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