opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/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;
  10
  11 import static akka.pattern.Patterns.ask;
  12 import akka.actor.ActorPath;
  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.Props;
  19 import akka.actor.SupervisorStrategy;
  20 import akka.cluster.ClusterEvent;
  21 import akka.dispatch.OnComplete;
  22 import akka.japi.Function;
  23 import akka.persistence.RecoveryCompleted;
  24 import akka.persistence.SaveSnapshotFailure;
  25 import akka.persistence.SaveSnapshotSuccess;
  26 import akka.persistence.SnapshotOffer;
  27 import akka.serialization.Serialization;
  28 import akka.util.Timeout;
  29 import com.google.common.annotations.VisibleForTesting;
  30 import com.google.common.base.Objects;
  31 import com.google.common.base.Optional;
  32 import com.google.common.base.Preconditions;
  33 import com.google.common.base.Strings;
  34 import com.google.common.base.Supplier;
  35 import com.google.common.collect.Sets;
  36 import java.io.Serializable;
  37 import java.util.ArrayList;
  38 import java.util.Collection;
  39 import java.util.Collections;
  40 import java.util.HashMap;
  41 import java.util.HashSet;
  42 import java.util.Iterator;
  43 import java.util.List;
  44 import java.util.Map;
  45 import java.util.Set;
  46 import java.util.concurrent.CountDownLatch;
  47 import java.util.concurrent.TimeUnit;
  48 import java.util.concurrent.TimeoutException;
  49 import javax.annotation.Nonnull;
  50 import javax.annotation.Nullable;
  51 import org.opendaylight.controller.cluster.common.actor.AbstractUntypedPersistentActorWithMetering;
  52 import org.opendaylight.controller.cluster.datastore.config.Configuration;
  53 import org.opendaylight.controller.cluster.datastore.config.ModuleShardConfiguration;
  54 import org.opendaylight.controller.cluster.datastore.exceptions.AlreadyExistsException;
  55 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
  56 import org.opendaylight.controller.cluster.datastore.exceptions.NotInitializedException;
  57 import org.opendaylight.controller.cluster.datastore.exceptions.PrimaryNotFoundException;
  58 import org.opendaylight.controller.cluster.datastore.identifiers.ShardIdentifier;
  59 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shardmanager.ShardManagerInfo;
  60 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shardmanager.ShardManagerInfoMBean;
  61 import org.opendaylight.controller.cluster.datastore.messages.ActorInitialized;
  62 import org.opendaylight.controller.cluster.datastore.messages.AddShardReplica;
  63 import org.opendaylight.controller.cluster.datastore.messages.CreateShard;
  64 import org.opendaylight.controller.cluster.datastore.messages.DatastoreSnapshot;
  65 import org.opendaylight.controller.cluster.datastore.messages.FindLocalShard;
  66 import org.opendaylight.controller.cluster.datastore.messages.FindPrimary;
  67 import org.opendaylight.controller.cluster.datastore.messages.LocalPrimaryShardFound;
  68 import org.opendaylight.controller.cluster.datastore.messages.LocalShardFound;
  69 import org.opendaylight.controller.cluster.datastore.messages.LocalShardNotFound;
  70 import org.opendaylight.controller.cluster.datastore.messages.PeerAddressResolved;
  71 import org.opendaylight.controller.cluster.datastore.messages.PeerDown;
  72 import org.opendaylight.controller.cluster.datastore.messages.PeerUp;
  73 import org.opendaylight.controller.cluster.datastore.messages.RemoteFindPrimary;
  74 import org.opendaylight.controller.cluster.datastore.messages.RemotePrimaryShardFound;
  75 import org.opendaylight.controller.cluster.datastore.messages.RemoveShardReplica;
  76 import org.opendaylight.controller.cluster.datastore.messages.ShardLeaderStateChanged;
  77 import org.opendaylight.controller.cluster.datastore.messages.SwitchShardBehavior;
  78 import org.opendaylight.controller.cluster.datastore.messages.UpdateSchemaContext;
  79 import org.opendaylight.controller.cluster.datastore.utils.Dispatchers;
  80 import org.opendaylight.controller.cluster.datastore.utils.PrimaryShardInfoFutureCache;
  81 import org.opendaylight.controller.cluster.notifications.RegisterRoleChangeListener;
  82 import org.opendaylight.controller.cluster.notifications.RoleChangeNotification;
  83 import org.opendaylight.controller.cluster.raft.RaftState;
  84 import org.opendaylight.controller.cluster.raft.base.messages.FollowerInitialSyncUpStatus;
  85 import org.opendaylight.controller.cluster.raft.base.messages.SwitchBehavior;
  86 import org.opendaylight.controller.cluster.raft.client.messages.GetSnapshot;
  87 import org.opendaylight.controller.cluster.raft.messages.AddServer;
  88 import org.opendaylight.controller.cluster.raft.messages.AddServerReply;
  89 import org.opendaylight.controller.cluster.raft.messages.ServerChangeStatus;
  90 import org.opendaylight.controller.cluster.raft.messages.ServerRemoved;
  91 import org.opendaylight.controller.cluster.raft.policy.DisableElectionsRaftPolicy;
  92 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree;
  93 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  94 import org.slf4j.Logger;
  95 import org.slf4j.LoggerFactory;
  96 import scala.concurrent.Future;
  97 import scala.concurrent.duration.Duration;
  98 import scala.concurrent.duration.FiniteDuration;
  99
 100 /**
 101  * The ShardManager has the following jobs,
 102  * <ul>
 103  * <li> Create all the local shard replicas that belong on this cluster member
 104  * <li> Find the address of the local shard
 105  * <li> Find the primary replica for any given shard
 106  * <li> Monitor the cluster members and store their addresses
 107  * <ul>
 108  */
 109 public class ShardManager extends AbstractUntypedPersistentActorWithMetering {
 110
 111     private static final Logger LOG = LoggerFactory.getLogger(ShardManager.class);
 112
 113     // Stores a mapping between a shard name and it's corresponding information
 114     // Shard names look like inventory, topology etc and are as specified in
 115     // configuration
 116     private final Map<String, ShardInformation> localShards = new HashMap<>();
 117
 118     // The type of a ShardManager reflects the type of the datastore itself
 119     // A data store could be of type config/operational
 120     private final String type;
 121
 122     private final ClusterWrapper cluster;
 123
 124     private final Configuration configuration;
 125
 126     private final String shardDispatcherPath;
 127
 128     private final ShardManagerInfo mBean;
 129
 130     private DatastoreContextFactory datastoreContextFactory;
 131
 132     private final CountDownLatch waitTillReadyCountdownLatch;
 133
 134     private final PrimaryShardInfoFutureCache primaryShardInfoCache;
 135
 136     private final ShardPeerAddressResolver peerAddressResolver;
 137
 138     private SchemaContext schemaContext;
 139
 140     private DatastoreSnapshot restoreFromSnapshot;
 141
 142     private final Set<String> shardReplicaOperationsInProgress = new HashSet<>();
 143
 144     private final String persistenceId;
 145
 146     /**
 147      */
 148     protected ShardManager(Builder builder) {
 149
 150         this.cluster = builder.cluster;
 151         this.configuration = builder.configuration;
 152         this.datastoreContextFactory = builder.datastoreContextFactory;
 153         this.type = builder.datastoreContextFactory.getBaseDatastoreContext().getDataStoreType();
 154         this.shardDispatcherPath =
 155                 new Dispatchers(context().system().dispatchers()).getDispatcherPath(Dispatchers.DispatcherType.Shard);
 156         this.waitTillReadyCountdownLatch = builder.waitTillReadyCountdownLatch;
 157         this.primaryShardInfoCache = builder.primaryShardInfoCache;
 158         this.restoreFromSnapshot = builder.restoreFromSnapshot;
 159
 160         String possiblePersistenceId = datastoreContextFactory.getBaseDatastoreContext().getShardManagerPersistenceId();
 161         persistenceId = possiblePersistenceId != null ? possiblePersistenceId : "shard-manager-" + type;
 162
 163         peerAddressResolver = new ShardPeerAddressResolver(type, cluster.getCurrentMemberName());
 164
 165         // Subscribe this actor to cluster member events
 166         cluster.subscribeToMemberEvents(getSelf());
 167
 168         List<String> localShardActorNames = new ArrayList<>();
 169         mBean = ShardManagerInfo.createShardManagerMBean(cluster.getCurrentMemberName(),
 170                 "shard-manager-" + this.type,
 171                 datastoreContextFactory.getBaseDatastoreContext().getDataStoreMXBeanType(),
 172                 localShardActorNames);
 173         mBean.setShardManager(this);
 174     }
 175
 176     @Override
 177     public void postStop() {
 178         LOG.info("Stopping ShardManager");
 179
 180         mBean.unregisterMBean();
 181     }
 182
 183     @Override
 184     public void handleCommand(Object message) throws Exception {
 185         if (message  instanceof FindPrimary) {
 186             findPrimary((FindPrimary)message);
 187         } else if(message instanceof FindLocalShard){
 188             findLocalShard((FindLocalShard) message);
 189         } else if (message instanceof UpdateSchemaContext) {
 190             updateSchemaContext(message);
 191         } else if(message instanceof ActorInitialized) {
 192             onActorInitialized(message);
 193         } else if (message instanceof ClusterEvent.MemberUp){
 194             memberUp((ClusterEvent.MemberUp) message);
 195         } else if (message instanceof ClusterEvent.MemberExited){
 196             memberExited((ClusterEvent.MemberExited) message);
 197         } else if(message instanceof ClusterEvent.MemberRemoved) {
 198             memberRemoved((ClusterEvent.MemberRemoved) message);
 199         } else if(message instanceof ClusterEvent.UnreachableMember) {
 200             memberUnreachable((ClusterEvent.UnreachableMember)message);
 201         } else if(message instanceof ClusterEvent.ReachableMember) {
 202             memberReachable((ClusterEvent.ReachableMember) message);
 203         } else if(message instanceof DatastoreContextFactory) {
 204             onDatastoreContextFactory((DatastoreContextFactory)message);
 205         } else if(message instanceof RoleChangeNotification) {
 206             onRoleChangeNotification((RoleChangeNotification) message);
 207         } else if(message instanceof FollowerInitialSyncUpStatus){
 208             onFollowerInitialSyncStatus((FollowerInitialSyncUpStatus) message);
 209         } else if(message instanceof ShardNotInitializedTimeout) {
 210             onShardNotInitializedTimeout((ShardNotInitializedTimeout)message);
 211         } else if(message instanceof ShardLeaderStateChanged) {
 212             onLeaderStateChanged((ShardLeaderStateChanged) message);
 213         } else if(message instanceof SwitchShardBehavior){
 214             onSwitchShardBehavior((SwitchShardBehavior) message);
 215         } else if(message instanceof CreateShard) {
 216             onCreateShard((CreateShard)message);
 217         } else if(message instanceof AddShardReplica){
 218             onAddShardReplica((AddShardReplica)message);
 219         } else if(message instanceof ForwardedAddServerReply) {
 220             ForwardedAddServerReply msg = (ForwardedAddServerReply)message;
 221             onAddServerReply(msg.shardInfo, msg.addServerReply, getSender(), msg.leaderPath,
 222                     msg.removeShardOnFailure);
 223         } else if(message instanceof ForwardedAddServerFailure) {
 224             ForwardedAddServerFailure msg = (ForwardedAddServerFailure)message;
 225             onAddServerFailure(msg.shardName, msg.failureMessage, msg.failure, getSender(), msg.removeShardOnFailure);
 226         } else if(message instanceof PrimaryShardFoundForContext) {
 227             PrimaryShardFoundForContext primaryShardFoundContext = (PrimaryShardFoundForContext)message;
 228             onPrimaryShardFoundContext(primaryShardFoundContext);
 229         } else if(message instanceof RemoveShardReplica){
 230             onRemoveShardReplica((RemoveShardReplica)message);
 231         } else if(message instanceof GetSnapshot) {
 232             onGetSnapshot();
 233         } else if(message instanceof ServerRemoved){
 234             onShardReplicaRemoved((ServerRemoved) message);
 235         } else if (message instanceof SaveSnapshotSuccess) {
 236             LOG.debug("{} saved ShardManager snapshot successfully", persistenceId());
 237         } else if (message instanceof SaveSnapshotFailure) {
 238             LOG.error("{}: SaveSnapshotFailure received for saving snapshot of shards",
 239                     persistenceId(), ((SaveSnapshotFailure) message).cause());
 240         } else {
 241             unknownMessage(message);
 242         }
 243     }
 244
 245     private void onPrimaryShardFoundContext(PrimaryShardFoundForContext primaryShardFoundContext) {
 246         if(primaryShardFoundContext.getContextMessage() instanceof AddShardReplica) {
 247             addShard(primaryShardFoundContext.shardName, primaryShardFoundContext.getRemotePrimaryShardFound(), getSender());
 248         }
 249     }
 250
 251     private void onShardReplicaRemoved(ServerRemoved message) {
 252         final ShardIdentifier shardId = new ShardIdentifier.Builder().fromShardIdString(message.getServerId()).build();
 253         final ShardInformation shardInformation = localShards.remove(shardId.getShardName());
 254         if(shardInformation == null) {
 255             LOG.debug("{} : Shard replica {} is not present in list", persistenceId(), shardId.toString());
 256             return;
 257         } else if(shardInformation.getActor() != null) {
 258             LOG.debug("{} : Sending PoisonPill to Shard actor {}", persistenceId(), shardInformation.getActor());
 259             shardInformation.getActor().tell(PoisonPill.getInstance(), self());
 260         }
 261         LOG.debug("{} : Local Shard replica for shard {} has been removed", persistenceId(), shardId.getShardName());
 262         persistShardList();
 263     }
 264
 265     private void onGetSnapshot() {
 266         LOG.debug("{}: onGetSnapshot", persistenceId());
 267
 268         List<String> notInitialized = null;
 269         for(ShardInformation shardInfo: localShards.values()) {
 270             if(!shardInfo.isShardInitialized()) {
 271                 if(notInitialized == null) {
 272                     notInitialized = new ArrayList<>();
 273                 }
 274
 275                 notInitialized.add(shardInfo.getShardName());
 276             }
 277         }
 278
 279         if(notInitialized != null) {
 280             getSender().tell(new akka.actor.Status.Failure(new IllegalStateException(String.format(
 281                     "%d shard(s) %s are not initialized", notInitialized.size(), notInitialized))), getSelf());
 282             return;
 283         }
 284
 285         byte[] shardManagerSnapshot = null;
 286         ActorRef replyActor = getContext().actorOf(ShardManagerGetSnapshotReplyActor.props(
 287                 new ArrayList<>(localShards.keySet()), type, shardManagerSnapshot , getSender(), persistenceId(),
 288                 datastoreContextFactory.getBaseDatastoreContext().getShardInitializationTimeout().duration()));
 289
 290         for(ShardInformation shardInfo: localShards.values()) {
 291             shardInfo.getActor().tell(GetSnapshot.INSTANCE, replyActor);
 292         }
 293     }
 294
 295     private void onCreateShard(CreateShard createShard) {
 296         Object reply;
 297         try {
 298             String shardName = createShard.getModuleShardConfig().getShardName();
 299             if(localShards.containsKey(shardName)) {
 300                 reply = new akka.actor.Status.Success(String.format("Shard with name %s already exists", shardName));
 301             } else {
 302                 doCreateShard(createShard);
 303                 reply = new akka.actor.Status.Success(null);
 304             }
 305         } catch (Exception e) {
 306             LOG.error("onCreateShard failed", e);
 307             reply = new akka.actor.Status.Failure(e);
 308         }
 309
 310         if(getSender() != null && !getContext().system().deadLetters().equals(getSender())) {
 311             getSender().tell(reply, getSelf());
 312         }
 313     }
 314
 315     private void doCreateShard(CreateShard createShard) {
 316         ModuleShardConfiguration moduleShardConfig = createShard.getModuleShardConfig();
 317         String shardName = moduleShardConfig.getShardName();
 318
 319         configuration.addModuleShardConfiguration(moduleShardConfig);
 320
 321         DatastoreContext shardDatastoreContext = createShard.getDatastoreContext();
 322         if(shardDatastoreContext == null) {
 323             shardDatastoreContext = newShardDatastoreContext(shardName);
 324         } else {
 325             shardDatastoreContext = DatastoreContext.newBuilderFrom(shardDatastoreContext).shardPeerAddressResolver(
 326                     peerAddressResolver).build();
 327         }
 328
 329         ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
 330
 331         Map<String, String> peerAddresses;
 332         boolean isActiveMember;
 333         if(configuration.getMembersFromShardName(shardName).contains(cluster.getCurrentMemberName())) {
 334             peerAddresses = getPeerAddresses(shardName);
 335             isActiveMember = true;
 336         } else {
 337             // The local member is not in the given shard member configuration. In this case we'll create
 338             // the shard with no peers and with elections disabled so it stays as follower. A
 339             // subsequent AddServer request will be needed to make it an active member.
 340             isActiveMember = false;
 341             peerAddresses = Collections.emptyMap();
 342             shardDatastoreContext = DatastoreContext.newBuilderFrom(shardDatastoreContext).
 343                     customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName()).build();
 344         }
 345
 346         LOG.debug("onCreateShard: shardId: {}, memberNames: {}. peerAddresses: {}", shardId,
 347                 moduleShardConfig.getShardMemberNames(), peerAddresses);
 348
 349         ShardInformation info = new ShardInformation(shardName, shardId, peerAddresses,
 350                 shardDatastoreContext, createShard.getShardBuilder(), peerAddressResolver);
 351         info.setActiveMember(isActiveMember);
 352         localShards.put(info.getShardName(), info);
 353
 354         mBean.addLocalShard(shardId.toString());
 355
 356         if(schemaContext != null) {
 357             info.setActor(newShardActor(schemaContext, info));
 358         }
 359     }
 360
 361     private DatastoreContext.Builder newShardDatastoreContextBuilder(String shardName) {
 362         return DatastoreContext.newBuilderFrom(datastoreContextFactory.getShardDatastoreContext(shardName)).
 363                 shardPeerAddressResolver(peerAddressResolver);
 364     }
 365
 366     private DatastoreContext newShardDatastoreContext(String shardName) {
 367         return newShardDatastoreContextBuilder(shardName).build();
 368     }
 369
 370     private void checkReady(){
 371         if (isReadyWithLeaderId()) {
 372             LOG.info("{}: All Shards are ready - data store {} is ready, available count is {}",
 373                     persistenceId(), type, waitTillReadyCountdownLatch.getCount());
 374
 375             waitTillReadyCountdownLatch.countDown();
 376         }
 377     }
 378
 379     private void onLeaderStateChanged(ShardLeaderStateChanged leaderStateChanged) {
 380         LOG.info("{}: Received LeaderStateChanged message: {}", persistenceId(), leaderStateChanged);
 381
 382         ShardInformation shardInformation = findShardInformation(leaderStateChanged.getMemberId());
 383         if(shardInformation != null) {
 384             shardInformation.setLocalDataTree(leaderStateChanged.getLocalShardDataTree());
 385             shardInformation.setLeaderVersion(leaderStateChanged.getLeaderPayloadVersion());
 386             if(shardInformation.setLeaderId(leaderStateChanged.getLeaderId())) {
 387                 primaryShardInfoCache.remove(shardInformation.getShardName());
 388             }
 389
 390             checkReady();
 391         } else {
 392             LOG.debug("No shard found with member Id {}", leaderStateChanged.getMemberId());
 393         }
 394     }
 395
 396     private void onShardNotInitializedTimeout(ShardNotInitializedTimeout message) {
 397         ShardInformation shardInfo = message.getShardInfo();
 398
 399         LOG.debug("{}: Received ShardNotInitializedTimeout message for shard {}", persistenceId(),
 400                 shardInfo.getShardName());
 401
 402         shardInfo.removeOnShardInitialized(message.getOnShardInitialized());
 403
 404         if(!shardInfo.isShardInitialized()) {
 405             LOG.debug("{}: Returning NotInitializedException for shard {}", persistenceId(), shardInfo.getShardName());
 406             message.getSender().tell(createNotInitializedException(shardInfo.shardId), getSelf());
 407         } else {
 408             LOG.debug("{}: Returning NoShardLeaderException for shard {}", persistenceId(), shardInfo.getShardName());
 409             message.getSender().tell(createNoShardLeaderException(shardInfo.shardId), getSelf());
 410         }
 411     }
 412
 413     private void onFollowerInitialSyncStatus(FollowerInitialSyncUpStatus status) {
 414         LOG.info("{} Received follower initial sync status for {} status sync done {}", persistenceId(),
 415                 status.getName(), status.isInitialSyncDone());
 416
 417         ShardInformation shardInformation = findShardInformation(status.getName());
 418
 419         if(shardInformation != null) {
 420             shardInformation.setFollowerSyncStatus(status.isInitialSyncDone());
 421
 422             mBean.setSyncStatus(isInSync());
 423         }
 424
 425     }
 426
 427     private void onRoleChangeNotification(RoleChangeNotification roleChanged) {
 428         LOG.info("{}: Received role changed for {} from {} to {}", persistenceId(), roleChanged.getMemberId(),
 429                 roleChanged.getOldRole(), roleChanged.getNewRole());
 430
 431         ShardInformation shardInformation = findShardInformation(roleChanged.getMemberId());
 432         if(shardInformation != null) {
 433             shardInformation.setRole(roleChanged.getNewRole());
 434             checkReady();
 435             mBean.setSyncStatus(isInSync());
 436         }
 437     }
 438
 439
 440     private ShardInformation findShardInformation(String memberId) {
 441         for(ShardInformation info : localShards.values()){
 442             if(info.getShardId().toString().equals(memberId)){
 443                 return info;
 444             }
 445         }
 446
 447         return null;
 448     }
 449
 450     private boolean isReadyWithLeaderId() {
 451         boolean isReady = true;
 452         for (ShardInformation info : localShards.values()) {
 453             if(!info.isShardReadyWithLeaderId()){
 454                 isReady = false;
 455                 break;
 456             }
 457         }
 458         return isReady;
 459     }
 460
 461     private boolean isInSync(){
 462         for (ShardInformation info : localShards.values()) {
 463             if(!info.isInSync()){
 464                 return false;
 465             }
 466         }
 467         return true;
 468     }
 469
 470     private void onActorInitialized(Object message) {
 471         final ActorRef sender = getSender();
 472
 473         if (sender == null) {
 474             return; //why is a non-actor sending this message? Just ignore.
 475         }
 476
 477         String actorName = sender.path().name();
 478         //find shard name from actor name; actor name is stringified shardId
 479         ShardIdentifier shardId = ShardIdentifier.builder().fromShardIdString(actorName).build();
 480
 481         if (shardId.getShardName() == null) {
 482             return;
 483         }
 484
 485         markShardAsInitialized(shardId.getShardName());
 486     }
 487
 488     private void markShardAsInitialized(String shardName) {
 489         LOG.debug("{}: Initializing shard [{}]", persistenceId(), shardName);
 490
 491         ShardInformation shardInformation = localShards.get(shardName);
 492         if (shardInformation != null) {
 493             shardInformation.setActorInitialized();
 494
 495             shardInformation.getActor().tell(new RegisterRoleChangeListener(), self());
 496         }
 497     }
 498
 499     @Override
 500     protected void handleRecover(Object message) throws Exception {
 501         if (message instanceof RecoveryCompleted) {
 502             LOG.info("Recovery complete : {}", persistenceId());
 503
 504             // We no longer persist SchemaContext modules so delete all the prior messages from the akka
 505             // journal on upgrade from Helium.
 506             deleteMessages(lastSequenceNr());
 507             createLocalShards();
 508         } else if (message instanceof SnapshotOffer) {
 509             handleShardRecovery((SnapshotOffer) message);
 510         }
 511     }
 512
 513     private void findLocalShard(FindLocalShard message) {
 514         final ShardInformation shardInformation = localShards.get(message.getShardName());
 515
 516         if(shardInformation == null){
 517             getSender().tell(new LocalShardNotFound(message.getShardName()), getSelf());
 518             return;
 519         }
 520
 521         sendResponse(shardInformation, message.isWaitUntilInitialized(), false, new Supplier<Object>() {
 522             @Override
 523             public Object get() {
 524                 return new LocalShardFound(shardInformation.getActor());
 525             }
 526         });
 527     }
 528
 529     private void sendResponse(ShardInformation shardInformation, boolean doWait,
 530             boolean wantShardReady, final Supplier<Object> messageSupplier) {
 531         if (!shardInformation.isShardInitialized() || (wantShardReady && !shardInformation.isShardReadyWithLeaderId())) {
 532             if(doWait) {
 533                 final ActorRef sender = getSender();
 534                 final ActorRef self = self();
 535
 536                 Runnable replyRunnable = new Runnable() {
 537                     @Override
 538                     public void run() {
 539                         sender.tell(messageSupplier.get(), self);
 540                     }
 541                 };
 542
 543                 OnShardInitialized onShardInitialized = wantShardReady ? new OnShardReady(replyRunnable) :
 544                     new OnShardInitialized(replyRunnable);
 545
 546                 shardInformation.addOnShardInitialized(onShardInitialized);
 547
 548                 FiniteDuration timeout = shardInformation.getDatastoreContext().getShardInitializationTimeout().duration();
 549                 if(shardInformation.isShardInitialized()) {
 550                     // If the shard is already initialized then we'll wait enough time for the shard to
 551                     // elect a leader, ie 2 times the election timeout.
 552                     timeout = FiniteDuration.create(shardInformation.getDatastoreContext().getShardRaftConfig()
 553                             .getElectionTimeOutInterval().toMillis() * 2, TimeUnit.MILLISECONDS);
 554                 }
 555
 556                 LOG.debug("{}: Scheduling {} ms timer to wait for shard {}", persistenceId(), timeout.toMillis(),
 557                         shardInformation.getShardName());
 558
 559                 Cancellable timeoutSchedule = getContext().system().scheduler().scheduleOnce(
 560                         timeout, getSelf(),
 561                         new ShardNotInitializedTimeout(shardInformation, onShardInitialized, sender),
 562                         getContext().dispatcher(), getSelf());
 563
 564                 onShardInitialized.setTimeoutSchedule(timeoutSchedule);
 565
 566             } else if (!shardInformation.isShardInitialized()) {
 567                 LOG.debug("{}: Returning NotInitializedException for shard {}", persistenceId(),
 568                         shardInformation.getShardName());
 569                 getSender().tell(createNotInitializedException(shardInformation.shardId), getSelf());
 570             } else {
 571                 LOG.debug("{}: Returning NoShardLeaderException for shard {}", persistenceId(),
 572                         shardInformation.getShardName());
 573                 getSender().tell(createNoShardLeaderException(shardInformation.shardId), getSelf());
 574             }
 575
 576             return;
 577         }
 578
 579         getSender().tell(messageSupplier.get(), getSelf());
 580     }
 581
 582     private static NoShardLeaderException createNoShardLeaderException(ShardIdentifier shardId) {
 583         return new NoShardLeaderException(null, shardId.toString());
 584     }
 585
 586     private static NotInitializedException createNotInitializedException(ShardIdentifier shardId) {
 587         return new NotInitializedException(String.format(
 588                 "Found primary shard %s but it's not initialized yet. Please try again later", shardId));
 589     }
 590
 591     private void memberRemoved(ClusterEvent.MemberRemoved message) {
 592         String memberName = message.member().roles().head();
 593
 594         LOG.debug("{}: Received MemberRemoved: memberName: {}, address: {}", persistenceId(), memberName,
 595                 message.member().address());
 596
 597         peerAddressResolver.removePeerAddress(memberName);
 598
 599         for(ShardInformation info : localShards.values()){
 600             info.peerDown(memberName, getShardIdentifier(memberName, info.getShardName()).toString(), getSelf());
 601         }
 602     }
 603
 604     private void memberExited(ClusterEvent.MemberExited message) {
 605         String memberName = message.member().roles().head();
 606
 607         LOG.debug("{}: Received MemberExited: memberName: {}, address: {}", persistenceId(), memberName,
 608                 message.member().address());
 609
 610         peerAddressResolver.removePeerAddress(memberName);
 611
 612         for(ShardInformation info : localShards.values()){
 613             info.peerDown(memberName, getShardIdentifier(memberName, info.getShardName()).toString(), getSelf());
 614         }
 615     }
 616
 617     private void memberUp(ClusterEvent.MemberUp message) {
 618         String memberName = message.member().roles().head();
 619
 620         LOG.debug("{}: Received MemberUp: memberName: {}, address: {}", persistenceId(), memberName,
 621                 message.member().address());
 622
 623         addPeerAddress(memberName, message.member().address());
 624
 625         checkReady();
 626     }
 627
 628     private void addPeerAddress(String memberName, Address address) {
 629         peerAddressResolver.addPeerAddress(memberName, address);
 630
 631         for(ShardInformation info : localShards.values()){
 632             String shardName = info.getShardName();
 633             String peerId = getShardIdentifier(memberName, shardName).toString();
 634             info.updatePeerAddress(peerId, peerAddressResolver.getShardActorAddress(shardName, memberName), getSelf());
 635
 636             info.peerUp(memberName, peerId, getSelf());
 637         }
 638     }
 639
 640     private void memberReachable(ClusterEvent.ReachableMember message) {
 641         String memberName = message.member().roles().head();
 642         LOG.debug("Received ReachableMember: memberName {}, address: {}", memberName, message.member().address());
 643
 644         addPeerAddress(memberName, message.member().address());
 645
 646         markMemberAvailable(memberName);
 647     }
 648
 649     private void memberUnreachable(ClusterEvent.UnreachableMember message) {
 650         String memberName = message.member().roles().head();
 651         LOG.debug("Received UnreachableMember: memberName {}, address: {}", memberName, message.member().address());
 652
 653         markMemberUnavailable(memberName);
 654     }
 655
 656     private void markMemberUnavailable(final String memberName) {
 657         for(ShardInformation info : localShards.values()){
 658             String leaderId = info.getLeaderId();
 659             if(leaderId != null && leaderId.contains(memberName)) {
 660                 LOG.debug("Marking Leader {} as unavailable.", leaderId);
 661                 info.setLeaderAvailable(false);
 662
 663                 primaryShardInfoCache.remove(info.getShardName());
 664             }
 665
 666             info.peerDown(memberName, getShardIdentifier(memberName, info.getShardName()).toString(), getSelf());
 667         }
 668     }
 669
 670     private void markMemberAvailable(final String memberName) {
 671         for(ShardInformation info : localShards.values()){
 672             String leaderId = info.getLeaderId();
 673             if(leaderId != null && leaderId.contains(memberName)) {
 674                 LOG.debug("Marking Leader {} as available.", leaderId);
 675                 info.setLeaderAvailable(true);
 676             }
 677
 678             info.peerUp(memberName, getShardIdentifier(memberName, info.getShardName()).toString(), getSelf());
 679         }
 680     }
 681
 682     private void onDatastoreContextFactory(DatastoreContextFactory factory) {
 683         datastoreContextFactory = factory;
 684         for (ShardInformation info : localShards.values()) {
 685             info.setDatastoreContext(newShardDatastoreContext(info.getShardName()), getSelf());
 686         }
 687     }
 688
 689     private void onSwitchShardBehavior(SwitchShardBehavior message) {
 690         ShardIdentifier identifier = ShardIdentifier.builder().fromShardIdString(message.getShardName()).build();
 691
 692         ShardInformation shardInformation = localShards.get(identifier.getShardName());
 693
 694         if(shardInformation != null && shardInformation.getActor() != null) {
 695             shardInformation.getActor().tell(
 696                     new SwitchBehavior(RaftState.valueOf(message.getNewState()), message.getTerm()), getSelf());
 697         } else {
 698             LOG.warn("Could not switch the behavior of shard {} to {} - shard is not yet available",
 699                     message.getShardName(), message.getNewState());
 700         }
 701     }
 702
 703     /**
 704      * Notifies all the local shards of a change in the schema context
 705      *
 706      * @param message
 707      */
 708     private void updateSchemaContext(final Object message) {
 709         schemaContext = ((UpdateSchemaContext) message).getSchemaContext();
 710
 711         LOG.debug("Got updated SchemaContext: # of modules {}", schemaContext.getAllModuleIdentifiers().size());
 712
 713         for (ShardInformation info : localShards.values()) {
 714             if (info.getActor() == null) {
 715                 LOG.debug("Creating Shard {}", info.getShardId());
 716                 info.setActor(newShardActor(schemaContext, info));
 717             } else {
 718                 info.getActor().tell(message, getSelf());
 719             }
 720         }
 721     }
 722
 723     @VisibleForTesting
 724     protected ClusterWrapper getCluster() {
 725         return cluster;
 726     }
 727
 728     @VisibleForTesting
 729     protected ActorRef newShardActor(final SchemaContext schemaContext, ShardInformation info) {
 730         return getContext().actorOf(info.newProps(schemaContext)
 731                 .withDispatcher(shardDispatcherPath), info.getShardId().toString());
 732     }
 733
 734     private void findPrimary(FindPrimary message) {
 735         LOG.debug("{}: In findPrimary: {}", persistenceId(), message);
 736
 737         final String shardName = message.getShardName();
 738         final boolean canReturnLocalShardState = !(message instanceof RemoteFindPrimary);
 739
 740         // First see if the there is a local replica for the shard
 741         final ShardInformation info = localShards.get(shardName);
 742         if (info != null && info.isActiveMember()) {
 743             sendResponse(info, message.isWaitUntilReady(), true, new Supplier<Object>() {
 744                 @Override
 745                 public Object get() {
 746                     String primaryPath = info.getSerializedLeaderActor();
 747                     Object found = canReturnLocalShardState && info.isLeader() ?
 748                             new LocalPrimaryShardFound(primaryPath, info.getLocalShardDataTree().get()) :
 749                                 new RemotePrimaryShardFound(primaryPath, info.getLeaderVersion());
 750
 751                             if(LOG.isDebugEnabled()) {
 752                                 LOG.debug("{}: Found primary for {}: {}", persistenceId(), shardName, found);
 753                             }
 754
 755                             return found;
 756                 }
 757             });
 758
 759             return;
 760         }
 761
 762         for(String address: peerAddressResolver.getShardManagerPeerActorAddresses()) {
 763             LOG.debug("{}: findPrimary for {} forwarding to remote ShardManager {}", persistenceId(),
 764                     shardName, address);
 765
 766             getContext().actorSelection(address).forward(new RemoteFindPrimary(shardName,
 767                     message.isWaitUntilReady()), getContext());
 768             return;
 769         }
 770
 771         LOG.debug("{}: No shard found for {}", persistenceId(), shardName);
 772
 773         getSender().tell(new PrimaryNotFoundException(
 774                 String.format("No primary shard found for %s.", shardName)), getSelf());
 775     }
 776
 777     /**
 778      * Construct the name of the shard actor given the name of the member on
 779      * which the shard resides and the name of the shard
 780      *
 781      * @param memberName
 782      * @param shardName
 783      * @return
 784      */
 785     private ShardIdentifier getShardIdentifier(String memberName, String shardName){
 786         return peerAddressResolver.getShardIdentifier(memberName, shardName);
 787     }
 788
 789     /**
 790      * Create shards that are local to the member on which the ShardManager
 791      * runs
 792      *
 793      */
 794     private void createLocalShards() {
 795         String memberName = this.cluster.getCurrentMemberName();
 796         Collection<String> memberShardNames = this.configuration.getMemberShardNames(memberName);
 797
 798         Map<String, DatastoreSnapshot.ShardSnapshot> shardSnapshots = new HashMap<>();
 799         if(restoreFromSnapshot != null)
 800         {
 801             for(DatastoreSnapshot.ShardSnapshot snapshot: restoreFromSnapshot.getShardSnapshots()) {
 802                 shardSnapshots.put(snapshot.getName(), snapshot);
 803             }
 804         }
 805
 806         restoreFromSnapshot = null; // null out to GC
 807
 808         for(String shardName : memberShardNames){
 809             ShardIdentifier shardId = getShardIdentifier(memberName, shardName);
 810             Map<String, String> peerAddresses = getPeerAddresses(shardName);
 811             localShards.put(shardName, new ShardInformation(shardName, shardId, peerAddresses,
 812                     newShardDatastoreContext(shardName), Shard.builder().restoreFromSnapshot(
 813                         shardSnapshots.get(shardName)), peerAddressResolver));
 814             mBean.addLocalShard(shardId.toString());
 815         }
 816     }
 817
 818     /**
 819      * Given the name of the shard find the addresses of all it's peers
 820      *
 821      * @param shardName
 822      */
 823     private Map<String, String> getPeerAddresses(String shardName) {
 824         Collection<String> members = configuration.getMembersFromShardName(shardName);
 825         Map<String, String> peerAddresses = new HashMap<>();
 826
 827         String currentMemberName = this.cluster.getCurrentMemberName();
 828
 829         for(String memberName : members) {
 830             if(!currentMemberName.equals(memberName)) {
 831                 ShardIdentifier shardId = getShardIdentifier(memberName, shardName);
 832                 String address = peerAddressResolver.getShardActorAddress(shardName, memberName);
 833                 peerAddresses.put(shardId.toString(), address);
 834             }
 835         }
 836         return peerAddresses;
 837     }
 838
 839     @Override
 840     public SupervisorStrategy supervisorStrategy() {
 841
 842         return new OneForOneStrategy(10, Duration.create("1 minute"),
 843                 new Function<Throwable, SupervisorStrategy.Directive>() {
 844             @Override
 845             public SupervisorStrategy.Directive apply(Throwable t) {
 846                 LOG.warn("Supervisor Strategy caught unexpected exception - resuming", t);
 847                 return SupervisorStrategy.resume();
 848             }
 849         }
 850                 );
 851
 852     }
 853
 854     @Override
 855     public String persistenceId() {
 856         return persistenceId;
 857     }
 858
 859     @VisibleForTesting
 860     ShardManagerInfoMBean getMBean(){
 861         return mBean;
 862     }
 863
 864     private boolean isShardReplicaOperationInProgress(final String shardName, final ActorRef sender) {
 865         if (shardReplicaOperationsInProgress.contains(shardName)) {
 866             String msg = String.format("A shard replica operation for %s is already in progress", shardName);
 867             LOG.debug ("{}: {}", persistenceId(), msg);
 868             sender.tell(new akka.actor.Status.Failure(new IllegalStateException(msg)), getSelf());
 869             return true;
 870         }
 871
 872         return false;
 873     }
 874
 875     private void onAddShardReplica (final AddShardReplica shardReplicaMsg) {
 876         final String shardName = shardReplicaMsg.getShardName();
 877
 878         LOG.debug("{}: onAddShardReplica: {}", persistenceId(), shardReplicaMsg);
 879
 880         // verify the shard with the specified name is present in the cluster configuration
 881         if (!(this.configuration.isShardConfigured(shardName))) {
 882             String msg = String.format("No module configuration exists for shard %s", shardName);
 883             LOG.debug ("{}: {}", persistenceId(), msg);
 884             getSender().tell(new akka.actor.Status.Failure(new IllegalArgumentException(msg)), getSelf());
 885             return;
 886         }
 887
 888         // Create the localShard
 889         if (schemaContext == null) {
 890             String msg = String.format(
 891                   "No SchemaContext is available in order to create a local shard instance for %s", shardName);
 892             LOG.debug ("{}: {}", persistenceId(), msg);
 893             getSender().tell(new akka.actor.Status.Failure(new IllegalStateException(msg)), getSelf());
 894             return;
 895         }
 896
 897         findPrimary(shardName, new AutoFindPrimaryFailureResponseHandler(getSender(), shardName, persistenceId(), getSelf()) {
 898             @Override
 899             public void onRemotePrimaryShardFound(RemotePrimaryShardFound response) {
 900                 getSelf().tell(new PrimaryShardFoundForContext(getShardName(), shardReplicaMsg, response), getTargetActor());
 901
 902             }
 903
 904             @Override
 905             public void onLocalPrimaryFound(LocalPrimaryShardFound message) {
 906                 sendLocalReplicaAlreadyExistsReply(getShardName(), getTargetActor());
 907             }
 908
 909         });
 910     }
 911
 912     private void sendLocalReplicaAlreadyExistsReply(String shardName, ActorRef sender) {
 913         String msg = String.format("Local shard %s already exists", shardName);
 914         LOG.debug ("{}: {}", persistenceId(), msg);
 915         sender.tell(new akka.actor.Status.Failure(new AlreadyExistsException(msg)), getSelf());
 916     }
 917
 918     private void addShard(final String shardName, final RemotePrimaryShardFound response, final ActorRef sender) {
 919         if(isShardReplicaOperationInProgress(shardName, sender)) {
 920             return;
 921         }
 922
 923         shardReplicaOperationsInProgress.add(shardName);
 924
 925         final ShardInformation shardInfo;
 926         final boolean removeShardOnFailure;
 927         ShardInformation existingShardInfo = localShards.get(shardName);
 928         if(existingShardInfo == null) {
 929             removeShardOnFailure = true;
 930             ShardIdentifier shardId = getShardIdentifier(cluster.getCurrentMemberName(), shardName);
 931
 932             DatastoreContext datastoreContext = newShardDatastoreContextBuilder(shardName).customRaftPolicyImplementation(
 933                     DisableElectionsRaftPolicy.class.getName()).build();
 934
 935             shardInfo = new ShardInformation(shardName, shardId, getPeerAddresses(shardName), datastoreContext,
 936                     Shard.builder(), peerAddressResolver);
 937             shardInfo.setActiveMember(false);
 938             localShards.put(shardName, shardInfo);
 939             shardInfo.setActor(newShardActor(schemaContext, shardInfo));
 940         } else {
 941             removeShardOnFailure = false;
 942             shardInfo = existingShardInfo;
 943         }
 944
 945         String localShardAddress = peerAddressResolver.getShardActorAddress(shardName, cluster.getCurrentMemberName());
 946
 947         //inform ShardLeader to add this shard as a replica by sending an AddServer message
 948         LOG.debug ("{}: Sending AddServer message to peer {} for shard {}", persistenceId(),
 949                 response.getPrimaryPath(), shardInfo.getShardId());
 950
 951         Timeout addServerTimeout = new Timeout(shardInfo.getDatastoreContext().getShardLeaderElectionTimeout().
 952                 duration());
 953         Future<Object> futureObj = ask(getContext().actorSelection(response.getPrimaryPath()),
 954             new AddServer(shardInfo.getShardId().toString(), localShardAddress, true), addServerTimeout);
 955
 956         futureObj.onComplete(new OnComplete<Object>() {
 957             @Override
 958             public void onComplete(Throwable failure, Object addServerResponse) {
 959                 if (failure != null) {
 960                     LOG.debug ("{}: AddServer request to {} for {} failed", persistenceId(),
 961                             response.getPrimaryPath(), shardName, failure);
 962
 963                     String msg = String.format("AddServer request to leader %s for shard %s failed",
 964                             response.getPrimaryPath(), shardName);
 965                     self().tell(new ForwardedAddServerFailure(shardName, msg, failure, removeShardOnFailure), sender);
 966                 } else {
 967                     self().tell(new ForwardedAddServerReply(shardInfo, (AddServerReply)addServerResponse,
 968                             response.getPrimaryPath(), removeShardOnFailure), sender);
 969                 }
 970             }
 971         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
 972     }
 973
 974     private void onAddServerFailure(String shardName, String message, Throwable failure, ActorRef sender,
 975             boolean removeShardOnFailure) {
 976         shardReplicaOperationsInProgress.remove(shardName);
 977
 978         if(removeShardOnFailure) {
 979             ShardInformation shardInfo = localShards.remove(shardName);
 980             if (shardInfo.getActor() != null) {
 981                 shardInfo.getActor().tell(PoisonPill.getInstance(), getSelf());
 982             }
 983         }
 984
 985         sender.tell(new akka.actor.Status.Failure(message == null ? failure :
 986             new RuntimeException(message, failure)), getSelf());
 987     }
 988
 989     private void onAddServerReply(ShardInformation shardInfo, AddServerReply replyMsg, ActorRef sender,
 990             String leaderPath, boolean removeShardOnFailure) {
 991         String shardName = shardInfo.getShardName();
 992         shardReplicaOperationsInProgress.remove(shardName);
 993
 994         LOG.debug ("{}: Received {} for shard {} from leader {}", persistenceId(), replyMsg, shardName, leaderPath);
 995
 996         if (replyMsg.getStatus() == ServerChangeStatus.OK) {
 997             LOG.debug ("{}: Leader shard successfully added the replica shard {}", persistenceId(), shardName);
 998
 999             // Make the local shard voting capable
1000             shardInfo.setDatastoreContext(newShardDatastoreContext(shardName), getSelf());
1001             shardInfo.setActiveMember(true);
1002             persistShardList();
1003
1004             mBean.addLocalShard(shardInfo.getShardId().toString());
1005             sender.tell(new akka.actor.Status.Success(null), getSelf());
1006         } else if(replyMsg.getStatus() == ServerChangeStatus.ALREADY_EXISTS) {
1007             sendLocalReplicaAlreadyExistsReply(shardName, sender);
1008         } else {
1009             LOG.warn ("{}: Leader failed to add shard replica {} with status {}",
1010                     persistenceId(), shardName, replyMsg.getStatus());
1011
1012             Exception failure;
1013             switch (replyMsg.getStatus()) {
1014                 case TIMEOUT:
1015                     failure = new TimeoutException(String.format(
1016                             "The shard leader %s timed out trying to replicate the initial data to the new shard %s." +
1017                             "Possible causes - there was a problem replicating the data or shard leadership changed while replicating the shard data",
1018                             leaderPath, shardName));
1019                     break;
1020                 case NO_LEADER:
1021                     failure = createNoShardLeaderException(shardInfo.getShardId());
1022                     break;
1023                 default :
1024                     failure = new RuntimeException(String.format(
1025                             "AddServer request to leader %s for shard %s failed with status %s",
1026                             leaderPath, shardName, replyMsg.getStatus()));
1027             }
1028
1029             onAddServerFailure(shardName, null, failure, sender, removeShardOnFailure);
1030         }
1031     }
1032
1033     private void onRemoveShardReplica (RemoveShardReplica shardReplicaMsg) {
1034         String shardName = shardReplicaMsg.getShardName();
1035
1036         // verify the local shard replica is available in the controller node
1037         if (!localShards.containsKey(shardName)) {
1038             String msg = String.format("Local shard %s does not", shardName);
1039             LOG.debug ("{}: {}", persistenceId(), msg);
1040             getSender().tell(new akka.actor.Status.Failure(new IllegalArgumentException(msg)), getSelf());
1041             return;
1042         }
1043         // call RemoveShard for the shardName
1044         getSender().tell(new akka.actor.Status.Success(true), getSelf());
1045         return;
1046     }
1047
1048     private void persistShardList() {
1049         List<String> shardList = new ArrayList<>(localShards.keySet());
1050         for (ShardInformation shardInfo : localShards.values()) {
1051             if (!shardInfo.isActiveMember()) {
1052                 shardList.remove(shardInfo.getShardName());
1053             }
1054         }
1055         LOG.debug ("{}: persisting the shard list {}", persistenceId(), shardList);
1056         saveSnapshot(new ShardManagerSnapshot(shardList));
1057     }
1058
1059     private void handleShardRecovery(SnapshotOffer offer) {
1060         LOG.debug ("{}: in handleShardRecovery", persistenceId());
1061         ShardManagerSnapshot snapshot = (ShardManagerSnapshot)offer.snapshot();
1062         String currentMember = cluster.getCurrentMemberName();
1063         Set<String> configuredShardList =
1064             new HashSet<>(configuration.getMemberShardNames(currentMember));
1065         for (String shard : snapshot.getShardList()) {
1066             if (!configuredShardList.contains(shard)) {
1067                 // add the current member as a replica for the shard
1068                 LOG.debug ("{}: adding shard {}", persistenceId(), shard);
1069                 configuration.addMemberReplicaForShard(shard, currentMember);
1070             } else {
1071                 configuredShardList.remove(shard);
1072             }
1073         }
1074         for (String shard : configuredShardList) {
1075             // remove the member as a replica for the shard
1076             LOG.debug ("{}: removing shard {}", persistenceId(), shard);
1077             configuration.removeMemberReplicaForShard(shard, currentMember);
1078         }
1079     }
1080
1081     private static class ForwardedAddServerReply {
1082         ShardInformation shardInfo;
1083         AddServerReply addServerReply;
1084         String leaderPath;
1085         boolean removeShardOnFailure;
1086
1087         ForwardedAddServerReply(ShardInformation shardInfo, AddServerReply addServerReply, String leaderPath,
1088                 boolean removeShardOnFailure) {
1089             this.shardInfo = shardInfo;
1090             this.addServerReply = addServerReply;
1091             this.leaderPath = leaderPath;
1092             this.removeShardOnFailure = removeShardOnFailure;
1093         }
1094     }
1095
1096     private static class ForwardedAddServerFailure {
1097         String shardName;
1098         String failureMessage;
1099         Throwable failure;
1100         boolean removeShardOnFailure;
1101
1102         ForwardedAddServerFailure(String shardName, String failureMessage, Throwable failure,
1103                 boolean removeShardOnFailure) {
1104             this.shardName = shardName;
1105             this.failureMessage = failureMessage;
1106             this.failure = failure;
1107             this.removeShardOnFailure = removeShardOnFailure;
1108         }
1109     }
1110
1111     @VisibleForTesting
1112     protected static class ShardInformation {
1113         private final ShardIdentifier shardId;
1114         private final String shardName;
1115         private ActorRef actor;
1116         private ActorPath actorPath;
1117         private final Map<String, String> initialPeerAddresses;
1118         private Optional<DataTree> localShardDataTree;
1119         private boolean leaderAvailable = false;
1120
1121         // flag that determines if the actor is ready for business
1122         private boolean actorInitialized = false;
1123
1124         private boolean followerSyncStatus = false;
1125
1126         private final Set<OnShardInitialized> onShardInitializedSet = Sets.newHashSet();
1127         private String role ;
1128         private String leaderId;
1129         private short leaderVersion;
1130
1131         private DatastoreContext datastoreContext;
1132         private Shard.AbstractBuilder<?, ?> builder;
1133         private final ShardPeerAddressResolver addressResolver;
1134         private boolean isActiveMember = true;
1135
1136         private ShardInformation(String shardName, ShardIdentifier shardId,
1137                 Map<String, String> initialPeerAddresses, DatastoreContext datastoreContext,
1138                 Shard.AbstractBuilder<?, ?> builder, ShardPeerAddressResolver addressResolver) {
1139             this.shardName = shardName;
1140             this.shardId = shardId;
1141             this.initialPeerAddresses = initialPeerAddresses;
1142             this.datastoreContext = datastoreContext;
1143             this.builder = builder;
1144             this.addressResolver = addressResolver;
1145         }
1146
1147         Props newProps(SchemaContext schemaContext) {
1148             Preconditions.checkNotNull(builder);
1149             Props props = builder.id(shardId).peerAddresses(initialPeerAddresses).datastoreContext(datastoreContext).
1150                     schemaContext(schemaContext).props();
1151             builder = null;
1152             return props;
1153         }
1154
1155         String getShardName() {
1156             return shardName;
1157         }
1158
1159         @Nullable
1160         ActorRef getActor(){
1161             return actor;
1162         }
1163
1164         ActorPath getActorPath() {
1165             return actorPath;
1166         }
1167
1168         void setActor(ActorRef actor) {
1169             this.actor = actor;
1170             this.actorPath = actor.path();
1171         }
1172
1173         ShardIdentifier getShardId() {
1174             return shardId;
1175         }
1176
1177         void setLocalDataTree(Optional<DataTree> localShardDataTree) {
1178             this.localShardDataTree = localShardDataTree;
1179         }
1180
1181         Optional<DataTree> getLocalShardDataTree() {
1182             return localShardDataTree;
1183         }
1184
1185         DatastoreContext getDatastoreContext() {
1186             return datastoreContext;
1187         }
1188
1189         void setDatastoreContext(DatastoreContext datastoreContext, ActorRef sender) {
1190             this.datastoreContext = datastoreContext;
1191             if (actor != null) {
1192                 LOG.debug ("Sending new DatastoreContext to {}", shardId);
1193                 actor.tell(this.datastoreContext, sender);
1194             }
1195         }
1196
1197         void updatePeerAddress(String peerId, String peerAddress, ActorRef sender){
1198             LOG.info("updatePeerAddress for peer {} with address {}", peerId, peerAddress);
1199
1200             if(actor != null) {
1201                 if(LOG.isDebugEnabled()) {
1202                     LOG.debug("Sending PeerAddressResolved for peer {} with address {} to {}",
1203                             peerId, peerAddress, actor.path());
1204                 }
1205
1206                 actor.tell(new PeerAddressResolved(peerId, peerAddress), sender);
1207             }
1208
1209             notifyOnShardInitializedCallbacks();
1210         }
1211
1212         void peerDown(String memberName, String peerId, ActorRef sender) {
1213             if(actor != null) {
1214                 actor.tell(new PeerDown(memberName, peerId), sender);
1215             }
1216         }
1217
1218         void peerUp(String memberName, String peerId, ActorRef sender) {
1219             if(actor != null) {
1220                 actor.tell(new PeerUp(memberName, peerId), sender);
1221             }
1222         }
1223
1224         boolean isShardReady() {
1225             return !RaftState.Candidate.name().equals(role) && !Strings.isNullOrEmpty(role);
1226         }
1227
1228         boolean isShardReadyWithLeaderId() {
1229             return leaderAvailable && isShardReady() && !RaftState.IsolatedLeader.name().equals(role) &&
1230                     (isLeader() || addressResolver.resolve(leaderId) != null);
1231         }
1232
1233         boolean isShardInitialized() {
1234             return getActor() != null && actorInitialized;
1235         }
1236
1237         boolean isLeader() {
1238             return Objects.equal(leaderId, shardId.toString());
1239         }
1240
1241         String getSerializedLeaderActor() {
1242             if(isLeader()) {
1243                 return Serialization.serializedActorPath(getActor());
1244             } else {
1245                 return addressResolver.resolve(leaderId);
1246             }
1247         }
1248
1249         void setActorInitialized() {
1250             LOG.debug("Shard {} is initialized", shardId);
1251
1252             this.actorInitialized = true;
1253
1254             notifyOnShardInitializedCallbacks();
1255         }
1256
1257         private void notifyOnShardInitializedCallbacks() {
1258             if(onShardInitializedSet.isEmpty()) {
1259                 return;
1260             }
1261
1262             boolean ready = isShardReadyWithLeaderId();
1263
1264             if(LOG.isDebugEnabled()) {
1265                 LOG.debug("Shard {} is {} - notifying {} OnShardInitialized callbacks", shardId,
1266                         ready ? "ready" : "initialized", onShardInitializedSet.size());
1267             }
1268
1269             Iterator<OnShardInitialized> iter = onShardInitializedSet.iterator();
1270             while(iter.hasNext()) {
1271                 OnShardInitialized onShardInitialized = iter.next();
1272                 if(!(onShardInitialized instanceof OnShardReady) || ready) {
1273                     iter.remove();
1274                     onShardInitialized.getTimeoutSchedule().cancel();
1275                     onShardInitialized.getReplyRunnable().run();
1276                 }
1277             }
1278         }
1279
1280         void addOnShardInitialized(OnShardInitialized onShardInitialized) {
1281             onShardInitializedSet.add(onShardInitialized);
1282         }
1283
1284         void removeOnShardInitialized(OnShardInitialized onShardInitialized) {
1285             onShardInitializedSet.remove(onShardInitialized);
1286         }
1287
1288         void setRole(String newRole) {
1289             this.role = newRole;
1290
1291             notifyOnShardInitializedCallbacks();
1292         }
1293
1294         void setFollowerSyncStatus(boolean syncStatus){
1295             this.followerSyncStatus = syncStatus;
1296         }
1297
1298         boolean isInSync(){
1299             if(RaftState.Follower.name().equals(this.role)){
1300                 return followerSyncStatus;
1301             } else if(RaftState.Leader.name().equals(this.role)){
1302                 return true;
1303             }
1304
1305             return false;
1306         }
1307
1308         boolean setLeaderId(String leaderId) {
1309             boolean changed = !Objects.equal(this.leaderId, leaderId);
1310             this.leaderId = leaderId;
1311             if(leaderId != null) {
1312                 this.leaderAvailable = true;
1313             }
1314             notifyOnShardInitializedCallbacks();
1315
1316             return changed;
1317         }
1318
1319         String getLeaderId() {
1320             return leaderId;
1321         }
1322
1323         void setLeaderAvailable(boolean leaderAvailable) {
1324             this.leaderAvailable = leaderAvailable;
1325         }
1326
1327         short getLeaderVersion() {
1328             return leaderVersion;
1329         }
1330
1331         void setLeaderVersion(short leaderVersion) {
1332             this.leaderVersion = leaderVersion;
1333         }
1334
1335         boolean isActiveMember() {
1336             return isActiveMember;
1337         }
1338
1339         void setActiveMember(boolean isActiveMember) {
1340             this.isActiveMember = isActiveMember;
1341         }
1342     }
1343
1344     private static class OnShardInitialized {
1345         private final Runnable replyRunnable;
1346         private Cancellable timeoutSchedule;
1347
1348         OnShardInitialized(Runnable replyRunnable) {
1349             this.replyRunnable = replyRunnable;
1350         }
1351
1352         Runnable getReplyRunnable() {
1353             return replyRunnable;
1354         }
1355
1356         Cancellable getTimeoutSchedule() {
1357             return timeoutSchedule;
1358         }
1359
1360         void setTimeoutSchedule(Cancellable timeoutSchedule) {
1361             this.timeoutSchedule = timeoutSchedule;
1362         }
1363     }
1364
1365     private static class OnShardReady extends OnShardInitialized {
1366         OnShardReady(Runnable replyRunnable) {
1367             super(replyRunnable);
1368         }
1369     }
1370
1371     private static class ShardNotInitializedTimeout {
1372         private final ActorRef sender;
1373         private final ShardInformation shardInfo;
1374         private final OnShardInitialized onShardInitialized;
1375
1376         ShardNotInitializedTimeout(ShardInformation shardInfo, OnShardInitialized onShardInitialized, ActorRef sender) {
1377             this.sender = sender;
1378             this.shardInfo = shardInfo;
1379             this.onShardInitialized = onShardInitialized;
1380         }
1381
1382         ActorRef getSender() {
1383             return sender;
1384         }
1385
1386         ShardInformation getShardInfo() {
1387             return shardInfo;
1388         }
1389
1390         OnShardInitialized getOnShardInitialized() {
1391             return onShardInitialized;
1392         }
1393     }
1394
1395     /**
1396      * We no longer persist SchemaContextModules but keep this class around for now for backwards
1397      * compatibility so we don't get de-serialization failures on upgrade from Helium.
1398      */
1399     @Deprecated
1400     static class SchemaContextModules implements Serializable {
1401         private static final long serialVersionUID = -8884620101025936590L;
1402
1403         private final Set<String> modules;
1404
1405         SchemaContextModules(Set<String> modules){
1406             this.modules = modules;
1407         }
1408
1409         public Set<String> getModules() {
1410             return modules;
1411         }
1412     }
1413
1414     public static Builder builder() {
1415         return new Builder();
1416     }
1417
1418     public static class Builder {
1419         private ClusterWrapper cluster;
1420         private Configuration configuration;
1421         private DatastoreContextFactory datastoreContextFactory;
1422         private CountDownLatch waitTillReadyCountdownLatch;
1423         private PrimaryShardInfoFutureCache primaryShardInfoCache;
1424         private DatastoreSnapshot restoreFromSnapshot;
1425         private volatile boolean sealed;
1426
1427         protected void checkSealed() {
1428             Preconditions.checkState(!sealed, "Builder is already sealed - further modifications are not allowed");
1429         }
1430
1431         public Builder cluster(ClusterWrapper cluster) {
1432             checkSealed();
1433             this.cluster = cluster;
1434             return this;
1435         }
1436
1437         public Builder configuration(Configuration configuration) {
1438             checkSealed();
1439             this.configuration = configuration;
1440             return this;
1441         }
1442
1443         public Builder datastoreContextFactory(DatastoreContextFactory datastoreContextFactory) {
1444             checkSealed();
1445             this.datastoreContextFactory = datastoreContextFactory;
1446             return this;
1447         }
1448
1449         public Builder waitTillReadyCountdownLatch(CountDownLatch waitTillReadyCountdownLatch) {
1450             checkSealed();
1451             this.waitTillReadyCountdownLatch = waitTillReadyCountdownLatch;
1452             return this;
1453         }
1454
1455         public Builder primaryShardInfoCache(PrimaryShardInfoFutureCache primaryShardInfoCache) {
1456             checkSealed();
1457             this.primaryShardInfoCache = primaryShardInfoCache;
1458             return this;
1459         }
1460
1461         public Builder restoreFromSnapshot(DatastoreSnapshot restoreFromSnapshot) {
1462             checkSealed();
1463             this.restoreFromSnapshot = restoreFromSnapshot;
1464             return this;
1465         }
1466
1467         protected void verify() {
1468             sealed = true;
1469             Preconditions.checkNotNull(cluster, "cluster should not be null");
1470             Preconditions.checkNotNull(configuration, "configuration should not be null");
1471             Preconditions.checkNotNull(datastoreContextFactory, "datastoreContextFactory should not be null");
1472             Preconditions.checkNotNull(waitTillReadyCountdownLatch, "waitTillReadyCountdownLatch should not be null");
1473             Preconditions.checkNotNull(primaryShardInfoCache, "primaryShardInfoCache should not be null");
1474         }
1475
1476         public Props props() {
1477             verify();
1478             return Props.create(ShardManager.class, this);
1479         }
1480     }
1481
1482     private void findPrimary(final String shardName, final FindPrimaryResponseHandler handler) {
1483         Timeout findPrimaryTimeout = new Timeout(datastoreContextFactory.getBaseDatastoreContext().
1484                 getShardInitializationTimeout().duration().$times(2));
1485
1486
1487         Future<Object> futureObj = ask(getSelf(), new FindPrimary(shardName, true), findPrimaryTimeout);
1488         futureObj.onComplete(new OnComplete<Object>() {
1489             @Override
1490             public void onComplete(Throwable failure, Object response) {
1491                 if (failure != null) {
1492                     handler.onFailure(failure);
1493                 } else {
1494                     if(response instanceof RemotePrimaryShardFound) {
1495                         handler.onRemotePrimaryShardFound((RemotePrimaryShardFound) response);
1496                     } else if(response instanceof LocalPrimaryShardFound) {
1497                         handler.onLocalPrimaryFound((LocalPrimaryShardFound) response);
1498                     } else {
1499                         handler.onUnknownResponse(response);
1500                     }
1501                 }
1502             }
1503         }, new Dispatchers(context().system().dispatchers()).getDispatcher(Dispatchers.DispatcherType.Client));
1504     }
1505
1506     /**
1507      * The FindPrimaryResponseHandler provides specific callback methods which are invoked when a response to the
1508      * a remote or local find primary message is processed
1509      */
1510     private static interface FindPrimaryResponseHandler {
1511         /**
1512          * Invoked when a Failure message is received as a response
1513          *
1514          * @param failure
1515          */
1516         void onFailure(Throwable failure);
1517
1518         /**
1519          * Invoked when a RemotePrimaryShardFound response is received
1520          *
1521          * @param response
1522          */
1523         void onRemotePrimaryShardFound(RemotePrimaryShardFound response);
1524
1525         /**
1526          * Invoked when a LocalPrimaryShardFound response is received
1527          * @param response
1528          */
1529         void onLocalPrimaryFound(LocalPrimaryShardFound response);
1530
1531         /**
1532          * Invoked when an unknown response is received. This is another type of failure.
1533          *
1534          * @param response
1535          */
1536         void onUnknownResponse(Object response);
1537     }
1538
1539     /**
1540      * The AutoFindPrimaryFailureResponseHandler automatically processes Failure responses when finding a primary
1541      * replica and sends a wrapped Failure response to some targetActor
1542      */
1543     private static abstract class AutoFindPrimaryFailureResponseHandler implements FindPrimaryResponseHandler {
1544         private final ActorRef targetActor;
1545         private final String shardName;
1546         private final String persistenceId;
1547         private final ActorRef shardManagerActor;
1548
1549         /**
1550          * @param targetActor The actor to whom the Failure response should be sent when a FindPrimary failure occurs
1551          * @param shardName The name of the shard for which the primary replica had to be found
1552          * @param persistenceId The persistenceId for the ShardManager
1553          * @param shardManagerActor The ShardManager actor which triggered the call to FindPrimary
1554          */
1555         protected AutoFindPrimaryFailureResponseHandler(ActorRef targetActor, String shardName, String persistenceId, ActorRef shardManagerActor){
1556             this.targetActor = Preconditions.checkNotNull(targetActor);
1557             this.shardName = Preconditions.checkNotNull(shardName);
1558             this.persistenceId = Preconditions.checkNotNull(persistenceId);
1559             this.shardManagerActor = Preconditions.checkNotNull(shardManagerActor);
1560         }
1561
1562         public ActorRef getTargetActor() {
1563             return targetActor;
1564         }
1565
1566         public String getShardName() {
1567             return shardName;
1568         }
1569
1570         public ActorRef getShardManagerActor() {
1571             return shardManagerActor;
1572         }
1573
1574         @Override
1575         public void onFailure(Throwable failure) {
1576             LOG.debug ("{}: Received failure from FindPrimary for shard {}", persistenceId, shardName, failure);
1577             targetActor.tell(new akka.actor.Status.Failure(new RuntimeException(
1578                     String.format("Failed to find leader for shard %s", shardName), failure)), shardManagerActor);
1579         }
1580
1581         @Override
1582         public void onUnknownResponse(Object response) {
1583             String msg = String.format("Failed to find leader for shard %s: received response: %s",
1584                     shardName, response);
1585             LOG.debug ("{}: {}", persistenceId, msg);
1586             targetActor.tell(new akka.actor.Status.Failure(response instanceof Throwable ? (Throwable) response :
1587                     new RuntimeException(msg)), shardManagerActor);
1588         }
1589     }
1590
1591
1592     /**
1593      * The PrimaryShardFoundForContext is a DTO which puts together a message (aka 'Context' message) which needs to be
1594      * forwarded to the primary replica of a shard and the message (aka 'PrimaryShardFound' message) that is received
1595      * as a successful response to find primary.
1596      */
1597     private static class PrimaryShardFoundForContext {
1598         private final String shardName;
1599         private final Object contextMessage;
1600         private final RemotePrimaryShardFound remotePrimaryShardFound;
1601         private final LocalPrimaryShardFound localPrimaryShardFound;
1602
1603         public PrimaryShardFoundForContext(@Nonnull String shardName, @Nonnull Object contextMessage, @Nonnull Object primaryFoundMessage) {
1604             this.shardName = Preconditions.checkNotNull(shardName);
1605             this.contextMessage = Preconditions.checkNotNull(contextMessage);
1606             Preconditions.checkNotNull(primaryFoundMessage);
1607             this.remotePrimaryShardFound = (primaryFoundMessage instanceof RemotePrimaryShardFound) ? (RemotePrimaryShardFound) primaryFoundMessage : null;
1608             this.localPrimaryShardFound = (primaryFoundMessage instanceof LocalPrimaryShardFound) ? (LocalPrimaryShardFound) primaryFoundMessage : null;
1609         }
1610
1611         @Nonnull
1612         public String getPrimaryPath(){
1613             if(remotePrimaryShardFound != null){
1614                 return remotePrimaryShardFound.getPrimaryPath();
1615             }
1616             return localPrimaryShardFound.getPrimaryPath();
1617         }
1618
1619         @Nonnull
1620         public Object getContextMessage() {
1621             return contextMessage;
1622         }
1623
1624         @Nullable
1625         public RemotePrimaryShardFound getRemotePrimaryShardFound(){
1626             return remotePrimaryShardFound;
1627         }
1628
1629         @Nullable
1630         public LocalPrimaryShardFound getLocalPrimaryShardFound(){
1631             return localPrimaryShardFound;
1632         }
1633
1634         boolean isPrimaryLocal(){
1635             return (remotePrimaryShardFound == null);
1636         }
1637
1638         @Nonnull
1639         public String getShardName() {
1640             return shardName;
1641         }
1642     }
1643 }
1644
1645
1646