opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/sharding/DistributedShardedDOMDataTree.java

   1 /*
   2  * Copyright (c) 2016, 2017 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.sharding;
  10
  11 import static akka.actor.ActorRef.noSender;
  12
  13 import akka.actor.ActorRef;
  14 import akka.actor.ActorSystem;
  15 import akka.actor.PoisonPill;
  16 import akka.actor.Props;
  17 import akka.dispatch.Mapper;
  18 import akka.dispatch.OnComplete;
  19 import akka.pattern.Patterns;
  20 import akka.util.Timeout;
  21 import com.google.common.base.Optional;
  22 import com.google.common.base.Preconditions;
  23 import com.google.common.base.Throwables;
  24 import com.google.common.collect.ClassToInstanceMap;
  25 import com.google.common.collect.ForwardingObject;
  26 import com.google.common.collect.ImmutableClassToInstanceMap;
  27 import com.google.common.util.concurrent.FutureCallback;
  28 import com.google.common.util.concurrent.Futures;
  29 import com.google.common.util.concurrent.ListenableFuture;
  30 import com.google.common.util.concurrent.MoreExecutors;
  31 import com.google.common.util.concurrent.SettableFuture;
  32 import com.google.common.util.concurrent.Uninterruptibles;
  33 import java.util.AbstractMap.SimpleEntry;
  34 import java.util.ArrayList;
  35 import java.util.Collection;
  36 import java.util.Collections;
  37 import java.util.EnumMap;
  38 import java.util.HashMap;
  39 import java.util.List;
  40 import java.util.Map;
  41 import java.util.Map.Entry;
  42 import java.util.Set;
  43 import java.util.concurrent.CompletionStage;
  44 import java.util.concurrent.ExecutionException;
  45 import java.util.concurrent.TimeUnit;
  46 import java.util.concurrent.TimeoutException;
  47 import javax.annotation.Nonnull;
  48 import javax.annotation.Nullable;
  49 import javax.annotation.concurrent.GuardedBy;
  50 import org.opendaylight.controller.cluster.ActorSystemProvider;
  51 import org.opendaylight.controller.cluster.access.concepts.MemberName;
  52 import org.opendaylight.controller.cluster.databroker.actors.dds.DataStoreClient;
  53 import org.opendaylight.controller.cluster.databroker.actors.dds.SimpleDataStoreClientActor;
  54 import org.opendaylight.controller.cluster.datastore.AbstractDataStore;
  55 import org.opendaylight.controller.cluster.datastore.Shard;
  56 import org.opendaylight.controller.cluster.datastore.config.Configuration;
  57 import org.opendaylight.controller.cluster.datastore.config.ModuleShardConfiguration;
  58 import org.opendaylight.controller.cluster.datastore.messages.CreateShard;
  59 import org.opendaylight.controller.cluster.datastore.shardstrategy.ModuleShardStrategy;
  60 import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
  61 import org.opendaylight.controller.cluster.datastore.utils.ClusterUtils;
  62 import org.opendaylight.controller.cluster.dom.api.CDSDataTreeProducer;
  63 import org.opendaylight.controller.cluster.dom.api.CDSShardAccess;
  64 import org.opendaylight.controller.cluster.sharding.ShardedDataTreeActor.ShardedDataTreeActorCreator;
  65 import org.opendaylight.controller.cluster.sharding.messages.InitConfigListener;
  66 import org.opendaylight.controller.cluster.sharding.messages.LookupPrefixShard;
  67 import org.opendaylight.controller.cluster.sharding.messages.PrefixShardRemovalLookup;
  68 import org.opendaylight.controller.cluster.sharding.messages.ProducerCreated;
  69 import org.opendaylight.controller.cluster.sharding.messages.ProducerRemoved;
  70 import org.opendaylight.controller.cluster.sharding.messages.StartConfigShardLookup;
  71 import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
  72 import org.opendaylight.mdsal.dom.api.DOMDataTreeCursorAwareTransaction;
  73 import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
  74 import org.opendaylight.mdsal.dom.api.DOMDataTreeListener;
  75 import org.opendaylight.mdsal.dom.api.DOMDataTreeLoopException;
  76 import org.opendaylight.mdsal.dom.api.DOMDataTreeProducer;
  77 import org.opendaylight.mdsal.dom.api.DOMDataTreeProducerException;
  78 import org.opendaylight.mdsal.dom.api.DOMDataTreeService;
  79 import org.opendaylight.mdsal.dom.api.DOMDataTreeServiceExtension;
  80 import org.opendaylight.mdsal.dom.api.DOMDataTreeShard;
  81 import org.opendaylight.mdsal.dom.api.DOMDataTreeShardingConflictException;
  82 import org.opendaylight.mdsal.dom.api.DOMDataTreeShardingService;
  83 import org.opendaylight.mdsal.dom.broker.DOMDataTreeShardRegistration;
  84 import org.opendaylight.mdsal.dom.broker.ShardedDOMDataTree;
  85 import org.opendaylight.mdsal.dom.spi.DOMDataTreePrefixTable;
  86 import org.opendaylight.mdsal.dom.spi.DOMDataTreePrefixTableEntry;
  87 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.controller.md.sal.clustering.prefix.shard.configuration.rev170110.PrefixShards;
  88 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  89 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  90 import org.slf4j.Logger;
  91 import org.slf4j.LoggerFactory;
  92 import scala.compat.java8.FutureConverters;
  93 import scala.concurrent.Future;
  94 import scala.concurrent.Promise;
  95 import scala.concurrent.duration.FiniteDuration;
  96
  97 /**
  98  * A layer on top of DOMDataTreeService that distributes producer/shard registrations to remote nodes via
  99  * {@link ShardedDataTreeActor}. Also provides QoL method for addition of prefix based clustered shard into the system.
 100  */
 101 public class DistributedShardedDOMDataTree implements DOMDataTreeService, DOMDataTreeShardingService,
 102         DistributedShardFactory {
 103
 104     private static final Logger LOG = LoggerFactory.getLogger(DistributedShardedDOMDataTree.class);
 105
 106     private static final int MAX_ACTOR_CREATION_RETRIES = 100;
 107     private static final int ACTOR_RETRY_DELAY = 100;
 108     private static final TimeUnit ACTOR_RETRY_TIME_UNIT = TimeUnit.MILLISECONDS;
 109     private static final int LOOKUP_TASK_MAX_RETRIES = 100;
 110     static final FiniteDuration SHARD_FUTURE_TIMEOUT_DURATION =
 111             new FiniteDuration(LOOKUP_TASK_MAX_RETRIES * LOOKUP_TASK_MAX_RETRIES * 3, TimeUnit.SECONDS);
 112     static final Timeout SHARD_FUTURE_TIMEOUT = new Timeout(SHARD_FUTURE_TIMEOUT_DURATION);
 113
 114     static final String ACTOR_ID = "ShardedDOMDataTreeFrontend";
 115
 116     private final ShardedDOMDataTree shardedDOMDataTree;
 117     private final ActorSystem actorSystem;
 118     private final AbstractDataStore distributedOperDatastore;
 119     private final AbstractDataStore distributedConfigDatastore;
 120
 121     private final ActorRef shardedDataTreeActor;
 122     private final MemberName memberName;
 123
 124     @GuardedBy("shards")
 125     private final DOMDataTreePrefixTable<DOMDataTreeShardRegistration<DOMDataTreeShard>> shards =
 126             DOMDataTreePrefixTable.create();
 127
 128     private final EnumMap<LogicalDatastoreType, Entry<DataStoreClient, ActorRef>> configurationShardMap =
 129             new EnumMap<>(LogicalDatastoreType.class);
 130
 131     private final EnumMap<LogicalDatastoreType, PrefixedShardConfigWriter> writerMap =
 132             new EnumMap<>(LogicalDatastoreType.class);
 133
 134     private final PrefixedShardConfigUpdateHandler updateHandler;
 135
 136     public DistributedShardedDOMDataTree(final ActorSystemProvider actorSystemProvider,
 137                                          final AbstractDataStore distributedOperDatastore,
 138                                          final AbstractDataStore distributedConfigDatastore) {
 139         this.actorSystem = Preconditions.checkNotNull(actorSystemProvider).getActorSystem();
 140         this.distributedOperDatastore = Preconditions.checkNotNull(distributedOperDatastore);
 141         this.distributedConfigDatastore = Preconditions.checkNotNull(distributedConfigDatastore);
 142         shardedDOMDataTree = new ShardedDOMDataTree();
 143
 144         shardedDataTreeActor = createShardedDataTreeActor(actorSystem,
 145                 new ShardedDataTreeActorCreator()
 146                         .setShardingService(this)
 147                         .setActorSystem(actorSystem)
 148                         .setClusterWrapper(distributedConfigDatastore.getActorContext().getClusterWrapper())
 149                         .setDistributedConfigDatastore(distributedConfigDatastore)
 150                         .setDistributedOperDatastore(distributedOperDatastore)
 151                         .setLookupTaskMaxRetries(LOOKUP_TASK_MAX_RETRIES),
 152                 ACTOR_ID);
 153
 154         this.memberName = distributedConfigDatastore.getActorContext().getCurrentMemberName();
 155
 156         updateHandler = new PrefixedShardConfigUpdateHandler(shardedDataTreeActor,
 157                 distributedConfigDatastore.getActorContext().getCurrentMemberName());
 158
 159         LOG.debug("{} - Starting prefix configuration shards", memberName);
 160         createPrefixConfigShard(distributedConfigDatastore);
 161         createPrefixConfigShard(distributedOperDatastore);
 162     }
 163
 164     private static void createPrefixConfigShard(final AbstractDataStore dataStore) {
 165         Configuration configuration = dataStore.getActorContext().getConfiguration();
 166         Collection<MemberName> memberNames = configuration.getUniqueMemberNamesForAllShards();
 167         CreateShard createShardMessage =
 168                 new CreateShard(new ModuleShardConfiguration(PrefixShards.QNAME.getNamespace(),
 169                         "prefix-shard-configuration", ClusterUtils.PREFIX_CONFIG_SHARD_ID, ModuleShardStrategy.NAME,
 170                         memberNames),
 171                         Shard.builder(), dataStore.getActorContext().getDatastoreContext());
 172
 173         dataStore.getActorContext().getShardManager().tell(createShardMessage, noSender());
 174     }
 175
 176     /**
 177      * This will try to initialize prefix configuration shards upon their
 178      * successful start. We need to create writers to these shards, so we can
 179      * satisfy future {@link #createDistributedShard} and
 180      * {@link #resolveShardAdditions} requests and update prefix configuration
 181      * shards accordingly.
 182      *
 183      * <p>
 184      * We also need to initialize listeners on these shards, so we can react
 185      * on changes made on them by other cluster members or even by ourselves.
 186      *
 187      * <p>
 188      * Finally, we need to be sure that default shards for both operational and
 189      * configuration data stores are up and running and we have distributed
 190      * shards frontend created for them.
 191      *
 192      * <p>
 193      * This is intended to be invoked by blueprint as initialization method.
 194      */
 195     public void init() {
 196         // create our writers to the configuration
 197         try {
 198             LOG.debug("{} - starting config shard lookup.", memberName);
 199
 200             // We have to wait for prefix config shards to be up and running
 201             // so we can create datastore clients for them
 202             handleConfigShardLookup().get(SHARD_FUTURE_TIMEOUT_DURATION.length(), SHARD_FUTURE_TIMEOUT_DURATION.unit());
 203         } catch (InterruptedException | ExecutionException | TimeoutException e) {
 204             throw new IllegalStateException("Prefix config shards not found", e);
 205         }
 206
 207         try {
 208             LOG.debug("{}: Prefix configuration shards ready - creating clients", memberName);
 209             configurationShardMap.put(LogicalDatastoreType.CONFIGURATION,
 210                     createDatastoreClient(ClusterUtils.PREFIX_CONFIG_SHARD_ID,
 211                             distributedConfigDatastore.getActorContext()));
 212         } catch (final DOMDataTreeShardCreationFailedException e) {
 213             throw new IllegalStateException(
 214                     "Unable to create datastoreClient for config DS prefix configuration shard.", e);
 215         }
 216
 217         try {
 218             configurationShardMap.put(LogicalDatastoreType.OPERATIONAL,
 219                     createDatastoreClient(ClusterUtils.PREFIX_CONFIG_SHARD_ID,
 220                             distributedOperDatastore.getActorContext()));
 221
 222         } catch (final DOMDataTreeShardCreationFailedException e) {
 223             throw new IllegalStateException(
 224                         "Unable to create datastoreClient for oper DS prefix configuration shard.", e);
 225         }
 226
 227         writerMap.put(LogicalDatastoreType.CONFIGURATION, new PrefixedShardConfigWriter(
 228                 configurationShardMap.get(LogicalDatastoreType.CONFIGURATION).getKey()));
 229
 230         writerMap.put(LogicalDatastoreType.OPERATIONAL, new PrefixedShardConfigWriter(
 231                 configurationShardMap.get(LogicalDatastoreType.OPERATIONAL).getKey()));
 232
 233         updateHandler.initListener(distributedConfigDatastore, LogicalDatastoreType.CONFIGURATION);
 234         updateHandler.initListener(distributedOperDatastore, LogicalDatastoreType.OPERATIONAL);
 235
 236         distributedConfigDatastore.getActorContext().getShardManager().tell(InitConfigListener.INSTANCE, noSender());
 237         distributedOperDatastore.getActorContext().getShardManager().tell(InitConfigListener.INSTANCE, noSender());
 238
 239
 240         //create shard registration for DEFAULT_SHARD
 241         try {
 242             initDefaultShard(LogicalDatastoreType.CONFIGURATION);
 243         } catch (final InterruptedException | ExecutionException e) {
 244             throw new IllegalStateException("Unable to create default shard frontend for config shard", e);
 245         }
 246
 247         try {
 248             initDefaultShard(LogicalDatastoreType.OPERATIONAL);
 249         } catch (final InterruptedException | ExecutionException e) {
 250             throw new IllegalStateException("Unable to create default shard frontend for operational shard", e);
 251         }
 252     }
 253
 254     private ListenableFuture<List<Void>> handleConfigShardLookup() {
 255
 256         final ListenableFuture<Void> configFuture = lookupConfigShard(LogicalDatastoreType.CONFIGURATION);
 257         final ListenableFuture<Void> operFuture = lookupConfigShard(LogicalDatastoreType.OPERATIONAL);
 258
 259         return Futures.allAsList(configFuture, operFuture);
 260     }
 261
 262     private ListenableFuture<Void> lookupConfigShard(final LogicalDatastoreType type) {
 263         final SettableFuture<Void> future = SettableFuture.create();
 264
 265         final Future<Object> ask =
 266                 Patterns.ask(shardedDataTreeActor, new StartConfigShardLookup(type), SHARD_FUTURE_TIMEOUT);
 267
 268         ask.onComplete(new OnComplete<Object>() {
 269             @Override
 270             public void onComplete(final Throwable throwable, final Object result) throws Throwable {
 271                 if (throwable != null) {
 272                     future.setException(throwable);
 273                 } else {
 274                     future.set(null);
 275                 }
 276             }
 277         }, actorSystem.dispatcher());
 278
 279         return future;
 280     }
 281
 282     @Nonnull
 283     @Override
 284     public <T extends DOMDataTreeListener> ListenerRegistration<T> registerListener(
 285             final T listener, final Collection<DOMDataTreeIdentifier> subtrees,
 286             final boolean allowRxMerges, final Collection<DOMDataTreeProducer> producers)
 287             throws DOMDataTreeLoopException {
 288         return shardedDOMDataTree.registerListener(listener, subtrees, allowRxMerges, producers);
 289     }
 290
 291     @Override
 292     @Deprecated
 293     public Map<Class<? extends DOMDataTreeServiceExtension>, DOMDataTreeServiceExtension> getSupportedExtensions() {
 294         return ImmutableClassToInstanceMap.of();
 295     }
 296
 297     @Override
 298     public ClassToInstanceMap<DOMDataTreeServiceExtension> getExtensions() {
 299         return ImmutableClassToInstanceMap.of();
 300     }
 301
 302     @Nonnull
 303     @Override
 304     public DOMDataTreeProducer createProducer(@Nonnull final Collection<DOMDataTreeIdentifier> subtrees) {
 305         LOG.debug("{} - Creating producer for {}", memberName, subtrees);
 306         final DOMDataTreeProducer producer = shardedDOMDataTree.createProducer(subtrees);
 307
 308         final Object response = distributedConfigDatastore.getActorContext()
 309                 .executeOperation(shardedDataTreeActor, new ProducerCreated(subtrees));
 310         if (response == null) {
 311             LOG.debug("{} - Received success from remote nodes, creating producer:{}", memberName, subtrees);
 312             return new ProxyProducer(producer, subtrees, shardedDataTreeActor,
 313                     distributedConfigDatastore.getActorContext(), shards);
 314         }
 315
 316         closeProducer(producer);
 317
 318         if (response instanceof Throwable) {
 319             Throwables.throwIfUnchecked((Throwable) response);
 320             throw new RuntimeException((Throwable) response);
 321         }
 322         throw new RuntimeException("Unexpected response to create producer received." + response);
 323     }
 324
 325     @Override
 326     public CompletionStage<DistributedShardRegistration> createDistributedShard(
 327             final DOMDataTreeIdentifier prefix, final Collection<MemberName> replicaMembers)
 328             throws DOMDataTreeShardingConflictException {
 329
 330         synchronized (shards) {
 331             final DOMDataTreePrefixTableEntry<DOMDataTreeShardRegistration<DOMDataTreeShard>> lookup =
 332                     shards.lookup(prefix);
 333             if (lookup != null && lookup.getValue().getPrefix().equals(prefix)) {
 334                 throw new DOMDataTreeShardingConflictException(
 335                         "Prefix " + prefix + " is already occupied by another shard.");
 336             }
 337         }
 338
 339         final PrefixedShardConfigWriter writer = writerMap.get(prefix.getDatastoreType());
 340
 341         final ListenableFuture<Void> writeFuture =
 342                 writer.writeConfig(prefix.getRootIdentifier(), replicaMembers);
 343
 344         final Promise<DistributedShardRegistration> shardRegistrationPromise = akka.dispatch.Futures.promise();
 345         Futures.addCallback(writeFuture, new FutureCallback<Void>() {
 346             @Override
 347             public void onSuccess(@Nullable final Void result) {
 348
 349                 final Future<Object> ask =
 350                         Patterns.ask(shardedDataTreeActor, new LookupPrefixShard(prefix), SHARD_FUTURE_TIMEOUT);
 351
 352                 shardRegistrationPromise.completeWith(ask.transform(
 353                         new Mapper<Object, DistributedShardRegistration>() {
 354                             @Override
 355                             public DistributedShardRegistration apply(final Object parameter) {
 356                                 return new DistributedShardRegistrationImpl(
 357                                         prefix, shardedDataTreeActor, DistributedShardedDOMDataTree.this);
 358                             }
 359                         },
 360                         new Mapper<Throwable, Throwable>() {
 361                             @Override
 362                             public Throwable apply(final Throwable throwable) {
 363                                 return new DOMDataTreeShardCreationFailedException(
 364                                         "Unable to create a cds shard.", throwable);
 365                             }
 366                         }, actorSystem.dispatcher()));
 367             }
 368
 369             @Override
 370             public void onFailure(final Throwable throwable) {
 371                 shardRegistrationPromise.failure(
 372                         new DOMDataTreeShardCreationFailedException("Unable to create a cds shard.", throwable));
 373             }
 374         }, MoreExecutors.directExecutor());
 375
 376         return FutureConverters.toJava(shardRegistrationPromise.future());
 377     }
 378
 379     void resolveShardAdditions(final Set<DOMDataTreeIdentifier> additions) {
 380         LOG.debug("{}: Resolving additions : {}", memberName, additions);
 381         final ArrayList<DOMDataTreeIdentifier> list = new ArrayList<>(additions);
 382         // we need to register the shards from top to bottom, so we need to atleast make sure the ordering reflects that
 383         Collections.sort(list, (o1, o2) -> {
 384             if (o1.getRootIdentifier().getPathArguments().size() < o2.getRootIdentifier().getPathArguments().size()) {
 385                 return -1;
 386             } else if (o1.getRootIdentifier().getPathArguments().size()
 387                     == o2.getRootIdentifier().getPathArguments().size()) {
 388                 return 0;
 389             } else {
 390                 return 1;
 391             }
 392         });
 393         list.forEach(this::createShardFrontend);
 394     }
 395
 396     void resolveShardRemovals(final Set<DOMDataTreeIdentifier> removals) {
 397         LOG.debug("{}: Resolving removals : {}", memberName, removals);
 398
 399         // do we need to go from bottom to top?
 400         removals.forEach(this::despawnShardFrontend);
 401     }
 402
 403     private void createShardFrontend(final DOMDataTreeIdentifier prefix) {
 404         LOG.debug("{}: Creating CDS shard for prefix: {}", memberName, prefix);
 405         final String shardName = ClusterUtils.getCleanShardName(prefix.getRootIdentifier());
 406         final AbstractDataStore distributedDataStore =
 407                 prefix.getDatastoreType().equals(org.opendaylight.mdsal.common.api.LogicalDatastoreType.CONFIGURATION)
 408                         ? distributedConfigDatastore : distributedOperDatastore;
 409
 410         try (DOMDataTreeProducer producer = localCreateProducer(Collections.singletonList(prefix))) {
 411             final Entry<DataStoreClient, ActorRef> entry =
 412                     createDatastoreClient(shardName, distributedDataStore.getActorContext());
 413
 414             final DistributedShardFrontend shard =
 415                     new DistributedShardFrontend(distributedDataStore, entry.getKey(), prefix);
 416
 417             final DOMDataTreeShardRegistration<DOMDataTreeShard> reg =
 418                     shardedDOMDataTree.registerDataTreeShard(prefix, shard, producer);
 419
 420             synchronized (shards) {
 421                 shards.store(prefix, reg);
 422             }
 423
 424         } catch (final DOMDataTreeShardingConflictException e) {
 425             LOG.error("{}: Prefix {} is already occupied by another shard",
 426                     distributedConfigDatastore.getActorContext().getClusterWrapper().getCurrentMemberName(), prefix, e);
 427         } catch (DOMDataTreeProducerException e) {
 428             LOG.error("Unable to close producer", e);
 429         } catch (DOMDataTreeShardCreationFailedException e) {
 430             LOG.error("Unable to create datastore client for shard {}", prefix, e);
 431         }
 432     }
 433
 434     private void despawnShardFrontend(final DOMDataTreeIdentifier prefix) {
 435         LOG.debug("{}: Removing CDS shard for prefix: {}", memberName, prefix);
 436         final DOMDataTreePrefixTableEntry<DOMDataTreeShardRegistration<DOMDataTreeShard>> lookup;
 437         synchronized (shards) {
 438             lookup = shards.lookup(prefix);
 439         }
 440
 441         if (lookup == null || !lookup.getValue().getPrefix().equals(prefix)) {
 442             LOG.debug("{}: Received despawn for non-existing CDS shard frontend, prefix: {}, ignoring..",
 443                     memberName, prefix);
 444             return;
 445         }
 446
 447         lookup.getValue().close();
 448         // need to remove from our local table thats used for tracking
 449         synchronized (shards) {
 450             shards.remove(prefix);
 451         }
 452
 453         final PrefixedShardConfigWriter writer = writerMap.get(prefix.getDatastoreType());
 454         final ListenableFuture<Void> future = writer.removeConfig(prefix.getRootIdentifier());
 455
 456         Futures.addCallback(future, new FutureCallback<Void>() {
 457             @Override
 458             public void onSuccess(@Nullable final Void result) {
 459                 LOG.debug("{} - Succesfuly removed shard for {}", memberName, prefix);
 460             }
 461
 462             @Override
 463             public void onFailure(final Throwable throwable) {
 464                 LOG.error("Removal of shard {} from configuration failed.", prefix, throwable);
 465             }
 466         }, MoreExecutors.directExecutor());
 467     }
 468
 469     DOMDataTreePrefixTableEntry<DOMDataTreeShardRegistration<DOMDataTreeShard>> lookupShardFrontend(
 470             final DOMDataTreeIdentifier prefix) {
 471         synchronized (shards) {
 472             return shards.lookup(prefix);
 473         }
 474     }
 475
 476     DOMDataTreeProducer localCreateProducer(final Collection<DOMDataTreeIdentifier> prefix) {
 477         return shardedDOMDataTree.createProducer(prefix);
 478     }
 479
 480     @Nonnull
 481     @Override
 482     public <T extends DOMDataTreeShard> ListenerRegistration<T> registerDataTreeShard(
 483             @Nonnull final DOMDataTreeIdentifier prefix,
 484             @Nonnull final T shard,
 485             @Nonnull final DOMDataTreeProducer producer)
 486             throws DOMDataTreeShardingConflictException {
 487
 488         LOG.debug("Registering shard[{}] at prefix: {}", shard, prefix);
 489
 490         if (producer instanceof ProxyProducer) {
 491             return shardedDOMDataTree.registerDataTreeShard(prefix, shard, ((ProxyProducer) producer).delegate());
 492         }
 493
 494         return shardedDOMDataTree.registerDataTreeShard(prefix, shard, producer);
 495     }
 496
 497     @SuppressWarnings("checkstyle:IllegalCatch")
 498     private Entry<DataStoreClient, ActorRef> createDatastoreClient(
 499             final String shardName, final ActorContext actorContext)
 500             throws DOMDataTreeShardCreationFailedException {
 501
 502         LOG.debug("{}: Creating distributed datastore client for shard {}", memberName, shardName);
 503         final Props distributedDataStoreClientProps =
 504                 SimpleDataStoreClientActor.props(memberName, "Shard-" + shardName, actorContext, shardName);
 505
 506         final ActorRef clientActor = actorSystem.actorOf(distributedDataStoreClientProps);
 507         try {
 508             return new SimpleEntry<>(SimpleDataStoreClientActor
 509                     .getDistributedDataStoreClient(clientActor, 30, TimeUnit.SECONDS), clientActor);
 510         } catch (final Exception e) {
 511             LOG.error("{}: Failed to get actor for {}", distributedDataStoreClientProps, memberName, e);
 512             clientActor.tell(PoisonPill.getInstance(), noSender());
 513             throw new DOMDataTreeShardCreationFailedException(
 514                     "Unable to create datastore client for shard{" + shardName + "}", e);
 515         }
 516     }
 517
 518     @SuppressWarnings("checkstyle:IllegalCatch")
 519     private void initDefaultShard(final LogicalDatastoreType logicalDatastoreType)
 520             throws ExecutionException, InterruptedException {
 521
 522         final PrefixedShardConfigWriter writer = writerMap.get(logicalDatastoreType);
 523
 524         if (writer.checkDefaultIsPresent()) {
 525             LOG.debug("{}: Default shard for {} is already present in the config. Possibly saved in snapshot.",
 526                     memberName, logicalDatastoreType);
 527         } else {
 528             try {
 529                 // Currently the default shard configuration is present in the out-of-box modules.conf and is
 530                 // expected to be present. So look up the local default shard here and create the frontend.
 531
 532                 // TODO we don't have to do it for config and operational default shard separately. Just one of them
 533                 // should be enough
 534                 final ActorContext actorContext = logicalDatastoreType == LogicalDatastoreType.CONFIGURATION
 535                         ? distributedConfigDatastore.getActorContext() : distributedOperDatastore.getActorContext();
 536
 537                 final Optional<ActorRef> defaultLocalShardOptional =
 538                         actorContext.findLocalShard(ClusterUtils.getCleanShardName(YangInstanceIdentifier.EMPTY));
 539
 540                 if (defaultLocalShardOptional.isPresent()) {
 541                     LOG.debug("{}: Default shard for {} is already started, creating just frontend", memberName,
 542                             logicalDatastoreType);
 543                     createShardFrontend(new DOMDataTreeIdentifier(logicalDatastoreType, YangInstanceIdentifier.EMPTY));
 544                 }
 545
 546                 // The local shard isn't present - we assume that means the local member isn't in the replica list
 547                 // and will be dynamically created later via an explicit add-shard-replica request. This is the
 548                 // bootstrapping mechanism to add a new node into an existing cluster. The following code to create
 549                 // the default shard as a prefix shard is problematic in this scenario so it is commented out. Since
 550                 // the default shard is a module-based shard by default, it makes sense to always treat it as such,
 551                 // ie bootstrap it in the same manner as the special prefix-configuration and EOS shards.
 552 //                final Collection<MemberName> names = distributedConfigDatastore.getActorContext().getConfiguration()
 553 //                        .getUniqueMemberNamesForAllShards();
 554 //                Await.result(FutureConverters.toScala(createDistributedShard(
 555 //                        new DOMDataTreeIdentifier(logicalDatastoreType, YangInstanceIdentifier.EMPTY), names)),
 556 //                        SHARD_FUTURE_TIMEOUT_DURATION);
 557 //            } catch (DOMDataTreeShardingConflictException e) {
 558 //                LOG.debug("{}: Default shard for {} already registered, possibly due to other node doing it faster",
 559 //                        memberName, logicalDatastoreType);
 560             } catch (Exception e) {
 561                 LOG.error("{}: Default shard initialization for {} failed", memberName, logicalDatastoreType, e);
 562                 throw new RuntimeException(e);
 563             }
 564         }
 565     }
 566
 567     private static void closeProducer(final DOMDataTreeProducer producer) {
 568         try {
 569             producer.close();
 570         } catch (final DOMDataTreeProducerException e) {
 571             LOG.error("Unable to close producer", e);
 572         }
 573     }
 574
 575     @SuppressWarnings("checkstyle:IllegalCatch")
 576     private static ActorRef createShardedDataTreeActor(final ActorSystem actorSystem,
 577                                                        final ShardedDataTreeActorCreator creator,
 578                                                        final String shardDataTreeActorId) {
 579         Exception lastException = null;
 580
 581         for (int i = 0; i < MAX_ACTOR_CREATION_RETRIES; i++) {
 582             try {
 583                 return actorSystem.actorOf(creator.props(), shardDataTreeActorId);
 584             } catch (final Exception e) {
 585                 lastException = e;
 586                 Uninterruptibles.sleepUninterruptibly(ACTOR_RETRY_DELAY, ACTOR_RETRY_TIME_UNIT);
 587                 LOG.debug("Could not create actor {} because of {} -"
 588                                 + " waiting for sometime before retrying (retry count = {})",
 589                         shardDataTreeActorId, e.getMessage(), i);
 590             }
 591         }
 592
 593         throw new IllegalStateException("Failed to create actor for ShardedDOMDataTree", lastException);
 594     }
 595
 596     private class DistributedShardRegistrationImpl implements DistributedShardRegistration {
 597
 598         private final DOMDataTreeIdentifier prefix;
 599         private final ActorRef shardedDataTreeActor;
 600         private final DistributedShardedDOMDataTree distributedShardedDOMDataTree;
 601
 602         DistributedShardRegistrationImpl(final DOMDataTreeIdentifier prefix,
 603                                          final ActorRef shardedDataTreeActor,
 604                                          final DistributedShardedDOMDataTree distributedShardedDOMDataTree) {
 605             this.prefix = prefix;
 606             this.shardedDataTreeActor = shardedDataTreeActor;
 607             this.distributedShardedDOMDataTree = distributedShardedDOMDataTree;
 608         }
 609
 610         @Override
 611         public CompletionStage<Void> close() {
 612             // first despawn on the local node
 613             distributedShardedDOMDataTree.despawnShardFrontend(prefix);
 614             // update the config so the remote nodes are updated
 615             final Future<Object> ask =
 616                     Patterns.ask(shardedDataTreeActor, new PrefixShardRemovalLookup(prefix), SHARD_FUTURE_TIMEOUT);
 617
 618             final Future<Void> closeFuture = ask.transform(
 619                     new Mapper<Object, Void>() {
 620                         @Override
 621                         public Void apply(final Object parameter) {
 622                             return null;
 623                         }
 624                     },
 625                     new Mapper<Throwable, Throwable>() {
 626                         @Override
 627                         public Throwable apply(final Throwable throwable) {
 628                             return throwable;
 629                         }
 630                     }, actorSystem.dispatcher());
 631
 632             return FutureConverters.toJava(closeFuture);
 633         }
 634     }
 635
 636     // TODO what about producers created by this producer?
 637     // They should also be CDSProducers
 638     private static final class ProxyProducer extends ForwardingObject implements CDSDataTreeProducer {
 639
 640         private final DOMDataTreeProducer delegate;
 641         private final Collection<DOMDataTreeIdentifier> subtrees;
 642         private final ActorRef shardDataTreeActor;
 643         private final ActorContext actorContext;
 644         @GuardedBy("shardAccessMap")
 645         private final Map<DOMDataTreeIdentifier, CDSShardAccessImpl> shardAccessMap = new HashMap<>();
 646
 647         // We don't have to guard access to shardTable in ProxyProducer.
 648         // ShardTable's entries relevant to this ProxyProducer shouldn't
 649         // change during producer's lifetime.
 650         private final DOMDataTreePrefixTable<DOMDataTreeShardRegistration<DOMDataTreeShard>> shardTable;
 651
 652         ProxyProducer(final DOMDataTreeProducer delegate,
 653                       final Collection<DOMDataTreeIdentifier> subtrees,
 654                       final ActorRef shardDataTreeActor,
 655                       final ActorContext actorContext,
 656                       final DOMDataTreePrefixTable<DOMDataTreeShardRegistration<DOMDataTreeShard>> shardLayout) {
 657             this.delegate = Preconditions.checkNotNull(delegate);
 658             this.subtrees = Preconditions.checkNotNull(subtrees);
 659             this.shardDataTreeActor = Preconditions.checkNotNull(shardDataTreeActor);
 660             this.actorContext = Preconditions.checkNotNull(actorContext);
 661             this.shardTable = Preconditions.checkNotNull(shardLayout);
 662         }
 663
 664         @Nonnull
 665         @Override
 666         public DOMDataTreeCursorAwareTransaction createTransaction(final boolean isolated) {
 667             return delegate.createTransaction(isolated);
 668         }
 669
 670         @Nonnull
 671         @Override
 672         @SuppressWarnings("checkstyle:hiddenField")
 673         public DOMDataTreeProducer createProducer(@Nonnull final Collection<DOMDataTreeIdentifier> subtrees) {
 674             // TODO we probably don't need to distribute this on the remote nodes since once we have this producer
 675             // open we surely have the rights to all the subtrees.
 676             return delegate.createProducer(subtrees);
 677         }
 678
 679         @Override
 680         @SuppressWarnings("checkstyle:IllegalCatch")
 681         public void close() throws DOMDataTreeProducerException {
 682             delegate.close();
 683
 684             synchronized (shardAccessMap) {
 685                 shardAccessMap.values().forEach(CDSShardAccessImpl::close);
 686             }
 687
 688             final Object o = actorContext.executeOperation(shardDataTreeActor, new ProducerRemoved(subtrees));
 689             if (o instanceof DOMDataTreeProducerException) {
 690                 throw (DOMDataTreeProducerException) o;
 691             } else if (o instanceof Throwable) {
 692                 throw new DOMDataTreeProducerException("Unable to close producer", (Throwable) o);
 693             }
 694         }
 695
 696         @Override
 697         protected DOMDataTreeProducer delegate() {
 698             return delegate;
 699         }
 700
 701         @Nonnull
 702         @Override
 703         public CDSShardAccess getShardAccess(@Nonnull final DOMDataTreeIdentifier subtree) {
 704             Preconditions.checkArgument(
 705                     subtrees.stream().anyMatch(dataTreeIdentifier -> dataTreeIdentifier.contains(subtree)),
 706                     "Subtree %s is not controlled by this producer %s", subtree, this);
 707
 708             final DOMDataTreePrefixTableEntry<DOMDataTreeShardRegistration<DOMDataTreeShard>> lookup =
 709                     shardTable.lookup(subtree);
 710             Preconditions.checkState(lookup != null, "Subtree %s is not contained in any registered shard.", subtree);
 711
 712             final DOMDataTreeIdentifier lookupId = lookup.getValue().getPrefix();
 713
 714             synchronized (shardAccessMap) {
 715                 if (shardAccessMap.get(lookupId) != null) {
 716                     return shardAccessMap.get(lookupId);
 717                 }
 718
 719                 // TODO Maybe we can have static factory method and return the same instance
 720                 // for same subtrees. But maybe it is not needed since there can be only one
 721                 // producer attached to some subtree at a time. And also how we can close ShardAccess
 722                 // then
 723                 final CDSShardAccessImpl shardAccess = new CDSShardAccessImpl(lookupId, actorContext);
 724                 shardAccessMap.put(lookupId, shardAccess);
 725                 return shardAccess;
 726             }
 727         }
 728     }
 729 }