: Returning NoShardLeaderException for shard {}", persistenceId(),
 960                         shardInformation.getShardName());
 961                 getSender().tell(new NoShardLeaderException(shardInformation.getShardId()), getSelf());
 962             }
 963
 964             return;
 965         }
 966
 967         getSender().tell(messageSupplier.get(), getSelf());
 968     }
 969
 970     private static NotInitializedException createNotInitializedException(final ShardIdentifier shardId) {
 971         return new NotInitializedException(String.format(
 972                 "Found primary shard %s but it's not initialized yet. Please try again later", shardId));
 973     }
 974
 975     @VisibleForTesting
 976     static MemberName memberToName(final Member member) {
 977         return MemberName.forName(member.roles().iterator().next());
 978     }
 979
 980     private void memberRemoved(final ClusterEvent.MemberRemoved message) {
 981         MemberName memberName = memberToName(message.member());
 982
 983         LOG.info("{}: Received MemberRemoved: memberName: {}, address: {}", persistenceId(), memberName,
 984                 message.member().address());
 985
 986         peerAddressResolver.removePeerAddress(memberName);
 987
 988         for (ShardInformation info : localShards.values()) {
 989             info.peerDown(memberName, getShardIdentifier(memberName, info.getShardName()).toString(), getSelf());
 990         }
 991     }
 992
 993     private void memberExited(final ClusterEvent.MemberExited message) {
 994         MemberName memberName = memberToName(message.member());
 995
 996         LOG.info("{}: Received MemberExited: memberName: {}, address: {}", persistenceId(), memberName,
 997                 message.member().address());
 998
 999         peerAddressResolver.removePeerAddress(memberName);
1000
1001         for (ShardInformation info : localShards.values()) {
1002             info.peerDown(memberName, getShardIdentifier(memberName, info.getShardName()).toString(), getSelf());
1003         }
1004     }
1005
1006     private void memberUp(final ClusterEvent.MemberUp message) {
1007         MemberName memberName = memberToName(message.member());
1008
1009         LOG.info("{}: Received MemberUp: memberName: {}, address: {}", persistenceId(), memberName,
1010                 message.member().address());
1011
1012         memberUp(memberName, message.member().address());
1013     }
1014
1015     private void memberUp(final MemberName memberName, final Address address) {
1016         addPeerAddress(memberName, address);
1017         checkReady();
1018     }
1019
1020     private void memberWeaklyUp(final MemberWeaklyUp message) {
1021         MemberName memberName = memberToName(message.member());
1022
1023         LOG.info("{}: Received MemberWeaklyUp: memberName: {}, address: {}", persistenceId(), memberName,
1024                 message.member().address());
1025
1026         memberUp(memberName, message.member().address());
1027     }
1028
1029     private void addPeerAddress(final MemberName memberName, final Address address) {
1030         peerAddressResolver.addPeerAddress(memberName, address);
1031
1032         for (ShardInformation info : localShards.values()) {
1033             String shardName = info.getShardName();
1034             String peerId = getShardIdentifier(memberName, shardName).toString();
1035             info.updatePeerAddress(peerId, peerAddressResolver.getShardActorAddress(shardName, memberName), getSelf());
1036
1037             info.peerUp(memberName, peerId, getSelf());
1038         }
1039     }
1040
1041     private void memberReachable(final ClusterEvent.ReachableMember message) {
1042         MemberName memberName = memberToName(message.member());
1043         LOG.info("Received ReachableMember: memberName {}, address: {}", memberName, message.member().address());
1044
1045         addPeerAddress(memberName, message.member().address());
1046
1047         markMemberAvailable(memberName);
1048     }
1049
1050     private void memberUnreachable(final ClusterEvent.UnreachableMember message) {
1051         MemberName memberName = memberToName(message.member());
1052         LOG.info("Received UnreachableMember: memberName {}, address: {}", memberName, message.member().address());
1053
1054         markMemberUnavailable(memberName);
1055     }
1056
1057     private void markMemberUnavailable(final MemberName memberName) {
1058         for (ShardInformation info : localShards.values()) {
1059             String leaderId = info.getLeaderId();
1060             if (leaderId != null && ShardIdentifier.fromShardIdString(leaderId).getMemberName().equals(memberName)) {
1061                 LOG.debug("Marking Leader {} as unavailable.", leaderId);
1062                 info.setLeaderAvailable(false);
1063
1064                 primaryShardInfoCache.remove(info.getShardName());
1065
1066                 notifyShardAvailabilityCallbacks(info);
1067             }
1068
1069             info.peerDown(memberName, getShardIdentifier(memberName, info.getShardName()).toString(), getSelf());
1070         }
1071     }
1072
1073     private void markMemberAvailable(final MemberName memberName) {
1074         for (ShardInformation info : localShards.values()) {
1075             String leaderId = info.getLeaderId();
1076             if (leaderId != null && ShardIdentifier.fromShardIdString(leaderId).getMemberName().equals(memberName)) {
1077                 LOG.debug("Marking Leader {} as available.", leaderId);
1078                 info.setLeaderAvailable(true);
1079             }
1080
1081             info.peerUp(memberName, getShardIdentifier(memberName, info.getShardName()).toString(), getSelf());
1082         }
1083     }
1084
1085     private void onDatastoreContextFactory(final DatastoreContextFactory factory) {
1086         datastoreContextFactory = factory;
1087         for (ShardInformation info : localShards.values()) {
1088             info.setDatastoreContext(newShardDatastoreContext(info.getShardName()), getSelf());
1089         }
1090     }
1091
1092     private void onGetLocalShardIds() {
1093         final List<String> response = new ArrayList<>(localShards.size());
1094
1095         for (ShardInformation info : localShards.values()) {
1096             response.add(info.getShardId().toString());
1097         }
1098
1099         getSender().tell(new Status.Success(response), getSelf());
1100     }
1101
1102     private void onSwitchShardBehavior(final SwitchShardBehavior message) {
1103         final ShardIdentifier identifier = message.getShardId();
1104
1105         if (identifier != null) {
1106             final ShardInformation info = localShards.get(identifier.getShardName());
1107             if (info == null) {
1108                 getSender().tell(new Status.Failure(
1109                     new IllegalArgumentException("Shard " + identifier + " is not local")), getSelf());
1110                 return;
1111             }
1112
1113             switchShardBehavior(info, new SwitchBehavior(message.getNewState(), message.getTerm()));
1114         } else {
1115             for (ShardInformation info : localShards.values()) {
1116                 switchShardBehavior(info, new SwitchBehavior(message.getNewState(), message.getTerm()));
1117             }
1118         }
1119
1120         getSender().tell(new Status.Success(null), getSelf());
1121     }
1122
1123     private void switchShardBehavior(final ShardInformation info, final SwitchBehavior switchBehavior) {
1124         final ActorRef actor = info.getActor();
1125         if (actor != null) {
1126             actor.tell(switchBehavior, getSelf());
1127         } else {
1128             LOG.warn("Could not switch the behavior of shard {} to {} - shard is not yet available",
1129                 info.getShardName(), switchBehavior.getNewState());
1130         }
1131     }
1132
1133     /**
1134      * Notifies all the local shards of a change in the schema context.
1135      *
1136      * @param message the message to send
1137      */
1138     private void updateSchemaContext(final Object message) {
1139         schemaContext = ((UpdateSchemaContext) message).getSchemaContext();
1140
1141         LOG.debug("Got updated SchemaContext: # of modules {}", schemaContext.getModules().size());
1142
1143         for (ShardInformation info : localShards.values()) {
1144             info.setSchemaContext(schemaContext);
1145
1146             if (info.getActor() == null) {
1147                 LOG.debug("Creating Shard {}", info.getShardId());
1148                 info.setActor(newShardActor(info));
1149                 // Update peer address for every existing peer memeber to avoid missing sending
1150                 // PeerAddressResolved and PeerUp to this shard while UpdateSchemaContext comes after MemberUp.
1151                 String shardName = info.getShardName();
1152                 for (MemberName memberName : peerAddressResolver.getPeerMembers()) {
1153                     String peerId = getShardIdentifier(memberName, shardName).toString() ;
1154                     String peerAddress = peerAddressResolver.getShardActorAddress(shardName, memberName);
1155                     info.updatePeerAddress(peerId, peerAddress, getSelf());
1156                     info.peerUp(memberName, peerId, getSelf());
1157                     LOG.debug("{}: updated peer {} on member {} with address {} on shard {} whose actor address is {}",
1158                             persistenceId(), peerId, memberName, peerAddress, info.getShardId(), info.getActor());
1159                 }
1160             } else {
1161                 info.getActor().tell(message, getSelf());
1162             }
1163         }
1164     }
1165
1166     @VisibleForTesting
1167     protected ClusterWrapper getCluster() {
1168         return cluster;
1169     }
1170
1171     @VisibleForTesting
1172     protected ActorRef newShardActor(final ShardInformation info) {
1173         return getContext().actorOf(info.newProps().withDispatcher(shardDispatcherPath),
1174                 info.getShardId().toString());
1175     }
1176
1177     private void findPrimary(final FindPrimary message) {
1178         LOG.debug("{}: In findPrimary: {}", persistenceId(), message);
1179
1180         final String shardName = message.getShardName();
1181         final boolean canReturnLocalShardState = !(message instanceof RemoteFindPrimary);
1182
1183         // First see if the there is a local replica for the shard
1184         final ShardInformation info = localShards.get(shardName);
1185         if (info != null && info.isActiveMember()) {
1186             sendResponse(info, message.isWaitUntilReady(), true, () -> {
1187                 String primaryPath = info.getSerializedLeaderActor();
1188                 Object found = canReturnLocalShardState && info.isLeader()
1189                         ? new LocalPrimaryShardFound(primaryPath, info.getLocalShardDataTree().get()) :
1190                             new RemotePrimaryShardFound(primaryPath, info.getLeaderVersion());
1191
1192                 LOG.debug("{}: Found primary for {}: {}", persistenceId(), shardName, found);
1193                 return found;
1194             });
1195
1196             return;
1197         }
1198
1199         final Collection<String> visitedAddresses;
1200         if (message instanceof RemoteFindPrimary) {
1201             visitedAddresses = ((RemoteFindPrimary)message).getVisitedAddresses();
1202         } else {
1203             visitedAddresses = new ArrayList<>(1);
1204         }
1205
1206         visitedAddresses.add(peerAddressResolver.getShardManagerActorPathBuilder(cluster.getSelfAddress()).toString());
1207
1208         for (String address: peerAddressResolver.getShardManagerPeerActorAddresses()) {
1209             if (visitedAddresses.contains(address)) {
1210                 continue;
1211             }
1212
1213             LOG.debug("{}: findPrimary for {} forwarding to remote ShardManager {}, visitedAddresses: {}",
1214                     persistenceId(), shardName, address, visitedAddresses);
1215
1216             getContext().actorSelection(address).forward(new RemoteFindPrimary(shardName,
1217                     message.isWaitUntilReady(), visitedAddresses), getContext());
1218             return;
1219         }
1220
1221         LOG.debug("{}: No shard found for {}", persistenceId(), shardName);
1222
1223         getSender().tell(new PrimaryNotFoundException(
1224                 String.format("No primary shard found for %s.", shardName)), getSelf());
1225     }
1226
1227     private void findPrimary(final String shardName, final FindPrimaryResponseHandler handler) {
1228         Timeout findPrimaryTimeout = new Timeout(datastoreContextFactory.getBaseDatastoreContext()
1229                 .getShardInitializationTimeout().duration().$times(2));
1230
1231         Future<Object> futureObj = ask(getSelf(), new FindPrimary(shardName, true), findPrimaryTimeout);
1232         futureObj.onComplete(new OnComplete<Object>() {
1233             @Override
1234             public void onComplete(final Throwable failure, final Object response) {
1235                 if (failure != null) {
1236                     handler.onFailure(failure);
1237                 } else {
1238                     if (response instanceof RemotePrimaryShardFound) {
1239                         handler.onRemotePrimaryShardFound((RemotePrimaryShardFound) response);
1240                     } else if (response instanceof LocalPrimaryShardFound) {
1241                         handler.onLocalPrimaryFound((LocalPrimaryShardFound) response);
1242                     } else {
1243                         handler.onUnknownResponse(response);
1244                     }
1245                 }
1246             }
1247         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1248     }
1249
1250     /**
1251      * Construct the name of the shard actor given the name of the member on
1252      * which the shard resides and the name of the shard.
1253      *
1254      * @param memberName the member name
1255      * @param shardName the shard name
1256      * @return a b
1257      */
1258     private ShardIdentifier getShardIdentifier(final MemberName memberName, final String shardName) {
1259         return peerAddressResolver.getShardIdentifier(memberName, shardName);
1260     }
1261
1262     /**
1263      * Create shards that are local to the member on which the ShardManager runs.
1264      */
1265     private void createLocalShards() {
1266         MemberName memberName = this.cluster.getCurrentMemberName();
1267         Collection<String> memberShardNames = this.configuration.getMemberShardNames(memberName);
1268
1269         Map<String, DatastoreSnapshot.ShardSnapshot> shardSnapshots = new HashMap<>();
1270         if (restoreFromSnapshot != null) {
1271             for (DatastoreSnapshot.ShardSnapshot snapshot: restoreFromSnapshot.getShardSnapshots()) {
1272                 shardSnapshots.put(snapshot.getName(), snapshot);
1273             }
1274         }
1275
1276         // null out to GC
1277         restoreFromSnapshot = null;
1278
1279         for (String shardName : memberShardNames) {
1280             ShardIdentifier shardId = getShardIdentifier(memberName, shardName);
1281
1282             LOG.debug("{}: Creating local shard: {}", persistenceId(), shardId);
1283
1284             Map<String, String> peerAddresses = getPeerAddresses(shardName);
1285             localShards.put(shardName, createShardInfoFor(shardName, shardId, peerAddresses,
1286                     newShardDatastoreContext(shardName), shardSnapshots));
1287         }
1288     }
1289
1290     @VisibleForTesting
1291     ShardInformation createShardInfoFor(String shardName, ShardIdentifier shardId,
1292                                         Map<String, String> peerAddresses,
1293                                         DatastoreContext datastoreContext,
1294                                         Map<String, DatastoreSnapshot.ShardSnapshot> shardSnapshots) {
1295         return new ShardInformation(shardName, shardId, peerAddresses,
1296                 datastoreContext, Shard.builder().restoreFromSnapshot(shardSnapshots.get(shardName)),
1297                 peerAddressResolver);
1298     }
1299
1300     /**
1301      * Given the name of the shard find the addresses of all it's peers.
1302      *
1303      * @param shardName the shard name
1304      */
1305     Map<String, String> getPeerAddresses(final String shardName) {
1306         final Collection<MemberName> members = configuration.getMembersFromShardName(shardName);
1307         return getPeerAddresses(shardName, members);
1308     }
1309
1310     private Map<String, String> getPeerAddresses(final String shardName, final Collection<MemberName> members) {
1311         Map<String, String> peerAddresses = new HashMap<>();
1312         MemberName currentMemberName = this.cluster.getCurrentMemberName();
1313
1314         for (MemberName memberName : members) {
1315             if (!currentMemberName.equals(memberName)) {
1316                 ShardIdentifier shardId = getShardIdentifier(memberName, shardName);
1317                 String address = peerAddressResolver.getShardActorAddress(shardName, memberName);
1318                 peerAddresses.put(shardId.toString(), address);
1319             }
1320         }
1321         return peerAddresses;
1322     }
1323
1324     @Override
1325     public SupervisorStrategy supervisorStrategy() {
1326
1327         return new OneForOneStrategy(10, FiniteDuration.create(1, TimeUnit.MINUTES),
1328                 (Function<Throwable, Directive>) t -> {
1329                     LOG.warn("Supervisor Strategy caught unexpected exception - resuming", t);
1330                     return SupervisorStrategy.resume();
1331                 });
1332     }
1333
1334     @Override
1335     public String persistenceId() {
1336         return persistenceId;
1337     }
1338
1339     @VisibleForTesting
1340     ShardManagerInfoMBean getMBean() {
1341         return shardManagerMBean;
1342     }
1343
1344     private boolean isShardReplicaOperationInProgress(final String shardName, final ActorRef sender) {
1345         if (shardReplicaOperationsInProgress.contains(shardName)) {
1346             LOG.debug("{}: A shard replica operation for {} is already in progress", persistenceId(), shardName);
1347             sender.tell(new Status.Failure(new IllegalStateException(
1348                 String.format("A shard replica operation for %s is already in progress", shardName))), getSelf());
1349             return true;
1350         }
1351
1352         return false;
1353     }
1354
1355     private void onAddPrefixShardReplica(final AddPrefixShardReplica message) {
1356         LOG.debug("{}: onAddPrefixShardReplica: {}", persistenceId(), message);
1357
1358         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(),
1359                 ClusterUtils.getCleanShardName(message.getShardPrefix()));
1360         final String shardName = shardId.getShardName();
1361
1362         // Create the localShard
1363         if (schemaContext == null) {
1364             LOG.debug("{}: No SchemaContext is available in order to create a local shard instance for {}",
1365                 persistenceId(), shardName);
1366             getSender().tell(new Status.Failure(new IllegalStateException(
1367                 "No SchemaContext is available in order to create a local shard instance for " + shardName)),
1368                 getSelf());
1369             return;
1370         }
1371
1372         findPrimary(shardName, new AutoFindPrimaryFailureResponseHandler(getSender(), shardName, persistenceId(),
1373                 getSelf()) {
1374             @Override
1375             public void onRemotePrimaryShardFound(final RemotePrimaryShardFound response) {
1376                 final RunnableMessage runnable = (RunnableMessage) () -> addPrefixShard(getShardName(),
1377                         message.getShardPrefix(), response, getSender());
1378                 if (!isPreviousShardActorStopInProgress(getShardName(), runnable)) {
1379                     getSelf().tell(runnable, getTargetActor());
1380                 }
1381             }
1382
1383             @Override
1384             public void onLocalPrimaryFound(final LocalPrimaryShardFound message) {
1385                 sendLocalReplicaAlreadyExistsReply(getShardName(), getTargetActor());
1386             }
1387         });
1388     }
1389
1390     private void onAddShardReplica(final AddShardReplica shardReplicaMsg) {
1391         final String shardName = shardReplicaMsg.getShardName();
1392
1393         LOG.debug("{}: onAddShardReplica: {}", persistenceId(), shardReplicaMsg);
1394
1395         // verify the shard with the specified name is present in the cluster configuration
1396         if (!this.configuration.isShardConfigured(shardName)) {
1397             LOG.debug("{}: No module configuration exists for shard {}", persistenceId(), shardName);
1398             getSender().tell(new Status.Failure(new IllegalArgumentException(
1399                 "No module configuration exists for shard " + shardName)), getSelf());
1400             return;
1401         }
1402
1403         // Create the localShard
1404         if (schemaContext == null) {
1405             LOG.debug("{}: No SchemaContext is available in order to create a local shard instance for {}",
1406                 persistenceId(), shardName);
1407             getSender().tell(new Status.Failure(new IllegalStateException(
1408                 "No SchemaContext is available in order to create a local shard instance for " + shardName)),
1409                 getSelf());
1410             return;
1411         }
1412
1413         findPrimary(shardName, new AutoFindPrimaryFailureResponseHandler(getSender(), shardName, persistenceId(),
1414                 getSelf()) {
1415             @Override
1416             public void onRemotePrimaryShardFound(final RemotePrimaryShardFound response) {
1417                 final RunnableMessage runnable = (RunnableMessage) () ->
1418                     addShard(getShardName(), response, getSender());
1419                 if (!isPreviousShardActorStopInProgress(getShardName(), runnable)) {
1420                     getSelf().tell(runnable, getTargetActor());
1421                 }
1422             }
1423
1424             @Override
1425             public void onLocalPrimaryFound(final LocalPrimaryShardFound message) {
1426                 sendLocalReplicaAlreadyExistsReply(getShardName(), getTargetActor());
1427             }
1428         });
1429     }
1430
1431     private void sendLocalReplicaAlreadyExistsReply(final String shardName, final ActorRef sender) {
1432         LOG.debug("{}: Local shard {} already exists", persistenceId(), shardName);
1433         sender.tell(new Status.Failure(new AlreadyExistsException(
1434             String.format("Local shard %s already exists", shardName))), getSelf());
1435     }
1436
1437     private void addPrefixShard(final String shardName, final YangInstanceIdentifier shardPrefix,
1438                                 final RemotePrimaryShardFound response, final ActorRef sender) {
1439         if (isShardReplicaOperationInProgress(shardName, sender)) {
1440             return;
1441         }
1442
1443         shardReplicaOperationsInProgress.add(shardName);
1444
1445         final ShardInformation shardInfo;
1446         final boolean removeShardOnFailure;
1447         ShardInformation existingShardInfo = localShards.get(shardName);
1448         if (existingShardInfo == null) {
1449             removeShardOnFailure = true;
1450             ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
1451
1452             final Builder builder = newShardDatastoreContextBuilder(shardName);
1453             builder.storeRoot(shardPrefix).customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName());
1454
1455             DatastoreContext datastoreContext = builder.build();
1456
1457             shardInfo = new ShardInformation(shardName, shardId, getPeerAddresses(shardName), datastoreContext,
1458                     Shard.builder(), peerAddressResolver);
1459             shardInfo.setActiveMember(false);
1460             shardInfo.setSchemaContext(schemaContext);
1461             localShards.put(shardName, shardInfo);
1462             shardInfo.setActor(newShardActor(shardInfo));
1463         } else {
1464             removeShardOnFailure = false;
1465             shardInfo = existingShardInfo;
1466         }
1467
1468         execAddShard(shardName, shardInfo, response, removeShardOnFailure, sender);
1469     }
1470
1471     private void addShard(final String shardName, final RemotePrimaryShardFound response, final ActorRef sender) {
1472         if (isShardReplicaOperationInProgress(shardName, sender)) {
1473             return;
1474         }
1475
1476         shardReplicaOperationsInProgress.add(shardName);
1477
1478         final ShardInformation shardInfo;
1479         final boolean removeShardOnFailure;
1480         ShardInformation existingShardInfo = localShards.get(shardName);
1481         if (existingShardInfo == null) {
1482             removeShardOnFailure = true;
1483             ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
1484
1485             DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName)
1486                     .customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName()).build();
1487
1488             shardInfo = new ShardInformation(shardName, shardId, getPeerAddresses(shardName), datastoreContext,
1489                     Shard.builder(), peerAddressResolver);
1490             shardInfo.setActiveMember(false);
1491             shardInfo.setSchemaContext(schemaContext);
1492             localShards.put(shardName, shardInfo);
1493             shardInfo.setActor(newShardActor(shardInfo));
1494         } else {
1495             removeShardOnFailure = false;
1496             shardInfo = existingShardInfo;
1497         }
1498
1499         execAddShard(shardName, shardInfo, response, removeShardOnFailure, sender);
1500     }
1501
1502     private void execAddShard(final String shardName,
1503                               final ShardInformation shardInfo,
1504                               final RemotePrimaryShardFound response,
1505                               final boolean removeShardOnFailure,
1506                               final ActorRef sender) {
1507
1508         final String localShardAddress =
1509                 peerAddressResolver.getShardActorAddress(shardName, cluster.getCurrentMemberName());
1510
1511         //inform ShardLeader to add this shard as a replica by sending an AddServer message
1512         LOG.debug("{}: Sending AddServer message to peer {} for shard {}", persistenceId(),
1513                 response.getPrimaryPath(), shardInfo.getShardId());
1514
1515         final Timeout addServerTimeout = new Timeout(shardInfo.getDatastoreContext()
1516                 .getShardLeaderElectionTimeout().duration());
1517         final Future<Object> futureObj = ask(getContext().actorSelection(response.getPrimaryPath()),
1518                 new AddServer(shardInfo.getShardId().toString(), localShardAddress, true), addServerTimeout);
1519
1520         futureObj.onComplete(new OnComplete<Object>() {
1521             @Override
1522             public void onComplete(final Throwable failure, final Object addServerResponse) {
1523                 if (failure != null) {
1524                     LOG.debug("{}: AddServer request to {} for {} failed", persistenceId(),
1525                             response.getPrimaryPath(), shardName, failure);
1526
1527                     final String msg = String.format("AddServer request to leader %s for shard %s failed",
1528                             response.getPrimaryPath(), shardName);
1529                     self().tell(new ForwardedAddServerFailure(shardName, msg, failure, removeShardOnFailure), sender);
1530                 } else {
1531                     self().tell(new ForwardedAddServerReply(shardInfo, (AddServerReply)addServerResponse,
1532                             response.getPrimaryPath(), removeShardOnFailure), sender);
1533                 }
1534             }
1535         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1536     }
1537
1538     private void onAddServerFailure(final String shardName, final String message, final Throwable failure,
1539             final ActorRef sender, final boolean removeShardOnFailure) {
1540         shardReplicaOperationsInProgress.remove(shardName);
1541
1542         if (removeShardOnFailure) {
1543             ShardInformation shardInfo = localShards.remove(shardName);
1544             if (shardInfo.getActor() != null) {
1545                 shardInfo.getActor().tell(PoisonPill.getInstance(), getSelf());
1546             }
1547         }
1548
1549         sender.tell(new Status.Failure(message == null ? failure :
1550             new RuntimeException(message, failure)), getSelf());
1551     }
1552
1553     private void onAddServerReply(final ShardInformation shardInfo, final AddServerReply replyMsg,
1554             final ActorRef sender, final String leaderPath, final boolean removeShardOnFailure) {
1555         String shardName = shardInfo.getShardName();
1556         shardReplicaOperationsInProgress.remove(shardName);
1557
1558         LOG.debug("{}: Received {} for shard {} from leader {}", persistenceId(), replyMsg, shardName, leaderPath);
1559
1560         if (replyMsg.getStatus() == ServerChangeStatus.OK) {
1561             LOG.debug("{}: Leader shard successfully added the replica shard {}", persistenceId(), shardName);
1562
1563             // Make the local shard voting capable
1564             shardInfo.setDatastoreContext(newShardDatastoreContext(shardName), getSelf());
1565             shardInfo.setActiveMember(true);
1566             persistShardList();
1567
1568             sender.tell(new Status.Success(null), getSelf());
1569         } else if (replyMsg.getStatus() == ServerChangeStatus.ALREADY_EXISTS) {
1570             sendLocalReplicaAlreadyExistsReply(shardName, sender);
1571         } else {
1572             LOG.warn("{}: Leader failed to add shard replica {} with status {}",
1573                     persistenceId(), shardName, replyMsg.getStatus());
1574
1575             Exception failure = getServerChangeException(AddServer.class, replyMsg.getStatus(), leaderPath,
1576                     shardInfo.getShardId());
1577
1578             onAddServerFailure(shardName, null, failure, sender, removeShardOnFailure);
1579         }
1580     }
1581
1582     private static Exception getServerChangeException(final Class<?> serverChange,
1583             final ServerChangeStatus serverChangeStatus, final String leaderPath, final ShardIdentifier shardId) {
1584         switch (serverChangeStatus) {
1585             case TIMEOUT:
1586                 return new TimeoutException(String.format(
1587                         "The shard leader %s timed out trying to replicate the initial data to the new shard %s."
1588                         + "Possible causes - there was a problem replicating the data or shard leadership changed "
1589                         + "while replicating the shard data", leaderPath, shardId.getShardName()));
1590             case NO_LEADER:
1591                 return new NoShardLeaderException(shardId);
1592             case NOT_SUPPORTED:
1593                 return new UnsupportedOperationException(String.format("%s request is not supported for shard %s",
1594                         serverChange.getSimpleName(), shardId.getShardName()));
1595             default :
1596                 return new RuntimeException(String.format("%s request to leader %s for shard %s failed with status %s",
1597                         serverChange.getSimpleName(), leaderPath, shardId.getShardName(), serverChangeStatus));
1598         }
1599     }
1600
1601     private void onRemoveShardReplica(final RemoveShardReplica shardReplicaMsg) {
1602         LOG.debug("{}: onRemoveShardReplica: {}", persistenceId(), shardReplicaMsg);
1603
1604         findPrimary(shardReplicaMsg.getShardName(), new AutoFindPrimaryFailureResponseHandler(getSender(),
1605                 shardReplicaMsg.getShardName(), persistenceId(), getSelf()) {
1606             @Override
1607             public void onRemotePrimaryShardFound(final RemotePrimaryShardFound response) {
1608                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1609             }
1610
1611             @Override
1612             public void onLocalPrimaryFound(final LocalPrimaryShardFound response) {
1613                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1614             }
1615
1616             private void doRemoveShardReplicaAsync(final String primaryPath) {
1617                 getSelf().tell((RunnableMessage) () -> removeShardReplica(shardReplicaMsg, getShardName(),
1618                         primaryPath, getSender()), getTargetActor());
1619             }
1620         });
1621     }
1622
1623     private void onRemovePrefixShardReplica(final RemovePrefixShardReplica message) {
1624         LOG.debug("{}: onRemovePrefixShardReplica: {}", persistenceId(), message);
1625
1626         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(),
1627                 ClusterUtils.getCleanShardName(message.getShardPrefix()));
1628         final String shardName = shardId.getShardName();
1629
1630         findPrimary(shardName, new AutoFindPrimaryFailureResponseHandler(getSender(),
1631                 shardName, persistenceId(), getSelf()) {
1632             @Override
1633             public void onRemotePrimaryShardFound(final RemotePrimaryShardFound response) {
1634                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1635             }
1636
1637             @Override
1638             public void onLocalPrimaryFound(final LocalPrimaryShardFound response) {
1639                 doRemoveShardReplicaAsync(response.getPrimaryPath());
1640             }
1641
1642             private void doRemoveShardReplicaAsync(final String primaryPath) {
1643                 getSelf().tell((RunnableMessage) () -> removePrefixShardReplica(message, getShardName(),
1644                         primaryPath, getSender()), getTargetActor());
1645             }
1646         });
1647     }
1648
1649     private void persistShardList() {
1650         List<String> shardList = new ArrayList<>(localShards.keySet());
1651         for (ShardInformation shardInfo : localShards.values()) {
1652             if (!shardInfo.isActiveMember()) {
1653                 shardList.remove(shardInfo.getShardName());
1654             }
1655         }
1656         LOG.debug("{}: persisting the shard list {}", persistenceId(), shardList);
1657         saveSnapshot(updateShardManagerSnapshot(shardList, configuration.getAllPrefixShardConfigurations()));
1658     }
1659
1660     private ShardManagerSnapshot updateShardManagerSnapshot(
1661             final List<String> shardList,
1662             final Map<DOMDataTreeIdentifier, PrefixShardConfiguration> allPrefixShardConfigurations) {
1663         currentSnapshot = new ShardManagerSnapshot(shardList, allPrefixShardConfigurations);
1664         return currentSnapshot;
1665     }
1666
1667     private void applyShardManagerSnapshot(final ShardManagerSnapshot snapshot) {
1668         currentSnapshot = snapshot;
1669
1670         LOG.debug("{}: onSnapshotOffer: {}", persistenceId(), currentSnapshot);
1671
1672         final MemberName currentMember = cluster.getCurrentMemberName();
1673         Set<String> configuredShardList =
1674             new HashSet<>(configuration.getMemberShardNames(currentMember));
1675         for (String shard : currentSnapshot.getShardList()) {
1676             if (!configuredShardList.contains(shard)) {
1677                 // add the current member as a replica for the shard
1678                 LOG.debug("{}: adding shard {}", persistenceId(), shard);
1679                 configuration.addMemberReplicaForShard(shard, currentMember);
1680             } else {
1681                 configuredShardList.remove(shard);
1682             }
1683         }
1684         for (String shard : configuredShardList) {
1685             // remove the member as a replica for the shard
1686             LOG.debug("{}: removing shard {}", persistenceId(), shard);
1687             configuration.removeMemberReplicaForShard(shard, currentMember);
1688         }
1689     }
1690
1691     private void onSaveSnapshotSuccess(final SaveSnapshotSuccess successMessage) {
1692         LOG.debug("{} saved ShardManager snapshot successfully. Deleting the prev snapshot if available",
1693             persistenceId());
1694         deleteSnapshots(new SnapshotSelectionCriteria(scala.Long.MaxValue(), successMessage.metadata().timestamp() - 1,
1695             0, 0));
1696     }
1697
1698     private void onChangeShardServersVotingStatus(final ChangeShardMembersVotingStatus changeMembersVotingStatus) {
1699         LOG.debug("{}: onChangeShardServersVotingStatus: {}", persistenceId(), changeMembersVotingStatus);
1700
1701         String shardName = changeMembersVotingStatus.getShardName();
1702         Map<String, Boolean> serverVotingStatusMap = new HashMap<>();
1703         for (Entry<String, Boolean> e: changeMembersVotingStatus.getMeberVotingStatusMap().entrySet()) {
1704             serverVotingStatusMap.put(getShardIdentifier(MemberName.forName(e.getKey()), shardName).toString(),
1705                     e.getValue());
1706         }
1707
1708         ChangeServersVotingStatus changeServersVotingStatus = new ChangeServersVotingStatus(serverVotingStatusMap);
1709
1710         findLocalShard(shardName, getSender(),
1711             localShardFound -> changeShardMembersVotingStatus(changeServersVotingStatus, shardName,
1712             localShardFound.getPath(), getSender()));
1713     }
1714
1715     private void onFlipShardMembersVotingStatus(final FlipShardMembersVotingStatus flipMembersVotingStatus) {
1716         LOG.debug("{}: onFlipShardMembersVotingStatus: {}", persistenceId(), flipMembersVotingStatus);
1717
1718         ActorRef sender = getSender();
1719         final String shardName = flipMembersVotingStatus.getShardName();
1720         findLocalShard(shardName, sender, localShardFound -> {
1721             Future<Object> future = ask(localShardFound.getPath(), GetOnDemandRaftState.INSTANCE,
1722                     Timeout.apply(30, TimeUnit.SECONDS));
1723
1724             future.onComplete(new OnComplete<Object>() {
1725                 @Override
1726                 public void onComplete(final Throwable failure, final Object response) {
1727                     if (failure != null) {
1728                         sender.tell(new Status.Failure(new RuntimeException(
1729                                 String.format("Failed to access local shard %s", shardName), failure)), self());
1730                         return;
1731                     }
1732
1733                     OnDemandRaftState raftState = (OnDemandRaftState) response;
1734                     Map<String, Boolean> serverVotingStatusMap = new HashMap<>();
1735                     for (Entry<String, Boolean> e: raftState.getPeerVotingStates().entrySet()) {
1736                         serverVotingStatusMap.put(e.getKey(), !e.getValue());
1737                     }
1738
1739                     serverVotingStatusMap.put(getShardIdentifier(cluster.getCurrentMemberName(), shardName)
1740                             .toString(), !raftState.isVoting());
1741
1742                     changeShardMembersVotingStatus(new ChangeServersVotingStatus(serverVotingStatusMap),
1743                             shardName, localShardFound.getPath(), sender);
1744                 }
1745             }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1746         });
1747
1748     }
1749
1750     private void findLocalShard(final FindLocalShard message) {
1751         LOG.debug("{}: findLocalShard : {}", persistenceId(), message.getShardName());
1752
1753         final ShardInformation shardInformation = localShards.get(message.getShardName());
1754
1755         if (shardInformation == null) {
1756             LOG.debug("{}: Local shard {} not found - shards present: {}",
1757                     persistenceId(), message.getShardName(), localShards.keySet());
1758
1759             getSender().tell(new LocalShardNotFound(message.getShardName()), getSelf());
1760             return;
1761         }
1762
1763         sendResponse(shardInformation, message.isWaitUntilInitialized(), false,
1764             () -> new LocalShardFound(shardInformation.getActor()));
1765     }
1766
1767     private void findLocalShard(final String shardName, final ActorRef sender,
1768             final Consumer<LocalShardFound> onLocalShardFound) {
1769         Timeout findLocalTimeout = new Timeout(datastoreContextFactory.getBaseDatastoreContext()
1770                 .getShardInitializationTimeout().duration().$times(2));
1771
1772         Future<Object> futureObj = ask(getSelf(), new FindLocalShard(shardName, true), findLocalTimeout);
1773         futureObj.onComplete(new OnComplete<Object>() {
1774             @Override
1775             public void onComplete(final Throwable failure, final Object response) {
1776                 if (failure != null) {
1777                     LOG.debug("{}: Received failure from FindLocalShard for shard {}", persistenceId, shardName,
1778                             failure);
1779                     sender.tell(new Status.Failure(new RuntimeException(
1780                             String.format("Failed to find local shard %s", shardName), failure)), self());
1781                 } else {
1782                     if (response instanceof LocalShardFound) {
1783                         getSelf().tell((RunnableMessage) () -> onLocalShardFound.accept((LocalShardFound) response),
1784                                 sender);
1785                     } else if (response instanceof LocalShardNotFound) {
1786                         LOG.debug("{}: Local shard {} does not exist", persistenceId, shardName);
1787                         sender.tell(new Status.Failure(new IllegalArgumentException(
1788                             String.format("Local shard %s does not exist", shardName))), self());
1789                     } else {
1790                         LOG.debug("{}: Failed to find local shard {}: received response: {}", persistenceId, shardName,
1791                             response);
1792                         sender.tell(new Status.Failure(response instanceof Throwable ? (Throwable) response
1793                                 : new RuntimeException(
1794                                     String.format("Failed to find local shard %s: received response: %s", shardName,
1795                                         response))), self());
1796                     }
1797                 }
1798             }
1799         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1800     }
1801
1802     private void changeShardMembersVotingStatus(final ChangeServersVotingStatus changeServersVotingStatus,
1803             final String shardName, final ActorRef shardActorRef, final ActorRef sender) {
1804         if (isShardReplicaOperationInProgress(shardName, sender)) {
1805             return;
1806         }
1807
1808         shardReplicaOperationsInProgress.add(shardName);
1809
1810         DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName).build();
1811         final ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
1812
1813         LOG.debug("{}: Sending ChangeServersVotingStatus message {} to local shard {}", persistenceId(),
1814                 changeServersVotingStatus, shardActorRef.path());
1815
1816         Timeout timeout = new Timeout(datastoreContext.getShardLeaderElectionTimeout().duration().$times(2));
1817         Future<Object> futureObj = ask(shardActorRef, changeServersVotingStatus, timeout);
1818
1819         futureObj.onComplete(new OnComplete<Object>() {
1820             @Override
1821             public void onComplete(final Throwable failure, final Object response) {
1822                 shardReplicaOperationsInProgress.remove(shardName);
1823                 if (failure != null) {
1824                     LOG.debug("{}: ChangeServersVotingStatus request to local shard {} failed", persistenceId(),
1825                         shardActorRef.path(), failure);
1826                     sender.tell(new Status.Failure(new RuntimeException(
1827                         String.format("ChangeServersVotingStatus request to local shard %s failed",
1828                             shardActorRef.path()), failure)), self());
1829                 } else {
1830                     LOG.debug("{}: Received {} from local shard {}", persistenceId(), response, shardActorRef.path());
1831
1832                     ServerChangeReply replyMsg = (ServerChangeReply) response;
1833                     if (replyMsg.getStatus() == ServerChangeStatus.OK) {
1834                         LOG.debug("{}: ChangeServersVotingStatus succeeded for shard {}", persistenceId(), shardName);
1835                         sender.tell(new Status.Success(null), getSelf());
1836                     } else if (replyMsg.getStatus() == ServerChangeStatus.INVALID_REQUEST) {
1837                         sender.tell(new Status.Failure(new IllegalArgumentException(String.format(
1838                                 "The requested voting state change for shard %s is invalid. At least one member "
1839                                 + "must be voting", shardId.getShardName()))), getSelf());
1840                     } else {
1841                         LOG.warn("{}: ChangeServersVotingStatus failed for shard {} with status {}",
1842                                 persistenceId(), shardName, replyMsg.getStatus());
1843
1844                         Exception error = getServerChangeException(ChangeServersVotingStatus.class,
1845                                 replyMsg.getStatus(), shardActorRef.path().toString(), shardId);
1846                         sender.tell(new Status.Failure(error), getSelf());
1847                     }
1848                 }
1849             }
1850         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1851     }
1852
1853     private static final class ForwardedAddServerReply {
1854         ShardInformation shardInfo;
1855         AddServerReply addServerReply;
1856         String leaderPath;
1857         boolean removeShardOnFailure;
1858
1859         ForwardedAddServerReply(final ShardInformation shardInfo, final AddServerReply addServerReply,
1860             final String leaderPath, final boolean removeShardOnFailure) {
1861             this.shardInfo = shardInfo;
1862             this.addServerReply = addServerReply;
1863             this.leaderPath = leaderPath;
1864             this.removeShardOnFailure = removeShardOnFailure;
1865         }
1866     }
1867
1868     private static final class ForwardedAddServerFailure {
1869         String shardName;
1870         String failureMessage;
1871         Throwable failure;
1872         boolean removeShardOnFailure;
1873
1874         ForwardedAddServerFailure(final String shardName, final String failureMessage, final Throwable failure,
1875                 final boolean removeShardOnFailure) {
1876             this.shardName = shardName;
1877             this.failureMessage = failureMessage;
1878             this.failure = failure;
1879             this.removeShardOnFailure = removeShardOnFailure;
1880         }
1881     }
1882
1883     static class OnShardInitialized {
1884         private final Runnable replyRunnable;
1885         private Cancellable timeoutSchedule;
1886
1887         OnShardInitialized(final Runnable replyRunnable) {
1888             this.replyRunnable = replyRunnable;
1889         }
1890
1891         Runnable getReplyRunnable() {
1892             return replyRunnable;
1893         }
1894
1895         Cancellable getTimeoutSchedule() {
1896             return timeoutSchedule;
1897         }
1898
1899         void setTimeoutSchedule(final Cancellable timeoutSchedule) {
1900             this.timeoutSchedule = timeoutSchedule;
1901         }
1902     }
1903
1904     static class OnShardReady extends OnShardInitialized {
1905         OnShardReady(final Runnable replyRunnable) {
1906             super(replyRunnable);
1907         }
1908     }
1909
1910     private interface RunnableMessage extends Runnable {
1911     }
1912
1913     /**
1914      * The FindPrimaryResponseHandler provides specific callback methods which are invoked when a response to the
1915      * a remote or local find primary message is processed.
1916      */
1917     private interface FindPrimaryResponseHandler {
1918         /**
1919          * Invoked when a Failure message is received as a response.
1920          *
1921          * @param failure the failure exception
1922          */
1923         void onFailure(Throwable failure);
1924
1925         /**
1926          * Invoked when a RemotePrimaryShardFound response is received.
1927          *
1928          * @param response the response
1929          */
1930         void onRemotePrimaryShardFound(RemotePrimaryShardFound response);
1931
1932         /**
1933          * Invoked when a LocalPrimaryShardFound response is received.
1934          *
1935          * @param response the response
1936          */
1937         void onLocalPrimaryFound(LocalPrimaryShardFound response);
1938
1939         /**
1940          * Invoked when an unknown response is received. This is another type of failure.
1941          *
1942          * @param response the response
1943          */
1944         void onUnknownResponse(Object response);
1945     }
1946
1947     /**
1948      * The AutoFindPrimaryFailureResponseHandler automatically processes Failure responses when finding a primary
1949      * replica and sends a wrapped Failure response to some targetActor.
1950      */
1951     private abstract static class AutoFindPrimaryFailureResponseHandler implements FindPrimaryResponseHandler {
1952         private final ActorRef targetActor;
1953         private final String shardName;
1954         private final String persistenceId;
1955         private final ActorRef shardManagerActor;
1956
1957         /**
1958          * Constructs an instance.
1959          *
1960          * @param targetActor The actor to whom the Failure response should be sent when a FindPrimary failure occurs
1961          * @param shardName The name of the shard for which the primary replica had to be found
1962          * @param persistenceId The persistenceId for the ShardManager
1963          * @param shardManagerActor The ShardManager actor which triggered the call to FindPrimary
1964          */
1965         protected AutoFindPrimaryFailureResponseHandler(final ActorRef targetActor, final String shardName,
1966                 final String persistenceId, final ActorRef shardManagerActor) {
1967             this.targetActor = Preconditions.checkNotNull(targetActor);
1968             this.shardName = Preconditions.checkNotNull(shardName);
1969             this.persistenceId = Preconditions.checkNotNull(persistenceId);
1970             this.shardManagerActor = Preconditions.checkNotNull(shardManagerActor);
1971         }
1972
1973         public ActorRef getTargetActor() {
1974             return targetActor;
1975         }
1976
1977         public String getShardName() {
1978             return shardName;
1979         }
1980
1981         @Override
1982         public void onFailure(final Throwable failure) {
1983             LOG.debug("{}: Received failure from FindPrimary for shard {}", persistenceId, shardName, failure);
1984             targetActor.tell(new Status.Failure(new RuntimeException(
1985                     String.format("Failed to find leader for shard %s", shardName), failure)), shardManagerActor);
1986         }
1987
1988         @Override
1989         public void onUnknownResponse(final Object response) {
1990             LOG.debug("{}: Failed to find leader for shard {}: received response: {}", persistenceId, shardName,
1991                 response);
1992             targetActor.tell(new Status.Failure(response instanceof Throwable ? (Throwable) response
1993                     : new RuntimeException(String.format("Failed to find leader for shard %s: received response: %s",
1994                         shardName, response))), shardManagerActor);
1995         }
1996     }
1997
1998     /**
1999      * The WrappedShardResponse class wraps a response from a Shard.
2000      */
2001     private static final class WrappedShardResponse {
2002         private final ShardIdentifier shardId;
2003         private final Object response;
2004         private final String leaderPath;
2005
2006         WrappedShardResponse(final ShardIdentifier shardId, final Object response, final String leaderPath) {
2007             this.shardId = shardId;
2008             this.response = response;
2009             this.leaderPath = leaderPath;
2010         }
2011
2012         ShardIdentifier getShardId() {
2013             return shardId;
2014         }
2015
2016         Object getResponse() {
2017             return response;
2018         }
2019
2020         String getLeaderPath() {
2021             return leaderPath;
2022         }
2023     }
2024
2025     private static final class ShardNotInitializedTimeout {
2026         private final ActorRef sender;
2027         private final ShardInformation shardInfo;
2028         private final OnShardInitialized onShardInitialized;
2029
2030         ShardNotInitializedTimeout(final ShardInformation shardInfo, final OnShardInitialized onShardInitialized,
2031             final ActorRef sender) {
2032             this.sender = sender;
2033             this.shardInfo = shardInfo;
2034             this.onShardInitialized = onShardInitialized;
2035         }
2036
2037         ActorRef getSender() {
2038             return sender;
2039         }
2040
2041         ShardInformation getShardInfo() {
2042             return shardInfo;
2043         }
2044
2045         OnShardInitialized getOnShardInitialized() {
2046             return onShardInitialized;
2047         }
2048     }
2049 }
2050
2051
2052