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 akka.actor.ActorPath;
  12 import akka.actor.ActorRef;
  13 import akka.actor.Address;
  14 import akka.actor.OneForOneStrategy;
  15 import akka.actor.Props;
  16 import akka.actor.SupervisorStrategy;
  17 import akka.cluster.ClusterEvent;
  18 import akka.japi.Creator;
  19 import akka.japi.Function;
  20 import akka.japi.Procedure;
  21 import akka.persistence.RecoveryCompleted;
  22 import akka.persistence.RecoveryFailure;
  23 import com.google.common.annotations.VisibleForTesting;
  24 import com.google.common.base.Preconditions;
  25 import com.google.common.base.Strings;
  26 import com.google.common.base.Supplier;
  27 import com.google.common.collect.ImmutableSet;
  28 import com.google.common.collect.Lists;
  29 import java.io.Serializable;
  30 import java.util.ArrayList;
  31 import java.util.Collection;
  32 import java.util.Collections;
  33 import java.util.HashMap;
  34 import java.util.HashSet;
  35 import java.util.List;
  36 import java.util.Map;
  37 import java.util.Set;
  38 import java.util.concurrent.CountDownLatch;
  39 import org.opendaylight.controller.cluster.DataPersistenceProvider;
  40 import org.opendaylight.controller.cluster.common.actor.AbstractUntypedPersistentActorWithMetering;
  41 import org.opendaylight.controller.cluster.datastore.identifiers.ShardIdentifier;
  42 import org.opendaylight.controller.cluster.datastore.identifiers.ShardManagerIdentifier;
  43 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shardmanager.ShardManagerInfo;
  44 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shardmanager.ShardManagerInfoMBean;
  45 import org.opendaylight.controller.cluster.datastore.messages.ActorInitialized;
  46 import org.opendaylight.controller.cluster.datastore.messages.ActorNotInitialized;
  47 import org.opendaylight.controller.cluster.datastore.messages.FindLocalShard;
  48 import org.opendaylight.controller.cluster.datastore.messages.FindPrimary;
  49 import org.opendaylight.controller.cluster.datastore.messages.LocalShardFound;
  50 import org.opendaylight.controller.cluster.datastore.messages.LocalShardNotFound;
  51 import org.opendaylight.controller.cluster.datastore.messages.PeerAddressResolved;
  52 import org.opendaylight.controller.cluster.datastore.messages.PrimaryFound;
  53 import org.opendaylight.controller.cluster.datastore.messages.PrimaryNotFound;
  54 import org.opendaylight.controller.cluster.datastore.messages.UpdateSchemaContext;
  55 import org.opendaylight.controller.cluster.datastore.utils.Dispatchers;
  56 import org.opendaylight.controller.cluster.notifications.RegisterRoleChangeListener;
  57 import org.opendaylight.controller.cluster.notifications.RoleChangeNotification;
  58 import org.opendaylight.controller.cluster.raft.RaftState;
  59 import org.opendaylight.controller.cluster.raft.base.messages.FollowerInitialSyncUpStatus;
  60 import org.opendaylight.yangtools.yang.model.api.ModuleIdentifier;
  61 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  62 import org.slf4j.Logger;
  63 import org.slf4j.LoggerFactory;
  64 import scala.concurrent.duration.Duration;
  65
  66 /**
  67  * The ShardManager has the following jobs,
  68  * <ul>
  69  * <li> Create all the local shard replicas that belong on this cluster member
  70  * <li> Find the address of the local shard
  71  * <li> Find the primary replica for any given shard
  72  * <li> Monitor the cluster members and store their addresses
  73  * <ul>
  74  */
  75 public class ShardManager extends AbstractUntypedPersistentActorWithMetering {
  76
  77     private final Logger LOG = LoggerFactory.getLogger(getClass());
  78
  79     // Stores a mapping between a member name and the address of the member
  80     // Member names look like "member-1", "member-2" etc and are as specified
  81     // in configuration
  82     private final Map<String, Address> memberNameToAddress = new HashMap<>();
  83
  84     // Stores a mapping between a shard name and it's corresponding information
  85     // Shard names look like inventory, topology etc and are as specified in
  86     // configuration
  87     private final Map<String, ShardInformation> localShards = new HashMap<>();
  88
  89     // The type of a ShardManager reflects the type of the datastore itself
  90     // A data store could be of type config/operational
  91     private final String type;
  92
  93     private final ClusterWrapper cluster;
  94
  95     private final Configuration configuration;
  96
  97     private final String shardDispatcherPath;
  98
  99     private ShardManagerInfo mBean;
 100
 101     private DatastoreContext datastoreContext;
 102
 103     private Collection<String> knownModules = Collections.emptySet();
 104
 105     private final DataPersistenceProvider dataPersistenceProvider;
 106
 107     private final CountDownLatch waitTillReadyCountdownLatch;
 108
 109     /**
 110      */
 111     protected ShardManager(ClusterWrapper cluster, Configuration configuration,
 112             DatastoreContext datastoreContext, CountDownLatch waitTillReadyCountdownLatch) {
 113
 114         this.cluster = Preconditions.checkNotNull(cluster, "cluster should not be null");
 115         this.configuration = Preconditions.checkNotNull(configuration, "configuration should not be null");
 116         this.datastoreContext = datastoreContext;
 117         this.dataPersistenceProvider = createDataPersistenceProvider(datastoreContext.isPersistent());
 118         this.type = datastoreContext.getDataStoreType();
 119         this.shardDispatcherPath =
 120                 new Dispatchers(context().system().dispatchers()).getDispatcherPath(Dispatchers.DispatcherType.Shard);
 121         this.waitTillReadyCountdownLatch = waitTillReadyCountdownLatch;
 122
 123         // Subscribe this actor to cluster member events
 124         cluster.subscribeToMemberEvents(getSelf());
 125
 126         createLocalShards();
 127     }
 128
 129     protected DataPersistenceProvider createDataPersistenceProvider(boolean persistent) {
 130         return (persistent) ? new PersistentDataProvider() : new NonPersistentDataProvider();
 131     }
 132
 133     public static Props props(
 134         final ClusterWrapper cluster,
 135         final Configuration configuration,
 136         final DatastoreContext datastoreContext,
 137         final CountDownLatch waitTillReadyCountdownLatch) {
 138
 139         Preconditions.checkNotNull(cluster, "cluster should not be null");
 140         Preconditions.checkNotNull(configuration, "configuration should not be null");
 141         Preconditions.checkNotNull(waitTillReadyCountdownLatch, "waitTillReadyCountdownLatch should not be null");
 142
 143         return Props.create(new ShardManagerCreator(cluster, configuration, datastoreContext, waitTillReadyCountdownLatch));
 144     }
 145
 146     @Override
 147     public void postStop() {
 148         LOG.info("Stopping ShardManager");
 149
 150         mBean.unregisterMBean();
 151     }
 152
 153     @Override
 154     public void handleCommand(Object message) throws Exception {
 155         if (FindPrimary.SERIALIZABLE_CLASS.isInstance(message)) {
 156             findPrimary(FindPrimary.fromSerializable(message));
 157         } else if(message instanceof FindLocalShard){
 158             findLocalShard((FindLocalShard) message);
 159         } else if (message instanceof UpdateSchemaContext) {
 160             updateSchemaContext(message);
 161         } else if(message instanceof ActorInitialized) {
 162             onActorInitialized(message);
 163         } else if (message instanceof ClusterEvent.MemberUp){
 164             memberUp((ClusterEvent.MemberUp) message);
 165         } else if(message instanceof ClusterEvent.MemberRemoved) {
 166             memberRemoved((ClusterEvent.MemberRemoved) message);
 167         } else if(message instanceof ClusterEvent.UnreachableMember) {
 168             ignoreMessage(message);
 169         } else if(message instanceof DatastoreContext) {
 170             onDatastoreContext((DatastoreContext)message);
 171         } else if(message instanceof RoleChangeNotification) {
 172             onRoleChangeNotification((RoleChangeNotification) message);
 173         } else if(message instanceof FollowerInitialSyncUpStatus){
 174             onFollowerInitialSyncStatus((FollowerInitialSyncUpStatus) message);
 175         } else{
 176             unknownMessage(message);
 177         }
 178
 179     }
 180
 181     private void onFollowerInitialSyncStatus(FollowerInitialSyncUpStatus status) {
 182         LOG.info("Received follower initial sync status for {} status sync done {}", status.getName(),
 183                 status.isInitialSyncDone());
 184
 185         ShardInformation shardInformation = findShardInformation(status.getName());
 186
 187         if(shardInformation != null) {
 188             shardInformation.setFollowerSyncStatus(status.isInitialSyncDone());
 189
 190             mBean.setSyncStatus(isInSync());
 191         }
 192
 193     }
 194
 195     private void onRoleChangeNotification(RoleChangeNotification roleChanged) {
 196         LOG.info("Received role changed for {} from {} to {}", roleChanged.getMemberId(),
 197                 roleChanged.getOldRole(), roleChanged.getNewRole());
 198
 199         ShardInformation shardInformation = findShardInformation(roleChanged.getMemberId());
 200         if(shardInformation != null) {
 201             shardInformation.setRole(roleChanged.getNewRole());
 202
 203             if (isReady()) {
 204                 LOG.info("All Shards are ready - data store {} is ready, available count is {}", type,
 205                         waitTillReadyCountdownLatch.getCount());
 206
 207                 waitTillReadyCountdownLatch.countDown();
 208             }
 209
 210             mBean.setSyncStatus(isInSync());
 211         }
 212     }
 213
 214
 215     private ShardInformation findShardInformation(String memberId) {
 216         for(ShardInformation info : localShards.values()){
 217             if(info.getShardId().toString().equals(memberId)){
 218                 return info;
 219             }
 220         }
 221
 222         return null;
 223     }
 224
 225     private boolean isReady() {
 226         boolean isReady = true;
 227         for (ShardInformation info : localShards.values()) {
 228             if(RaftState.Candidate.name().equals(info.getRole()) || Strings.isNullOrEmpty(info.getRole())){
 229                 isReady = false;
 230                 break;
 231             }
 232         }
 233         return isReady;
 234     }
 235
 236     private boolean isInSync(){
 237         for (ShardInformation info : localShards.values()) {
 238             if(!info.isInSync()){
 239                 return false;
 240             }
 241         }
 242         return true;
 243     }
 244
 245     private void onActorInitialized(Object message) {
 246         final ActorRef sender = getSender();
 247
 248         if (sender == null) {
 249             return; //why is a non-actor sending this message? Just ignore.
 250         }
 251
 252         String actorName = sender.path().name();
 253         //find shard name from actor name; actor name is stringified shardId
 254         ShardIdentifier shardId = ShardIdentifier.builder().fromShardIdString(actorName).build();
 255
 256         if (shardId.getShardName() == null) {
 257             return;
 258         }
 259         markShardAsInitialized(shardId.getShardName());
 260     }
 261
 262     private void markShardAsInitialized(String shardName) {
 263         LOG.debug("Initializing shard [{}]", shardName);
 264         ShardInformation shardInformation = localShards.get(shardName);
 265         if (shardInformation != null) {
 266             shardInformation.setActorInitialized();
 267         }
 268     }
 269
 270     @Override
 271     protected void handleRecover(Object message) throws Exception {
 272         if(dataPersistenceProvider.isRecoveryApplicable()) {
 273             if (message instanceof SchemaContextModules) {
 274                 SchemaContextModules msg = (SchemaContextModules) message;
 275                 knownModules = ImmutableSet.copyOf(msg.getModules());
 276             } else if (message instanceof RecoveryFailure) {
 277                 RecoveryFailure failure = (RecoveryFailure) message;
 278                 LOG.error("Recovery failed", failure.cause());
 279             } else if (message instanceof RecoveryCompleted) {
 280                 LOG.info("Recovery complete : {}", persistenceId());
 281
 282                 // Delete all the messages from the akka journal except the last one
 283                 deleteMessages(lastSequenceNr() - 1);
 284             }
 285         } else {
 286             if (message instanceof RecoveryCompleted) {
 287                 LOG.info("Recovery complete : {}", persistenceId());
 288
 289                 // Delete all the messages from the akka journal
 290                 deleteMessages(lastSequenceNr());
 291             }
 292         }
 293     }
 294
 295     private void findLocalShard(FindLocalShard message) {
 296         final ShardInformation shardInformation = localShards.get(message.getShardName());
 297
 298         if(shardInformation == null){
 299             getSender().tell(new LocalShardNotFound(message.getShardName()), getSelf());
 300             return;
 301         }
 302
 303         sendResponse(shardInformation, message.isWaitUntilInitialized(), new Supplier<Object>() {
 304             @Override
 305             public Object get() {
 306                 return new LocalShardFound(shardInformation.getActor());
 307             }
 308         });
 309     }
 310
 311     private void sendResponse(ShardInformation shardInformation, boolean waitUntilInitialized,
 312             final Supplier<Object> messageSupplier) {
 313         if (!shardInformation.isShardInitialized()) {
 314             if(waitUntilInitialized) {
 315                 final ActorRef sender = getSender();
 316                 final ActorRef self = self();
 317                 shardInformation.addRunnableOnInitialized(new Runnable() {
 318                     @Override
 319                     public void run() {
 320                         sender.tell(messageSupplier.get(), self);
 321                     }
 322                 });
 323             } else {
 324                 getSender().tell(new ActorNotInitialized(), getSelf());
 325             }
 326
 327             return;
 328         }
 329
 330         getSender().tell(messageSupplier.get(), getSelf());
 331     }
 332
 333     private void memberRemoved(ClusterEvent.MemberRemoved message) {
 334         memberNameToAddress.remove(message.member().roles().head());
 335     }
 336
 337     private void memberUp(ClusterEvent.MemberUp message) {
 338         String memberName = message.member().roles().head();
 339
 340         memberNameToAddress.put(memberName, message.member().address());
 341
 342         for(ShardInformation info : localShards.values()){
 343             String shardName = info.getShardName();
 344             info.updatePeerAddress(getShardIdentifier(memberName, shardName),
 345                 getShardActorPath(shardName, memberName));
 346         }
 347     }
 348
 349     private void onDatastoreContext(DatastoreContext context) {
 350         datastoreContext = context;
 351         for (ShardInformation info : localShards.values()) {
 352             if (info.getActor() != null) {
 353                 info.getActor().tell(datastoreContext, getSelf());
 354             }
 355         }
 356     }
 357
 358     /**
 359      * Notifies all the local shards of a change in the schema context
 360      *
 361      * @param message
 362      */
 363     private void updateSchemaContext(final Object message) {
 364         final SchemaContext schemaContext = ((UpdateSchemaContext) message).getSchemaContext();
 365
 366         Set<ModuleIdentifier> allModuleIdentifiers = schemaContext.getAllModuleIdentifiers();
 367         Set<String> newModules = new HashSet<>(128);
 368
 369         for(ModuleIdentifier moduleIdentifier : allModuleIdentifiers){
 370             String s = moduleIdentifier.getNamespace().toString();
 371             newModules.add(s);
 372         }
 373
 374         if(newModules.containsAll(knownModules)) {
 375
 376             LOG.debug("New SchemaContext has a super set of current knownModules - persisting info");
 377
 378             knownModules = ImmutableSet.copyOf(newModules);
 379
 380             dataPersistenceProvider.persist(new SchemaContextModules(newModules), new Procedure<SchemaContextModules>() {
 381
 382                 @Override
 383                 public void apply(SchemaContextModules param) throws Exception {
 384                     LOG.debug("Sending new SchemaContext to Shards");
 385                     for (ShardInformation info : localShards.values()) {
 386                         if (info.getActor() == null) {
 387                             info.setActor(getContext().actorOf(Shard.props(info.getShardId(),
 388                                     info.getPeerAddresses(), datastoreContext, schemaContext)
 389                                             .withDispatcher(shardDispatcherPath), info.getShardId().toString()));
 390                         } else {
 391                             info.getActor().tell(message, getSelf());
 392                         }
 393                         info.getActor().tell(new RegisterRoleChangeListener(), self());
 394                     }
 395                 }
 396
 397             });
 398         } else {
 399             LOG.debug("Rejecting schema context update - not a super set of previously known modules:\nUPDATE: {}\nKNOWN: {}",
 400                     newModules, knownModules);
 401         }
 402
 403     }
 404
 405     private void findPrimary(FindPrimary message) {
 406         String shardName = message.getShardName();
 407
 408         // First see if the there is a local replica for the shard
 409         final ShardInformation info = localShards.get(shardName);
 410         if (info != null) {
 411             sendResponse(info, message.isWaitUntilInitialized(), new Supplier<Object>() {
 412                 @Override
 413                 public Object get() {
 414                     return new PrimaryFound(info.getActorPath().toString()).toSerializable();
 415                 }
 416             });
 417
 418             return;
 419         }
 420
 421         List<String> members = configuration.getMembersFromShardName(shardName);
 422
 423         if(cluster.getCurrentMemberName() != null) {
 424             members.remove(cluster.getCurrentMemberName());
 425         }
 426
 427         /**
 428          * FIXME: Instead of sending remote shard actor path back to sender,
 429          * forward FindPrimary message to remote shard manager
 430          */
 431         // There is no way for us to figure out the primary (for now) so assume
 432         // that one of the remote nodes is a primary
 433         for(String memberName : members) {
 434             Address address = memberNameToAddress.get(memberName);
 435             if(address != null){
 436                 String path =
 437                     getShardActorPath(shardName, memberName);
 438                 getSender().tell(new PrimaryFound(path).toSerializable(), getSelf());
 439                 return;
 440             }
 441         }
 442         getSender().tell(new PrimaryNotFound(shardName).toSerializable(), getSelf());
 443     }
 444
 445     private String getShardActorPath(String shardName, String memberName) {
 446         Address address = memberNameToAddress.get(memberName);
 447         if(address != null) {
 448             StringBuilder builder = new StringBuilder();
 449             builder.append(address.toString())
 450                 .append("/user/")
 451                 .append(ShardManagerIdentifier.builder().type(type).build().toString())
 452                 .append("/")
 453                 .append(getShardIdentifier(memberName, shardName));
 454             return builder.toString();
 455         }
 456         return null;
 457     }
 458
 459     /**
 460      * Construct the name of the shard actor given the name of the member on
 461      * which the shard resides and the name of the shard
 462      *
 463      * @param memberName
 464      * @param shardName
 465      * @return
 466      */
 467     private ShardIdentifier getShardIdentifier(String memberName, String shardName){
 468         return ShardIdentifier.builder().memberName(memberName).shardName(shardName).type(type).build();
 469     }
 470
 471     /**
 472      * Create shards that are local to the member on which the ShardManager
 473      * runs
 474      *
 475      */
 476     private void createLocalShards() {
 477         String memberName = this.cluster.getCurrentMemberName();
 478         List<String> memberShardNames =
 479             this.configuration.getMemberShardNames(memberName);
 480
 481         List<String> localShardActorNames = new ArrayList<>();
 482         for(String shardName : memberShardNames){
 483             ShardIdentifier shardId = getShardIdentifier(memberName, shardName);
 484             Map<ShardIdentifier, String> peerAddresses = getPeerAddresses(shardName);
 485             localShardActorNames.add(shardId.toString());
 486             localShards.put(shardName, new ShardInformation(shardName, shardId, peerAddresses));
 487         }
 488
 489         mBean = ShardManagerInfo.createShardManagerMBean("shard-manager-" + this.type,
 490                     datastoreContext.getDataStoreMXBeanType(), localShardActorNames);
 491     }
 492
 493     /**
 494      * Given the name of the shard find the addresses of all it's peers
 495      *
 496      * @param shardName
 497      * @return
 498      */
 499     private Map<ShardIdentifier, String> getPeerAddresses(String shardName){
 500
 501         Map<ShardIdentifier, String> peerAddresses = new HashMap<>();
 502
 503         List<String> members =
 504             this.configuration.getMembersFromShardName(shardName);
 505
 506         String currentMemberName = this.cluster.getCurrentMemberName();
 507
 508         for(String memberName : members){
 509             if(!currentMemberName.equals(memberName)){
 510                 ShardIdentifier shardId = getShardIdentifier(memberName,
 511                     shardName);
 512                 String path =
 513                     getShardActorPath(shardName, currentMemberName);
 514                 peerAddresses.put(shardId, path);
 515             }
 516         }
 517         return peerAddresses;
 518     }
 519
 520     @Override
 521     public SupervisorStrategy supervisorStrategy() {
 522
 523         return new OneForOneStrategy(10, Duration.create("1 minute"),
 524             new Function<Throwable, SupervisorStrategy.Directive>() {
 525                 @Override
 526                 public SupervisorStrategy.Directive apply(Throwable t) {
 527                     LOG.warn("Supervisor Strategy caught unexpected exception - resuming", t);
 528                     return SupervisorStrategy.resume();
 529                 }
 530             }
 531         );
 532
 533     }
 534
 535     @Override
 536     public String persistenceId() {
 537         return "shard-manager-" + type;
 538     }
 539
 540     @VisibleForTesting
 541     Collection<String> getKnownModules() {
 542         return knownModules;
 543     }
 544
 545     @VisibleForTesting
 546     DataPersistenceProvider getDataPersistenceProvider() {
 547         return dataPersistenceProvider;
 548     }
 549
 550     @VisibleForTesting
 551     ShardManagerInfoMBean getMBean(){
 552         return mBean;
 553     }
 554
 555     private class ShardInformation {
 556         private final ShardIdentifier shardId;
 557         private final String shardName;
 558         private ActorRef actor;
 559         private ActorPath actorPath;
 560         private final Map<ShardIdentifier, String> peerAddresses;
 561
 562         // flag that determines if the actor is ready for business
 563         private boolean actorInitialized = false;
 564
 565         private boolean followerSyncStatus = false;
 566
 567         private final List<Runnable> runnablesOnInitialized = Lists.newArrayList();
 568         private String role ;
 569
 570         private ShardInformation(String shardName, ShardIdentifier shardId,
 571                 Map<ShardIdentifier, String> peerAddresses) {
 572             this.shardName = shardName;
 573             this.shardId = shardId;
 574             this.peerAddresses = peerAddresses;
 575         }
 576
 577         String getShardName() {
 578             return shardName;
 579         }
 580
 581         ActorRef getActor(){
 582             return actor;
 583         }
 584
 585         ActorPath getActorPath() {
 586             return actorPath;
 587         }
 588
 589         void setActor(ActorRef actor) {
 590             this.actor = actor;
 591             this.actorPath = actor.path();
 592         }
 593
 594         ShardIdentifier getShardId() {
 595             return shardId;
 596         }
 597
 598         Map<ShardIdentifier, String> getPeerAddresses() {
 599             return peerAddresses;
 600         }
 601
 602         void updatePeerAddress(ShardIdentifier peerId, String peerAddress){
 603             LOG.info("updatePeerAddress for peer {} with address {}", peerId,
 604                 peerAddress);
 605             if(peerAddresses.containsKey(peerId)){
 606                 peerAddresses.put(peerId, peerAddress);
 607
 608                 if(actor != null) {
 609                     if(LOG.isDebugEnabled()) {
 610                         LOG.debug("Sending PeerAddressResolved for peer {} with address {} to {}",
 611                                 peerId, peerAddress, actor.path());
 612                     }
 613
 614                     actor.tell(new PeerAddressResolved(peerId, peerAddress), getSelf());
 615                 }
 616             }
 617         }
 618
 619         boolean isShardInitialized() {
 620             return getActor() != null && actorInitialized;
 621         }
 622
 623         void setActorInitialized() {
 624             this.actorInitialized = true;
 625
 626             for(Runnable runnable: runnablesOnInitialized) {
 627                 runnable.run();
 628             }
 629
 630             runnablesOnInitialized.clear();
 631         }
 632
 633         void addRunnableOnInitialized(Runnable runnable) {
 634             runnablesOnInitialized.add(runnable);
 635         }
 636
 637         public void setRole(String newRole) {
 638             this.role = newRole;
 639         }
 640
 641         public String getRole(){
 642             return this.role;
 643         }
 644
 645         public void setFollowerSyncStatus(boolean syncStatus){
 646             this.followerSyncStatus = syncStatus;
 647         }
 648
 649         public boolean isInSync(){
 650             if(RaftState.Follower.name().equals(this.role)){
 651                 return followerSyncStatus;
 652             } else if(RaftState.Leader.name().equals(this.role)){
 653                 return true;
 654             }
 655
 656             return false;
 657         }
 658
 659     }
 660
 661     private static class ShardManagerCreator implements Creator<ShardManager> {
 662         private static final long serialVersionUID = 1L;
 663
 664         final ClusterWrapper cluster;
 665         final Configuration configuration;
 666         final DatastoreContext datastoreContext;
 667         private final CountDownLatch waitTillReadyCountdownLatch;
 668
 669         ShardManagerCreator(ClusterWrapper cluster,
 670                             Configuration configuration, DatastoreContext datastoreContext, CountDownLatch waitTillReadyCountdownLatch) {
 671             this.cluster = cluster;
 672             this.configuration = configuration;
 673             this.datastoreContext = datastoreContext;
 674             this.waitTillReadyCountdownLatch = waitTillReadyCountdownLatch;
 675         }
 676
 677         @Override
 678         public ShardManager create() throws Exception {
 679             return new ShardManager(cluster, configuration, datastoreContext, waitTillReadyCountdownLatch);
 680         }
 681     }
 682
 683     static class SchemaContextModules implements Serializable {
 684         private static final long serialVersionUID = -8884620101025936590L;
 685
 686         private final Set<String> modules;
 687
 688         SchemaContextModules(Set<String> modules){
 689             this.modules = modules;
 690         }
 691
 692         public Set<String> getModules() {
 693             return modules;
 694         }
 695     }
 696 }
 697
 698
 699