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 package org.opendaylight.controller.cluster.sharding;
   9
  10 import static akka.actor.ActorRef.noSender;
  11 import static com.google.common.base.Preconditions.checkArgument;
  12 import static com.google.common.base.Preconditions.checkState;
  13 import static java.util.Objects.requireNonNull;
  14
  15 import akka.actor.ActorRef;
  16 import akka.actor.ActorSystem;
  17 import akka.actor.PoisonPill;
  18 import akka.actor.Props;
  19 import akka.dispatch.Mapper;
  20 import akka.dispatch.OnComplete;
  21 import akka.pattern.Patterns;
  22 import akka.util.Timeout;
  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.Collection;
  35 import java.util.Collections;
  36 import java.util.Comparator;
  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.Optional;
  43 import java.util.Set;
  44 import java.util.concurrent.CompletionStage;
  45 import java.util.concurrent.ExecutionException;
  46 import java.util.concurrent.TimeUnit;
  47 import java.util.concurrent.TimeoutException;
  48 import org.checkerframework.checker.lock.qual.GuardedBy;
  49 import org.opendaylight.controller.cluster.ActorSystemProvider;
  50 import org.opendaylight.controller.cluster.access.concepts.MemberName;
  51 import org.opendaylight.controller.cluster.databroker.actors.dds.DataStoreClient;
  52 import org.opendaylight.controller.cluster.databroker.actors.dds.SimpleDataStoreClientActor;
  53 import org.opendaylight.controller.cluster.datastore.DistributedDataStoreInterface;
  54 import org.opendaylight.controller.cluster.datastore.Shard;
  55 import org.opendaylight.controller.cluster.datastore.config.Configuration;
  56 import org.opendaylight.controller.cluster.datastore.config.ModuleShardConfiguration;
  57 import org.opendaylight.controller.cluster.datastore.messages.CreateShard;
  58 import org.opendaylight.controller.cluster.datastore.shardstrategy.ModuleShardStrategy;
  59 import org.opendaylight.controller.cluster.datastore.utils.ActorUtils;
  60 import org.opendaylight.controller.cluster.datastore.utils.ClusterUtils;
  61 import org.opendaylight.controller.cluster.dom.api.CDSDataTreeProducer;
  62 import org.opendaylight.controller.cluster.dom.api.CDSShardAccess;
  63 import org.opendaylight.controller.cluster.sharding.ShardedDataTreeActor.ShardedDataTreeActorCreator;
  64 import org.opendaylight.controller.cluster.sharding.messages.InitConfigListener;
  65 import org.opendaylight.controller.cluster.sharding.messages.LookupPrefixShard;
  66 import org.opendaylight.controller.cluster.sharding.messages.PrefixShardRemovalLookup;
  67 import org.opendaylight.controller.cluster.sharding.messages.ProducerCreated;
  68 import org.opendaylight.controller.cluster.sharding.messages.ProducerRemoved;
  69 import org.opendaylight.controller.cluster.sharding.messages.StartConfigShardLookup;
  70 import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
  71 import org.opendaylight.mdsal.dom.api.DOMDataTreeCursorAwareTransaction;
  72 import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
  73 import org.opendaylight.mdsal.dom.api.DOMDataTreeListener;
  74 import org.opendaylight.mdsal.dom.api.DOMDataTreeLoopException;
  75 import org.opendaylight.mdsal.dom.api.DOMDataTreeProducer;
  76 import org.opendaylight.mdsal.dom.api.DOMDataTreeProducerException;
  77 import org.opendaylight.mdsal.dom.api.DOMDataTreeService;
  78 import org.opendaylight.mdsal.dom.api.DOMDataTreeServiceExtension;
  79 import org.opendaylight.mdsal.dom.api.DOMDataTreeShard;
  80 import org.opendaylight.mdsal.dom.api.DOMDataTreeShardingConflictException;
  81 import org.opendaylight.mdsal.dom.api.DOMDataTreeShardingService;
  82 import org.opendaylight.mdsal.dom.broker.DOMDataTreeShardRegistration;
  83 import org.opendaylight.mdsal.dom.broker.ShardedDOMDataTree;
  84 import org.opendaylight.mdsal.dom.spi.DOMDataTreePrefixTable;
  85 import org.opendaylight.mdsal.dom.spi.DOMDataTreePrefixTableEntry;
  86 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.controller.md.sal.clustering.prefix.shard.configuration.rev170110.PrefixShards;
  87 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  88 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  89 import org.slf4j.Logger;
  90 import org.slf4j.LoggerFactory;
  91 import scala.compat.java8.FutureConverters;
  92 import scala.concurrent.Future;
  93 import scala.concurrent.Promise;
  94 import scala.concurrent.duration.FiniteDuration;
  95
  96 /**
  97  * A layer on top of DOMDataTreeService that distributes producer/shard registrations to remote nodes via
  98  * {@link ShardedDataTreeActor}. Also provides QoL method for addition of prefix based clustered shard into the system.
  99  */
 100 @Deprecated(forRemoval = true)
 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 DistributedDataStoreInterface distributedOperDatastore;
 119     private final DistributedDataStoreInterface 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 DistributedDataStoreInterface distributedOperDatastore,
 138                                          final DistributedDataStoreInterface distributedConfigDatastore) {
 139         this.actorSystem = requireNonNull(actorSystemProvider).getActorSystem();
 140         this.distributedOperDatastore = requireNonNull(distributedOperDatastore);
 141         this.distributedConfigDatastore = requireNonNull(distributedConfigDatastore);
 142         shardedDOMDataTree = new ShardedDOMDataTree();
 143
 144         shardedDataTreeActor = createShardedDataTreeActor(actorSystem,
 145                 new ShardedDataTreeActorCreator()
 146                         .setShardingService(this)
 147                         .setActorSystem(actorSystem)
 148                         .setClusterWrapper(distributedConfigDatastore.getActorUtils().getClusterWrapper())
 149                         .setDistributedConfigDatastore(distributedConfigDatastore)
 150                         .setDistributedOperDatastore(distributedOperDatastore)
 151                         .setLookupTaskMaxRetries(LOOKUP_TASK_MAX_RETRIES),
 152                 ACTOR_ID);
 153
 154         this.memberName = distributedConfigDatastore.getActorUtils().getCurrentMemberName();
 155
 156         updateHandler = new PrefixedShardConfigUpdateHandler(shardedDataTreeActor,
 157                 distributedConfigDatastore.getActorUtils().getCurrentMemberName());
 158
 159         LOG.debug("{} - Starting prefix configuration shards", memberName);
 160         createPrefixConfigShard(distributedConfigDatastore);
 161         createPrefixConfigShard(distributedOperDatastore);
 162     }
 163
 164     private static void createPrefixConfigShard(final DistributedDataStoreInterface dataStore) {
 165         Configuration configuration = dataStore.getActorUtils().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.getActorUtils().getDatastoreContext());
 172
 173         dataStore.getActorUtils().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.getActorUtils()));
 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.getActorUtils()));
 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.getActorUtils().getShardManager().tell(InitConfigListener.INSTANCE, noSender());
 237         distributedOperDatastore.getActorUtils().getShardManager().tell(InitConfigListener.INSTANCE, noSender());
 238
 239
 240         //create shard registration for DEFAULT_SHARD
 241         initDefaultShard(LogicalDatastoreType.CONFIGURATION);
 242         initDefaultShard(LogicalDatastoreType.OPERATIONAL);
 243     }
 244
 245     private ListenableFuture<List<Void>> handleConfigShardLookup() {
 246
 247         final ListenableFuture<Void> configFuture = lookupConfigShard(LogicalDatastoreType.CONFIGURATION);
 248         final ListenableFuture<Void> operFuture = lookupConfigShard(LogicalDatastoreType.OPERATIONAL);
 249
 250         return Futures.allAsList(configFuture, operFuture);
 251     }
 252
 253     private ListenableFuture<Void> lookupConfigShard(final LogicalDatastoreType type) {
 254         final SettableFuture<Void> future = SettableFuture.create();
 255
 256         final Future<Object> ask =
 257                 Patterns.ask(shardedDataTreeActor, new StartConfigShardLookup(type), SHARD_FUTURE_TIMEOUT);
 258
 259         ask.onComplete(new OnComplete<>() {
 260             @Override
 261             public void onComplete(final Throwable throwable, final Object result) {
 262                 if (throwable != null) {
 263                     future.setException(throwable);
 264                 } else {
 265                     future.set(null);
 266                 }
 267             }
 268         }, actorSystem.dispatcher());
 269
 270         return future;
 271     }
 272
 273     @Override
 274     public <T extends DOMDataTreeListener> ListenerRegistration<T> registerListener(
 275             final T listener, final Collection<DOMDataTreeIdentifier> subtrees,
 276             final boolean allowRxMerges, final Collection<DOMDataTreeProducer> producers)
 277             throws DOMDataTreeLoopException {
 278         return shardedDOMDataTree.registerListener(listener, subtrees, allowRxMerges, producers);
 279     }
 280
 281     @Override
 282     public ClassToInstanceMap<DOMDataTreeServiceExtension> getExtensions() {
 283         return ImmutableClassToInstanceMap.of();
 284     }
 285
 286     @Override
 287     public DOMDataTreeProducer createProducer(final Collection<DOMDataTreeIdentifier> subtrees) {
 288         LOG.debug("{} - Creating producer for {}", memberName, subtrees);
 289         final DOMDataTreeProducer producer = shardedDOMDataTree.createProducer(subtrees);
 290
 291         final Object response = distributedConfigDatastore.getActorUtils()
 292                 .executeOperation(shardedDataTreeActor, new ProducerCreated(subtrees));
 293         if (response == null) {
 294             LOG.debug("{} - Received success from remote nodes, creating producer:{}", memberName, subtrees);
 295             return new ProxyProducer(producer, subtrees, shardedDataTreeActor,
 296                     distributedConfigDatastore.getActorUtils(), shards);
 297         }
 298
 299         closeProducer(producer);
 300
 301         if (response instanceof Throwable) {
 302             Throwables.throwIfUnchecked((Throwable) response);
 303             throw new RuntimeException((Throwable) response);
 304         }
 305         throw new RuntimeException("Unexpected response to create producer received." + response);
 306     }
 307
 308     @Override
 309     public CompletionStage<DistributedShardRegistration> createDistributedShard(
 310             final DOMDataTreeIdentifier prefix, final Collection<MemberName> replicaMembers)
 311             throws DOMDataTreeShardingConflictException {
 312
 313         synchronized (shards) {
 314             final DOMDataTreePrefixTableEntry<DOMDataTreeShardRegistration<DOMDataTreeShard>> lookup =
 315                     shards.lookup(prefix);
 316             if (lookup != null && lookup.getValue().getPrefix().equals(prefix)) {
 317                 throw new DOMDataTreeShardingConflictException(
 318                         "Prefix " + prefix + " is already occupied by another shard.");
 319             }
 320         }
 321
 322         final PrefixedShardConfigWriter writer = writerMap.get(prefix.getDatastoreType());
 323
 324         final ListenableFuture<Void> writeFuture =
 325                 writer.writeConfig(prefix.getRootIdentifier(), replicaMembers);
 326
 327         final Promise<DistributedShardRegistration> shardRegistrationPromise = akka.dispatch.Futures.promise();
 328         Futures.addCallback(writeFuture, new FutureCallback<Void>() {
 329             @Override
 330             public void onSuccess(final Void result) {
 331
 332                 final Future<Object> ask =
 333                         Patterns.ask(shardedDataTreeActor, new LookupPrefixShard(prefix), SHARD_FUTURE_TIMEOUT);
 334
 335                 shardRegistrationPromise.completeWith(ask.transform(
 336                         new Mapper<Object, DistributedShardRegistration>() {
 337                             @Override
 338                             public DistributedShardRegistration apply(final Object parameter) {
 339                                 return new DistributedShardRegistrationImpl(
 340                                         prefix, shardedDataTreeActor, DistributedShardedDOMDataTree.this);
 341                             }
 342                         },
 343                         new Mapper<Throwable, Throwable>() {
 344                             @Override
 345                             public Throwable apply(final Throwable throwable) {
 346                                 return new DOMDataTreeShardCreationFailedException(
 347                                         "Unable to create a cds shard.", throwable);
 348                             }
 349                         }, actorSystem.dispatcher()));
 350             }
 351
 352             @Override
 353             public void onFailure(final Throwable throwable) {
 354                 shardRegistrationPromise.failure(
 355                         new DOMDataTreeShardCreationFailedException("Unable to create a cds shard.", throwable));
 356             }
 357         }, MoreExecutors.directExecutor());
 358
 359         return FutureConverters.toJava(shardRegistrationPromise.future());
 360     }
 361
 362     void resolveShardAdditions(final Set<DOMDataTreeIdentifier> additions) {
 363         LOG.debug("{}: Resolving additions : {}", memberName, additions);
 364         // we need to register the shards from top to bottom, so we need to atleast make sure the ordering reflects that
 365         additions
 366             .stream()
 367             .sorted(Comparator.comparingInt(o -> o.getRootIdentifier().getPathArguments().size()))
 368             .forEachOrdered(this::createShardFrontend);
 369     }
 370
 371     void resolveShardRemovals(final Set<DOMDataTreeIdentifier> removals) {
 372         LOG.debug("{}: Resolving removals : {}", memberName, removals);
 373
 374         // do we need to go from bottom to top?
 375         removals.forEach(this::despawnShardFrontend);
 376     }
 377
 378     private void createShardFrontend(final DOMDataTreeIdentifier prefix) {
 379         LOG.debug("{}: Creating CDS shard for prefix: {}", memberName, prefix);
 380         final String shardName = ClusterUtils.getCleanShardName(prefix.getRootIdentifier());
 381         final DistributedDataStoreInterface distributedDataStore =
 382                 prefix.getDatastoreType().equals(LogicalDatastoreType.CONFIGURATION)
 383                         ? distributedConfigDatastore : distributedOperDatastore;
 384
 385         try (DOMDataTreeProducer producer = localCreateProducer(Collections.singletonList(prefix))) {
 386             final Entry<DataStoreClient, ActorRef> entry =
 387                     createDatastoreClient(shardName, distributedDataStore.getActorUtils());
 388
 389             final DistributedShardFrontend shard =
 390                     new DistributedShardFrontend(distributedDataStore, entry.getKey(), prefix);
 391
 392             final DOMDataTreeShardRegistration<DOMDataTreeShard> reg =
 393                     shardedDOMDataTree.registerDataTreeShard(prefix, shard, producer);
 394
 395             synchronized (shards) {
 396                 shards.store(prefix, reg);
 397             }
 398
 399         } catch (final DOMDataTreeShardingConflictException e) {
 400             LOG.error("{}: Prefix {} is already occupied by another shard",
 401                     distributedConfigDatastore.getActorUtils().getClusterWrapper().getCurrentMemberName(), prefix, e);
 402         } catch (DOMDataTreeProducerException e) {
 403             LOG.error("Unable to close producer", e);
 404         } catch (DOMDataTreeShardCreationFailedException e) {
 405             LOG.error("Unable to create datastore client for shard {}", prefix, e);
 406         }
 407     }
 408
 409     private void despawnShardFrontend(final DOMDataTreeIdentifier prefix) {
 410         LOG.debug("{}: Removing CDS shard for prefix: {}", memberName, prefix);
 411         final DOMDataTreePrefixTableEntry<DOMDataTreeShardRegistration<DOMDataTreeShard>> lookup;
 412         synchronized (shards) {
 413             lookup = shards.lookup(prefix);
 414         }
 415
 416         if (lookup == null || !lookup.getValue().getPrefix().equals(prefix)) {
 417             LOG.debug("{}: Received despawn for non-existing CDS shard frontend, prefix: {}, ignoring..",
 418                     memberName, prefix);
 419             return;
 420         }
 421
 422         lookup.getValue().close();
 423         // need to remove from our local table thats used for tracking
 424         synchronized (shards) {
 425             shards.remove(prefix);
 426         }
 427
 428         final PrefixedShardConfigWriter writer = writerMap.get(prefix.getDatastoreType());
 429         final ListenableFuture<Void> future = writer.removeConfig(prefix.getRootIdentifier());
 430
 431         Futures.addCallback(future, new FutureCallback<Void>() {
 432             @Override
 433             public void onSuccess(final Void result) {
 434                 LOG.debug("{} - Succesfuly removed shard for {}", memberName, prefix);
 435             }
 436
 437             @Override
 438             public void onFailure(final Throwable throwable) {
 439                 LOG.error("Removal of shard {} from configuration failed.", prefix, throwable);
 440             }
 441         }, MoreExecutors.directExecutor());
 442     }
 443
 444     DOMDataTreePrefixTableEntry<DOMDataTreeShardRegistration<DOMDataTreeShard>> lookupShardFrontend(
 445             final DOMDataTreeIdentifier prefix) {
 446         synchronized (shards) {
 447             return shards.lookup(prefix);
 448         }
 449     }
 450
 451     DOMDataTreeProducer localCreateProducer(final Collection<DOMDataTreeIdentifier> prefix) {
 452         return shardedDOMDataTree.createProducer(prefix);
 453     }
 454
 455     @Override
 456     public <T extends DOMDataTreeShard> ListenerRegistration<T> registerDataTreeShard(
 457             final DOMDataTreeIdentifier prefix, final T shard, final DOMDataTreeProducer producer)
 458                     throws DOMDataTreeShardingConflictException {
 459
 460         LOG.debug("Registering shard[{}] at prefix: {}", shard, prefix);
 461
 462         if (producer instanceof ProxyProducer) {
 463             return shardedDOMDataTree.registerDataTreeShard(prefix, shard, ((ProxyProducer) producer).delegate());
 464         }
 465
 466         return shardedDOMDataTree.registerDataTreeShard(prefix, shard, producer);
 467     }
 468
 469     @SuppressWarnings("checkstyle:IllegalCatch")
 470     private Entry<DataStoreClient, ActorRef> createDatastoreClient(final String shardName, final ActorUtils actorUtils)
 471             throws DOMDataTreeShardCreationFailedException {
 472
 473         LOG.debug("{}: Creating distributed datastore client for shard {}", memberName, shardName);
 474         final Props distributedDataStoreClientProps =
 475                 SimpleDataStoreClientActor.props(memberName, "Shard-" + shardName, actorUtils, shardName);
 476
 477         final ActorRef clientActor = actorSystem.actorOf(distributedDataStoreClientProps);
 478         try {
 479             return new SimpleEntry<>(SimpleDataStoreClientActor
 480                     .getDistributedDataStoreClient(clientActor, 30, TimeUnit.SECONDS), clientActor);
 481         } catch (final Exception e) {
 482             LOG.error("{}: Failed to get actor for {}", distributedDataStoreClientProps, memberName, e);
 483             clientActor.tell(PoisonPill.getInstance(), noSender());
 484             throw new DOMDataTreeShardCreationFailedException(
 485                     "Unable to create datastore client for shard{" + shardName + "}", e);
 486         }
 487     }
 488
 489     @SuppressWarnings("checkstyle:IllegalCatch")
 490     private void initDefaultShard(final LogicalDatastoreType logicalDatastoreType) {
 491
 492         final PrefixedShardConfigWriter writer = writerMap.get(logicalDatastoreType);
 493
 494         if (writer.checkDefaultIsPresent()) {
 495             LOG.debug("{}: Default shard for {} is already present in the config. Possibly saved in snapshot.",
 496                     memberName, logicalDatastoreType);
 497         } else {
 498             try {
 499                 // Currently the default shard configuration is present in the out-of-box modules.conf and is
 500                 // expected to be present. So look up the local default shard here and create the frontend.
 501
 502                 // TODO we don't have to do it for config and operational default shard separately. Just one of them
 503                 // should be enough
 504                 final ActorUtils actorUtils = logicalDatastoreType == LogicalDatastoreType.CONFIGURATION
 505                         ? distributedConfigDatastore.getActorUtils() : distributedOperDatastore.getActorUtils();
 506
 507                 final Optional<ActorRef> defaultLocalShardOptional =
 508                         actorUtils.findLocalShard(ClusterUtils.getCleanShardName(YangInstanceIdentifier.empty()));
 509
 510                 if (defaultLocalShardOptional.isPresent()) {
 511                     LOG.debug("{}: Default shard for {} is already started, creating just frontend", memberName,
 512                             logicalDatastoreType);
 513                     createShardFrontend(new DOMDataTreeIdentifier(logicalDatastoreType,
 514                                 YangInstanceIdentifier.empty()));
 515                 }
 516
 517                 // The local shard isn't present - we assume that means the local member isn't in the replica list
 518                 // and will be dynamically created later via an explicit add-shard-replica request. This is the
 519                 // bootstrapping mechanism to add a new node into an existing cluster. The following code to create
 520                 // the default shard as a prefix shard is problematic in this scenario so it is commented out. Since
 521                 // the default shard is a module-based shard by default, it makes sense to always treat it as such,
 522                 // ie bootstrap it in the same manner as the special prefix-configuration and EOS shards.
 523 //                final Collection<MemberName> names = distributedConfigDatastore.getActorUtils().getConfiguration()
 524 //                        .getUniqueMemberNamesForAllShards();
 525 //                Await.result(FutureConverters.toScala(createDistributedShard(
 526 //                        new DOMDataTreeIdentifier(logicalDatastoreType, YangInstanceIdentifier.empty()), names)),
 527 //                        SHARD_FUTURE_TIMEOUT_DURATION);
 528 //            } catch (DOMDataTreeShardingConflictException e) {
 529 //                LOG.debug("{}: Default shard for {} already registered, possibly due to other node doing it faster",
 530 //                        memberName, logicalDatastoreType);
 531             } catch (Exception e) {
 532                 LOG.error("{}: Default shard initialization for {} failed", memberName, logicalDatastoreType, e);
 533                 throw new RuntimeException(e);
 534             }
 535         }
 536     }
 537
 538     private static void closeProducer(final DOMDataTreeProducer producer) {
 539         try {
 540             producer.close();
 541         } catch (final DOMDataTreeProducerException e) {
 542             LOG.error("Unable to close producer", e);
 543         }
 544     }
 545
 546     @SuppressWarnings("checkstyle:IllegalCatch")
 547     private static ActorRef createShardedDataTreeActor(final ActorSystem actorSystem,
 548                                                        final ShardedDataTreeActorCreator creator,
 549                                                        final String shardDataTreeActorId) {
 550         Exception lastException = null;
 551
 552         for (int i = 0; i < MAX_ACTOR_CREATION_RETRIES; i++) {
 553             try {
 554                 return actorSystem.actorOf(creator.props(), shardDataTreeActorId);
 555             } catch (final Exception e) {
 556                 lastException = e;
 557                 Uninterruptibles.sleepUninterruptibly(ACTOR_RETRY_DELAY, ACTOR_RETRY_TIME_UNIT);
 558                 LOG.debug("Could not create actor {} because of {} -"
 559                                 + " waiting for sometime before retrying (retry count = {})",
 560                         shardDataTreeActorId, e.getMessage(), i);
 561             }
 562         }
 563
 564         throw new IllegalStateException("Failed to create actor for ShardedDOMDataTree", lastException);
 565     }
 566
 567     private class DistributedShardRegistrationImpl implements DistributedShardRegistration {
 568
 569         private final DOMDataTreeIdentifier prefix;
 570         private final ActorRef shardedDataTreeActor;
 571         private final DistributedShardedDOMDataTree distributedShardedDOMDataTree;
 572
 573         DistributedShardRegistrationImpl(final DOMDataTreeIdentifier prefix,
 574                                          final ActorRef shardedDataTreeActor,
 575                                          final DistributedShardedDOMDataTree distributedShardedDOMDataTree) {
 576             this.prefix = prefix;
 577             this.shardedDataTreeActor = shardedDataTreeActor;
 578             this.distributedShardedDOMDataTree = distributedShardedDOMDataTree;
 579         }
 580
 581         @Override
 582         public CompletionStage<Void> close() {
 583             // first despawn on the local node
 584             distributedShardedDOMDataTree.despawnShardFrontend(prefix);
 585             // update the config so the remote nodes are updated
 586             final Future<Object> ask =
 587                     Patterns.ask(shardedDataTreeActor, new PrefixShardRemovalLookup(prefix), SHARD_FUTURE_TIMEOUT);
 588
 589             final Future<Void> closeFuture = ask.transform(
 590                     new Mapper<Object, Void>() {
 591                         @Override
 592                         public Void apply(final Object parameter) {
 593                             return null;
 594                         }
 595                     },
 596                     new Mapper<Throwable, Throwable>() {
 597                         @Override
 598                         public Throwable apply(final Throwable throwable) {
 599                             return throwable;
 600                         }
 601                     }, actorSystem.dispatcher());
 602
 603             return FutureConverters.toJava(closeFuture);
 604         }
 605     }
 606
 607     // TODO what about producers created by this producer?
 608     // They should also be CDSProducers
 609     private static final class ProxyProducer extends ForwardingObject implements CDSDataTreeProducer {
 610
 611         private final DOMDataTreeProducer delegate;
 612         private final Collection<DOMDataTreeIdentifier> subtrees;
 613         private final ActorRef shardDataTreeActor;
 614         private final ActorUtils actorUtils;
 615         @GuardedBy("shardAccessMap")
 616         private final Map<DOMDataTreeIdentifier, CDSShardAccessImpl> shardAccessMap = new HashMap<>();
 617
 618         // We don't have to guard access to shardTable in ProxyProducer.
 619         // ShardTable's entries relevant to this ProxyProducer shouldn't
 620         // change during producer's lifetime.
 621         private final DOMDataTreePrefixTable<DOMDataTreeShardRegistration<DOMDataTreeShard>> shardTable;
 622
 623         ProxyProducer(final DOMDataTreeProducer delegate,
 624                       final Collection<DOMDataTreeIdentifier> subtrees,
 625                       final ActorRef shardDataTreeActor,
 626                       final ActorUtils actorUtils,
 627                       final DOMDataTreePrefixTable<DOMDataTreeShardRegistration<DOMDataTreeShard>> shardLayout) {
 628             this.delegate = requireNonNull(delegate);
 629             this.subtrees = requireNonNull(subtrees);
 630             this.shardDataTreeActor = requireNonNull(shardDataTreeActor);
 631             this.actorUtils = requireNonNull(actorUtils);
 632             this.shardTable = requireNonNull(shardLayout);
 633         }
 634
 635         @Override
 636         public DOMDataTreeCursorAwareTransaction createTransaction(final boolean isolated) {
 637             return delegate.createTransaction(isolated);
 638         }
 639
 640         @Override
 641         @SuppressWarnings("checkstyle:hiddenField")
 642         public DOMDataTreeProducer createProducer(final Collection<DOMDataTreeIdentifier> subtrees) {
 643             // TODO we probably don't need to distribute this on the remote nodes since once we have this producer
 644             // open we surely have the rights to all the subtrees.
 645             return delegate.createProducer(subtrees);
 646         }
 647
 648         @Override
 649         @SuppressWarnings("checkstyle:IllegalCatch")
 650         public void close() throws DOMDataTreeProducerException {
 651             delegate.close();
 652
 653             synchronized (shardAccessMap) {
 654                 shardAccessMap.values().forEach(CDSShardAccessImpl::close);
 655             }
 656
 657             final Object o = actorUtils.executeOperation(shardDataTreeActor, new ProducerRemoved(subtrees));
 658             if (o instanceof DOMDataTreeProducerException) {
 659                 throw (DOMDataTreeProducerException) o;
 660             } else if (o instanceof Throwable) {
 661                 throw new DOMDataTreeProducerException("Unable to close producer", (Throwable) o);
 662             }
 663         }
 664
 665         @Override
 666         protected DOMDataTreeProducer delegate() {
 667             return delegate;
 668         }
 669
 670         @Override
 671         public CDSShardAccess getShardAccess(final DOMDataTreeIdentifier subtree) {
 672             checkArgument(subtrees.stream().anyMatch(dataTreeIdentifier -> dataTreeIdentifier.contains(subtree)),
 673                 "Subtree %s is not controlled by this producer %s", subtree, this);
 674
 675             final DOMDataTreePrefixTableEntry<DOMDataTreeShardRegistration<DOMDataTreeShard>> lookup =
 676                     shardTable.lookup(subtree);
 677             checkState(lookup != null, "Subtree %s is not contained in any registered shard.", subtree);
 678
 679             final DOMDataTreeIdentifier lookupId = lookup.getValue().getPrefix();
 680
 681             synchronized (shardAccessMap) {
 682                 if (shardAccessMap.get(lookupId) != null) {
 683                     return shardAccessMap.get(lookupId);
 684                 }
 685
 686                 // TODO Maybe we can have static factory method and return the same instance
 687                 // for same subtrees. But maybe it is not needed since there can be only one
 688                 // producer attached to some subtree at a time. And also how we can close ShardAccess
 689                 // then
 690                 final CDSShardAccessImpl shardAccess = new CDSShardAccessImpl(lookupId, actorUtils);
 691                 shardAccessMap.put(lookupId, shardAccess);
 692                 return shardAccess;
 693             }
 694         }
 695     }
 696 }