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.base.messages.FollowerInitialSyncUpStatus;
  71 import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply;
  72 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationByteStringPayload;
  73 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationPayload;
  74 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.Payload;
  75 import org.opendaylight.controller.md.sal.common.api.data.AsyncDataChangeListener;
  76 import org.opendaylight.controller.md.sal.dom.store.impl.InMemoryDOMDataStore;
  77 import org.opendaylight.controller.md.sal.dom.store.impl.InMemoryDOMDataStoreFactory;
  78 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  79 import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransaction;
  80 import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransactionChain;
  81 import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransactionFactory;
  82 import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
  83 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  84 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  85 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  86 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  87 import scala.concurrent.duration.Duration;
  88 import scala.concurrent.duration.FiniteDuration;
  89
  90 /**
  91  * A Shard represents a portion of the logical data tree <br/>
  92  * <p>
  93  * Our Shard uses InMemoryDataStore as it's internal representation and delegates all requests it
  94  * </p>
  95  */
  96 public class Shard extends RaftActor {
  97
  98     private static final YangInstanceIdentifier DATASTORE_ROOT = YangInstanceIdentifier.builder().build();
  99
 100     private static final Object TX_COMMIT_TIMEOUT_CHECK_MESSAGE = "txCommitTimeoutCheck";
 101
 102     @VisibleForTesting
 103     static final String DEFAULT_NAME = "default";
 104
 105     // The state of this Shard
 106     private final InMemoryDOMDataStore store;
 107
 108     /// The name of this shard
 109     private final ShardIdentifier name;
 110
 111     private final ShardStats shardMBean;
 112
 113     private final List<ActorSelection> dataChangeListeners =  Lists.newArrayList();
 114
 115     private final List<DelayedListenerRegistration> delayedListenerRegistrations =
 116                                                                        Lists.newArrayList();
 117
 118     private DatastoreContext datastoreContext;
 119
 120     private DataPersistenceProvider dataPersistenceProvider;
 121
 122     private SchemaContext schemaContext;
 123
 124     private int createSnapshotTransactionCounter;
 125
 126     private final ShardCommitCoordinator commitCoordinator;
 127
 128     private long transactionCommitTimeout;
 129
 130     private Cancellable txCommitTimeoutCheckSchedule;
 131
 132     private final Optional<ActorRef> roleChangeNotifier;
 133
 134     private final MessageTracker appendEntriesReplyTracker;
 135
 136     private final ReadyTransactionReply READY_TRANSACTION_REPLY = new ReadyTransactionReply(
 137             Serialization.serializedActorPath(getSelf()));
 138
 139
 140     /**
 141      * Coordinates persistence recovery on startup.
 142      */
 143     private ShardRecoveryCoordinator recoveryCoordinator;
 144     private List<Object> currentLogRecoveryBatch;
 145
 146     private final Map<String, DOMStoreTransactionChain> transactionChains = new HashMap<>();
 147
 148     private final String txnDispatcherPath;
 149
 150     protected Shard(final ShardIdentifier name, final Map<ShardIdentifier, String> peerAddresses,
 151             final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 152         super(name.toString(), mapPeerAddresses(peerAddresses),
 153                 Optional.of(datastoreContext.getShardRaftConfig()));
 154
 155         this.name = name;
 156         this.datastoreContext = datastoreContext;
 157         this.schemaContext = schemaContext;
 158         this.dataPersistenceProvider = (datastoreContext.isPersistent())
 159                 ? new PersistentDataProvider() : new NonPersistentRaftDataProvider();
 160         this.txnDispatcherPath = new Dispatchers(context().system().dispatchers())
 161                 .getDispatcherPath(Dispatchers.DispatcherType.Transaction);
 162
 163
 164         LOG.info("Shard created : {}, persistent : {}", name, datastoreContext.isPersistent());
 165
 166         store = InMemoryDOMDataStoreFactory.create(name.toString(), null,
 167                 datastoreContext.getDataStoreProperties());
 168
 169         if(schemaContext != null) {
 170             store.onGlobalContextUpdated(schemaContext);
 171         }
 172
 173         shardMBean = ShardMBeanFactory.getShardStatsMBean(name.toString(),
 174                 datastoreContext.getDataStoreMXBeanType());
 175         shardMBean.setNotificationManager(store.getDataChangeListenerNotificationManager());
 176
 177         if (isMetricsCaptureEnabled()) {
 178             getContext().become(new MeteringBehavior(this));
 179         }
 180
 181         commitCoordinator = new ShardCommitCoordinator(TimeUnit.SECONDS.convert(1, TimeUnit.MINUTES),
 182                 datastoreContext.getShardTransactionCommitQueueCapacity(), LOG, name.toString());
 183
 184         setTransactionCommitTimeout();
 185
 186         // create a notifier actor for each cluster member
 187         roleChangeNotifier = createRoleChangeNotifier(name.toString());
 188
 189         appendEntriesReplyTracker = new MessageTracker(AppendEntriesReply.class,
 190                 getRaftActorContext().getConfigParams().getIsolatedCheckIntervalInMillis());
 191     }
 192
 193     private void setTransactionCommitTimeout() {
 194         transactionCommitTimeout = TimeUnit.MILLISECONDS.convert(
 195                 datastoreContext.getShardTransactionCommitTimeoutInSeconds(), TimeUnit.SECONDS);
 196     }
 197
 198     private static Map<String, String> mapPeerAddresses(
 199         final Map<ShardIdentifier, String> peerAddresses) {
 200         Map<String, String> map = new HashMap<>();
 201
 202         for (Map.Entry<ShardIdentifier, String> entry : peerAddresses
 203             .entrySet()) {
 204             map.put(entry.getKey().toString(), entry.getValue());
 205         }
 206
 207         return map;
 208     }
 209
 210     public static Props props(final ShardIdentifier name,
 211         final Map<ShardIdentifier, String> peerAddresses,
 212         final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 213         Preconditions.checkNotNull(name, "name should not be null");
 214         Preconditions.checkNotNull(peerAddresses, "peerAddresses should not be null");
 215         Preconditions.checkNotNull(datastoreContext, "dataStoreContext should not be null");
 216         Preconditions.checkNotNull(schemaContext, "schemaContext should not be null");
 217
 218         return Props.create(new ShardCreator(name, peerAddresses, datastoreContext, schemaContext));
 219     }
 220
 221     private Optional<ActorRef> createRoleChangeNotifier(String shardId) {
 222         ActorRef shardRoleChangeNotifier = this.getContext().actorOf(
 223             RoleChangeNotifier.getProps(shardId), shardId + "-notifier");
 224         return Optional.of(shardRoleChangeNotifier);
 225     }
 226
 227     @Override
 228     public void postStop() {
 229         LOG.info("Stopping Shard {}", persistenceId());
 230
 231         super.postStop();
 232
 233         if(txCommitTimeoutCheckSchedule != null) {
 234             txCommitTimeoutCheckSchedule.cancel();
 235         }
 236
 237         shardMBean.unregisterMBean();
 238     }
 239
 240     @Override
 241     public void onReceiveRecover(final Object message) throws Exception {
 242         if(LOG.isDebugEnabled()) {
 243             LOG.debug("{}: onReceiveRecover: Received message {} from {}", persistenceId(),
 244                 message.getClass().toString(), getSender());
 245         }
 246
 247         if (message instanceof RecoveryFailure){
 248             LOG.error("{}: Recovery failed because of this cause",
 249                     persistenceId(), ((RecoveryFailure) message).cause());
 250
 251             // Even though recovery failed, we still need to finish our recovery, eg send the
 252             // ActorInitialized message and start the txCommitTimeoutCheckSchedule.
 253             onRecoveryComplete();
 254         } else {
 255             super.onReceiveRecover(message);
 256             if(LOG.isTraceEnabled()) {
 257                 appendEntriesReplyTracker.begin();
 258             }
 259         }
 260     }
 261
 262     @Override
 263     public void onReceiveCommand(final Object message) throws Exception {
 264
 265         MessageTracker.Context context = appendEntriesReplyTracker.received(message);
 266
 267         if(context.error().isPresent()){
 268             LOG.trace("{} : AppendEntriesReply failed to arrive at the expected interval {}", persistenceId(),
 269                     context.error());
 270         }
 271
 272         try {
 273             if (CreateTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 274                 handleCreateTransaction(message);
 275             } else if (message instanceof ForwardedReadyTransaction) {
 276                 handleForwardedReadyTransaction((ForwardedReadyTransaction) message);
 277             } else if (CanCommitTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 278                 handleCanCommitTransaction(CanCommitTransaction.fromSerializable(message));
 279             } else if (CommitTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 280                 handleCommitTransaction(CommitTransaction.fromSerializable(message));
 281             } else if (AbortTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 282                 handleAbortTransaction(AbortTransaction.fromSerializable(message));
 283             } else if (CloseTransactionChain.SERIALIZABLE_CLASS.isInstance(message)) {
 284                 closeTransactionChain(CloseTransactionChain.fromSerializable(message));
 285             } else if (message instanceof RegisterChangeListener) {
 286                 registerChangeListener((RegisterChangeListener) message);
 287             } else if (message instanceof UpdateSchemaContext) {
 288                 updateSchemaContext((UpdateSchemaContext) message);
 289             } else if (message instanceof PeerAddressResolved) {
 290                 PeerAddressResolved resolved = (PeerAddressResolved) message;
 291                 setPeerAddress(resolved.getPeerId().toString(),
 292                         resolved.getPeerAddress());
 293             } else if (message.equals(TX_COMMIT_TIMEOUT_CHECK_MESSAGE)) {
 294                 handleTransactionCommitTimeoutCheck();
 295             } else if(message instanceof DatastoreContext) {
 296                 onDatastoreContext((DatastoreContext)message);
 297             } else if(message instanceof RegisterRoleChangeListener){
 298                 roleChangeNotifier.get().forward(message, context());
 299             } else if (message instanceof FollowerInitialSyncUpStatus){
 300                 shardMBean.setFollowerInitialSyncStatus(((FollowerInitialSyncUpStatus) message).isInitialSyncDone());
 301                 context().parent().tell(message, self());
 302             } else {
 303                 super.onReceiveCommand(message);
 304             }
 305         } finally {
 306             context.done();
 307         }
 308     }
 309
 310     @Override
 311     protected Optional<ActorRef> getRoleChangeNotifier() {
 312         return roleChangeNotifier;
 313     }
 314
 315     private void onDatastoreContext(DatastoreContext context) {
 316         datastoreContext = context;
 317
 318         commitCoordinator.setQueueCapacity(datastoreContext.getShardTransactionCommitQueueCapacity());
 319
 320         setTransactionCommitTimeout();
 321
 322         if(datastoreContext.isPersistent() &&
 323                 dataPersistenceProvider instanceof NonPersistentRaftDataProvider) {
 324             dataPersistenceProvider = new PersistentDataProvider();
 325         } else if(!datastoreContext.isPersistent() &&
 326                 dataPersistenceProvider instanceof PersistentDataProvider) {
 327             dataPersistenceProvider = new NonPersistentRaftDataProvider();
 328         }
 329
 330         updateConfigParams(datastoreContext.getShardRaftConfig());
 331     }
 332
 333     private void handleTransactionCommitTimeoutCheck() {
 334         CohortEntry cohortEntry = commitCoordinator.getCurrentCohortEntry();
 335         if(cohortEntry != null) {
 336             long elapsed = System.currentTimeMillis() - cohortEntry.getLastAccessTime();
 337             if(elapsed > transactionCommitTimeout) {
 338                 LOG.warn("{}: Current transaction {} has timed out after {} ms - aborting",
 339                         persistenceId(), cohortEntry.getTransactionID(), transactionCommitTimeout);
 340
 341                 doAbortTransaction(cohortEntry.getTransactionID(), null);
 342             }
 343         }
 344     }
 345
 346     private void handleCommitTransaction(final CommitTransaction commit) {
 347         final String transactionID = commit.getTransactionID();
 348
 349         LOG.debug("{}: Committing transaction {}", persistenceId(), transactionID);
 350
 351         // Get the current in-progress cohort entry in the commitCoordinator if it corresponds to
 352         // this transaction.
 353         final CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 354         if(cohortEntry == null) {
 355             // We're not the current Tx - the Tx was likely expired b/c it took too long in
 356             // between the canCommit and commit messages.
 357             IllegalStateException ex = new IllegalStateException(
 358                     String.format("%s: Cannot commit transaction %s - it is not the current transaction",
 359                             persistenceId(), transactionID));
 360             LOG.error(ex.getMessage());
 361             shardMBean.incrementFailedTransactionsCount();
 362             getSender().tell(new akka.actor.Status.Failure(ex), getSelf());
 363             return;
 364         }
 365
 366         // We perform the preCommit phase here atomically with the commit phase. This is an
 367         // optimization to eliminate the overhead of an extra preCommit message. We lose front-end
 368         // coordination of preCommit across shards in case of failure but preCommit should not
 369         // normally fail since we ensure only one concurrent 3-phase commit.
 370
 371         try {
 372             // We block on the future here so we don't have to worry about possibly accessing our
 373             // state on a different thread outside of our dispatcher. Also, the data store
 374             // currently uses a same thread executor anyway.
 375             cohortEntry.getCohort().preCommit().get();
 376
 377             // If we do not have any followers and we are not using persistence we can
 378             // apply modification to the state immediately
 379             if(!hasFollowers() && !persistence().isRecoveryApplicable()){
 380                 applyModificationToState(getSender(), transactionID, cohortEntry.getModification());
 381             } else {
 382                 Shard.this.persistData(getSender(), transactionID,
 383                         new ModificationPayload(cohortEntry.getModification()));
 384             }
 385         } catch (Exception e) {
 386             LOG.error("{} An exception occurred while preCommitting transaction {}",
 387                     persistenceId(), cohortEntry.getTransactionID(), e);
 388             shardMBean.incrementFailedTransactionsCount();
 389             getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 390         }
 391
 392         cohortEntry.updateLastAccessTime();
 393     }
 394
 395     private void finishCommit(@Nonnull final ActorRef sender, final @Nonnull String transactionID) {
 396         // With persistence enabled, this method is called via applyState by the leader strategy
 397         // after the commit has been replicated to a majority of the followers.
 398
 399         CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 400         if(cohortEntry == null) {
 401             // The transaction is no longer the current commit. This can happen if the transaction
 402             // was aborted prior, most likely due to timeout in the front-end. We need to finish
 403             // committing the transaction though since it was successfully persisted and replicated
 404             // however we can't use the original cohort b/c it was already preCommitted and may
 405             // conflict with the current commit or may have been aborted so we commit with a new
 406             // transaction.
 407             cohortEntry = commitCoordinator.getAndRemoveCohortEntry(transactionID);
 408             if(cohortEntry != null) {
 409                 commitWithNewTransaction(cohortEntry.getModification());
 410                 sender.tell(CommitTransactionReply.INSTANCE.toSerializable(), getSelf());
 411             } else {
 412                 // This really shouldn't happen - it likely means that persistence or replication
 413                 // took so long to complete such that the cohort entry was expired from the cache.
 414                 IllegalStateException ex = new IllegalStateException(
 415                         String.format("%s: Could not finish committing transaction %s - no CohortEntry found",
 416                                 persistenceId(), transactionID));
 417                 LOG.error(ex.getMessage());
 418                 sender.tell(new akka.actor.Status.Failure(ex), getSelf());
 419             }
 420
 421             return;
 422         }
 423
 424         LOG.debug("{}: Finishing commit for transaction {}", persistenceId(), cohortEntry.getTransactionID());
 425
 426         try {
 427             // We block on the future here so we don't have to worry about possibly accessing our
 428             // state on a different thread outside of our dispatcher. Also, the data store
 429             // currently uses a same thread executor anyway.
 430             cohortEntry.getCohort().commit().get();
 431
 432             sender.tell(CommitTransactionReply.INSTANCE.toSerializable(), getSelf());
 433
 434             shardMBean.incrementCommittedTransactionCount();
 435             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 436
 437         } catch (Exception e) {
 438             sender.tell(new akka.actor.Status.Failure(e), getSelf());
 439
 440             LOG.error("{}, An exception occurred while committing transaction {}", persistenceId(),
 441                     transactionID, e);
 442             shardMBean.incrementFailedTransactionsCount();
 443         } finally {
 444             commitCoordinator.currentTransactionComplete(transactionID, true);
 445         }
 446     }
 447
 448     private void handleCanCommitTransaction(final CanCommitTransaction canCommit) {
 449         LOG.debug("{}: Can committing transaction {}", persistenceId(), canCommit.getTransactionID());
 450         commitCoordinator.handleCanCommit(canCommit, getSender(), self());
 451     }
 452
 453     private void handleForwardedReadyTransaction(ForwardedReadyTransaction ready) {
 454         LOG.debug("{}: Readying transaction {}, client version {}", persistenceId(),
 455                 ready.getTransactionID(), ready.getTxnClientVersion());
 456
 457         // This message is forwarded by the ShardTransaction on ready. We cache the cohort in the
 458         // commitCoordinator in preparation for the subsequent three phase commit initiated by
 459         // the front-end.
 460         commitCoordinator.transactionReady(ready.getTransactionID(), ready.getCohort(),
 461                 ready.getModification());
 462
 463         // Return our actor path as we'll handle the three phase commit, except if the Tx client
 464         // version < 1 (Helium-1 version). This means the Tx was initiated by a base Helium version
 465         // node. In that case, the subsequent 3-phase commit messages won't contain the
 466         // transactionId so to maintain backwards compatibility, we create a separate cohort actor
 467         // to provide the compatible behavior.
 468         if(ready.getTxnClientVersion() < DataStoreVersions.HELIUM_1_VERSION) {
 469             LOG.debug("{}: Creating BackwardsCompatibleThreePhaseCommitCohort", persistenceId());
 470             ActorRef replyActorPath = getContext().actorOf(BackwardsCompatibleThreePhaseCommitCohort.props(
 471                     ready.getTransactionID()));
 472
 473             ReadyTransactionReply readyTransactionReply =
 474                     new ReadyTransactionReply(Serialization.serializedActorPath(replyActorPath));
 475             getSender().tell(ready.isReturnSerialized() ? readyTransactionReply.toSerializable() :
 476                     readyTransactionReply, getSelf());
 477
 478         } else {
 479
 480             getSender().tell(ready.isReturnSerialized() ? READY_TRANSACTION_REPLY.toSerializable() :
 481                     READY_TRANSACTION_REPLY, getSelf());
 482         }
 483     }
 484
 485     private void handleAbortTransaction(final AbortTransaction abort) {
 486         doAbortTransaction(abort.getTransactionID(), getSender());
 487     }
 488
 489     void doAbortTransaction(final String transactionID, final ActorRef sender) {
 490         final CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 491         if(cohortEntry != null) {
 492             LOG.debug("{}: Aborting transaction {}", persistenceId(), transactionID);
 493
 494             // We don't remove the cached cohort entry here (ie pass false) in case the Tx was
 495             // aborted during replication in which case we may still commit locally if replication
 496             // succeeds.
 497             commitCoordinator.currentTransactionComplete(transactionID, false);
 498
 499             final ListenableFuture<Void> future = cohortEntry.getCohort().abort();
 500             final ActorRef self = getSelf();
 501
 502             Futures.addCallback(future, new FutureCallback<Void>() {
 503                 @Override
 504                 public void onSuccess(final Void v) {
 505                     shardMBean.incrementAbortTransactionsCount();
 506
 507                     if(sender != null) {
 508                         sender.tell(AbortTransactionReply.INSTANCE.toSerializable(), self);
 509                     }
 510                 }
 511
 512                 @Override
 513                 public void onFailure(final Throwable t) {
 514                     LOG.error("{}: An exception happened during abort", persistenceId(), t);
 515
 516                     if(sender != null) {
 517                         sender.tell(new akka.actor.Status.Failure(t), self);
 518                     }
 519                 }
 520             });
 521         }
 522     }
 523
 524     private void handleCreateTransaction(final Object message) {
 525         if (isLeader()) {
 526             createTransaction(CreateTransaction.fromSerializable(message));
 527         } else if (getLeader() != null) {
 528             getLeader().forward(message, getContext());
 529         } else {
 530             getSender().tell(new akka.actor.Status.Failure(new NoShardLeaderException(String.format(
 531                 "Could not find leader for shard %s so transaction cannot be created. This typically happens" +
 532                 " when the system is coming up or recovering and a leader is being elected. Try again" +
 533                 " later.", persistenceId()))), getSelf());
 534         }
 535     }
 536
 537     private void closeTransactionChain(final CloseTransactionChain closeTransactionChain) {
 538         DOMStoreTransactionChain chain =
 539             transactionChains.remove(closeTransactionChain.getTransactionChainId());
 540
 541         if(chain != null) {
 542             chain.close();
 543         }
 544     }
 545
 546     private ActorRef createTypedTransactionActor(int transactionType,
 547             ShardTransactionIdentifier transactionId, String transactionChainId,
 548             short clientVersion ) {
 549
 550         DOMStoreTransactionFactory factory = store;
 551
 552         if(!transactionChainId.isEmpty()) {
 553             factory = transactionChains.get(transactionChainId);
 554             if(factory == null){
 555                 DOMStoreTransactionChain transactionChain = store.createTransactionChain();
 556                 transactionChains.put(transactionChainId, transactionChain);
 557                 factory = transactionChain;
 558             }
 559         }
 560
 561         if(this.schemaContext == null) {
 562             throw new IllegalStateException("SchemaContext is not set");
 563         }
 564
 565         if (transactionType == TransactionProxy.TransactionType.WRITE_ONLY.ordinal()) {
 566
 567             shardMBean.incrementWriteOnlyTransactionCount();
 568
 569             return createShardTransaction(factory.newWriteOnlyTransaction(), transactionId, clientVersion);
 570
 571         } else if (transactionType == TransactionProxy.TransactionType.READ_WRITE.ordinal()) {
 572
 573             shardMBean.incrementReadWriteTransactionCount();
 574
 575             return createShardTransaction(factory.newReadWriteTransaction(), transactionId, clientVersion);
 576
 577         } else if (transactionType == TransactionProxy.TransactionType.READ_ONLY.ordinal()) {
 578
 579             shardMBean.incrementReadOnlyTransactionCount();
 580
 581             return createShardTransaction(factory.newReadOnlyTransaction(), transactionId, clientVersion);
 582
 583         } else {
 584             throw new IllegalArgumentException(
 585                 "Shard="+name + ":CreateTransaction message has unidentified transaction type="
 586                     + transactionType);
 587         }
 588     }
 589
 590     private ActorRef createShardTransaction(DOMStoreTransaction transaction, ShardTransactionIdentifier transactionId,
 591                                             short clientVersion){
 592         return getContext().actorOf(
 593                 ShardTransaction.props(transaction, getSelf(),
 594                         schemaContext, datastoreContext, shardMBean,
 595                         transactionId.getRemoteTransactionId(), clientVersion)
 596                         .withDispatcher(txnDispatcherPath),
 597                 transactionId.toString());
 598
 599     }
 600
 601     private void createTransaction(CreateTransaction createTransaction) {
 602         try {
 603             ActorRef transactionActor = createTransaction(createTransaction.getTransactionType(),
 604                 createTransaction.getTransactionId(), createTransaction.getTransactionChainId(),
 605                 createTransaction.getVersion());
 606
 607             getSender().tell(new CreateTransactionReply(Serialization.serializedActorPath(transactionActor),
 608                     createTransaction.getTransactionId()).toSerializable(), getSelf());
 609         } catch (Exception e) {
 610             getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 611         }
 612     }
 613
 614     private ActorRef createTransaction(int transactionType, String remoteTransactionId,
 615             String transactionChainId, short clientVersion) {
 616
 617
 618         ShardTransactionIdentifier transactionId = new ShardTransactionIdentifier(remoteTransactionId);
 619
 620         if(LOG.isDebugEnabled()) {
 621             LOG.debug("{}: Creating transaction : {} ", persistenceId(), transactionId);
 622         }
 623
 624         ActorRef transactionActor = createTypedTransactionActor(transactionType, transactionId,
 625                 transactionChainId, clientVersion);
 626
 627         return transactionActor;
 628     }
 629
 630     private void syncCommitTransaction(final DOMStoreWriteTransaction transaction)
 631         throws ExecutionException, InterruptedException {
 632         DOMStoreThreePhaseCommitCohort commitCohort = transaction.ready();
 633         commitCohort.preCommit().get();
 634         commitCohort.commit().get();
 635     }
 636
 637     private void commitWithNewTransaction(final Modification modification) {
 638         DOMStoreWriteTransaction tx = store.newWriteOnlyTransaction();
 639         modification.apply(tx);
 640         try {
 641             syncCommitTransaction(tx);
 642             shardMBean.incrementCommittedTransactionCount();
 643             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 644         } catch (InterruptedException | ExecutionException e) {
 645             shardMBean.incrementFailedTransactionsCount();
 646             LOG.error("{}: Failed to commit", persistenceId(), e);
 647         }
 648     }
 649
 650     private void updateSchemaContext(final UpdateSchemaContext message) {
 651         this.schemaContext = message.getSchemaContext();
 652         updateSchemaContext(message.getSchemaContext());
 653         store.onGlobalContextUpdated(message.getSchemaContext());
 654     }
 655
 656     @VisibleForTesting
 657     void updateSchemaContext(final SchemaContext schemaContext) {
 658         store.onGlobalContextUpdated(schemaContext);
 659     }
 660
 661     private void registerChangeListener(final RegisterChangeListener registerChangeListener) {
 662
 663         LOG.debug("{}: registerDataChangeListener for {}", persistenceId(), registerChangeListener.getPath());
 664
 665         ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
 666                                                      NormalizedNode<?, ?>>> registration;
 667         if(isLeader()) {
 668             registration = doChangeListenerRegistration(registerChangeListener);
 669         } else {
 670             LOG.debug("{}: Shard is not the leader - delaying registration", persistenceId());
 671
 672             DelayedListenerRegistration delayedReg =
 673                     new DelayedListenerRegistration(registerChangeListener);
 674             delayedListenerRegistrations.add(delayedReg);
 675             registration = delayedReg;
 676         }
 677
 678         ActorRef listenerRegistration = getContext().actorOf(
 679                 DataChangeListenerRegistration.props(registration));
 680
 681         LOG.debug("{}: registerDataChangeListener sending reply, listenerRegistrationPath = {} ",
 682                 persistenceId(), listenerRegistration.path());
 683
 684         getSender().tell(new RegisterChangeListenerReply(listenerRegistration.path()), getSelf());
 685     }
 686
 687     private ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
 688                                                NormalizedNode<?, ?>>> doChangeListenerRegistration(
 689             final RegisterChangeListener registerChangeListener) {
 690
 691         ActorSelection dataChangeListenerPath = getContext().system().actorSelection(
 692                 registerChangeListener.getDataChangeListenerPath());
 693
 694         // Notify the listener if notifications should be enabled or not
 695         // If this shard is the leader then it will enable notifications else
 696         // it will not
 697         dataChangeListenerPath.tell(new EnableNotification(true), getSelf());
 698
 699         // Now store a reference to the data change listener so it can be notified
 700         // at a later point if notifications should be enabled or disabled
 701         dataChangeListeners.add(dataChangeListenerPath);
 702
 703         AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>> listener =
 704                 new DataChangeListenerProxy(dataChangeListenerPath);
 705
 706         LOG.debug("{}: Registering for path {}", persistenceId(), registerChangeListener.getPath());
 707
 708         return store.registerChangeListener(registerChangeListener.getPath(), listener,
 709                 registerChangeListener.getScope());
 710     }
 711
 712     private boolean isMetricsCaptureEnabled(){
 713         CommonConfig config = new CommonConfig(getContext().system().settings().config());
 714         return config.isMetricCaptureEnabled();
 715     }
 716
 717     @Override
 718     protected
 719     void startLogRecoveryBatch(final int maxBatchSize) {
 720         currentLogRecoveryBatch = Lists.newArrayListWithCapacity(maxBatchSize);
 721
 722         if(LOG.isDebugEnabled()) {
 723             LOG.debug("{}: starting log recovery batch with max size {}", persistenceId(), maxBatchSize);
 724         }
 725     }
 726
 727     @Override
 728     protected void appendRecoveredLogEntry(final Payload data) {
 729         if(data instanceof ModificationPayload) {
 730             try {
 731                 currentLogRecoveryBatch.add(((ModificationPayload) data).getModification());
 732             } catch (ClassNotFoundException | IOException e) {
 733                 LOG.error("{}: Error extracting ModificationPayload", persistenceId(), e);
 734             }
 735         } else if (data instanceof CompositeModificationPayload) {
 736             currentLogRecoveryBatch.add(((CompositeModificationPayload) data).getModification());
 737         } else if (data instanceof CompositeModificationByteStringPayload) {
 738             currentLogRecoveryBatch.add(((CompositeModificationByteStringPayload) data).getModification());
 739         } else {
 740             LOG.error("{}: Unknown state received {} during recovery", persistenceId(), data);
 741         }
 742     }
 743
 744     @Override
 745     protected void applyRecoverySnapshot(final byte[] snapshotBytes) {
 746         if(recoveryCoordinator == null) {
 747             recoveryCoordinator = new ShardRecoveryCoordinator(persistenceId(), schemaContext,
 748                     LOG, name.toString());
 749         }
 750
 751         recoveryCoordinator.submit(snapshotBytes, store.newWriteOnlyTransaction());
 752
 753         if(LOG.isDebugEnabled()) {
 754             LOG.debug("{}: submitted recovery sbapshot", persistenceId());
 755         }
 756     }
 757
 758     @Override
 759     protected void applyCurrentLogRecoveryBatch() {
 760         if(recoveryCoordinator == null) {
 761             recoveryCoordinator = new ShardRecoveryCoordinator(persistenceId(), schemaContext,
 762                     LOG, name.toString());
 763         }
 764
 765         recoveryCoordinator.submit(currentLogRecoveryBatch, store.newWriteOnlyTransaction());
 766
 767         if(LOG.isDebugEnabled()) {
 768             LOG.debug("{}: submitted log recovery batch with size {}", persistenceId(),
 769                     currentLogRecoveryBatch.size());
 770         }
 771     }
 772
 773     @Override
 774     protected void onRecoveryComplete() {
 775         if(recoveryCoordinator != null) {
 776             Collection<DOMStoreWriteTransaction> txList = recoveryCoordinator.getTransactions();
 777
 778             if(LOG.isDebugEnabled()) {
 779                 LOG.debug("{}: recovery complete - committing {} Tx's", persistenceId(), txList.size());
 780             }
 781
 782             for(DOMStoreWriteTransaction tx: txList) {
 783                 try {
 784                     syncCommitTransaction(tx);
 785                     shardMBean.incrementCommittedTransactionCount();
 786                 } catch (InterruptedException | ExecutionException e) {
 787                     shardMBean.incrementFailedTransactionsCount();
 788                     LOG.error("{}: Failed to commit", persistenceId(), e);
 789                 }
 790             }
 791         }
 792
 793         recoveryCoordinator = null;
 794         currentLogRecoveryBatch = null;
 795         updateJournalStats();
 796
 797         //notify shard manager
 798         getContext().parent().tell(new ActorInitialized(), getSelf());
 799
 800         // Being paranoid here - this method should only be called once but just in case...
 801         if(txCommitTimeoutCheckSchedule == null) {
 802             // Schedule a message to be periodically sent to check if the current in-progress
 803             // transaction should be expired and aborted.
 804             FiniteDuration period = Duration.create(transactionCommitTimeout / 3, TimeUnit.MILLISECONDS);
 805             txCommitTimeoutCheckSchedule = getContext().system().scheduler().schedule(
 806                     period, period, getSelf(),
 807                     TX_COMMIT_TIMEOUT_CHECK_MESSAGE, getContext().dispatcher(), ActorRef.noSender());
 808         }
 809     }
 810
 811     @Override
 812     protected void applyState(final ActorRef clientActor, final String identifier, final Object data) {
 813
 814         if(data instanceof ModificationPayload) {
 815             try {
 816                 applyModificationToState(clientActor, identifier, ((ModificationPayload) data).getModification());
 817             } catch (ClassNotFoundException | IOException e) {
 818                 LOG.error("{}: Error extracting ModificationPayload", persistenceId(), e);
 819             }
 820         }
 821         else if (data instanceof CompositeModificationPayload) {
 822             Object modification = ((CompositeModificationPayload) data).getModification();
 823
 824             applyModificationToState(clientActor, identifier, modification);
 825         } else if(data instanceof CompositeModificationByteStringPayload ){
 826             Object modification = ((CompositeModificationByteStringPayload) data).getModification();
 827
 828             applyModificationToState(clientActor, identifier, modification);
 829         } else {
 830             LOG.error("{}: Unknown state received {} Class loader = {} CompositeNodeMod.ClassLoader = {}",
 831                     persistenceId(), data, data.getClass().getClassLoader(),
 832                     CompositeModificationPayload.class.getClassLoader());
 833         }
 834
 835         updateJournalStats();
 836
 837     }
 838
 839     private void applyModificationToState(ActorRef clientActor, String identifier, Object modification) {
 840         if(modification == null) {
 841             LOG.error(
 842                     "{}: modification is null - this is very unexpected, clientActor = {}, identifier = {}",
 843                     persistenceId(), identifier, clientActor != null ? clientActor.path().toString() : null);
 844         } else if(clientActor == null) {
 845             // There's no clientActor to which to send a commit reply so we must be applying
 846             // replicated state from the leader.
 847             commitWithNewTransaction(MutableCompositeModification.fromSerializable(modification));
 848         } else {
 849             // This must be the OK to commit after replication consensus.
 850             finishCommit(clientActor, identifier);
 851         }
 852     }
 853
 854     private void updateJournalStats() {
 855         ReplicatedLogEntry lastLogEntry = getLastLogEntry();
 856
 857         if (lastLogEntry != null) {
 858             shardMBean.setLastLogIndex(lastLogEntry.getIndex());
 859             shardMBean.setLastLogTerm(lastLogEntry.getTerm());
 860         }
 861
 862         shardMBean.setCommitIndex(getCommitIndex());
 863         shardMBean.setLastApplied(getLastApplied());
 864         shardMBean.setInMemoryJournalDataSize(getRaftActorContext().getReplicatedLog().dataSize());
 865     }
 866
 867     @Override
 868     protected void createSnapshot() {
 869         // Create a transaction actor. We are really going to treat the transaction as a worker
 870         // so that this actor does not get block building the snapshot. THe transaction actor will
 871         // after processing the CreateSnapshot message.
 872
 873         ActorRef createSnapshotTransaction = createTransaction(
 874                 TransactionProxy.TransactionType.READ_ONLY.ordinal(),
 875                 "createSnapshot" + ++createSnapshotTransactionCounter, "",
 876                 DataStoreVersions.CURRENT_VERSION);
 877
 878         createSnapshotTransaction.tell(CreateSnapshot.INSTANCE, self());
 879     }
 880
 881     @VisibleForTesting
 882     @Override
 883     protected void applySnapshot(final byte[] snapshotBytes) {
 884         // Since this will be done only on Recovery or when this actor is a Follower
 885         // we can safely commit everything in here. We not need to worry about event notifications
 886         // as they would have already been disabled on the follower
 887
 888         LOG.info("{}: Applying snapshot", persistenceId());
 889         try {
 890             DOMStoreWriteTransaction transaction = store.newWriteOnlyTransaction();
 891
 892             NormalizedNode<?, ?> node = SerializationUtils.deserializeNormalizedNode(snapshotBytes);
 893
 894             // delete everything first
 895             transaction.delete(DATASTORE_ROOT);
 896
 897             // Add everything from the remote node back
 898             transaction.write(DATASTORE_ROOT, node);
 899             syncCommitTransaction(transaction);
 900         } catch (InterruptedException | ExecutionException e) {
 901             LOG.error("{}: An exception occurred when applying snapshot", persistenceId(), e);
 902         } finally {
 903             LOG.info("{}: Done applying snapshot", persistenceId());
 904         }
 905     }
 906
 907     @Override
 908     protected void onStateChanged() {
 909         boolean isLeader = isLeader();
 910         for (ActorSelection dataChangeListener : dataChangeListeners) {
 911             dataChangeListener.tell(new EnableNotification(isLeader), getSelf());
 912         }
 913
 914         if(isLeader) {
 915             for(DelayedListenerRegistration reg: delayedListenerRegistrations) {
 916                 if(!reg.isClosed()) {
 917                     reg.setDelegate(doChangeListenerRegistration(reg.getRegisterChangeListener()));
 918                 }
 919             }
 920
 921             delayedListenerRegistrations.clear();
 922         }
 923
 924         shardMBean.setRaftState(getRaftState().name());
 925         shardMBean.setCurrentTerm(getCurrentTerm());
 926
 927         // If this actor is no longer the leader close all the transaction chains
 928         if(!isLeader){
 929             for(Map.Entry<String, DOMStoreTransactionChain> entry : transactionChains.entrySet()){
 930                 if(LOG.isDebugEnabled()) {
 931                     LOG.debug(
 932                         "{}: onStateChanged: Closing transaction chain {} because shard {} is no longer the leader",
 933                         persistenceId(), entry.getKey(), getId());
 934                 }
 935                 entry.getValue().close();
 936             }
 937
 938             transactionChains.clear();
 939         }
 940     }
 941
 942     @Override
 943     protected DataPersistenceProvider persistence() {
 944         return dataPersistenceProvider;
 945     }
 946
 947     @Override protected void onLeaderChanged(final String oldLeader, final String newLeader) {
 948         shardMBean.setLeader(newLeader);
 949     }
 950
 951     @Override public String persistenceId() {
 952         return this.name.toString();
 953     }
 954
 955     @VisibleForTesting
 956     DataPersistenceProvider getDataPersistenceProvider() {
 957         return dataPersistenceProvider;
 958     }
 959
 960     private static class ShardCreator implements Creator<Shard> {
 961
 962         private static final long serialVersionUID = 1L;
 963
 964         final ShardIdentifier name;
 965         final Map<ShardIdentifier, String> peerAddresses;
 966         final DatastoreContext datastoreContext;
 967         final SchemaContext schemaContext;
 968
 969         ShardCreator(final ShardIdentifier name, final Map<ShardIdentifier, String> peerAddresses,
 970                 final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 971             this.name = name;
 972             this.peerAddresses = peerAddresses;
 973             this.datastoreContext = datastoreContext;
 974             this.schemaContext = schemaContext;
 975         }
 976
 977         @Override
 978         public Shard create() throws Exception {
 979             return new Shard(name, peerAddresses, datastoreContext, schemaContext);
 980         }
 981     }
 982
 983     @VisibleForTesting
 984     InMemoryDOMDataStore getDataStore() {
 985         return store;
 986     }
 987
 988     @VisibleForTesting
 989     ShardStats getShardMBean() {
 990         return shardMBean;
 991     }
 992
 993     private static class DelayedListenerRegistration implements
 994         ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>>> {
 995
 996         private volatile boolean closed;
 997
 998         private final RegisterChangeListener registerChangeListener;
 999
1000         private volatile ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
1001                                                              NormalizedNode<?, ?>>> delegate;
1002
1003         DelayedListenerRegistration(final RegisterChangeListener registerChangeListener) {
1004             this.registerChangeListener = registerChangeListener;
1005         }
1006
1007         void setDelegate( final ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
1008                                             NormalizedNode<?, ?>>> registration) {
1009             this.delegate = registration;
1010         }
1011
1012         boolean isClosed() {
1013             return closed;
1014         }
1015
1016         RegisterChangeListener getRegisterChangeListener() {
1017             return registerChangeListener;
1018         }
1019
1020         @Override
1021         public AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>> getInstance() {
1022             return delegate != null ? delegate.getInstance() : null;
1023         }
1024
1025         @Override
1026         public void close() {
1027             closed = true;
1028             if(delegate != null) {
1029                 delegate.close();
1030             }
1031         }
1032     }
1033 }