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