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