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

   1 /*
   2  * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8
   9 package org.opendaylight.controller.cluster.datastore;
  10
  11 import akka.actor.ActorRef;
  12 import akka.actor.ActorSelection;
  13 import akka.actor.Cancellable;
  14 import akka.actor.Props;
  15 import akka.japi.Creator;
  16 import akka.persistence.RecoveryFailure;
  17 import akka.serialization.Serialization;
  18 import com.google.common.annotations.VisibleForTesting;
  19 import com.google.common.base.Optional;
  20 import com.google.common.base.Preconditions;
  21 import com.google.common.collect.Lists;
  22 import com.google.common.util.concurrent.FutureCallback;
  23 import com.google.common.util.concurrent.Futures;
  24 import com.google.common.util.concurrent.ListenableFuture;
  25 import java.io.IOException;
  26 import java.util.Collection;
  27 import java.util.HashMap;
  28 import java.util.List;
  29 import java.util.Map;
  30 import java.util.concurrent.ExecutionException;
  31 import java.util.concurrent.TimeUnit;
  32 import javax.annotation.Nonnull;
  33 import org.opendaylight.controller.cluster.DataPersistenceProvider;
  34 import org.opendaylight.controller.cluster.common.actor.CommonConfig;
  35 import org.opendaylight.controller.cluster.common.actor.MeteringBehavior;
  36 import org.opendaylight.controller.cluster.datastore.ShardCommitCoordinator.CohortEntry;
  37 import org.opendaylight.controller.cluster.datastore.compat.BackwardsCompatibleThreePhaseCommitCohort;
  38 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
  39 import org.opendaylight.controller.cluster.datastore.identifiers.ShardIdentifier;
  40 import org.opendaylight.controller.cluster.datastore.identifiers.ShardTransactionIdentifier;
  41 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardMBeanFactory;
  42 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardStats;
  43 import org.opendaylight.controller.cluster.datastore.messages.AbortTransaction;
  44 import org.opendaylight.controller.cluster.datastore.messages.AbortTransactionReply;
  45 import org.opendaylight.controller.cluster.datastore.messages.ActorInitialized;
  46 import org.opendaylight.controller.cluster.datastore.messages.CanCommitTransaction;
  47 import org.opendaylight.controller.cluster.datastore.messages.CloseTransactionChain;
  48 import org.opendaylight.controller.cluster.datastore.messages.CommitTransaction;
  49 import org.opendaylight.controller.cluster.datastore.messages.CommitTransactionReply;
  50 import org.opendaylight.controller.cluster.datastore.messages.CreateSnapshot;
  51 import org.opendaylight.controller.cluster.datastore.messages.CreateTransaction;
  52 import org.opendaylight.controller.cluster.datastore.messages.CreateTransactionReply;
  53 import org.opendaylight.controller.cluster.datastore.messages.EnableNotification;
  54 import org.opendaylight.controller.cluster.datastore.messages.ForwardedReadyTransaction;
  55 import org.opendaylight.controller.cluster.datastore.messages.PeerAddressResolved;
  56 import org.opendaylight.controller.cluster.datastore.messages.ReadyTransactionReply;
  57 import org.opendaylight.controller.cluster.datastore.messages.RegisterChangeListener;
  58 import org.opendaylight.controller.cluster.datastore.messages.RegisterChangeListenerReply;
  59 import org.opendaylight.controller.cluster.datastore.messages.UpdateSchemaContext;
  60 import org.opendaylight.controller.cluster.datastore.modification.Modification;
  61 import org.opendaylight.controller.cluster.datastore.modification.ModificationPayload;
  62 import org.opendaylight.controller.cluster.datastore.modification.MutableCompositeModification;
  63 import org.opendaylight.controller.cluster.datastore.utils.Dispatchers;
  64 import org.opendaylight.controller.cluster.datastore.utils.MessageTracker;
  65 import org.opendaylight.controller.cluster.datastore.utils.SerializationUtils;
  66 import org.opendaylight.controller.cluster.notifications.RegisterRoleChangeListener;
  67 import org.opendaylight.controller.cluster.notifications.RoleChangeNotifier;
  68 import org.opendaylight.controller.cluster.raft.RaftActor;
  69 import org.opendaylight.controller.cluster.raft.ReplicatedLogEntry;
  70 import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply;
  71 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationByteStringPayload;
  72 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationPayload;
  73 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.Payload;
  74 import org.opendaylight.controller.md.sal.common.api.data.AsyncDataChangeListener;
  75 import org.opendaylight.controller.md.sal.dom.store.impl.InMemoryDOMDataStore;
  76 import org.opendaylight.controller.md.sal.dom.store.impl.InMemoryDOMDataStoreFactory;
  77 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  78 import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransaction;
  79 import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransactionChain;
  80 import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransactionFactory;
  81 import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
  82 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  83 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  84 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  85 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  86 import scala.concurrent.duration.Duration;
  87 import scala.concurrent.duration.FiniteDuration;
  88
  89 /**
  90  * A Shard represents a portion of the logical data tree <br/>
  91  * <p>
  92  * Our Shard uses InMemoryDataStore as it's internal representation and delegates all requests it
  93  * </p>
  94  */
  95 public class Shard extends RaftActor {
  96
  97     private static final YangInstanceIdentifier DATASTORE_ROOT = YangInstanceIdentifier.builder().build();
  98
  99     private static final Object TX_COMMIT_TIMEOUT_CHECK_MESSAGE = "txCommitTimeoutCheck";
 100
 101     @VisibleForTesting
 102     static final String DEFAULT_NAME = "default";
 103
 104     // The state of this Shard
 105     private final InMemoryDOMDataStore store;
 106
 107     /// The name of this shard
 108     private final ShardIdentifier name;
 109
 110     private final ShardStats shardMBean;
 111
 112     private final List<ActorSelection> dataChangeListeners =  Lists.newArrayList();
 113
 114     private final List<DelayedListenerRegistration> delayedListenerRegistrations =
 115                                                                        Lists.newArrayList();
 116
 117     private DatastoreContext datastoreContext;
 118
 119     private DataPersistenceProvider dataPersistenceProvider;
 120
 121     private SchemaContext schemaContext;
 122
 123     private int createSnapshotTransactionCounter;
 124
 125     private final ShardCommitCoordinator commitCoordinator;
 126
 127     private long transactionCommitTimeout;
 128
 129     private Cancellable txCommitTimeoutCheckSchedule;
 130
 131     private final Optional<ActorRef> roleChangeNotifier;
 132
 133     private final MessageTracker appendEntriesReplyTracker;
 134
 135     private final ReadyTransactionReply READY_TRANSACTION_REPLY = new ReadyTransactionReply(
 136             Serialization.serializedActorPath(getSelf()));
 137
 138
 139     /**
 140      * Coordinates persistence recovery on startup.
 141      */
 142     private ShardRecoveryCoordinator recoveryCoordinator;
 143     private List<Object> currentLogRecoveryBatch;
 144
 145     private final Map<String, DOMStoreTransactionChain> transactionChains = new HashMap<>();
 146
 147     private final String txnDispatcherPath;
 148
 149     protected Shard(final ShardIdentifier name, final Map<ShardIdentifier, String> peerAddresses,
 150             final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 151         super(name.toString(), mapPeerAddresses(peerAddresses),
 152                 Optional.of(datastoreContext.getShardRaftConfig()));
 153
 154         this.name = name;
 155         this.datastoreContext = datastoreContext;
 156         this.schemaContext = schemaContext;
 157         this.dataPersistenceProvider = (datastoreContext.isPersistent())
 158                 ? new PersistentDataProvider() : new NonPersistentRaftDataProvider();
 159         this.txnDispatcherPath = new Dispatchers(context().system().dispatchers())
 160                 .getDispatcherPath(Dispatchers.DispatcherType.Transaction);
 161
 162
 163         LOG.info("Shard created : {}, persistent : {}", name, datastoreContext.isPersistent());
 164
 165         store = InMemoryDOMDataStoreFactory.create(name.toString(), null,
 166                 datastoreContext.getDataStoreProperties());
 167
 168         if(schemaContext != null) {
 169             store.onGlobalContextUpdated(schemaContext);
 170         }
 171
 172         shardMBean = ShardMBeanFactory.getShardStatsMBean(name.toString(),
 173                 datastoreContext.getDataStoreMXBeanType());
 174         shardMBean.setNotificationManager(store.getDataChangeListenerNotificationManager());
 175
 176         if (isMetricsCaptureEnabled()) {
 177             getContext().become(new MeteringBehavior(this));
 178         }
 179
 180         commitCoordinator = new ShardCommitCoordinator(TimeUnit.SECONDS.convert(1, TimeUnit.MINUTES),
 181                 datastoreContext.getShardTransactionCommitQueueCapacity(), LOG, name.toString());
 182
 183         setTransactionCommitTimeout();
 184
 185         // create a notifier actor for each cluster member
 186         roleChangeNotifier = createRoleChangeNotifier(name.toString());
 187
 188         appendEntriesReplyTracker = new MessageTracker(AppendEntriesReply.class,
 189                 getRaftActorContext().getConfigParams().getIsolatedCheckIntervalInMillis());
 190     }
 191
 192     private void setTransactionCommitTimeout() {
 193         transactionCommitTimeout = TimeUnit.MILLISECONDS.convert(
 194                 datastoreContext.getShardTransactionCommitTimeoutInSeconds(), TimeUnit.SECONDS);
 195     }
 196
 197     private static Map<String, String> mapPeerAddresses(
 198         final Map<ShardIdentifier, String> peerAddresses) {
 199         Map<String, String> map = new HashMap<>();
 200
 201         for (Map.Entry<ShardIdentifier, String> entry : peerAddresses
 202             .entrySet()) {
 203             map.put(entry.getKey().toString(), entry.getValue());
 204         }
 205
 206         return map;
 207     }
 208
 209     public static Props props(final ShardIdentifier name,
 210         final Map<ShardIdentifier, String> peerAddresses,
 211         final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 212         Preconditions.checkNotNull(name, "name should not be null");
 213         Preconditions.checkNotNull(peerAddresses, "peerAddresses should not be null");
 214         Preconditions.checkNotNull(datastoreContext, "dataStoreContext should not be null");
 215         Preconditions.checkNotNull(schemaContext, "schemaContext should not be null");
 216
 217         return Props.create(new ShardCreator(name, peerAddresses, datastoreContext, schemaContext));
 218     }
 219
 220     private Optional<ActorRef> createRoleChangeNotifier(String shardId) {
 221         ActorRef shardRoleChangeNotifier = this.getContext().actorOf(
 222             RoleChangeNotifier.getProps(shardId), shardId + "-notifier");
 223         return Optional.of(shardRoleChangeNotifier);
 224     }
 225
 226     @Override
 227     public void postStop() {
 228         LOG.info("Stopping Shard {}", persistenceId());
 229
 230         super.postStop();
 231
 232         if(txCommitTimeoutCheckSchedule != null) {
 233             txCommitTimeoutCheckSchedule.cancel();
 234         }
 235
 236         shardMBean.unregisterMBean();
 237     }
 238
 239     @Override
 240     public void onReceiveRecover(final Object message) throws Exception {
 241         if(LOG.isDebugEnabled()) {
 242             LOG.debug("{}: onReceiveRecover: Received message {} from {}", persistenceId(),
 243                 message.getClass().toString(), getSender());
 244         }
 245
 246         if (message instanceof RecoveryFailure){
 247             LOG.error("{}: Recovery failed because of this cause",
 248                     persistenceId(), ((RecoveryFailure) message).cause());
 249
 250             // Even though recovery failed, we still need to finish our recovery, eg send the
 251             // ActorInitialized message and start the txCommitTimeoutCheckSchedule.
 252             onRecoveryComplete();
 253         } else {
 254             super.onReceiveRecover(message);
 255             if(LOG.isTraceEnabled()) {
 256                 appendEntriesReplyTracker.begin();
 257             }
 258         }
 259     }
 260
 261     @Override
 262     public void onReceiveCommand(final Object message) throws Exception {
 263
 264         MessageTracker.Context context = appendEntriesReplyTracker.received(message);
 265
 266         if(context.error().isPresent()){
 267             LOG.trace("{} : AppendEntriesReply failed to arrive at the expected interval {}", persistenceId(),
 268                     context.error());
 269         }
 270
 271         try {
 272             if (CreateTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 273                 handleCreateTransaction(message);
 274             } else if (message instanceof ForwardedReadyTransaction) {
 275                 handleForwardedReadyTransaction((ForwardedReadyTransaction) message);
 276             } else if (CanCommitTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 277                 handleCanCommitTransaction(CanCommitTransaction.fromSerializable(message));
 278             } else if (CommitTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 279                 handleCommitTransaction(CommitTransaction.fromSerializable(message));
 280             } else if (AbortTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 281                 handleAbortTransaction(AbortTransaction.fromSerializable(message));
 282             } else if (CloseTransactionChain.SERIALIZABLE_CLASS.isInstance(message)) {
 283                 closeTransactionChain(CloseTransactionChain.fromSerializable(message));
 284             } else if (message instanceof RegisterChangeListener) {
 285                 registerChangeListener((RegisterChangeListener) message);
 286             } else if (message instanceof UpdateSchemaContext) {
 287                 updateSchemaContext((UpdateSchemaContext) message);
 288             } else if (message instanceof PeerAddressResolved) {
 289                 PeerAddressResolved resolved = (PeerAddressResolved) message;
 290                 setPeerAddress(resolved.getPeerId().toString(),
 291                         resolved.getPeerAddress());
 292             } else if (message.equals(TX_COMMIT_TIMEOUT_CHECK_MESSAGE)) {
 293                 handleTransactionCommitTimeoutCheck();
 294             } else if(message instanceof DatastoreContext) {
 295                 onDatastoreContext((DatastoreContext)message);
 296             } else if(message instanceof RegisterRoleChangeListener){
 297                 roleChangeNotifier.get().forward(message, context());
 298             } else {
 299                 super.onReceiveCommand(message);
 300             }
 301         } finally {
 302             context.done();
 303         }
 304     }
 305
 306     @Override
 307     protected Optional<ActorRef> getRoleChangeNotifier() {
 308         return roleChangeNotifier;
 309     }
 310
 311     private void onDatastoreContext(DatastoreContext context) {
 312         datastoreContext = context;
 313
 314         commitCoordinator.setQueueCapacity(datastoreContext.getShardTransactionCommitQueueCapacity());
 315
 316         setTransactionCommitTimeout();
 317
 318         if(datastoreContext.isPersistent() &&
 319                 dataPersistenceProvider instanceof NonPersistentRaftDataProvider) {
 320             dataPersistenceProvider = new PersistentDataProvider();
 321         } else if(!datastoreContext.isPersistent() &&
 322                 dataPersistenceProvider instanceof PersistentDataProvider) {
 323             dataPersistenceProvider = new NonPersistentRaftDataProvider();
 324         }
 325
 326         updateConfigParams(datastoreContext.getShardRaftConfig());
 327     }
 328
 329     private void handleTransactionCommitTimeoutCheck() {
 330         CohortEntry cohortEntry = commitCoordinator.getCurrentCohortEntry();
 331         if(cohortEntry != null) {
 332             long elapsed = System.currentTimeMillis() - cohortEntry.getLastAccessTime();
 333             if(elapsed > transactionCommitTimeout) {
 334                 LOG.warn("{}: Current transaction {} has timed out after {} ms - aborting",
 335                         persistenceId(), cohortEntry.getTransactionID(), transactionCommitTimeout);
 336
 337                 doAbortTransaction(cohortEntry.getTransactionID(), null);
 338             }
 339         }
 340     }
 341
 342     private void handleCommitTransaction(final CommitTransaction commit) {
 343         final String transactionID = commit.getTransactionID();
 344
 345         LOG.debug("{}: Committing transaction {}", persistenceId(), transactionID);
 346
 347         // Get the current in-progress cohort entry in the commitCoordinator if it corresponds to
 348         // this transaction.
 349         final CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 350         if(cohortEntry == null) {
 351             // We're not the current Tx - the Tx was likely expired b/c it took too long in
 352             // between the canCommit and commit messages.
 353             IllegalStateException ex = new IllegalStateException(
 354                     String.format("%s: Cannot commit transaction %s - it is not the current transaction",
 355                             persistenceId(), transactionID));
 356             LOG.error(ex.getMessage());
 357             shardMBean.incrementFailedTransactionsCount();
 358             getSender().tell(new akka.actor.Status.Failure(ex), getSelf());
 359             return;
 360         }
 361
 362         // We perform the preCommit phase here atomically with the commit phase. This is an
 363         // optimization to eliminate the overhead of an extra preCommit message. We lose front-end
 364         // coordination of preCommit across shards in case of failure but preCommit should not
 365         // normally fail since we ensure only one concurrent 3-phase commit.
 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().preCommit().get();
 372
 373             // If we do not have any followers and we are not using persistence we can
 374             // apply modification to the state immediately
 375             if(!hasFollowers() && !persistence().isRecoveryApplicable()){
 376                 applyModificationToState(getSender(), transactionID, cohortEntry.getModification());
 377             } else {
 378                 Shard.this.persistData(getSender(), transactionID,
 379                         new ModificationPayload(cohortEntry.getModification()));
 380             }
 381         } catch (Exception e) {
 382             LOG.error("{} An exception occurred while preCommitting transaction {}",
 383                     persistenceId(), cohortEntry.getTransactionID(), e);
 384             shardMBean.incrementFailedTransactionsCount();
 385             getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 386         }
 387
 388         cohortEntry.updateLastAccessTime();
 389     }
 390
 391     private void finishCommit(@Nonnull final ActorRef sender, final @Nonnull String transactionID) {
 392         // With persistence enabled, this method is called via applyState by the leader strategy
 393         // after the commit has been replicated to a majority of the followers.
 394
 395         CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 396         if(cohortEntry == null) {
 397             // The transaction is no longer the current commit. This can happen if the transaction
 398             // was aborted prior, most likely due to timeout in the front-end. We need to finish
 399             // committing the transaction though since it was successfully persisted and replicated
 400             // however we can't use the original cohort b/c it was already preCommitted and may
 401             // conflict with the current commit or may have been aborted so we commit with a new
 402             // transaction.
 403             cohortEntry = commitCoordinator.getAndRemoveCohortEntry(transactionID);
 404             if(cohortEntry != null) {
 405                 commitWithNewTransaction(cohortEntry.getModification());
 406                 sender.tell(CommitTransactionReply.INSTANCE.toSerializable(), getSelf());
 407             } else {
 408                 // This really shouldn't happen - it likely means that persistence or replication
 409                 // took so long to complete such that the cohort entry was expired from the cache.
 410                 IllegalStateException ex = new IllegalStateException(
 411                         String.format("%s: Could not finish committing transaction %s - no CohortEntry found",
 412                                 persistenceId(), transactionID));
 413                 LOG.error(ex.getMessage());
 414                 sender.tell(new akka.actor.Status.Failure(ex), getSelf());
 415             }
 416
 417             return;
 418         }
 419
 420         LOG.debug("{}: Finishing commit for transaction {}", persistenceId(), cohortEntry.getTransactionID());
 421
 422         try {
 423             // We block on the future here so we don't have to worry about possibly accessing our
 424             // state on a different thread outside of our dispatcher. Also, the data store
 425             // currently uses a same thread executor anyway.
 426             cohortEntry.getCohort().commit().get();
 427
 428             sender.tell(CommitTransactionReply.INSTANCE.toSerializable(), getSelf());
 429
 430             shardMBean.incrementCommittedTransactionCount();
 431             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 432
 433         } catch (Exception e) {
 434             sender.tell(new akka.actor.Status.Failure(e), getSelf());
 435
 436             LOG.error("{}, An exception occurred while committing transaction {}", persistenceId(),
 437                     transactionID, e);
 438             shardMBean.incrementFailedTransactionsCount();
 439         } finally {
 440             commitCoordinator.currentTransactionComplete(transactionID, true);
 441         }
 442     }
 443
 444     private void handleCanCommitTransaction(final CanCommitTransaction canCommit) {
 445         LOG.debug("{}: Can committing transaction {}", persistenceId(), canCommit.getTransactionID());
 446         commitCoordinator.handleCanCommit(canCommit, getSender(), self());
 447     }
 448
 449     private void handleForwardedReadyTransaction(ForwardedReadyTransaction ready) {
 450         LOG.debug("{}: Readying transaction {}, client version {}", persistenceId(),
 451                 ready.getTransactionID(), ready.getTxnClientVersion());
 452
 453         // This message is forwarded by the ShardTransaction on ready. We cache the cohort in the
 454         // commitCoordinator in preparation for the subsequent three phase commit initiated by
 455         // the front-end.
 456         commitCoordinator.transactionReady(ready.getTransactionID(), ready.getCohort(),
 457                 ready.getModification());
 458
 459         // Return our actor path as we'll handle the three phase commit, except if the Tx client
 460         // version < 1 (Helium-1 version). This means the Tx was initiated by a base Helium version
 461         // node. In that case, the subsequent 3-phase commit messages won't contain the
 462         // transactionId so to maintain backwards compatibility, we create a separate cohort actor
 463         // to provide the compatible behavior.
 464         if(ready.getTxnClientVersion() < DataStoreVersions.HELIUM_1_VERSION) {
 465             LOG.debug("{}: Creating BackwardsCompatibleThreePhaseCommitCohort", persistenceId());
 466             ActorRef replyActorPath = getContext().actorOf(BackwardsCompatibleThreePhaseCommitCohort.props(
 467                     ready.getTransactionID()));
 468
 469             ReadyTransactionReply readyTransactionReply =
 470                     new ReadyTransactionReply(Serialization.serializedActorPath(replyActorPath));
 471             getSender().tell(ready.isReturnSerialized() ? readyTransactionReply.toSerializable() :
 472                     readyTransactionReply, getSelf());
 473
 474         } else {
 475
 476             getSender().tell(ready.isReturnSerialized() ? READY_TRANSACTION_REPLY.toSerializable() :
 477                     READY_TRANSACTION_REPLY, getSelf());
 478         }
 479     }
 480
 481     private void handleAbortTransaction(final AbortTransaction abort) {
 482         doAbortTransaction(abort.getTransactionID(), getSender());
 483     }
 484
 485     void doAbortTransaction(final String transactionID, final ActorRef sender) {
 486         final CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 487         if(cohortEntry != null) {
 488             LOG.debug("{}: Aborting transaction {}", persistenceId(), transactionID);
 489
 490             // We don't remove the cached cohort entry here (ie pass false) in case the Tx was
 491             // aborted during replication in which case we may still commit locally if replication
 492             // succeeds.
 493             commitCoordinator.currentTransactionComplete(transactionID, false);
 494
 495             final ListenableFuture<Void> future = cohortEntry.getCohort().abort();
 496             final ActorRef self = getSelf();
 497
 498             Futures.addCallback(future, new FutureCallback<Void>() {
 499                 @Override
 500                 public void onSuccess(final Void v) {
 501                     shardMBean.incrementAbortTransactionsCount();
 502
 503                     if(sender != null) {
 504                         sender.tell(AbortTransactionReply.INSTANCE.toSerializable(), self);
 505                     }
 506                 }
 507
 508                 @Override
 509                 public void onFailure(final Throwable t) {
 510                     LOG.error("{}: An exception happened during abort", persistenceId(), t);
 511
 512                     if(sender != null) {
 513                         sender.tell(new akka.actor.Status.Failure(t), self);
 514                     }
 515                 }
 516             });
 517         }
 518     }
 519
 520     private void handleCreateTransaction(final Object message) {
 521         if (isLeader()) {
 522             createTransaction(CreateTransaction.fromSerializable(message));
 523         } else if (getLeader() != null) {
 524             getLeader().forward(message, getContext());
 525         } else {
 526             getSender().tell(new akka.actor.Status.Failure(new NoShardLeaderException(String.format(
 527                 "Could not find leader for shard %s so transaction cannot be created. This typically happens" +
 528                 " when the system is coming up or recovering and a leader is being elected. Try again" +
 529                 " later.", persistenceId()))), getSelf());
 530         }
 531     }
 532
 533     private void closeTransactionChain(final CloseTransactionChain closeTransactionChain) {
 534         DOMStoreTransactionChain chain =
 535             transactionChains.remove(closeTransactionChain.getTransactionChainId());
 536
 537         if(chain != null) {
 538             chain.close();
 539         }
 540     }
 541
 542     private ActorRef createTypedTransactionActor(int transactionType,
 543             ShardTransactionIdentifier transactionId, String transactionChainId,
 544             short clientVersion ) {
 545
 546         DOMStoreTransactionFactory factory = store;
 547
 548         if(!transactionChainId.isEmpty()) {
 549             factory = transactionChains.get(transactionChainId);
 550             if(factory == null){
 551                 DOMStoreTransactionChain transactionChain = store.createTransactionChain();
 552                 transactionChains.put(transactionChainId, transactionChain);
 553                 factory = transactionChain;
 554             }
 555         }
 556
 557         if(this.schemaContext == null) {
 558             throw new IllegalStateException("SchemaContext is not set");
 559         }
 560
 561         if (transactionType == TransactionProxy.TransactionType.WRITE_ONLY.ordinal()) {
 562
 563             shardMBean.incrementWriteOnlyTransactionCount();
 564
 565             return createShardTransaction(factory.newWriteOnlyTransaction(), transactionId, clientVersion);
 566
 567         } else if (transactionType == TransactionProxy.TransactionType.READ_WRITE.ordinal()) {
 568
 569             shardMBean.incrementReadWriteTransactionCount();
 570
 571             return createShardTransaction(factory.newReadWriteTransaction(), transactionId, clientVersion);
 572
 573         } else if (transactionType == TransactionProxy.TransactionType.READ_ONLY.ordinal()) {
 574
 575             shardMBean.incrementReadOnlyTransactionCount();
 576
 577             return createShardTransaction(factory.newReadOnlyTransaction(), transactionId, clientVersion);
 578
 579         } else {
 580             throw new IllegalArgumentException(
 581                 "Shard="+name + ":CreateTransaction message has unidentified transaction type="
 582                     + transactionType);
 583         }
 584     }
 585
 586     private ActorRef createShardTransaction(DOMStoreTransaction transaction, ShardTransactionIdentifier transactionId,
 587                                             short clientVersion){
 588         return getContext().actorOf(
 589                 ShardTransaction.props(transaction, getSelf(),
 590                         schemaContext, datastoreContext, shardMBean,
 591                         transactionId.getRemoteTransactionId(), clientVersion)
 592                         .withDispatcher(txnDispatcherPath),
 593                 transactionId.toString());
 594
 595     }
 596
 597     private void createTransaction(CreateTransaction createTransaction) {
 598         try {
 599             ActorRef transactionActor = createTransaction(createTransaction.getTransactionType(),
 600                 createTransaction.getTransactionId(), createTransaction.getTransactionChainId(),
 601                 createTransaction.getVersion());
 602
 603             getSender().tell(new CreateTransactionReply(Serialization.serializedActorPath(transactionActor),
 604                     createTransaction.getTransactionId()).toSerializable(), getSelf());
 605         } catch (Exception e) {
 606             getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 607         }
 608     }
 609
 610     private ActorRef createTransaction(int transactionType, String remoteTransactionId,
 611             String transactionChainId, short clientVersion) {
 612
 613
 614         ShardTransactionIdentifier transactionId = new ShardTransactionIdentifier(remoteTransactionId);
 615
 616         if(LOG.isDebugEnabled()) {
 617             LOG.debug("{}: Creating transaction : {} ", persistenceId(), transactionId);
 618         }
 619
 620         ActorRef transactionActor = createTypedTransactionActor(transactionType, transactionId,
 621                 transactionChainId, clientVersion);
 622
 623         return transactionActor;
 624     }
 625
 626     private void syncCommitTransaction(final DOMStoreWriteTransaction transaction)
 627         throws ExecutionException, InterruptedException {
 628         DOMStoreThreePhaseCommitCohort commitCohort = transaction.ready();
 629         commitCohort.preCommit().get();
 630         commitCohort.commit().get();
 631     }
 632
 633     private void commitWithNewTransaction(final Modification modification) {
 634         DOMStoreWriteTransaction tx = store.newWriteOnlyTransaction();
 635         modification.apply(tx);
 636         try {
 637             syncCommitTransaction(tx);
 638             shardMBean.incrementCommittedTransactionCount();
 639             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 640         } catch (InterruptedException | ExecutionException e) {
 641             shardMBean.incrementFailedTransactionsCount();
 642             LOG.error("{}: Failed to commit", persistenceId(), e);
 643         }
 644     }
 645
 646     private void updateSchemaContext(final UpdateSchemaContext message) {
 647         this.schemaContext = message.getSchemaContext();
 648         updateSchemaContext(message.getSchemaContext());
 649         store.onGlobalContextUpdated(message.getSchemaContext());
 650     }
 651
 652     @VisibleForTesting
 653     void updateSchemaContext(final SchemaContext schemaContext) {
 654         store.onGlobalContextUpdated(schemaContext);
 655     }
 656
 657     private void registerChangeListener(final RegisterChangeListener registerChangeListener) {
 658
 659         LOG.debug("{}: registerDataChangeListener for {}", persistenceId(), registerChangeListener.getPath());
 660
 661         ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
 662                                                      NormalizedNode<?, ?>>> registration;
 663         if(isLeader()) {
 664             registration = doChangeListenerRegistration(registerChangeListener);
 665         } else {
 666             LOG.debug("{}: Shard is not the leader - delaying registration", persistenceId());
 667
 668             DelayedListenerRegistration delayedReg =
 669                     new DelayedListenerRegistration(registerChangeListener);
 670             delayedListenerRegistrations.add(delayedReg);
 671             registration = delayedReg;
 672         }
 673
 674         ActorRef listenerRegistration = getContext().actorOf(
 675                 DataChangeListenerRegistration.props(registration));
 676
 677         LOG.debug("{}: registerDataChangeListener sending reply, listenerRegistrationPath = {} ",
 678                 persistenceId(), listenerRegistration.path());
 679
 680         getSender().tell(new RegisterChangeListenerReply(listenerRegistration.path()), getSelf());
 681     }
 682
 683     private ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
 684                                                NormalizedNode<?, ?>>> doChangeListenerRegistration(
 685             final RegisterChangeListener registerChangeListener) {
 686
 687         ActorSelection dataChangeListenerPath = getContext().system().actorSelection(
 688                 registerChangeListener.getDataChangeListenerPath());
 689
 690         // Notify the listener if notifications should be enabled or not
 691         // If this shard is the leader then it will enable notifications else
 692         // it will not
 693         dataChangeListenerPath.tell(new EnableNotification(true), getSelf());
 694
 695         // Now store a reference to the data change listener so it can be notified
 696         // at a later point if notifications should be enabled or disabled
 697         dataChangeListeners.add(dataChangeListenerPath);
 698
 699         AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>> listener =
 700                 new DataChangeListenerProxy(dataChangeListenerPath);
 701
 702         LOG.debug("{}: Registering for path {}", persistenceId(), registerChangeListener.getPath());
 703
 704         return store.registerChangeListener(registerChangeListener.getPath(), listener,
 705                 registerChangeListener.getScope());
 706     }
 707
 708     private boolean isMetricsCaptureEnabled(){
 709         CommonConfig config = new CommonConfig(getContext().system().settings().config());
 710         return config.isMetricCaptureEnabled();
 711     }
 712
 713     @Override
 714     protected
 715     void startLogRecoveryBatch(final int maxBatchSize) {
 716         currentLogRecoveryBatch = Lists.newArrayListWithCapacity(maxBatchSize);
 717
 718         if(LOG.isDebugEnabled()) {
 719             LOG.debug("{}: starting log recovery batch with max size {}", persistenceId(), maxBatchSize);
 720         }
 721     }
 722
 723     @Override
 724     protected void appendRecoveredLogEntry(final Payload data) {
 725         if(data instanceof ModificationPayload) {
 726             try {
 727                 currentLogRecoveryBatch.add(((ModificationPayload) data).getModification());
 728             } catch (ClassNotFoundException | IOException e) {
 729                 LOG.error("{}: Error extracting ModificationPayload", persistenceId(), e);
 730             }
 731         } else if (data instanceof CompositeModificationPayload) {
 732             currentLogRecoveryBatch.add(((CompositeModificationPayload) data).getModification());
 733         } else if (data instanceof CompositeModificationByteStringPayload) {
 734             currentLogRecoveryBatch.add(((CompositeModificationByteStringPayload) data).getModification());
 735         } else {
 736             LOG.error("{}: Unknown state received {} during recovery", persistenceId(), data);
 737         }
 738     }
 739
 740     @Override
 741     protected void applyRecoverySnapshot(final byte[] snapshotBytes) {
 742         if(recoveryCoordinator == null) {
 743             recoveryCoordinator = new ShardRecoveryCoordinator(persistenceId(), schemaContext,
 744                     LOG, name.toString());
 745         }
 746
 747         recoveryCoordinator.submit(snapshotBytes, store.newWriteOnlyTransaction());
 748
 749         if(LOG.isDebugEnabled()) {
 750             LOG.debug("{}: submitted recovery sbapshot", persistenceId());
 751         }
 752     }
 753
 754     @Override
 755     protected void applyCurrentLogRecoveryBatch() {
 756         if(recoveryCoordinator == null) {
 757             recoveryCoordinator = new ShardRecoveryCoordinator(persistenceId(), schemaContext,
 758                     LOG, name.toString());
 759         }
 760
 761         recoveryCoordinator.submit(currentLogRecoveryBatch, store.newWriteOnlyTransaction());
 762
 763         if(LOG.isDebugEnabled()) {
 764             LOG.debug("{}: submitted log recovery batch with size {}", persistenceId(),
 765                     currentLogRecoveryBatch.size());
 766         }
 767     }
 768
 769     @Override
 770     protected void onRecoveryComplete() {
 771         if(recoveryCoordinator != null) {
 772             Collection<DOMStoreWriteTransaction> txList = recoveryCoordinator.getTransactions();
 773
 774             if(LOG.isDebugEnabled()) {
 775                 LOG.debug("{}: recovery complete - committing {} Tx's", persistenceId(), txList.size());
 776             }
 777
 778             for(DOMStoreWriteTransaction tx: txList) {
 779                 try {
 780                     syncCommitTransaction(tx);
 781                     shardMBean.incrementCommittedTransactionCount();
 782                 } catch (InterruptedException | ExecutionException e) {
 783                     shardMBean.incrementFailedTransactionsCount();
 784                     LOG.error("{}: Failed to commit", persistenceId(), e);
 785                 }
 786             }
 787         }
 788
 789         recoveryCoordinator = null;
 790         currentLogRecoveryBatch = null;
 791         updateJournalStats();
 792
 793         //notify shard manager
 794         getContext().parent().tell(new ActorInitialized(), getSelf());
 795
 796         // Being paranoid here - this method should only be called once but just in case...
 797         if(txCommitTimeoutCheckSchedule == null) {
 798             // Schedule a message to be periodically sent to check if the current in-progress
 799             // transaction should be expired and aborted.
 800             FiniteDuration period = Duration.create(transactionCommitTimeout / 3, TimeUnit.MILLISECONDS);
 801             txCommitTimeoutCheckSchedule = getContext().system().scheduler().schedule(
 802                     period, period, getSelf(),
 803                     TX_COMMIT_TIMEOUT_CHECK_MESSAGE, getContext().dispatcher(), ActorRef.noSender());
 804         }
 805     }
 806
 807     @Override
 808     protected void applyState(final ActorRef clientActor, final String identifier, final Object data) {
 809
 810         if(data instanceof ModificationPayload) {
 811             try {
 812                 applyModificationToState(clientActor, identifier, ((ModificationPayload) data).getModification());
 813             } catch (ClassNotFoundException | IOException e) {
 814                 LOG.error("{}: Error extracting ModificationPayload", persistenceId(), e);
 815             }
 816         }
 817         else if (data instanceof CompositeModificationPayload) {
 818             Object modification = ((CompositeModificationPayload) data).getModification();
 819
 820             applyModificationToState(clientActor, identifier, modification);
 821         } else if(data instanceof CompositeModificationByteStringPayload ){
 822             Object modification = ((CompositeModificationByteStringPayload) data).getModification();
 823
 824             applyModificationToState(clientActor, identifier, modification);
 825         } else {
 826             LOG.error("{}: Unknown state received {} Class loader = {} CompositeNodeMod.ClassLoader = {}",
 827                     persistenceId(), data, data.getClass().getClassLoader(),
 828                     CompositeModificationPayload.class.getClassLoader());
 829         }
 830
 831         updateJournalStats();
 832
 833     }
 834
 835     private void applyModificationToState(ActorRef clientActor, String identifier, Object modification) {
 836         if(modification == null) {
 837             LOG.error(
 838                     "{}: modification is null - this is very unexpected, clientActor = {}, identifier = {}",
 839                     persistenceId(), identifier, clientActor != null ? clientActor.path().toString() : null);
 840         } else if(clientActor == null) {
 841             // There's no clientActor to which to send a commit reply so we must be applying
 842             // replicated state from the leader.
 843             commitWithNewTransaction(MutableCompositeModification.fromSerializable(modification));
 844         } else {
 845             // This must be the OK to commit after replication consensus.
 846             finishCommit(clientActor, identifier);
 847         }
 848     }
 849
 850     private void updateJournalStats() {
 851         ReplicatedLogEntry lastLogEntry = getLastLogEntry();
 852
 853         if (lastLogEntry != null) {
 854             shardMBean.setLastLogIndex(lastLogEntry.getIndex());
 855             shardMBean.setLastLogTerm(lastLogEntry.getTerm());
 856         }
 857
 858         shardMBean.setCommitIndex(getCommitIndex());
 859         shardMBean.setLastApplied(getLastApplied());
 860         shardMBean.setInMemoryJournalDataSize(getRaftActorContext().getReplicatedLog().dataSize());
 861     }
 862
 863     @Override
 864     protected void createSnapshot() {
 865         // Create a transaction actor. We are really going to treat the transaction as a worker
 866         // so that this actor does not get block building the snapshot. THe transaction actor will
 867         // after processing the CreateSnapshot message.
 868
 869         ActorRef createSnapshotTransaction = createTransaction(
 870                 TransactionProxy.TransactionType.READ_ONLY.ordinal(),
 871                 "createSnapshot" + ++createSnapshotTransactionCounter, "",
 872                 DataStoreVersions.CURRENT_VERSION);
 873
 874         createSnapshotTransaction.tell(CreateSnapshot.INSTANCE, self());
 875     }
 876
 877     @VisibleForTesting
 878     @Override
 879     protected void applySnapshot(final byte[] snapshotBytes) {
 880         // Since this will be done only on Recovery or when this actor is a Follower
 881         // we can safely commit everything in here. We not need to worry about event notifications
 882         // as they would have already been disabled on the follower
 883
 884         LOG.info("{}: Applying snapshot", persistenceId());
 885         try {
 886             DOMStoreWriteTransaction transaction = store.newWriteOnlyTransaction();
 887
 888             NormalizedNode<?, ?> node = SerializationUtils.deserializeNormalizedNode(snapshotBytes);
 889
 890             // delete everything first
 891             transaction.delete(DATASTORE_ROOT);
 892
 893             // Add everything from the remote node back
 894             transaction.write(DATASTORE_ROOT, node);
 895             syncCommitTransaction(transaction);
 896         } catch (InterruptedException | ExecutionException e) {
 897             LOG.error("{}: An exception occurred when applying snapshot", persistenceId(), e);
 898         } finally {
 899             LOG.info("{}: Done applying snapshot", persistenceId());
 900         }
 901     }
 902
 903     @Override
 904     protected void onStateChanged() {
 905         boolean isLeader = isLeader();
 906         for (ActorSelection dataChangeListener : dataChangeListeners) {
 907             dataChangeListener.tell(new EnableNotification(isLeader), getSelf());
 908         }
 909
 910         if(isLeader) {
 911             for(DelayedListenerRegistration reg: delayedListenerRegistrations) {
 912                 if(!reg.isClosed()) {
 913                     reg.setDelegate(doChangeListenerRegistration(reg.getRegisterChangeListener()));
 914                 }
 915             }
 916
 917             delayedListenerRegistrations.clear();
 918         }
 919
 920         shardMBean.setRaftState(getRaftState().name());
 921         shardMBean.setCurrentTerm(getCurrentTerm());
 922
 923         // If this actor is no longer the leader close all the transaction chains
 924         if(!isLeader){
 925             for(Map.Entry<String, DOMStoreTransactionChain> entry : transactionChains.entrySet()){
 926                 if(LOG.isDebugEnabled()) {
 927                     LOG.debug(
 928                         "{}: onStateChanged: Closing transaction chain {} because shard {} is no longer the leader",
 929                         persistenceId(), entry.getKey(), getId());
 930                 }
 931                 entry.getValue().close();
 932             }
 933
 934             transactionChains.clear();
 935         }
 936     }
 937
 938     @Override
 939     protected DataPersistenceProvider persistence() {
 940         return dataPersistenceProvider;
 941     }
 942
 943     @Override protected void onLeaderChanged(final String oldLeader, final String newLeader) {
 944         shardMBean.setLeader(newLeader);
 945     }
 946
 947     @Override public String persistenceId() {
 948         return this.name.toString();
 949     }
 950
 951     @VisibleForTesting
 952     DataPersistenceProvider getDataPersistenceProvider() {
 953         return dataPersistenceProvider;
 954     }
 955
 956     private static class ShardCreator implements Creator<Shard> {
 957
 958         private static final long serialVersionUID = 1L;
 959
 960         final ShardIdentifier name;
 961         final Map<ShardIdentifier, String> peerAddresses;
 962         final DatastoreContext datastoreContext;
 963         final SchemaContext schemaContext;
 964
 965         ShardCreator(final ShardIdentifier name, final Map<ShardIdentifier, String> peerAddresses,
 966                 final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 967             this.name = name;
 968             this.peerAddresses = peerAddresses;
 969             this.datastoreContext = datastoreContext;
 970             this.schemaContext = schemaContext;
 971         }
 972
 973         @Override
 974         public Shard create() throws Exception {
 975             return new Shard(name, peerAddresses, datastoreContext, schemaContext);
 976         }
 977     }
 978
 979     @VisibleForTesting
 980     InMemoryDOMDataStore getDataStore() {
 981         return store;
 982     }
 983
 984     @VisibleForTesting
 985     ShardStats getShardMBean() {
 986         return shardMBean;
 987     }
 988
 989     private static class DelayedListenerRegistration implements
 990         ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>>> {
 991
 992         private volatile boolean closed;
 993
 994         private final RegisterChangeListener registerChangeListener;
 995
 996         private volatile ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
 997                                                              NormalizedNode<?, ?>>> delegate;
 998
 999         DelayedListenerRegistration(final RegisterChangeListener registerChangeListener) {
1000             this.registerChangeListener = registerChangeListener;
1001         }
1002
1003         void setDelegate( final ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
1004                                             NormalizedNode<?, ?>>> registration) {
1005             this.delegate = registration;
1006         }
1007
1008         boolean isClosed() {
1009             return closed;
1010         }
1011
1012         RegisterChangeListener getRegisterChangeListener() {
1013             return registerChangeListener;
1014         }
1015
1016         @Override
1017         public AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>> getInstance() {
1018             return delegate != null ? delegate.getInstance() : null;
1019         }
1020
1021         @Override
1022         public void close() {
1023             closed = true;
1024             if(delegate != null) {
1025                 delegate.close();
1026             }
1027         }
1028     }
1029 }