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 java.util.Collection;
  31 import java.util.HashMap;
  32 import java.util.List;
  33 import java.util.Map;
  34 import java.util.concurrent.ExecutionException;
  35 import java.util.concurrent.TimeUnit;
  36 import javax.annotation.Nonnull;
  37 import org.opendaylight.controller.cluster.DataPersistenceProvider;
  38 import org.opendaylight.controller.cluster.common.actor.CommonConfig;
  39 import org.opendaylight.controller.cluster.common.actor.MeteringBehavior;
  40 import org.opendaylight.controller.cluster.datastore.ShardCommitCoordinator.CohortEntry;
  41 import org.opendaylight.controller.cluster.datastore.compat.BackwardsCompatibleThreePhaseCommitCohort;
  42 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
  43 import org.opendaylight.controller.cluster.datastore.identifiers.ShardIdentifier;
  44 import org.opendaylight.controller.cluster.datastore.identifiers.ShardTransactionIdentifier;
  45 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardMBeanFactory;
  46 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardStats;
  47 import org.opendaylight.controller.cluster.datastore.messages.AbortTransaction;
  48 import org.opendaylight.controller.cluster.datastore.messages.AbortTransactionReply;
  49 import org.opendaylight.controller.cluster.datastore.messages.ActorInitialized;
  50 import org.opendaylight.controller.cluster.datastore.messages.CanCommitTransaction;
  51 import org.opendaylight.controller.cluster.datastore.messages.CloseTransactionChain;
  52 import org.opendaylight.controller.cluster.datastore.messages.CommitTransaction;
  53 import org.opendaylight.controller.cluster.datastore.messages.CommitTransactionReply;
  54 import org.opendaylight.controller.cluster.datastore.messages.CreateTransaction;
  55 import org.opendaylight.controller.cluster.datastore.messages.CreateTransactionReply;
  56 import org.opendaylight.controller.cluster.datastore.messages.EnableNotification;
  57 import org.opendaylight.controller.cluster.datastore.messages.ForwardedReadyTransaction;
  58 import org.opendaylight.controller.cluster.datastore.messages.PeerAddressResolved;
  59 import org.opendaylight.controller.cluster.datastore.messages.ReadData;
  60 import org.opendaylight.controller.cluster.datastore.messages.ReadDataReply;
  61 import org.opendaylight.controller.cluster.datastore.messages.ReadyTransactionReply;
  62 import org.opendaylight.controller.cluster.datastore.messages.RegisterChangeListener;
  63 import org.opendaylight.controller.cluster.datastore.messages.RegisterChangeListenerReply;
  64 import org.opendaylight.controller.cluster.datastore.messages.UpdateSchemaContext;
  65 import org.opendaylight.controller.cluster.datastore.modification.Modification;
  66 import org.opendaylight.controller.cluster.datastore.modification.MutableCompositeModification;
  67 import org.opendaylight.controller.cluster.datastore.node.NormalizedNodeToNodeCodec;
  68 import org.opendaylight.controller.cluster.notifications.RoleChangeNotifier;
  69 import org.opendaylight.controller.cluster.raft.RaftActor;
  70 import org.opendaylight.controller.cluster.raft.ReplicatedLogEntry;
  71 import org.opendaylight.controller.cluster.raft.base.messages.CaptureSnapshotReply;
  72 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationByteStringPayload;
  73 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationPayload;
  74 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.Payload;
  75 import org.opendaylight.controller.md.sal.common.api.data.AsyncDataChangeListener;
  76 import org.opendaylight.controller.md.sal.dom.store.impl.InMemoryDOMDataStore;
  77 import org.opendaylight.controller.md.sal.dom.store.impl.InMemoryDOMDataStoreFactory;
  78 import org.opendaylight.controller.protobuff.messages.common.NormalizedNodeMessages;
  79 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  80 import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransactionChain;
  81 import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransactionFactory;
  82 import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
  83 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  84 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  85 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  86 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  87 import scala.concurrent.duration.Duration;
  88 import scala.concurrent.duration.FiniteDuration;
  89
  90 /**
  91  * A Shard represents a portion of the logical data tree <br/>
  92  * <p>
  93  * Our Shard uses InMemoryDataStore as it's internal representation and delegates all requests it
  94  * </p>
  95  */
  96 public class Shard extends RaftActor {
  97
  98     private static final Object COMMIT_TRANSACTION_REPLY = new CommitTransactionReply().toSerializable();
  99
 100     private static final Object TX_COMMIT_TIMEOUT_CHECK_MESSAGE = "txCommitTimeoutCheck";
 101
 102     public static final String DEFAULT_NAME = "default";
 103
 104     // The state of this Shard
 105     private final InMemoryDOMDataStore store;
 106
 107     private final LoggingAdapter LOG =
 108         Logging.getLogger(getContext().system(), this);
 109
 110     /// The name of this shard
 111     private final ShardIdentifier name;
 112
 113     private final ShardStats shardMBean;
 114
 115     private final List<ActorSelection> dataChangeListeners =  Lists.newArrayList();
 116
 117     private final List<DelayedListenerRegistration> delayedListenerRegistrations =
 118                                                                        Lists.newArrayList();
 119
 120     private final DatastoreContext datastoreContext;
 121
 122     private final DataPersistenceProvider dataPersistenceProvider;
 123
 124     private SchemaContext schemaContext;
 125
 126     private ActorRef createSnapshotTransaction;
 127
 128     private int createSnapshotTransactionCounter;
 129
 130     private final ShardCommitCoordinator commitCoordinator;
 131
 132     private final long transactionCommitTimeout;
 133
 134     private Cancellable txCommitTimeoutCheckSchedule;
 135
 136     private Optional<ActorRef> roleChangeNotifier;
 137
 138     /**
 139      * Coordinates persistence recovery on startup.
 140      */
 141     private ShardRecoveryCoordinator recoveryCoordinator;
 142     private List<Object> currentLogRecoveryBatch;
 143
 144     private final Map<String, DOMStoreTransactionChain> transactionChains = new HashMap<>();
 145
 146     protected Shard(final ShardIdentifier name, final Map<ShardIdentifier, String> peerAddresses,
 147             final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 148         super(name.toString(), mapPeerAddresses(peerAddresses),
 149                 Optional.of(datastoreContext.getShardRaftConfig()));
 150
 151         this.name = name;
 152         this.datastoreContext = datastoreContext;
 153         this.schemaContext = schemaContext;
 154         this.dataPersistenceProvider = (datastoreContext.isPersistent()) ? new PersistentDataProvider() : new NonPersistentRaftDataProvider();
 155
 156         LOG.info("Shard created : {} persistent : {}", name, datastoreContext.isPersistent());
 157
 158         store = InMemoryDOMDataStoreFactory.create(name.toString(), null,
 159                 datastoreContext.getDataStoreProperties());
 160
 161         if(schemaContext != null) {
 162             store.onGlobalContextUpdated(schemaContext);
 163         }
 164
 165         shardMBean = ShardMBeanFactory.getShardStatsMBean(name.toString(),
 166                 datastoreContext.getDataStoreMXBeanType());
 167         shardMBean.setNotificationManager(store.getDataChangeListenerNotificationManager());
 168
 169         if (isMetricsCaptureEnabled()) {
 170             getContext().become(new MeteringBehavior(this));
 171         }
 172
 173         commitCoordinator = new ShardCommitCoordinator(TimeUnit.SECONDS.convert(1, TimeUnit.MINUTES),
 174                 datastoreContext.getShardTransactionCommitQueueCapacity());
 175
 176         transactionCommitTimeout = TimeUnit.MILLISECONDS.convert(
 177                 datastoreContext.getShardTransactionCommitTimeoutInSeconds(), TimeUnit.SECONDS);
 178
 179         // create a notifier actor for each cluster member
 180         roleChangeNotifier = createRoleChangeNotifier(name.toString());
 181     }
 182
 183     private static Map<String, String> mapPeerAddresses(
 184         final Map<ShardIdentifier, String> peerAddresses) {
 185         Map<String, String> map = new HashMap<>();
 186
 187         for (Map.Entry<ShardIdentifier, String> entry : peerAddresses
 188             .entrySet()) {
 189             map.put(entry.getKey().toString(), entry.getValue());
 190         }
 191
 192         return map;
 193     }
 194
 195     public static Props props(final ShardIdentifier name,
 196         final Map<ShardIdentifier, String> peerAddresses,
 197         final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 198         Preconditions.checkNotNull(name, "name should not be null");
 199         Preconditions.checkNotNull(peerAddresses, "peerAddresses should not be null");
 200         Preconditions.checkNotNull(datastoreContext, "dataStoreContext should not be null");
 201         Preconditions.checkNotNull(schemaContext, "schemaContext should not be null");
 202
 203         return Props.create(new ShardCreator(name, peerAddresses, datastoreContext, schemaContext));
 204     }
 205
 206     private Optional<ActorRef> createRoleChangeNotifier(String shardId) {
 207         ActorRef shardRoleChangeNotifier = this.getContext().actorOf(
 208             RoleChangeNotifier.getProps(shardId), shardId + "-notifier");
 209         return Optional.<ActorRef>of(shardRoleChangeNotifier);
 210     }
 211
 212     @Override
 213     public void postStop() {
 214         super.postStop();
 215
 216         if(txCommitTimeoutCheckSchedule != null) {
 217             txCommitTimeoutCheckSchedule.cancel();
 218         }
 219     }
 220
 221     @Override
 222     public void onReceiveRecover(final Object message) throws Exception {
 223         if(LOG.isDebugEnabled()) {
 224             LOG.debug("onReceiveRecover: Received message {} from {}",
 225                 message.getClass().toString(),
 226                 getSender());
 227         }
 228
 229         if (message instanceof RecoveryFailure){
 230             LOG.error(((RecoveryFailure) message).cause(), "Recovery failed because of this cause");
 231
 232             // Even though recovery failed, we still need to finish our recovery, eg send the
 233             // ActorInitialized message and start the txCommitTimeoutCheckSchedule.
 234             onRecoveryComplete();
 235         } else {
 236             super.onReceiveRecover(message);
 237         }
 238     }
 239
 240     @Override
 241     public void onReceiveCommand(final Object message) throws Exception {
 242         if(LOG.isDebugEnabled()) {
 243             LOG.debug("onReceiveCommand: Received message {} from {}", message, getSender());
 244         }
 245
 246         if(message.getClass().equals(ReadDataReply.SERIALIZABLE_CLASS)) {
 247             handleReadDataReply(message);
 248         } else if (message.getClass().equals(CreateTransaction.SERIALIZABLE_CLASS)) {
 249             handleCreateTransaction(message);
 250         } else if(message instanceof ForwardedReadyTransaction) {
 251             handleForwardedReadyTransaction((ForwardedReadyTransaction)message);
 252         } else if(message.getClass().equals(CanCommitTransaction.SERIALIZABLE_CLASS)) {
 253             handleCanCommitTransaction(CanCommitTransaction.fromSerializable(message));
 254         } else if(message.getClass().equals(CommitTransaction.SERIALIZABLE_CLASS)) {
 255             handleCommitTransaction(CommitTransaction.fromSerializable(message));
 256         } else if(message.getClass().equals(AbortTransaction.SERIALIZABLE_CLASS)) {
 257             handleAbortTransaction(AbortTransaction.fromSerializable(message));
 258         } else if (message.getClass().equals(CloseTransactionChain.SERIALIZABLE_CLASS)){
 259             closeTransactionChain(CloseTransactionChain.fromSerializable(message));
 260         } else if (message instanceof RegisterChangeListener) {
 261             registerChangeListener((RegisterChangeListener) message);
 262         } else if (message instanceof UpdateSchemaContext) {
 263             updateSchemaContext((UpdateSchemaContext) message);
 264         } else if (message instanceof PeerAddressResolved) {
 265             PeerAddressResolved resolved = (PeerAddressResolved) message;
 266             setPeerAddress(resolved.getPeerId().toString(),
 267                 resolved.getPeerAddress());
 268         } else if(message.equals(TX_COMMIT_TIMEOUT_CHECK_MESSAGE)) {
 269             handleTransactionCommitTimeoutCheck();
 270         } else {
 271             super.onReceiveCommand(message);
 272         }
 273     }
 274
 275     @Override
 276     protected Optional<ActorRef> getRoleChangeNotifier() {
 277         return roleChangeNotifier;
 278     }
 279
 280     private void handleTransactionCommitTimeoutCheck() {
 281         CohortEntry cohortEntry = commitCoordinator.getCurrentCohortEntry();
 282         if(cohortEntry != null) {
 283             long elapsed = System.currentTimeMillis() - cohortEntry.getLastAccessTime();
 284             if(elapsed > transactionCommitTimeout) {
 285                 LOG.warning("Current transaction {} has timed out after {} ms - aborting",
 286                         cohortEntry.getTransactionID(), transactionCommitTimeout);
 287
 288                 doAbortTransaction(cohortEntry.getTransactionID(), null);
 289             }
 290         }
 291     }
 292
 293     private void handleCommitTransaction(final CommitTransaction commit) {
 294         final String transactionID = commit.getTransactionID();
 295
 296         LOG.debug("Committing transaction {}", transactionID);
 297
 298         // Get the current in-progress cohort entry in the commitCoordinator if it corresponds to
 299         // this transaction.
 300         final CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 301         if(cohortEntry == null) {
 302             // We're not the current Tx - the Tx was likely expired b/c it took too long in
 303             // between the canCommit and commit messages.
 304             IllegalStateException ex = new IllegalStateException(
 305                     String.format("Cannot commit transaction %s - it is not the current transaction",
 306                             transactionID));
 307             LOG.error(ex.getMessage());
 308             shardMBean.incrementFailedTransactionsCount();
 309             getSender().tell(new akka.actor.Status.Failure(ex), getSelf());
 310             return;
 311         }
 312
 313         // We perform the preCommit phase here atomically with the commit phase. This is an
 314         // optimization to eliminate the overhead of an extra preCommit message. We lose front-end
 315         // coordination of preCommit across shards in case of failure but preCommit should not
 316         // normally fail since we ensure only one concurrent 3-phase commit.
 317
 318         try {
 319             // We block on the future here so we don't have to worry about possibly accessing our
 320             // state on a different thread outside of our dispatcher. Also, the data store
 321             // currently uses a same thread executor anyway.
 322             cohortEntry.getCohort().preCommit().get();
 323
 324             Shard.this.persistData(getSender(), transactionID,
 325                     new CompositeModificationByteStringPayload(cohortEntry.getModification().toSerializable()));
 326         } catch (InterruptedException | ExecutionException e) {
 327             LOG.error(e, "An exception occurred while preCommitting transaction {}",
 328                     cohortEntry.getTransactionID());
 329             shardMBean.incrementFailedTransactionsCount();
 330             getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 331         }
 332
 333         cohortEntry.updateLastAccessTime();
 334     }
 335
 336     private void finishCommit(@Nonnull final ActorRef sender, final @Nonnull String transactionID) {
 337         // With persistence enabled, this method is called via applyState by the leader strategy
 338         // after the commit has been replicated to a majority of the followers.
 339
 340         CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 341         if(cohortEntry == null) {
 342             // The transaction is no longer the current commit. This can happen if the transaction
 343             // was aborted prior, most likely due to timeout in the front-end. We need to finish
 344             // committing the transaction though since it was successfully persisted and replicated
 345             // however we can't use the original cohort b/c it was already preCommitted and may
 346             // conflict with the current commit or may have been aborted so we commit with a new
 347             // transaction.
 348             cohortEntry = commitCoordinator.getAndRemoveCohortEntry(transactionID);
 349             if(cohortEntry != null) {
 350                 commitWithNewTransaction(cohortEntry.getModification());
 351                 sender.tell(COMMIT_TRANSACTION_REPLY, getSelf());
 352             } else {
 353                 // This really shouldn't happen - it likely means that persistence or replication
 354                 // took so long to complete such that the cohort entry was expired from the cache.
 355                 IllegalStateException ex = new IllegalStateException(
 356                         String.format("Could not finish committing transaction %s - no CohortEntry found",
 357                                 transactionID));
 358                 LOG.error(ex.getMessage());
 359                 sender.tell(new akka.actor.Status.Failure(ex), getSelf());
 360             }
 361
 362             return;
 363         }
 364
 365         LOG.debug("Finishing commit for transaction {}", cohortEntry.getTransactionID());
 366
 367         try {
 368             // We block on the future here so we don't have to worry about possibly accessing our
 369             // state on a different thread outside of our dispatcher. Also, the data store
 370             // currently uses a same thread executor anyway.
 371             cohortEntry.getCohort().commit().get();
 372
 373             sender.tell(COMMIT_TRANSACTION_REPLY, getSelf());
 374
 375             shardMBean.incrementCommittedTransactionCount();
 376             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 377
 378         } catch (InterruptedException | ExecutionException e) {
 379             sender.tell(new akka.actor.Status.Failure(e), getSelf());
 380
 381             LOG.error(e, "An exception occurred while committing transaction {}", transactionID);
 382             shardMBean.incrementFailedTransactionsCount();
 383         }
 384
 385         commitCoordinator.currentTransactionComplete(transactionID, true);
 386     }
 387
 388     private void handleCanCommitTransaction(final CanCommitTransaction canCommit) {
 389         LOG.debug("Can committing transaction {}", canCommit.getTransactionID());
 390         commitCoordinator.handleCanCommit(canCommit, getSender(), self());
 391     }
 392
 393     private void handleForwardedReadyTransaction(ForwardedReadyTransaction ready) {
 394         LOG.debug("Readying transaction {}, client version {}", ready.getTransactionID(),
 395                 ready.getTxnClientVersion());
 396
 397         // This message is forwarded by the ShardTransaction on ready. We cache the cohort in the
 398         // commitCoordinator in preparation for the subsequent three phase commit initiated by
 399         // the front-end.
 400         commitCoordinator.transactionReady(ready.getTransactionID(), ready.getCohort(),
 401                 ready.getModification());
 402
 403         // Return our actor path as we'll handle the three phase commit, except if the Tx client
 404         // version < 1 (Helium-1 version). This means the Tx was initiated by a base Helium version
 405         // node. In that case, the subsequent 3-phase commit messages won't contain the
 406         // transactionId so to maintain backwards compatibility, we create a separate cohort actor
 407         // to provide the compatible behavior.
 408         ActorRef replyActorPath = self();
 409         if(ready.getTxnClientVersion() < CreateTransaction.HELIUM_1_VERSION) {
 410             LOG.debug("Creating BackwardsCompatibleThreePhaseCommitCohort");
 411             replyActorPath = getContext().actorOf(BackwardsCompatibleThreePhaseCommitCohort.props(
 412                     ready.getTransactionID()));
 413         }
 414
 415         ReadyTransactionReply readyTransactionReply = new ReadyTransactionReply(
 416                 Serialization.serializedActorPath(replyActorPath));
 417         getSender().tell(ready.isReturnSerialized() ? readyTransactionReply.toSerializable() :
 418                 readyTransactionReply, getSelf());
 419     }
 420
 421     private void handleAbortTransaction(final AbortTransaction abort) {
 422         doAbortTransaction(abort.getTransactionID(), getSender());
 423     }
 424
 425     private void doAbortTransaction(final String transactionID, final ActorRef sender) {
 426         final CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 427         if(cohortEntry != null) {
 428             LOG.debug("Aborting transaction {}", transactionID);
 429
 430             // We don't remove the cached cohort entry here (ie pass false) in case the Tx was
 431             // aborted during replication in which case we may still commit locally if replication
 432             // succeeds.
 433             commitCoordinator.currentTransactionComplete(transactionID, false);
 434
 435             final ListenableFuture<Void> future = cohortEntry.getCohort().abort();
 436             final ActorRef self = getSelf();
 437
 438             Futures.addCallback(future, new FutureCallback<Void>() {
 439                 @Override
 440                 public void onSuccess(final Void v) {
 441                     shardMBean.incrementAbortTransactionsCount();
 442
 443                     if(sender != null) {
 444                         sender.tell(new AbortTransactionReply().toSerializable(), self);
 445                     }
 446                 }
 447
 448                 @Override
 449                 public void onFailure(final Throwable t) {
 450                     LOG.error(t, "An exception happened during abort");
 451
 452                     if(sender != null) {
 453                         sender.tell(new akka.actor.Status.Failure(t), self);
 454                     }
 455                 }
 456             });
 457         }
 458     }
 459
 460     private void handleCreateTransaction(final Object message) {
 461         if (isLeader()) {
 462             createTransaction(CreateTransaction.fromSerializable(message));
 463         } else if (getLeader() != null) {
 464             getLeader().forward(message, getContext());
 465         } else {
 466             getSender().tell(new akka.actor.Status.Failure(new NoShardLeaderException(
 467                 "Could not find shard leader so transaction cannot be created. This typically happens" +
 468                 " when the system is coming up or recovering and a leader is being elected. Try again" +
 469                 " later.")), getSelf());
 470         }
 471     }
 472
 473     private void handleReadDataReply(final Object message) {
 474         // This must be for install snapshot. Don't want to open this up and trigger
 475         // deSerialization
 476
 477         self().tell(new CaptureSnapshotReply(ReadDataReply.getNormalizedNodeByteString(message)),
 478                 self());
 479
 480         createSnapshotTransaction = null;
 481
 482         // Send a PoisonPill instead of sending close transaction because we do not really need
 483         // a response
 484         getSender().tell(PoisonPill.getInstance(), self());
 485     }
 486
 487     private void closeTransactionChain(final CloseTransactionChain closeTransactionChain) {
 488         DOMStoreTransactionChain chain =
 489             transactionChains.remove(closeTransactionChain.getTransactionChainId());
 490
 491         if(chain != null) {
 492             chain.close();
 493         }
 494     }
 495
 496     private ActorRef createTypedTransactionActor(int transactionType,
 497             ShardTransactionIdentifier transactionId, String transactionChainId, int clientVersion ) {
 498
 499         DOMStoreTransactionFactory factory = store;
 500
 501         if(!transactionChainId.isEmpty()) {
 502             factory = transactionChains.get(transactionChainId);
 503             if(factory == null){
 504                 DOMStoreTransactionChain transactionChain = store.createTransactionChain();
 505                 transactionChains.put(transactionChainId, transactionChain);
 506                 factory = transactionChain;
 507             }
 508         }
 509
 510         if(this.schemaContext == null) {
 511             throw new IllegalStateException("SchemaContext is not set");
 512         }
 513
 514         if (transactionType == TransactionProxy.TransactionType.READ_ONLY.ordinal()) {
 515
 516             shardMBean.incrementReadOnlyTransactionCount();
 517
 518             return getContext().actorOf(
 519                 ShardTransaction.props(factory.newReadOnlyTransaction(), getSelf(),
 520                         schemaContext,datastoreContext, shardMBean,
 521                         transactionId.getRemoteTransactionId(), clientVersion),
 522                         transactionId.toString());
 523
 524         } else if (transactionType == TransactionProxy.TransactionType.READ_WRITE.ordinal()) {
 525
 526             shardMBean.incrementReadWriteTransactionCount();
 527
 528             return getContext().actorOf(
 529                 ShardTransaction.props(factory.newReadWriteTransaction(), getSelf(),
 530                         schemaContext, datastoreContext, shardMBean,
 531                         transactionId.getRemoteTransactionId(), clientVersion),
 532                         transactionId.toString());
 533
 534
 535         } else if (transactionType == TransactionProxy.TransactionType.WRITE_ONLY.ordinal()) {
 536
 537             shardMBean.incrementWriteOnlyTransactionCount();
 538
 539             return getContext().actorOf(
 540                 ShardTransaction.props(factory.newWriteOnlyTransaction(), getSelf(),
 541                         schemaContext, datastoreContext, shardMBean,
 542                         transactionId.getRemoteTransactionId(), clientVersion),
 543                         transactionId.toString());
 544         } else {
 545             throw new IllegalArgumentException(
 546                 "Shard="+name + ":CreateTransaction message has unidentified transaction type="
 547                     + transactionType);
 548         }
 549     }
 550
 551     private void createTransaction(CreateTransaction createTransaction) {
 552         try {
 553             ActorRef transactionActor = createTransaction(createTransaction.getTransactionType(),
 554                 createTransaction.getTransactionId(), createTransaction.getTransactionChainId(),
 555                 createTransaction.getVersion());
 556
 557             getSender().tell(new CreateTransactionReply(Serialization.serializedActorPath(transactionActor),
 558                     createTransaction.getTransactionId()).toSerializable(), getSelf());
 559         } catch (Exception e) {
 560             getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 561         }
 562     }
 563
 564     private ActorRef createTransaction(int transactionType, String remoteTransactionId,
 565             String transactionChainId, int clientVersion) {
 566
 567         ShardTransactionIdentifier transactionId =
 568             ShardTransactionIdentifier.builder()
 569                 .remoteTransactionId(remoteTransactionId)
 570                 .build();
 571
 572         if(LOG.isDebugEnabled()) {
 573             LOG.debug("Creating transaction : {} ", transactionId);
 574         }
 575
 576         ActorRef transactionActor = createTypedTransactionActor(transactionType, transactionId,
 577                 transactionChainId, clientVersion);
 578
 579         return transactionActor;
 580     }
 581
 582     private void syncCommitTransaction(final DOMStoreWriteTransaction transaction)
 583         throws ExecutionException, InterruptedException {
 584         DOMStoreThreePhaseCommitCohort commitCohort = transaction.ready();
 585         commitCohort.preCommit().get();
 586         commitCohort.commit().get();
 587     }
 588
 589     private void commitWithNewTransaction(final Modification modification) {
 590         DOMStoreWriteTransaction tx = store.newWriteOnlyTransaction();
 591         modification.apply(tx);
 592         try {
 593             syncCommitTransaction(tx);
 594             shardMBean.incrementCommittedTransactionCount();
 595             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 596         } catch (InterruptedException | ExecutionException e) {
 597             shardMBean.incrementFailedTransactionsCount();
 598             LOG.error(e, "Failed to commit");
 599         }
 600     }
 601
 602     private void updateSchemaContext(final UpdateSchemaContext message) {
 603         this.schemaContext = message.getSchemaContext();
 604         updateSchemaContext(message.getSchemaContext());
 605         store.onGlobalContextUpdated(message.getSchemaContext());
 606     }
 607
 608     @VisibleForTesting
 609     void updateSchemaContext(final SchemaContext schemaContext) {
 610         store.onGlobalContextUpdated(schemaContext);
 611     }
 612
 613     private void registerChangeListener(final RegisterChangeListener registerChangeListener) {
 614
 615         LOG.debug("registerDataChangeListener for {}", registerChangeListener.getPath());
 616
 617         ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
 618                                                      NormalizedNode<?, ?>>> registration;
 619         if(isLeader()) {
 620             registration = doChangeListenerRegistration(registerChangeListener);
 621         } else {
 622             LOG.debug("Shard is not the leader - delaying registration");
 623
 624             DelayedListenerRegistration delayedReg =
 625                     new DelayedListenerRegistration(registerChangeListener);
 626             delayedListenerRegistrations.add(delayedReg);
 627             registration = delayedReg;
 628         }
 629
 630         ActorRef listenerRegistration = getContext().actorOf(
 631                 DataChangeListenerRegistration.props(registration));
 632
 633         LOG.debug("registerDataChangeListener sending reply, listenerRegistrationPath = {} ",
 634                     listenerRegistration.path());
 635
 636         getSender().tell(new RegisterChangeListenerReply(listenerRegistration.path()), getSelf());
 637     }
 638
 639     private ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
 640                                                NormalizedNode<?, ?>>> doChangeListenerRegistration(
 641             final RegisterChangeListener registerChangeListener) {
 642
 643         ActorSelection dataChangeListenerPath = getContext().system().actorSelection(
 644                 registerChangeListener.getDataChangeListenerPath());
 645
 646         // Notify the listener if notifications should be enabled or not
 647         // If this shard is the leader then it will enable notifications else
 648         // it will not
 649         dataChangeListenerPath.tell(new EnableNotification(true), getSelf());
 650
 651         // Now store a reference to the data change listener so it can be notified
 652         // at a later point if notifications should be enabled or disabled
 653         dataChangeListeners.add(dataChangeListenerPath);
 654
 655         AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>> listener =
 656                 new DataChangeListenerProxy(schemaContext, dataChangeListenerPath);
 657
 658         LOG.debug("Registering for path {}", registerChangeListener.getPath());
 659
 660         return store.registerChangeListener(registerChangeListener.getPath(), listener,
 661                 registerChangeListener.getScope());
 662     }
 663
 664     private boolean isMetricsCaptureEnabled(){
 665         CommonConfig config = new CommonConfig(getContext().system().settings().config());
 666         return config.isMetricCaptureEnabled();
 667     }
 668
 669     @Override
 670     protected
 671     void startLogRecoveryBatch(final int maxBatchSize) {
 672         currentLogRecoveryBatch = Lists.newArrayListWithCapacity(maxBatchSize);
 673
 674         if(LOG.isDebugEnabled()) {
 675             LOG.debug("{} : starting log recovery batch with max size {}", persistenceId(), maxBatchSize);
 676         }
 677     }
 678
 679     @Override
 680     protected void appendRecoveredLogEntry(final Payload data) {
 681         if (data instanceof CompositeModificationPayload) {
 682             currentLogRecoveryBatch.add(((CompositeModificationPayload) data).getModification());
 683         } else if (data instanceof CompositeModificationByteStringPayload) {
 684             currentLogRecoveryBatch.add(((CompositeModificationByteStringPayload) data).getModification());
 685         } else {
 686             LOG.error("Unknown state received {} during recovery", data);
 687         }
 688     }
 689
 690     @Override
 691     protected void applyRecoverySnapshot(final ByteString snapshot) {
 692         if(recoveryCoordinator == null) {
 693             recoveryCoordinator = new ShardRecoveryCoordinator(persistenceId(), schemaContext);
 694         }
 695
 696         recoveryCoordinator.submit(snapshot, store.newWriteOnlyTransaction());
 697
 698         if(LOG.isDebugEnabled()) {
 699             LOG.debug("{} : submitted recovery sbapshot", persistenceId());
 700         }
 701     }
 702
 703     @Override
 704     protected void applyCurrentLogRecoveryBatch() {
 705         if(recoveryCoordinator == null) {
 706             recoveryCoordinator = new ShardRecoveryCoordinator(persistenceId(), schemaContext);
 707         }
 708
 709         recoveryCoordinator.submit(currentLogRecoveryBatch, store.newWriteOnlyTransaction());
 710
 711         if(LOG.isDebugEnabled()) {
 712             LOG.debug("{} : submitted log recovery batch with size {}", persistenceId(),
 713                     currentLogRecoveryBatch.size());
 714         }
 715     }
 716
 717     @Override
 718     protected void onRecoveryComplete() {
 719         if(recoveryCoordinator != null) {
 720             Collection<DOMStoreWriteTransaction> txList = recoveryCoordinator.getTransactions();
 721
 722             if(LOG.isDebugEnabled()) {
 723                 LOG.debug("{} : recovery complete - committing {} Tx's", persistenceId(), txList.size());
 724             }
 725
 726             for(DOMStoreWriteTransaction tx: txList) {
 727                 try {
 728                     syncCommitTransaction(tx);
 729                     shardMBean.incrementCommittedTransactionCount();
 730                 } catch (InterruptedException | ExecutionException e) {
 731                     shardMBean.incrementFailedTransactionsCount();
 732                     LOG.error(e, "Failed to commit");
 733                 }
 734             }
 735         }
 736
 737         recoveryCoordinator = null;
 738         currentLogRecoveryBatch = null;
 739         updateJournalStats();
 740
 741         //notify shard manager
 742         getContext().parent().tell(new ActorInitialized(), getSelf());
 743
 744         // Being paranoid here - this method should only be called once but just in case...
 745         if(txCommitTimeoutCheckSchedule == null) {
 746             // Schedule a message to be periodically sent to check if the current in-progress
 747             // transaction should be expired and aborted.
 748             FiniteDuration period = Duration.create(transactionCommitTimeout / 3, TimeUnit.MILLISECONDS);
 749             txCommitTimeoutCheckSchedule = getContext().system().scheduler().schedule(
 750                     period, period, getSelf(),
 751                     TX_COMMIT_TIMEOUT_CHECK_MESSAGE, getContext().dispatcher(), ActorRef.noSender());
 752         }
 753     }
 754
 755     @Override
 756     protected void applyState(final ActorRef clientActor, final String identifier, final Object data) {
 757
 758         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
 767         } else {
 768             LOG.error("Unknown state received {} Class loader = {} CompositeNodeMod.ClassLoader = {}",
 769                     data, data.getClass().getClassLoader(),
 770                     CompositeModificationPayload.class.getClassLoader());
 771         }
 772
 773         updateJournalStats();
 774
 775     }
 776
 777     private void applyModificationToState(ActorRef clientActor, String identifier, Object modification) {
 778         if(modification == null) {
 779             LOG.error(
 780                     "modification is null - this is very unexpected, clientActor = {}, identifier = {}",
 781                     identifier, clientActor != null ? clientActor.path().toString() : null);
 782         } else if(clientActor == null) {
 783             // There's no clientActor to which to send a commit reply so we must be applying
 784             // replicated state from the leader.
 785             commitWithNewTransaction(MutableCompositeModification.fromSerializable(
 786                     modification, schemaContext));
 787         } else {
 788             // This must be the OK to commit after replication consensus.
 789             finishCommit(clientActor, identifier);
 790         }
 791     }
 792
 793     private void updateJournalStats() {
 794         ReplicatedLogEntry lastLogEntry = getLastLogEntry();
 795
 796         if (lastLogEntry != null) {
 797             shardMBean.setLastLogIndex(lastLogEntry.getIndex());
 798             shardMBean.setLastLogTerm(lastLogEntry.getTerm());
 799         }
 800
 801         shardMBean.setCommitIndex(getCommitIndex());
 802         shardMBean.setLastApplied(getLastApplied());
 803         shardMBean.setInMemoryJournalDataSize(getRaftActorContext().getReplicatedLog().dataSize());
 804     }
 805
 806     @Override
 807     protected void createSnapshot() {
 808         if (createSnapshotTransaction == null) {
 809
 810             // Create a transaction. We are really going to treat the transaction as a worker
 811             // so that this actor does not get block building the snapshot
 812             createSnapshotTransaction = createTransaction(
 813                 TransactionProxy.TransactionType.READ_ONLY.ordinal(),
 814                 "createSnapshot" + ++createSnapshotTransactionCounter, "",
 815                 CreateTransaction.CURRENT_VERSION);
 816
 817             createSnapshotTransaction.tell(
 818                 new ReadData(YangInstanceIdentifier.builder().build()).toSerializable(), self());
 819
 820         }
 821     }
 822
 823     @VisibleForTesting
 824     @Override
 825     protected void applySnapshot(final ByteString snapshot) {
 826         // Since this will be done only on Recovery or when this actor is a Follower
 827         // we can safely commit everything in here. We not need to worry about event notifications
 828         // as they would have already been disabled on the follower
 829
 830         LOG.info("Applying snapshot");
 831         try {
 832             DOMStoreWriteTransaction transaction = store.newWriteOnlyTransaction();
 833             NormalizedNodeMessages.Node serializedNode = NormalizedNodeMessages.Node.parseFrom(snapshot);
 834             NormalizedNode<?, ?> node = new NormalizedNodeToNodeCodec(schemaContext)
 835                 .decode(serializedNode);
 836
 837             // delete everything first
 838             transaction.delete(YangInstanceIdentifier.builder().build());
 839
 840             // Add everything from the remote node back
 841             transaction.write(YangInstanceIdentifier.builder().build(), node);
 842             syncCommitTransaction(transaction);
 843         } catch (InvalidProtocolBufferException | InterruptedException | ExecutionException e) {
 844             LOG.error(e, "An exception occurred when applying snapshot");
 845         } finally {
 846             LOG.info("Done applying snapshot");
 847         }
 848     }
 849
 850     @Override
 851     protected void onStateChanged() {
 852         boolean isLeader = isLeader();
 853         for (ActorSelection dataChangeListener : dataChangeListeners) {
 854             dataChangeListener.tell(new EnableNotification(isLeader), getSelf());
 855         }
 856
 857         if(isLeader) {
 858             for(DelayedListenerRegistration reg: delayedListenerRegistrations) {
 859                 if(!reg.isClosed()) {
 860                     reg.setDelegate(doChangeListenerRegistration(reg.getRegisterChangeListener()));
 861                 }
 862             }
 863
 864             delayedListenerRegistrations.clear();
 865         }
 866
 867         shardMBean.setRaftState(getRaftState().name());
 868         shardMBean.setCurrentTerm(getCurrentTerm());
 869
 870         // If this actor is no longer the leader close all the transaction chains
 871         if(!isLeader){
 872             for(Map.Entry<String, DOMStoreTransactionChain> entry : transactionChains.entrySet()){
 873                 if(LOG.isDebugEnabled()) {
 874                     LOG.debug(
 875                         "onStateChanged: Closing transaction chain {} because shard {} is no longer the leader",
 876                         entry.getKey(), getId());
 877                 }
 878                 entry.getValue().close();
 879             }
 880
 881             transactionChains.clear();
 882         }
 883     }
 884
 885     @Override
 886     protected DataPersistenceProvider persistence() {
 887         return dataPersistenceProvider;
 888     }
 889
 890     @Override protected void onLeaderChanged(final String oldLeader, final String newLeader) {
 891         shardMBean.setLeader(newLeader);
 892     }
 893
 894     @Override public String persistenceId() {
 895         return this.name.toString();
 896     }
 897
 898     @VisibleForTesting
 899     DataPersistenceProvider getDataPersistenceProvider() {
 900         return dataPersistenceProvider;
 901     }
 902
 903     private static class ShardCreator implements Creator<Shard> {
 904
 905         private static final long serialVersionUID = 1L;
 906
 907         final ShardIdentifier name;
 908         final Map<ShardIdentifier, String> peerAddresses;
 909         final DatastoreContext datastoreContext;
 910         final SchemaContext schemaContext;
 911
 912         ShardCreator(final ShardIdentifier name, final Map<ShardIdentifier, String> peerAddresses,
 913                 final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 914             this.name = name;
 915             this.peerAddresses = peerAddresses;
 916             this.datastoreContext = datastoreContext;
 917             this.schemaContext = schemaContext;
 918         }
 919
 920         @Override
 921         public Shard create() throws Exception {
 922             return new Shard(name, peerAddresses, datastoreContext, schemaContext);
 923         }
 924     }
 925
 926     @VisibleForTesting
 927     InMemoryDOMDataStore getDataStore() {
 928         return store;
 929     }
 930
 931     @VisibleForTesting
 932     ShardStats getShardMBean() {
 933         return shardMBean;
 934     }
 935
 936     private static class DelayedListenerRegistration implements
 937         ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>>> {
 938
 939         private volatile boolean closed;
 940
 941         private final RegisterChangeListener registerChangeListener;
 942
 943         private volatile ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
 944                                                              NormalizedNode<?, ?>>> delegate;
 945
 946         DelayedListenerRegistration(final RegisterChangeListener registerChangeListener) {
 947             this.registerChangeListener = registerChangeListener;
 948         }
 949
 950         void setDelegate( final ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
 951                                             NormalizedNode<?, ?>>> registration) {
 952             this.delegate = registration;
 953         }
 954
 955         boolean isClosed() {
 956             return closed;
 957         }
 958
 959         RegisterChangeListener getRegisterChangeListener() {
 960             return registerChangeListener;
 961         }
 962
 963         @Override
 964         public AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>> getInstance() {
 965             return delegate != null ? delegate.getInstance() : null;
 966         }
 967
 968         @Override
 969         public void close() {
 970             closed = true;
 971             if(delegate != null) {
 972                 delegate.close();
 973             }
 974         }
 975     }
 976 }