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