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

   1 /*
   2  * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8
   9 package org.opendaylight.controller.cluster.datastore;
  10
  11 import akka.actor.ActorRef;
  12 import akka.actor.ActorSelection;
  13 import akka.actor.Cancellable;
  14 import akka.actor.Props;
  15 import akka.event.Logging;
  16 import akka.event.LoggingAdapter;
  17 import akka.japi.Creator;
  18 import akka.persistence.RecoveryFailure;
  19 import akka.serialization.Serialization;
  20 import com.google.common.annotations.VisibleForTesting;
  21 import com.google.common.base.Optional;
  22 import com.google.common.base.Preconditions;
  23 import com.google.common.collect.Lists;
  24 import com.google.common.util.concurrent.FutureCallback;
  25 import com.google.common.util.concurrent.Futures;
  26 import com.google.common.util.concurrent.ListenableFuture;
  27 import java.io.IOException;
  28 import java.util.Collection;
  29 import java.util.HashMap;
  30 import java.util.List;
  31 import java.util.Map;
  32 import java.util.concurrent.ExecutionException;
  33 import java.util.concurrent.TimeUnit;
  34 import javax.annotation.Nonnull;
  35 import org.opendaylight.controller.cluster.DataPersistenceProvider;
  36 import org.opendaylight.controller.cluster.common.actor.CommonConfig;
  37 import org.opendaylight.controller.cluster.common.actor.MeteringBehavior;
  38 import org.opendaylight.controller.cluster.datastore.ShardCommitCoordinator.CohortEntry;
  39 import org.opendaylight.controller.cluster.datastore.compat.BackwardsCompatibleThreePhaseCommitCohort;
  40 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
  41 import org.opendaylight.controller.cluster.datastore.identifiers.ShardIdentifier;
  42 import org.opendaylight.controller.cluster.datastore.identifiers.ShardTransactionIdentifier;
  43 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardMBeanFactory;
  44 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardStats;
  45 import org.opendaylight.controller.cluster.datastore.messages.AbortTransaction;
  46 import org.opendaylight.controller.cluster.datastore.messages.AbortTransactionReply;
  47 import org.opendaylight.controller.cluster.datastore.messages.ActorInitialized;
  48 import org.opendaylight.controller.cluster.datastore.messages.CanCommitTransaction;
  49 import org.opendaylight.controller.cluster.datastore.messages.CloseTransactionChain;
  50 import org.opendaylight.controller.cluster.datastore.messages.CommitTransaction;
  51 import org.opendaylight.controller.cluster.datastore.messages.CommitTransactionReply;
  52 import org.opendaylight.controller.cluster.datastore.messages.CreateSnapshot;
  53 import org.opendaylight.controller.cluster.datastore.messages.CreateTransaction;
  54 import org.opendaylight.controller.cluster.datastore.messages.CreateTransactionReply;
  55 import org.opendaylight.controller.cluster.datastore.messages.EnableNotification;
  56 import org.opendaylight.controller.cluster.datastore.messages.ForwardedReadyTransaction;
  57 import org.opendaylight.controller.cluster.datastore.messages.PeerAddressResolved;
  58 import org.opendaylight.controller.cluster.datastore.messages.ReadyTransactionReply;
  59 import org.opendaylight.controller.cluster.datastore.messages.RegisterChangeListener;
  60 import org.opendaylight.controller.cluster.datastore.messages.RegisterChangeListenerReply;
  61 import org.opendaylight.controller.cluster.datastore.messages.UpdateSchemaContext;
  62 import org.opendaylight.controller.cluster.datastore.modification.Modification;
  63 import org.opendaylight.controller.cluster.datastore.modification.ModificationPayload;
  64 import org.opendaylight.controller.cluster.datastore.modification.MutableCompositeModification;
  65 import org.opendaylight.controller.cluster.datastore.utils.SerializationUtils;
  66 import org.opendaylight.controller.cluster.notifications.RoleChangeNotifier;
  67 import org.opendaylight.controller.cluster.raft.RaftActor;
  68 import org.opendaylight.controller.cluster.raft.ReplicatedLogEntry;
  69 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationByteStringPayload;
  70 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationPayload;
  71 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.Payload;
  72 import org.opendaylight.controller.md.sal.common.api.data.AsyncDataChangeListener;
  73 import org.opendaylight.controller.md.sal.dom.store.impl.InMemoryDOMDataStore;
  74 import org.opendaylight.controller.md.sal.dom.store.impl.InMemoryDOMDataStoreFactory;
  75 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  76 import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransactionChain;
  77 import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransactionFactory;
  78 import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
  79 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  80 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  81 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  82 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  83 import scala.concurrent.duration.Duration;
  84 import scala.concurrent.duration.FiniteDuration;
  85
  86 /**
  87  * A Shard represents a portion of the logical data tree <br/>
  88  * <p>
  89  * Our Shard uses InMemoryDataStore as it's internal representation and delegates all requests it
  90  * </p>
  91  */
  92 public class Shard extends RaftActor {
  93
  94     private static final YangInstanceIdentifier DATASTORE_ROOT = YangInstanceIdentifier.builder().build();
  95
  96     private static final Object TX_COMMIT_TIMEOUT_CHECK_MESSAGE = "txCommitTimeoutCheck";
  97
  98     @VisibleForTesting
  99     static final String DEFAULT_NAME = "default";
 100
 101     // The state of this Shard
 102     private final InMemoryDOMDataStore store;
 103
 104     private final LoggingAdapter LOG = Logging.getLogger(getContext().system(), this);
 105
 106     /// The name of this shard
 107     private final ShardIdentifier name;
 108
 109     private final ShardStats shardMBean;
 110
 111     private final List<ActorSelection> dataChangeListeners =  Lists.newArrayList();
 112
 113     private final List<DelayedListenerRegistration> delayedListenerRegistrations =
 114                                                                        Lists.newArrayList();
 115
 116     private final DatastoreContext datastoreContext;
 117
 118     private final DataPersistenceProvider dataPersistenceProvider;
 119
 120     private SchemaContext schemaContext;
 121
 122     private int createSnapshotTransactionCounter;
 123
 124     private final ShardCommitCoordinator commitCoordinator;
 125
 126     private final long transactionCommitTimeout;
 127
 128     private Cancellable txCommitTimeoutCheckSchedule;
 129
 130     private final Optional<ActorRef> roleChangeNotifier;
 131
 132     /**
 133      * Coordinates persistence recovery on startup.
 134      */
 135     private ShardRecoveryCoordinator recoveryCoordinator;
 136     private List<Object> currentLogRecoveryBatch;
 137
 138     private final Map<String, DOMStoreTransactionChain> transactionChains = new HashMap<>();
 139
 140     protected Shard(final ShardIdentifier name, final Map<ShardIdentifier, String> peerAddresses,
 141             final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 142         super(name.toString(), mapPeerAddresses(peerAddresses),
 143                 Optional.of(datastoreContext.getShardRaftConfig()));
 144
 145         this.name = name;
 146         this.datastoreContext = datastoreContext;
 147         this.schemaContext = schemaContext;
 148         this.dataPersistenceProvider = (datastoreContext.isPersistent()) ? new PersistentDataProvider() : new NonPersistentRaftDataProvider();
 149
 150         LOG.info("Shard created : {}, persistent : {}", name, datastoreContext.isPersistent());
 151
 152         store = InMemoryDOMDataStoreFactory.create(name.toString(), null,
 153                 datastoreContext.getDataStoreProperties());
 154
 155         if(schemaContext != null) {
 156             store.onGlobalContextUpdated(schemaContext);
 157         }
 158
 159         shardMBean = ShardMBeanFactory.getShardStatsMBean(name.toString(),
 160                 datastoreContext.getDataStoreMXBeanType());
 161         shardMBean.setNotificationManager(store.getDataChangeListenerNotificationManager());
 162
 163         if (isMetricsCaptureEnabled()) {
 164             getContext().become(new MeteringBehavior(this));
 165         }
 166
 167         commitCoordinator = new ShardCommitCoordinator(TimeUnit.SECONDS.convert(1, TimeUnit.MINUTES),
 168                 datastoreContext.getShardTransactionCommitQueueCapacity(), LOG, name.toString());
 169
 170         transactionCommitTimeout = TimeUnit.MILLISECONDS.convert(
 171                 datastoreContext.getShardTransactionCommitTimeoutInSeconds(), TimeUnit.SECONDS);
 172
 173         // create a notifier actor for each cluster member
 174         roleChangeNotifier = createRoleChangeNotifier(name.toString());
 175     }
 176
 177     private static Map<String, String> mapPeerAddresses(
 178         final Map<ShardIdentifier, String> peerAddresses) {
 179         Map<String, String> map = new HashMap<>();
 180
 181         for (Map.Entry<ShardIdentifier, String> entry : peerAddresses
 182             .entrySet()) {
 183             map.put(entry.getKey().toString(), entry.getValue());
 184         }
 185
 186         return map;
 187     }
 188
 189     public static Props props(final ShardIdentifier name,
 190         final Map<ShardIdentifier, String> peerAddresses,
 191         final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 192         Preconditions.checkNotNull(name, "name should not be null");
 193         Preconditions.checkNotNull(peerAddresses, "peerAddresses should not be null");
 194         Preconditions.checkNotNull(datastoreContext, "dataStoreContext should not be null");
 195         Preconditions.checkNotNull(schemaContext, "schemaContext should not be null");
 196
 197         return Props.create(new ShardCreator(name, peerAddresses, datastoreContext, schemaContext));
 198     }
 199
 200     private Optional<ActorRef> createRoleChangeNotifier(String shardId) {
 201         ActorRef shardRoleChangeNotifier = this.getContext().actorOf(
 202             RoleChangeNotifier.getProps(shardId), shardId + "-notifier");
 203         return Optional.<ActorRef>of(shardRoleChangeNotifier);
 204     }
 205
 206     @Override
 207     public void postStop() {
 208         super.postStop();
 209
 210         if(txCommitTimeoutCheckSchedule != null) {
 211             txCommitTimeoutCheckSchedule.cancel();
 212         }
 213     }
 214
 215     @Override
 216     public void onReceiveRecover(final Object message) throws Exception {
 217         if(LOG.isDebugEnabled()) {
 218             LOG.debug("{}: onReceiveRecover: Received message {} from {}", persistenceId(),
 219                 message.getClass().toString(), getSender());
 220         }
 221
 222         if (message instanceof RecoveryFailure){
 223             LOG.error(((RecoveryFailure) message).cause(), "{}: Recovery failed because of this cause",
 224                     persistenceId());
 225
 226             // Even though recovery failed, we still need to finish our recovery, eg send the
 227             // ActorInitialized message and start the txCommitTimeoutCheckSchedule.
 228             onRecoveryComplete();
 229         } else {
 230             super.onReceiveRecover(message);
 231         }
 232     }
 233
 234     @Override
 235     public void onReceiveCommand(final Object message) throws Exception {
 236         if(LOG.isDebugEnabled()) {
 237             LOG.debug("{}: onReceiveCommand: Received message {} from {}", persistenceId(), message, getSender());
 238         }
 239
 240         if (message.getClass().equals(CreateTransaction.SERIALIZABLE_CLASS)) {
 241             handleCreateTransaction(message);
 242         } else if(message instanceof ForwardedReadyTransaction) {
 243             handleForwardedReadyTransaction((ForwardedReadyTransaction)message);
 244         } else if(message.getClass().equals(CanCommitTransaction.SERIALIZABLE_CLASS)) {
 245             handleCanCommitTransaction(CanCommitTransaction.fromSerializable(message));
 246         } else if(message.getClass().equals(CommitTransaction.SERIALIZABLE_CLASS)) {
 247             handleCommitTransaction(CommitTransaction.fromSerializable(message));
 248         } else if(message.getClass().equals(AbortTransaction.SERIALIZABLE_CLASS)) {
 249             handleAbortTransaction(AbortTransaction.fromSerializable(message));
 250         } else if (message.getClass().equals(CloseTransactionChain.SERIALIZABLE_CLASS)){
 251             closeTransactionChain(CloseTransactionChain.fromSerializable(message));
 252         } else if (message instanceof RegisterChangeListener) {
 253             registerChangeListener((RegisterChangeListener) message);
 254         } else if (message instanceof UpdateSchemaContext) {
 255             updateSchemaContext((UpdateSchemaContext) message);
 256         } else if (message instanceof PeerAddressResolved) {
 257             PeerAddressResolved resolved = (PeerAddressResolved) message;
 258             setPeerAddress(resolved.getPeerId().toString(),
 259                 resolved.getPeerAddress());
 260         } else if(message.equals(TX_COMMIT_TIMEOUT_CHECK_MESSAGE)) {
 261             handleTransactionCommitTimeoutCheck();
 262         } else {
 263             super.onReceiveCommand(message);
 264         }
 265     }
 266
 267     @Override
 268     protected Optional<ActorRef> getRoleChangeNotifier() {
 269         return roleChangeNotifier;
 270     }
 271
 272     private void handleTransactionCommitTimeoutCheck() {
 273         CohortEntry cohortEntry = commitCoordinator.getCurrentCohortEntry();
 274         if(cohortEntry != null) {
 275             long elapsed = System.currentTimeMillis() - cohortEntry.getLastAccessTime();
 276             if(elapsed > transactionCommitTimeout) {
 277                 LOG.warning("{}: Current transaction {} has timed out after {} ms - aborting",
 278                         persistenceId(), cohortEntry.getTransactionID(), transactionCommitTimeout);
 279
 280                 doAbortTransaction(cohortEntry.getTransactionID(), null);
 281             }
 282         }
 283     }
 284
 285     private void handleCommitTransaction(final CommitTransaction commit) {
 286         final String transactionID = commit.getTransactionID();
 287
 288         LOG.debug("{}: Committing transaction {}", persistenceId(), transactionID);
 289
 290         // Get the current in-progress cohort entry in the commitCoordinator if it corresponds to
 291         // this transaction.
 292         final CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 293         if(cohortEntry == null) {
 294             // We're not the current Tx - the Tx was likely expired b/c it took too long in
 295             // between the canCommit and commit messages.
 296             IllegalStateException ex = new IllegalStateException(
 297                     String.format("%s: Cannot commit transaction %s - it is not the current transaction",
 298                             persistenceId(), transactionID));
 299             LOG.error(ex.getMessage());
 300             shardMBean.incrementFailedTransactionsCount();
 301             getSender().tell(new akka.actor.Status.Failure(ex), getSelf());
 302             return;
 303         }
 304
 305         // We perform the preCommit phase here atomically with the commit phase. This is an
 306         // optimization to eliminate the overhead of an extra preCommit message. We lose front-end
 307         // coordination of preCommit across shards in case of failure but preCommit should not
 308         // normally fail since we ensure only one concurrent 3-phase commit.
 309
 310         try {
 311             // We block on the future here so we don't have to worry about possibly accessing our
 312             // state on a different thread outside of our dispatcher. Also, the data store
 313             // currently uses a same thread executor anyway.
 314             cohortEntry.getCohort().preCommit().get();
 315
 316             // If we do not have any followers and we are not using persistence we can
 317             // apply modification to the state immediately
 318             if(!hasFollowers() && !persistence().isRecoveryApplicable()){
 319                 applyModificationToState(getSender(), transactionID, cohortEntry.getModification());
 320             } else {
 321                 Shard.this.persistData(getSender(), transactionID,
 322                         new ModificationPayload(cohortEntry.getModification()));
 323             }
 324         } catch (Exception e) {
 325             LOG.error(e, "{} An exception occurred while preCommitting transaction {}",
 326                     persistenceId(), cohortEntry.getTransactionID());
 327             shardMBean.incrementFailedTransactionsCount();
 328             getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 329         }
 330
 331         cohortEntry.updateLastAccessTime();
 332     }
 333
 334     private void finishCommit(@Nonnull final ActorRef sender, final @Nonnull String transactionID) {
 335         // With persistence enabled, this method is called via applyState by the leader strategy
 336         // after the commit has been replicated to a majority of the followers.
 337
 338         CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 339         if(cohortEntry == null) {
 340             // The transaction is no longer the current commit. This can happen if the transaction
 341             // was aborted prior, most likely due to timeout in the front-end. We need to finish
 342             // committing the transaction though since it was successfully persisted and replicated
 343             // however we can't use the original cohort b/c it was already preCommitted and may
 344             // conflict with the current commit or may have been aborted so we commit with a new
 345             // transaction.
 346             cohortEntry = commitCoordinator.getAndRemoveCohortEntry(transactionID);
 347             if(cohortEntry != null) {
 348                 commitWithNewTransaction(cohortEntry.getModification());
 349                 sender.tell(CommitTransactionReply.INSTANCE.toSerializable(), getSelf());
 350             } else {
 351                 // This really shouldn't happen - it likely means that persistence or replication
 352                 // took so long to complete such that the cohort entry was expired from the cache.
 353                 IllegalStateException ex = new IllegalStateException(
 354                         String.format("%s: Could not finish committing transaction %s - no CohortEntry found",
 355                                 persistenceId(), transactionID));
 356                 LOG.error(ex.getMessage());
 357                 sender.tell(new akka.actor.Status.Failure(ex), getSelf());
 358             }
 359
 360             return;
 361         }
 362
 363         LOG.debug("{}: Finishing commit for transaction {}", persistenceId(), cohortEntry.getTransactionID());
 364
 365         try {
 366             // We block on the future here so we don't have to worry about possibly accessing our
 367             // state on a different thread outside of our dispatcher. Also, the data store
 368             // currently uses a same thread executor anyway.
 369             cohortEntry.getCohort().commit().get();
 370
 371             sender.tell(CommitTransactionReply.INSTANCE.toSerializable(), getSelf());
 372
 373             shardMBean.incrementCommittedTransactionCount();
 374             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 375
 376         } catch (Exception e) {
 377             sender.tell(new akka.actor.Status.Failure(e), getSelf());
 378
 379             LOG.error(e, "{}, An exception occurred while committing transaction {}", persistenceId(), transactionID);
 380             shardMBean.incrementFailedTransactionsCount();
 381         } finally {
 382             commitCoordinator.currentTransactionComplete(transactionID, true);
 383         }
 384     }
 385
 386     private void handleCanCommitTransaction(final CanCommitTransaction canCommit) {
 387         LOG.debug("{}: Can committing transaction {}", persistenceId(), canCommit.getTransactionID());
 388         commitCoordinator.handleCanCommit(canCommit, getSender(), self());
 389     }
 390
 391     private void handleForwardedReadyTransaction(ForwardedReadyTransaction ready) {
 392         LOG.debug("{}: Readying transaction {}, client version {}", persistenceId(),
 393                 ready.getTransactionID(), ready.getTxnClientVersion());
 394
 395         // This message is forwarded by the ShardTransaction on ready. We cache the cohort in the
 396         // commitCoordinator in preparation for the subsequent three phase commit initiated by
 397         // the front-end.
 398         commitCoordinator.transactionReady(ready.getTransactionID(), ready.getCohort(),
 399                 ready.getModification());
 400
 401         // Return our actor path as we'll handle the three phase commit, except if the Tx client
 402         // version < 1 (Helium-1 version). This means the Tx was initiated by a base Helium version
 403         // node. In that case, the subsequent 3-phase commit messages won't contain the
 404         // transactionId so to maintain backwards compatibility, we create a separate cohort actor
 405         // to provide the compatible behavior.
 406         ActorRef replyActorPath = self();
 407         if(ready.getTxnClientVersion() < DataStoreVersions.HELIUM_1_VERSION) {
 408             LOG.debug("{}: Creating BackwardsCompatibleThreePhaseCommitCohort", persistenceId());
 409             replyActorPath = getContext().actorOf(BackwardsCompatibleThreePhaseCommitCohort.props(
 410                     ready.getTransactionID()));
 411         }
 412
 413         ReadyTransactionReply readyTransactionReply = new ReadyTransactionReply(
 414                 Serialization.serializedActorPath(replyActorPath));
 415         getSender().tell(ready.isReturnSerialized() ? readyTransactionReply.toSerializable() :
 416                 readyTransactionReply, getSelf());
 417     }
 418
 419     private void handleAbortTransaction(final AbortTransaction abort) {
 420         doAbortTransaction(abort.getTransactionID(), getSender());
 421     }
 422
 423     void doAbortTransaction(final String transactionID, final ActorRef sender) {
 424         final CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 425         if(cohortEntry != null) {
 426             LOG.debug("{}: Aborting transaction {}", persistenceId(), transactionID);
 427
 428             // We don't remove the cached cohort entry here (ie pass false) in case the Tx was
 429             // aborted during replication in which case we may still commit locally if replication
 430             // succeeds.
 431             commitCoordinator.currentTransactionComplete(transactionID, false);
 432
 433             final ListenableFuture<Void> future = cohortEntry.getCohort().abort();
 434             final ActorRef self = getSelf();
 435
 436             Futures.addCallback(future, new FutureCallback<Void>() {
 437                 @Override
 438                 public void onSuccess(final Void v) {
 439                     shardMBean.incrementAbortTransactionsCount();
 440
 441                     if(sender != null) {
 442                         sender.tell(AbortTransactionReply.INSTANCE.toSerializable(), self);
 443                     }
 444                 }
 445
 446                 @Override
 447                 public void onFailure(final Throwable t) {
 448                     LOG.error(t, "{}: An exception happened during abort", persistenceId());
 449
 450                     if(sender != null) {
 451                         sender.tell(new akka.actor.Status.Failure(t), self);
 452                     }
 453                 }
 454             });
 455         }
 456     }
 457
 458     private void handleCreateTransaction(final Object message) {
 459         if (isLeader()) {
 460             createTransaction(CreateTransaction.fromSerializable(message));
 461         } else if (getLeader() != null) {
 462             getLeader().forward(message, getContext());
 463         } else {
 464             getSender().tell(new akka.actor.Status.Failure(new NoShardLeaderException(String.format(
 465                 "Could not find leader for shard %s so transaction cannot be created. This typically happens" +
 466                 " when the system is coming up or recovering and a leader is being elected. Try again" +
 467                 " later.", persistenceId()))), getSelf());
 468         }
 469     }
 470
 471     private void closeTransactionChain(final CloseTransactionChain closeTransactionChain) {
 472         DOMStoreTransactionChain chain =
 473             transactionChains.remove(closeTransactionChain.getTransactionChainId());
 474
 475         if(chain != null) {
 476             chain.close();
 477         }
 478     }
 479
 480     private ActorRef createTypedTransactionActor(int transactionType,
 481             ShardTransactionIdentifier transactionId, String transactionChainId,
 482             short clientVersion ) {
 483
 484         DOMStoreTransactionFactory factory = store;
 485
 486         if(!transactionChainId.isEmpty()) {
 487             factory = transactionChains.get(transactionChainId);
 488             if(factory == null){
 489                 DOMStoreTransactionChain transactionChain = store.createTransactionChain();
 490                 transactionChains.put(transactionChainId, transactionChain);
 491                 factory = transactionChain;
 492             }
 493         }
 494
 495         if(this.schemaContext == null) {
 496             throw new IllegalStateException("SchemaContext is not set");
 497         }
 498
 499         if (transactionType == TransactionProxy.TransactionType.READ_ONLY.ordinal()) {
 500
 501             shardMBean.incrementReadOnlyTransactionCount();
 502
 503             return getContext().actorOf(
 504                 ShardTransaction.props(factory.newReadOnlyTransaction(), getSelf(),
 505                         schemaContext,datastoreContext, shardMBean,
 506                         transactionId.getRemoteTransactionId(), clientVersion),
 507                         transactionId.toString());
 508
 509         } else if (transactionType == TransactionProxy.TransactionType.READ_WRITE.ordinal()) {
 510
 511             shardMBean.incrementReadWriteTransactionCount();
 512
 513             return getContext().actorOf(
 514                 ShardTransaction.props(factory.newReadWriteTransaction(), getSelf(),
 515                         schemaContext, datastoreContext, shardMBean,
 516                         transactionId.getRemoteTransactionId(), clientVersion),
 517                         transactionId.toString());
 518
 519
 520         } else if (transactionType == TransactionProxy.TransactionType.WRITE_ONLY.ordinal()) {
 521
 522             shardMBean.incrementWriteOnlyTransactionCount();
 523
 524             return getContext().actorOf(
 525                 ShardTransaction.props(factory.newWriteOnlyTransaction(), getSelf(),
 526                         schemaContext, datastoreContext, shardMBean,
 527                         transactionId.getRemoteTransactionId(), clientVersion),
 528                         transactionId.toString());
 529         } else {
 530             throw new IllegalArgumentException(
 531                 "Shard="+name + ":CreateTransaction message has unidentified transaction type="
 532                     + transactionType);
 533         }
 534     }
 535
 536     private void createTransaction(CreateTransaction createTransaction) {
 537         try {
 538             ActorRef transactionActor = createTransaction(createTransaction.getTransactionType(),
 539                 createTransaction.getTransactionId(), createTransaction.getTransactionChainId(),
 540                 createTransaction.getVersion());
 541
 542             getSender().tell(new CreateTransactionReply(Serialization.serializedActorPath(transactionActor),
 543                     createTransaction.getTransactionId()).toSerializable(), getSelf());
 544         } catch (Exception e) {
 545             getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 546         }
 547     }
 548
 549     private ActorRef createTransaction(int transactionType, String remoteTransactionId,
 550             String transactionChainId, short clientVersion) {
 551
 552         ShardTransactionIdentifier transactionId =
 553             ShardTransactionIdentifier.builder()
 554                 .remoteTransactionId(remoteTransactionId)
 555                 .build();
 556
 557         if(LOG.isDebugEnabled()) {
 558             LOG.debug("{}: Creating transaction : {} ", persistenceId(), transactionId);
 559         }
 560
 561         ActorRef transactionActor = createTypedTransactionActor(transactionType, transactionId,
 562                 transactionChainId, clientVersion);
 563
 564         return transactionActor;
 565     }
 566
 567     private void syncCommitTransaction(final DOMStoreWriteTransaction transaction)
 568         throws ExecutionException, InterruptedException {
 569         DOMStoreThreePhaseCommitCohort commitCohort = transaction.ready();
 570         commitCohort.preCommit().get();
 571         commitCohort.commit().get();
 572     }
 573
 574     private void commitWithNewTransaction(final Modification modification) {
 575         DOMStoreWriteTransaction tx = store.newWriteOnlyTransaction();
 576         modification.apply(tx);
 577         try {
 578             syncCommitTransaction(tx);
 579             shardMBean.incrementCommittedTransactionCount();
 580             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 581         } catch (InterruptedException | ExecutionException e) {
 582             shardMBean.incrementFailedTransactionsCount();
 583             LOG.error(e, "{}: Failed to commit", persistenceId());
 584         }
 585     }
 586
 587     private void updateSchemaContext(final UpdateSchemaContext message) {
 588         this.schemaContext = message.getSchemaContext();
 589         updateSchemaContext(message.getSchemaContext());
 590         store.onGlobalContextUpdated(message.getSchemaContext());
 591     }
 592
 593     @VisibleForTesting
 594     void updateSchemaContext(final SchemaContext schemaContext) {
 595         store.onGlobalContextUpdated(schemaContext);
 596     }
 597
 598     private void registerChangeListener(final RegisterChangeListener registerChangeListener) {
 599
 600         LOG.debug("{}: registerDataChangeListener for {}", persistenceId(), registerChangeListener.getPath());
 601
 602         ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
 603                                                      NormalizedNode<?, ?>>> registration;
 604         if(isLeader()) {
 605             registration = doChangeListenerRegistration(registerChangeListener);
 606         } else {
 607             LOG.debug("{}: Shard is not the leader - delaying registration", persistenceId());
 608
 609             DelayedListenerRegistration delayedReg =
 610                     new DelayedListenerRegistration(registerChangeListener);
 611             delayedListenerRegistrations.add(delayedReg);
 612             registration = delayedReg;
 613         }
 614
 615         ActorRef listenerRegistration = getContext().actorOf(
 616                 DataChangeListenerRegistration.props(registration));
 617
 618         LOG.debug("{}: registerDataChangeListener sending reply, listenerRegistrationPath = {} ",
 619                 persistenceId(), listenerRegistration.path());
 620
 621         getSender().tell(new RegisterChangeListenerReply(listenerRegistration.path()), getSelf());
 622     }
 623
 624     private ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
 625                                                NormalizedNode<?, ?>>> doChangeListenerRegistration(
 626             final RegisterChangeListener registerChangeListener) {
 627
 628         ActorSelection dataChangeListenerPath = getContext().system().actorSelection(
 629                 registerChangeListener.getDataChangeListenerPath());
 630
 631         // Notify the listener if notifications should be enabled or not
 632         // If this shard is the leader then it will enable notifications else
 633         // it will not
 634         dataChangeListenerPath.tell(new EnableNotification(true), getSelf());
 635
 636         // Now store a reference to the data change listener so it can be notified
 637         // at a later point if notifications should be enabled or disabled
 638         dataChangeListeners.add(dataChangeListenerPath);
 639
 640         AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>> listener =
 641                 new DataChangeListenerProxy(dataChangeListenerPath);
 642
 643         LOG.debug("{}: Registering for path {}", persistenceId(), registerChangeListener.getPath());
 644
 645         return store.registerChangeListener(registerChangeListener.getPath(), listener,
 646                 registerChangeListener.getScope());
 647     }
 648
 649     private boolean isMetricsCaptureEnabled(){
 650         CommonConfig config = new CommonConfig(getContext().system().settings().config());
 651         return config.isMetricCaptureEnabled();
 652     }
 653
 654     @Override
 655     protected
 656     void startLogRecoveryBatch(final int maxBatchSize) {
 657         currentLogRecoveryBatch = Lists.newArrayListWithCapacity(maxBatchSize);
 658
 659         if(LOG.isDebugEnabled()) {
 660             LOG.debug("{}: starting log recovery batch with max size {}", persistenceId(), maxBatchSize);
 661         }
 662     }
 663
 664     @Override
 665     protected void appendRecoveredLogEntry(final Payload data) {
 666         if(data instanceof ModificationPayload) {
 667             try {
 668                 currentLogRecoveryBatch.add(((ModificationPayload) data).getModification());
 669             } catch (ClassNotFoundException | IOException e) {
 670                 LOG.error(e, "{}: Error extracting ModificationPayload", persistenceId());
 671             }
 672         } else if (data instanceof CompositeModificationPayload) {
 673             currentLogRecoveryBatch.add(((CompositeModificationPayload) data).getModification());
 674         } else if (data instanceof CompositeModificationByteStringPayload) {
 675             currentLogRecoveryBatch.add(((CompositeModificationByteStringPayload) data).getModification());
 676         } else {
 677             LOG.error("{}: Unknown state received {} during recovery", persistenceId(), data);
 678         }
 679     }
 680
 681     @Override
 682     protected void applyRecoverySnapshot(final byte[] snapshotBytes) {
 683         if(recoveryCoordinator == null) {
 684             recoveryCoordinator = new ShardRecoveryCoordinator(persistenceId(), schemaContext,
 685                     LOG, name.toString());
 686         }
 687
 688         recoveryCoordinator.submit(snapshotBytes, store.newWriteOnlyTransaction());
 689
 690         if(LOG.isDebugEnabled()) {
 691             LOG.debug("{}: submitted recovery sbapshot", persistenceId());
 692         }
 693     }
 694
 695     @Override
 696     protected void applyCurrentLogRecoveryBatch() {
 697         if(recoveryCoordinator == null) {
 698             recoveryCoordinator = new ShardRecoveryCoordinator(persistenceId(), schemaContext,
 699                     LOG, name.toString());
 700         }
 701
 702         recoveryCoordinator.submit(currentLogRecoveryBatch, store.newWriteOnlyTransaction());
 703
 704         if(LOG.isDebugEnabled()) {
 705             LOG.debug("{}: submitted log recovery batch with size {}", persistenceId(),
 706                     currentLogRecoveryBatch.size());
 707         }
 708     }
 709
 710     @Override
 711     protected void onRecoveryComplete() {
 712         if(recoveryCoordinator != null) {
 713             Collection<DOMStoreWriteTransaction> txList = recoveryCoordinator.getTransactions();
 714
 715             if(LOG.isDebugEnabled()) {
 716                 LOG.debug("{}: recovery complete - committing {} Tx's", persistenceId(), txList.size());
 717             }
 718
 719             for(DOMStoreWriteTransaction tx: txList) {
 720                 try {
 721                     syncCommitTransaction(tx);
 722                     shardMBean.incrementCommittedTransactionCount();
 723                 } catch (InterruptedException | ExecutionException e) {
 724                     shardMBean.incrementFailedTransactionsCount();
 725                     LOG.error(e, "{}: Failed to commit", persistenceId());
 726                 }
 727             }
 728         }
 729
 730         recoveryCoordinator = null;
 731         currentLogRecoveryBatch = null;
 732         updateJournalStats();
 733
 734         //notify shard manager
 735         getContext().parent().tell(new ActorInitialized(), getSelf());
 736
 737         // Being paranoid here - this method should only be called once but just in case...
 738         if(txCommitTimeoutCheckSchedule == null) {
 739             // Schedule a message to be periodically sent to check if the current in-progress
 740             // transaction should be expired and aborted.
 741             FiniteDuration period = Duration.create(transactionCommitTimeout / 3, TimeUnit.MILLISECONDS);
 742             txCommitTimeoutCheckSchedule = getContext().system().scheduler().schedule(
 743                     period, period, getSelf(),
 744                     TX_COMMIT_TIMEOUT_CHECK_MESSAGE, getContext().dispatcher(), ActorRef.noSender());
 745         }
 746     }
 747
 748     @Override
 749     protected void applyState(final ActorRef clientActor, final String identifier, final Object data) {
 750
 751         if(data instanceof ModificationPayload) {
 752             try {
 753                 applyModificationToState(clientActor, identifier, ((ModificationPayload) data).getModification());
 754             } catch (ClassNotFoundException | IOException e) {
 755                 LOG.error(e, "{}: Error extracting ModificationPayload", persistenceId());
 756             }
 757         }
 758         else if (data instanceof CompositeModificationPayload) {
 759             Object modification = ((CompositeModificationPayload) data).getModification();
 760
 761             applyModificationToState(clientActor, identifier, modification);
 762         } else if(data instanceof CompositeModificationByteStringPayload ){
 763             Object modification = ((CompositeModificationByteStringPayload) data).getModification();
 764
 765             applyModificationToState(clientActor, identifier, modification);
 766         } else {
 767             LOG.error("{}: Unknown state received {} Class loader = {} CompositeNodeMod.ClassLoader = {}",
 768                     persistenceId(), data, data.getClass().getClassLoader(),
 769                     CompositeModificationPayload.class.getClassLoader());
 770         }
 771
 772         updateJournalStats();
 773
 774     }
 775
 776     private void applyModificationToState(ActorRef clientActor, String identifier, Object modification) {
 777         if(modification == null) {
 778             LOG.error(
 779                     "{}: modification is null - this is very unexpected, clientActor = {}, identifier = {}",
 780                     persistenceId(), identifier, clientActor != null ? clientActor.path().toString() : null);
 781         } else if(clientActor == null) {
 782             // There's no clientActor to which to send a commit reply so we must be applying
 783             // replicated state from the leader.
 784             commitWithNewTransaction(MutableCompositeModification.fromSerializable(modification));
 785         } else {
 786             // This must be the OK to commit after replication consensus.
 787             finishCommit(clientActor, identifier);
 788         }
 789     }
 790
 791     private void updateJournalStats() {
 792         ReplicatedLogEntry lastLogEntry = getLastLogEntry();
 793
 794         if (lastLogEntry != null) {
 795             shardMBean.setLastLogIndex(lastLogEntry.getIndex());
 796             shardMBean.setLastLogTerm(lastLogEntry.getTerm());
 797         }
 798
 799         shardMBean.setCommitIndex(getCommitIndex());
 800         shardMBean.setLastApplied(getLastApplied());
 801         shardMBean.setInMemoryJournalDataSize(getRaftActorContext().getReplicatedLog().dataSize());
 802     }
 803
 804     @Override
 805     protected void createSnapshot() {
 806         // Create a transaction actor. We are really going to treat the transaction as a worker
 807         // so that this actor does not get block building the snapshot. THe transaction actor will
 808         // after processing the CreateSnapshot message.
 809
 810         ActorRef createSnapshotTransaction = createTransaction(
 811                 TransactionProxy.TransactionType.READ_ONLY.ordinal(),
 812                 "createSnapshot" + ++createSnapshotTransactionCounter, "",
 813                 DataStoreVersions.CURRENT_VERSION);
 814
 815         createSnapshotTransaction.tell(CreateSnapshot.INSTANCE, self());
 816     }
 817
 818     @VisibleForTesting
 819     @Override
 820     protected void applySnapshot(final byte[] snapshotBytes) {
 821         // Since this will be done only on Recovery or when this actor is a Follower
 822         // we can safely commit everything in here. We not need to worry about event notifications
 823         // as they would have already been disabled on the follower
 824
 825         LOG.info("{}: Applying snapshot", persistenceId());
 826         try {
 827             DOMStoreWriteTransaction transaction = store.newWriteOnlyTransaction();
 828
 829             NormalizedNode<?, ?> node = SerializationUtils.deserializeNormalizedNode(snapshotBytes);
 830
 831             // delete everything first
 832             transaction.delete(DATASTORE_ROOT);
 833
 834             // Add everything from the remote node back
 835             transaction.write(DATASTORE_ROOT, node);
 836             syncCommitTransaction(transaction);
 837         } catch (InterruptedException | ExecutionException e) {
 838             LOG.error(e, "{}: An exception occurred when applying snapshot", persistenceId());
 839         } finally {
 840             LOG.info("{}: Done applying snapshot", persistenceId());
 841         }
 842     }
 843
 844     @Override
 845     protected void onStateChanged() {
 846         boolean isLeader = isLeader();
 847         for (ActorSelection dataChangeListener : dataChangeListeners) {
 848             dataChangeListener.tell(new EnableNotification(isLeader), getSelf());
 849         }
 850
 851         if(isLeader) {
 852             for(DelayedListenerRegistration reg: delayedListenerRegistrations) {
 853                 if(!reg.isClosed()) {
 854                     reg.setDelegate(doChangeListenerRegistration(reg.getRegisterChangeListener()));
 855                 }
 856             }
 857
 858             delayedListenerRegistrations.clear();
 859         }
 860
 861         shardMBean.setRaftState(getRaftState().name());
 862         shardMBean.setCurrentTerm(getCurrentTerm());
 863
 864         // If this actor is no longer the leader close all the transaction chains
 865         if(!isLeader){
 866             for(Map.Entry<String, DOMStoreTransactionChain> entry : transactionChains.entrySet()){
 867                 if(LOG.isDebugEnabled()) {
 868                     LOG.debug(
 869                         "{}: onStateChanged: Closing transaction chain {} because shard {} is no longer the leader",
 870                         persistenceId(), entry.getKey(), getId());
 871                 }
 872                 entry.getValue().close();
 873             }
 874
 875             transactionChains.clear();
 876         }
 877     }
 878
 879     @Override
 880     protected DataPersistenceProvider persistence() {
 881         return dataPersistenceProvider;
 882     }
 883
 884     @Override protected void onLeaderChanged(final String oldLeader, final String newLeader) {
 885         shardMBean.setLeader(newLeader);
 886     }
 887
 888     @Override public String persistenceId() {
 889         return this.name.toString();
 890     }
 891
 892     @VisibleForTesting
 893     DataPersistenceProvider getDataPersistenceProvider() {
 894         return dataPersistenceProvider;
 895     }
 896
 897     private static class ShardCreator implements Creator<Shard> {
 898
 899         private static final long serialVersionUID = 1L;
 900
 901         final ShardIdentifier name;
 902         final Map<ShardIdentifier, String> peerAddresses;
 903         final DatastoreContext datastoreContext;
 904         final SchemaContext schemaContext;
 905
 906         ShardCreator(final ShardIdentifier name, final Map<ShardIdentifier, String> peerAddresses,
 907                 final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 908             this.name = name;
 909             this.peerAddresses = peerAddresses;
 910             this.datastoreContext = datastoreContext;
 911             this.schemaContext = schemaContext;
 912         }
 913
 914         @Override
 915         public Shard create() throws Exception {
 916             return new Shard(name, peerAddresses, datastoreContext, schemaContext);
 917         }
 918     }
 919
 920     @VisibleForTesting
 921     InMemoryDOMDataStore getDataStore() {
 922         return store;
 923     }
 924
 925     @VisibleForTesting
 926     ShardStats getShardMBean() {
 927         return shardMBean;
 928     }
 929
 930     private static class DelayedListenerRegistration implements
 931         ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>>> {
 932
 933         private volatile boolean closed;
 934
 935         private final RegisterChangeListener registerChangeListener;
 936
 937         private volatile ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
 938                                                              NormalizedNode<?, ?>>> delegate;
 939
 940         DelayedListenerRegistration(final RegisterChangeListener registerChangeListener) {
 941             this.registerChangeListener = registerChangeListener;
 942         }
 943
 944         void setDelegate( final ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
 945                                             NormalizedNode<?, ?>>> registration) {
 946             this.delegate = registration;
 947         }
 948
 949         boolean isClosed() {
 950             return closed;
 951         }
 952
 953         RegisterChangeListener getRegisterChangeListener() {
 954             return registerChangeListener;
 955         }
 956
 957         @Override
 958         public AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>> getInstance() {
 959             return delegate != null ? delegate.getInstance() : null;
 960         }
 961
 962         @Override
 963         public void close() {
 964             closed = true;
 965             if(delegate != null) {
 966                 delegate.close();
 967             }
 968         }
 969     }
 970 }