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     /**
 137      * Coordinates persistence recovery on startup.
 138      */
 139     private ShardRecoveryCoordinator recoveryCoordinator;
 140     private List<Object> currentLogRecoveryBatch;
 141
 142     private final Map<String, DOMStoreTransactionChain> transactionChains = new HashMap<>();
 143
 144     private final String txnDispatcherPath;
 145
 146     protected Shard(final ShardIdentifier name, final Map<ShardIdentifier, String> peerAddresses,
 147             final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 148         super(name.toString(), mapPeerAddresses(peerAddresses),
 149                 Optional.of(datastoreContext.getShardRaftConfig()));
 150
 151         this.name = name;
 152         this.datastoreContext = datastoreContext;
 153         this.schemaContext = schemaContext;
 154         this.dataPersistenceProvider = (datastoreContext.isPersistent())
 155                 ? new PersistentDataProvider() : new NonPersistentRaftDataProvider();
 156         this.txnDispatcherPath = new Dispatchers(context().system().dispatchers())
 157                 .getDispatcherPath(Dispatchers.DispatcherType.Transaction);
 158
 159
 160         LOG.info("Shard created : {}, persistent : {}", name, datastoreContext.isPersistent());
 161
 162         store = InMemoryDOMDataStoreFactory.create(name.toString(), null,
 163                 datastoreContext.getDataStoreProperties());
 164
 165         if(schemaContext != null) {
 166             store.onGlobalContextUpdated(schemaContext);
 167         }
 168
 169         shardMBean = ShardMBeanFactory.getShardStatsMBean(name.toString(),
 170                 datastoreContext.getDataStoreMXBeanType());
 171         shardMBean.setNotificationManager(store.getDataChangeListenerNotificationManager());
 172
 173         if (isMetricsCaptureEnabled()) {
 174             getContext().become(new MeteringBehavior(this));
 175         }
 176
 177         commitCoordinator = new ShardCommitCoordinator(TimeUnit.SECONDS.convert(1, TimeUnit.MINUTES),
 178                 datastoreContext.getShardTransactionCommitQueueCapacity(), LOG, name.toString());
 179
 180         setTransactionCommitTimeout();
 181
 182         // create a notifier actor for each cluster member
 183         roleChangeNotifier = createRoleChangeNotifier(name.toString());
 184
 185         appendEntriesReplyTracker = new MessageTracker(AppendEntriesReply.class,
 186                 getRaftActorContext().getConfigParams().getIsolatedCheckIntervalInMillis());
 187     }
 188
 189     private void setTransactionCommitTimeout() {
 190         transactionCommitTimeout = TimeUnit.MILLISECONDS.convert(
 191                 datastoreContext.getShardTransactionCommitTimeoutInSeconds(), TimeUnit.SECONDS);
 192     }
 193
 194     private static Map<String, String> mapPeerAddresses(
 195         final Map<ShardIdentifier, String> peerAddresses) {
 196         Map<String, String> map = new HashMap<>();
 197
 198         for (Map.Entry<ShardIdentifier, String> entry : peerAddresses
 199             .entrySet()) {
 200             map.put(entry.getKey().toString(), entry.getValue());
 201         }
 202
 203         return map;
 204     }
 205
 206     public static Props props(final ShardIdentifier name,
 207         final Map<ShardIdentifier, String> peerAddresses,
 208         final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 209         Preconditions.checkNotNull(name, "name should not be null");
 210         Preconditions.checkNotNull(peerAddresses, "peerAddresses should not be null");
 211         Preconditions.checkNotNull(datastoreContext, "dataStoreContext should not be null");
 212         Preconditions.checkNotNull(schemaContext, "schemaContext should not be null");
 213
 214         return Props.create(new ShardCreator(name, peerAddresses, datastoreContext, schemaContext));
 215     }
 216
 217     private Optional<ActorRef> createRoleChangeNotifier(String shardId) {
 218         ActorRef shardRoleChangeNotifier = this.getContext().actorOf(
 219             RoleChangeNotifier.getProps(shardId), shardId + "-notifier");
 220         return Optional.of(shardRoleChangeNotifier);
 221     }
 222
 223     @Override
 224     public void postStop() {
 225         LOG.info("Stopping Shard {}", persistenceId());
 226
 227         super.postStop();
 228
 229         if(txCommitTimeoutCheckSchedule != null) {
 230             txCommitTimeoutCheckSchedule.cancel();
 231         }
 232
 233         shardMBean.unregisterMBean();
 234     }
 235
 236     @Override
 237     public void onReceiveRecover(final Object message) throws Exception {
 238         if(LOG.isDebugEnabled()) {
 239             LOG.debug("{}: onReceiveRecover: Received message {} from {}", persistenceId(),
 240                 message.getClass().toString(), getSender());
 241         }
 242
 243         if (message instanceof RecoveryFailure){
 244             LOG.error("{}: Recovery failed because of this cause",
 245                     persistenceId(), ((RecoveryFailure) message).cause());
 246
 247             // Even though recovery failed, we still need to finish our recovery, eg send the
 248             // ActorInitialized message and start the txCommitTimeoutCheckSchedule.
 249             onRecoveryComplete();
 250         } else {
 251             super.onReceiveRecover(message);
 252             if(LOG.isTraceEnabled()) {
 253                 appendEntriesReplyTracker.begin();
 254             }
 255         }
 256     }
 257
 258     @Override
 259     public void onReceiveCommand(final Object message) throws Exception {
 260
 261         MessageTracker.Context context = appendEntriesReplyTracker.received(message);
 262
 263         if(context.error().isPresent()){
 264             LOG.trace("{} : AppendEntriesReply failed to arrive at the expected interval {}", persistenceId(),
 265                     context.error());
 266         }
 267
 268         try {
 269             if (message.getClass().equals(CreateTransaction.SERIALIZABLE_CLASS)) {
 270                 handleCreateTransaction(message);
 271             } else if (message instanceof ForwardedReadyTransaction) {
 272                 handleForwardedReadyTransaction((ForwardedReadyTransaction) message);
 273             } else if (message.getClass().equals(CanCommitTransaction.SERIALIZABLE_CLASS)) {
 274                 handleCanCommitTransaction(CanCommitTransaction.fromSerializable(message));
 275             } else if (message.getClass().equals(CommitTransaction.SERIALIZABLE_CLASS)) {
 276                 handleCommitTransaction(CommitTransaction.fromSerializable(message));
 277             } else if (message.getClass().equals(AbortTransaction.SERIALIZABLE_CLASS)) {
 278                 handleAbortTransaction(AbortTransaction.fromSerializable(message));
 279             } else if (message.getClass().equals(CloseTransactionChain.SERIALIZABLE_CLASS)) {
 280                 closeTransactionChain(CloseTransactionChain.fromSerializable(message));
 281             } else if (message instanceof RegisterChangeListener) {
 282                 registerChangeListener((RegisterChangeListener) message);
 283             } else if (message instanceof UpdateSchemaContext) {
 284                 updateSchemaContext((UpdateSchemaContext) message);
 285             } else if (message instanceof PeerAddressResolved) {
 286                 PeerAddressResolved resolved = (PeerAddressResolved) message;
 287                 setPeerAddress(resolved.getPeerId().toString(),
 288                         resolved.getPeerAddress());
 289             } else if (message.equals(TX_COMMIT_TIMEOUT_CHECK_MESSAGE)) {
 290                 handleTransactionCommitTimeoutCheck();
 291             } else if(message instanceof DatastoreContext) {
 292                 onDatastoreContext((DatastoreContext)message);
 293             } else if(message instanceof RegisterRoleChangeListener){
 294                 roleChangeNotifier.get().forward(message, context());
 295             } else if (message instanceof FollowerInitialSyncUpStatus){
 296                 shardMBean.setFollowerInitialSyncStatus(((FollowerInitialSyncUpStatus) message).isInitialSyncDone());
 297                 context().parent().tell(message, self());
 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         ActorRef replyActorPath = self();
 465         if(ready.getTxnClientVersion() < DataStoreVersions.HELIUM_1_VERSION) {
 466             LOG.debug("{}: Creating BackwardsCompatibleThreePhaseCommitCohort", persistenceId());
 467             replyActorPath = getContext().actorOf(BackwardsCompatibleThreePhaseCommitCohort.props(
 468                     ready.getTransactionID()));
 469         }
 470
 471         ReadyTransactionReply readyTransactionReply = new ReadyTransactionReply(
 472                 Serialization.serializedActorPath(replyActorPath));
 473         getSender().tell(ready.isReturnSerialized() ? readyTransactionReply.toSerializable() :
 474                 readyTransactionReply, getSelf());
 475     }
 476
 477     private void handleAbortTransaction(final AbortTransaction abort) {
 478         doAbortTransaction(abort.getTransactionID(), getSender());
 479     }
 480
 481     void doAbortTransaction(final String transactionID, final ActorRef sender) {
 482         final CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 483         if(cohortEntry != null) {
 484             LOG.debug("{}: Aborting transaction {}", persistenceId(), transactionID);
 485
 486             // We don't remove the cached cohort entry here (ie pass false) in case the Tx was
 487             // aborted during replication in which case we may still commit locally if replication
 488             // succeeds.
 489             commitCoordinator.currentTransactionComplete(transactionID, false);
 490
 491             final ListenableFuture<Void> future = cohortEntry.getCohort().abort();
 492             final ActorRef self = getSelf();
 493
 494             Futures.addCallback(future, new FutureCallback<Void>() {
 495                 @Override
 496                 public void onSuccess(final Void v) {
 497                     shardMBean.incrementAbortTransactionsCount();
 498
 499                     if(sender != null) {
 500                         sender.tell(AbortTransactionReply.INSTANCE.toSerializable(), self);
 501                     }
 502                 }
 503
 504                 @Override
 505                 public void onFailure(final Throwable t) {
 506                     LOG.error("{}: An exception happened during abort", persistenceId(), t);
 507
 508                     if(sender != null) {
 509                         sender.tell(new akka.actor.Status.Failure(t), self);
 510                     }
 511                 }
 512             });
 513         }
 514     }
 515
 516     private void handleCreateTransaction(final Object message) {
 517         if (isLeader()) {
 518             createTransaction(CreateTransaction.fromSerializable(message));
 519         } else if (getLeader() != null) {
 520             getLeader().forward(message, getContext());
 521         } else {
 522             getSender().tell(new akka.actor.Status.Failure(new NoShardLeaderException(String.format(
 523                 "Could not find leader for shard %s so transaction cannot be created. This typically happens" +
 524                 " when the system is coming up or recovering and a leader is being elected. Try again" +
 525                 " later.", persistenceId()))), getSelf());
 526         }
 527     }
 528
 529     private void closeTransactionChain(final CloseTransactionChain closeTransactionChain) {
 530         DOMStoreTransactionChain chain =
 531             transactionChains.remove(closeTransactionChain.getTransactionChainId());
 532
 533         if(chain != null) {
 534             chain.close();
 535         }
 536     }
 537
 538     private ActorRef createTypedTransactionActor(int transactionType,
 539             ShardTransactionIdentifier transactionId, String transactionChainId,
 540             short clientVersion ) {
 541
 542         DOMStoreTransactionFactory factory = store;
 543
 544         if(!transactionChainId.isEmpty()) {
 545             factory = transactionChains.get(transactionChainId);
 546             if(factory == null){
 547                 DOMStoreTransactionChain transactionChain = store.createTransactionChain();
 548                 transactionChains.put(transactionChainId, transactionChain);
 549                 factory = transactionChain;
 550             }
 551         }
 552
 553         if(this.schemaContext == null) {
 554             throw new IllegalStateException("SchemaContext is not set");
 555         }
 556
 557         if (transactionType == TransactionProxy.TransactionType.READ_ONLY.ordinal()) {
 558
 559             shardMBean.incrementReadOnlyTransactionCount();
 560
 561             return createShardTransaction(factory.newReadOnlyTransaction(), transactionId, clientVersion);
 562
 563         } else if (transactionType == TransactionProxy.TransactionType.READ_WRITE.ordinal()) {
 564
 565             shardMBean.incrementReadWriteTransactionCount();
 566
 567             return createShardTransaction(factory.newReadWriteTransaction(), transactionId, clientVersion);
 568
 569         } else if (transactionType == TransactionProxy.TransactionType.WRITE_ONLY.ordinal()) {
 570
 571             shardMBean.incrementWriteOnlyTransactionCount();
 572
 573             return createShardTransaction(factory.newWriteOnlyTransaction(), transactionId, clientVersion);
 574         } else {
 575             throw new IllegalArgumentException(
 576                 "Shard="+name + ":CreateTransaction message has unidentified transaction type="
 577                     + transactionType);
 578         }
 579     }
 580
 581     private ActorRef createShardTransaction(DOMStoreTransaction transaction, ShardTransactionIdentifier transactionId,
 582                                             short clientVersion){
 583         return getContext().actorOf(
 584                 ShardTransaction.props(transaction, getSelf(),
 585                         schemaContext, datastoreContext, shardMBean,
 586                         transactionId.getRemoteTransactionId(), clientVersion)
 587                         .withDispatcher(txnDispatcherPath),
 588                 transactionId.toString());
 589
 590     }
 591
 592     private void createTransaction(CreateTransaction createTransaction) {
 593         try {
 594             ActorRef transactionActor = createTransaction(createTransaction.getTransactionType(),
 595                 createTransaction.getTransactionId(), createTransaction.getTransactionChainId(),
 596                 createTransaction.getVersion());
 597
 598             getSender().tell(new CreateTransactionReply(Serialization.serializedActorPath(transactionActor),
 599                     createTransaction.getTransactionId()).toSerializable(), getSelf());
 600         } catch (Exception e) {
 601             getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 602         }
 603     }
 604
 605     private ActorRef createTransaction(int transactionType, String remoteTransactionId,
 606             String transactionChainId, short clientVersion) {
 607
 608         ShardTransactionIdentifier transactionId =
 609             ShardTransactionIdentifier.builder()
 610                 .remoteTransactionId(remoteTransactionId)
 611                 .build();
 612
 613         if(LOG.isDebugEnabled()) {
 614             LOG.debug("{}: Creating transaction : {} ", persistenceId(), transactionId);
 615         }
 616
 617         ActorRef transactionActor = createTypedTransactionActor(transactionType, transactionId,
 618                 transactionChainId, clientVersion);
 619
 620         return transactionActor;
 621     }
 622
 623     private void syncCommitTransaction(final DOMStoreWriteTransaction transaction)
 624         throws ExecutionException, InterruptedException {
 625         DOMStoreThreePhaseCommitCohort commitCohort = transaction.ready();
 626         commitCohort.preCommit().get();
 627         commitCohort.commit().get();
 628     }
 629
 630     private void commitWithNewTransaction(final Modification modification) {
 631         DOMStoreWriteTransaction tx = store.newWriteOnlyTransaction();
 632         modification.apply(tx);
 633         try {
 634             syncCommitTransaction(tx);
 635             shardMBean.incrementCommittedTransactionCount();
 636             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 637         } catch (InterruptedException | ExecutionException e) {
 638             shardMBean.incrementFailedTransactionsCount();
 639             LOG.error("{}: Failed to commit", persistenceId(), e);
 640         }
 641     }
 642
 643     private void updateSchemaContext(final UpdateSchemaContext message) {
 644         this.schemaContext = message.getSchemaContext();
 645         updateSchemaContext(message.getSchemaContext());
 646         store.onGlobalContextUpdated(message.getSchemaContext());
 647     }
 648
 649     @VisibleForTesting
 650     void updateSchemaContext(final SchemaContext schemaContext) {
 651         store.onGlobalContextUpdated(schemaContext);
 652     }
 653
 654     private void registerChangeListener(final RegisterChangeListener registerChangeListener) {
 655
 656         LOG.debug("{}: registerDataChangeListener for {}", persistenceId(), registerChangeListener.getPath());
 657
 658         ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
 659                                                      NormalizedNode<?, ?>>> registration;
 660         if(isLeader()) {
 661             registration = doChangeListenerRegistration(registerChangeListener);
 662         } else {
 663             LOG.debug("{}: Shard is not the leader - delaying registration", persistenceId());
 664
 665             DelayedListenerRegistration delayedReg =
 666                     new DelayedListenerRegistration(registerChangeListener);
 667             delayedListenerRegistrations.add(delayedReg);
 668             registration = delayedReg;
 669         }
 670
 671         ActorRef listenerRegistration = getContext().actorOf(
 672                 DataChangeListenerRegistration.props(registration));
 673
 674         LOG.debug("{}: registerDataChangeListener sending reply, listenerRegistrationPath = {} ",
 675                 persistenceId(), listenerRegistration.path());
 676
 677         getSender().tell(new RegisterChangeListenerReply(listenerRegistration.path()), getSelf());
 678     }
 679
 680     private ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
 681                                                NormalizedNode<?, ?>>> doChangeListenerRegistration(
 682             final RegisterChangeListener registerChangeListener) {
 683
 684         ActorSelection dataChangeListenerPath = getContext().system().actorSelection(
 685                 registerChangeListener.getDataChangeListenerPath());
 686
 687         // Notify the listener if notifications should be enabled or not
 688         // If this shard is the leader then it will enable notifications else
 689         // it will not
 690         dataChangeListenerPath.tell(new EnableNotification(true), getSelf());
 691
 692         // Now store a reference to the data change listener so it can be notified
 693         // at a later point if notifications should be enabled or disabled
 694         dataChangeListeners.add(dataChangeListenerPath);
 695
 696         AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>> listener =
 697                 new DataChangeListenerProxy(dataChangeListenerPath);
 698
 699         LOG.debug("{}: Registering for path {}", persistenceId(), registerChangeListener.getPath());
 700
 701         return store.registerChangeListener(registerChangeListener.getPath(), listener,
 702                 registerChangeListener.getScope());
 703     }
 704
 705     private boolean isMetricsCaptureEnabled(){
 706         CommonConfig config = new CommonConfig(getContext().system().settings().config());
 707         return config.isMetricCaptureEnabled();
 708     }
 709
 710     @Override
 711     protected
 712     void startLogRecoveryBatch(final int maxBatchSize) {
 713         currentLogRecoveryBatch = Lists.newArrayListWithCapacity(maxBatchSize);
 714
 715         if(LOG.isDebugEnabled()) {
 716             LOG.debug("{}: starting log recovery batch with max size {}", persistenceId(), maxBatchSize);
 717         }
 718     }
 719
 720     @Override
 721     protected void appendRecoveredLogEntry(final Payload data) {
 722         if(data instanceof ModificationPayload) {
 723             try {
 724                 currentLogRecoveryBatch.add(((ModificationPayload) data).getModification());
 725             } catch (ClassNotFoundException | IOException e) {
 726                 LOG.error("{}: Error extracting ModificationPayload", persistenceId(), e);
 727             }
 728         } else if (data instanceof CompositeModificationPayload) {
 729             currentLogRecoveryBatch.add(((CompositeModificationPayload) data).getModification());
 730         } else if (data instanceof CompositeModificationByteStringPayload) {
 731             currentLogRecoveryBatch.add(((CompositeModificationByteStringPayload) data).getModification());
 732         } else {
 733             LOG.error("{}: Unknown state received {} during recovery", persistenceId(), data);
 734         }
 735     }
 736
 737     @Override
 738     protected void applyRecoverySnapshot(final byte[] snapshotBytes) {
 739         if(recoveryCoordinator == null) {
 740             recoveryCoordinator = new ShardRecoveryCoordinator(persistenceId(), schemaContext,
 741                     LOG, name.toString());
 742         }
 743
 744         recoveryCoordinator.submit(snapshotBytes, store.newWriteOnlyTransaction());
 745
 746         if(LOG.isDebugEnabled()) {
 747             LOG.debug("{}: submitted recovery sbapshot", persistenceId());
 748         }
 749     }
 750
 751     @Override
 752     protected void applyCurrentLogRecoveryBatch() {
 753         if(recoveryCoordinator == null) {
 754             recoveryCoordinator = new ShardRecoveryCoordinator(persistenceId(), schemaContext,
 755                     LOG, name.toString());
 756         }
 757
 758         recoveryCoordinator.submit(currentLogRecoveryBatch, store.newWriteOnlyTransaction());
 759
 760         if(LOG.isDebugEnabled()) {
 761             LOG.debug("{}: submitted log recovery batch with size {}", persistenceId(),
 762                     currentLogRecoveryBatch.size());
 763         }
 764     }
 765
 766     @Override
 767     protected void onRecoveryComplete() {
 768         if(recoveryCoordinator != null) {
 769             Collection<DOMStoreWriteTransaction> txList = recoveryCoordinator.getTransactions();
 770
 771             if(LOG.isDebugEnabled()) {
 772                 LOG.debug("{}: recovery complete - committing {} Tx's", persistenceId(), txList.size());
 773             }
 774
 775             for(DOMStoreWriteTransaction tx: txList) {
 776                 try {
 777                     syncCommitTransaction(tx);
 778                     shardMBean.incrementCommittedTransactionCount();
 779                 } catch (InterruptedException | ExecutionException e) {
 780                     shardMBean.incrementFailedTransactionsCount();
 781                     LOG.error("{}: Failed to commit", persistenceId(), e);
 782                 }
 783             }
 784         }
 785
 786         recoveryCoordinator = null;
 787         currentLogRecoveryBatch = null;
 788         updateJournalStats();
 789
 790         //notify shard manager
 791         getContext().parent().tell(new ActorInitialized(), getSelf());
 792
 793         // Being paranoid here - this method should only be called once but just in case...
 794         if(txCommitTimeoutCheckSchedule == null) {
 795             // Schedule a message to be periodically sent to check if the current in-progress
 796             // transaction should be expired and aborted.
 797             FiniteDuration period = Duration.create(transactionCommitTimeout / 3, TimeUnit.MILLISECONDS);
 798             txCommitTimeoutCheckSchedule = getContext().system().scheduler().schedule(
 799                     period, period, getSelf(),
 800                     TX_COMMIT_TIMEOUT_CHECK_MESSAGE, getContext().dispatcher(), ActorRef.noSender());
 801         }
 802     }
 803
 804     @Override
 805     protected void applyState(final ActorRef clientActor, final String identifier, final Object data) {
 806
 807         if(data instanceof ModificationPayload) {
 808             try {
 809                 applyModificationToState(clientActor, identifier, ((ModificationPayload) data).getModification());
 810             } catch (ClassNotFoundException | IOException e) {
 811                 LOG.error("{}: Error extracting ModificationPayload", persistenceId(), e);
 812             }
 813         }
 814         else if (data instanceof CompositeModificationPayload) {
 815             Object modification = ((CompositeModificationPayload) data).getModification();
 816
 817             applyModificationToState(clientActor, identifier, modification);
 818         } else if(data instanceof CompositeModificationByteStringPayload ){
 819             Object modification = ((CompositeModificationByteStringPayload) data).getModification();
 820
 821             applyModificationToState(clientActor, identifier, modification);
 822         } else {
 823             LOG.error("{}: Unknown state received {} Class loader = {} CompositeNodeMod.ClassLoader = {}",
 824                     persistenceId(), data, data.getClass().getClassLoader(),
 825                     CompositeModificationPayload.class.getClassLoader());
 826         }
 827
 828         updateJournalStats();
 829
 830     }
 831
 832     private void applyModificationToState(ActorRef clientActor, String identifier, Object modification) {
 833         if(modification == null) {
 834             LOG.error(
 835                     "{}: modification is null - this is very unexpected, clientActor = {}, identifier = {}",
 836                     persistenceId(), identifier, clientActor != null ? clientActor.path().toString() : null);
 837         } else if(clientActor == null) {
 838             // There's no clientActor to which to send a commit reply so we must be applying
 839             // replicated state from the leader.
 840             commitWithNewTransaction(MutableCompositeModification.fromSerializable(modification));
 841         } else {
 842             // This must be the OK to commit after replication consensus.
 843             finishCommit(clientActor, identifier);
 844         }
 845     }
 846
 847     private void updateJournalStats() {
 848         ReplicatedLogEntry lastLogEntry = getLastLogEntry();
 849
 850         if (lastLogEntry != null) {
 851             shardMBean.setLastLogIndex(lastLogEntry.getIndex());
 852             shardMBean.setLastLogTerm(lastLogEntry.getTerm());
 853         }
 854
 855         shardMBean.setCommitIndex(getCommitIndex());
 856         shardMBean.setLastApplied(getLastApplied());
 857         shardMBean.setInMemoryJournalDataSize(getRaftActorContext().getReplicatedLog().dataSize());
 858     }
 859
 860     @Override
 861     protected void createSnapshot() {
 862         // Create a transaction actor. We are really going to treat the transaction as a worker
 863         // so that this actor does not get block building the snapshot. THe transaction actor will
 864         // after processing the CreateSnapshot message.
 865
 866         ActorRef createSnapshotTransaction = createTransaction(
 867                 TransactionProxy.TransactionType.READ_ONLY.ordinal(),
 868                 "createSnapshot" + ++createSnapshotTransactionCounter, "",
 869                 DataStoreVersions.CURRENT_VERSION);
 870
 871         createSnapshotTransaction.tell(CreateSnapshot.INSTANCE, self());
 872     }
 873
 874     @VisibleForTesting
 875     @Override
 876     protected void applySnapshot(final byte[] snapshotBytes) {
 877         // Since this will be done only on Recovery or when this actor is a Follower
 878         // we can safely commit everything in here. We not need to worry about event notifications
 879         // as they would have already been disabled on the follower
 880
 881         LOG.info("{}: Applying snapshot", persistenceId());
 882         try {
 883             DOMStoreWriteTransaction transaction = store.newWriteOnlyTransaction();
 884
 885             NormalizedNode<?, ?> node = SerializationUtils.deserializeNormalizedNode(snapshotBytes);
 886
 887             // delete everything first
 888             transaction.delete(DATASTORE_ROOT);
 889
 890             // Add everything from the remote node back
 891             transaction.write(DATASTORE_ROOT, node);
 892             syncCommitTransaction(transaction);
 893         } catch (InterruptedException | ExecutionException e) {
 894             LOG.error("{}: An exception occurred when applying snapshot", persistenceId(), e);
 895         } finally {
 896             LOG.info("{}: Done applying snapshot", persistenceId());
 897         }
 898     }
 899
 900     @Override
 901     protected void onStateChanged() {
 902         boolean isLeader = isLeader();
 903         for (ActorSelection dataChangeListener : dataChangeListeners) {
 904             dataChangeListener.tell(new EnableNotification(isLeader), getSelf());
 905         }
 906
 907         if(isLeader) {
 908             for(DelayedListenerRegistration reg: delayedListenerRegistrations) {
 909                 if(!reg.isClosed()) {
 910                     reg.setDelegate(doChangeListenerRegistration(reg.getRegisterChangeListener()));
 911                 }
 912             }
 913
 914             delayedListenerRegistrations.clear();
 915         }
 916
 917         shardMBean.setRaftState(getRaftState().name());
 918         shardMBean.setCurrentTerm(getCurrentTerm());
 919
 920         // If this actor is no longer the leader close all the transaction chains
 921         if(!isLeader){
 922             for(Map.Entry<String, DOMStoreTransactionChain> entry : transactionChains.entrySet()){
 923                 if(LOG.isDebugEnabled()) {
 924                     LOG.debug(
 925                         "{}: onStateChanged: Closing transaction chain {} because shard {} is no longer the leader",
 926                         persistenceId(), entry.getKey(), getId());
 927                 }
 928                 entry.getValue().close();
 929             }
 930
 931             transactionChains.clear();
 932         }
 933     }
 934
 935     @Override
 936     protected DataPersistenceProvider persistence() {
 937         return dataPersistenceProvider;
 938     }
 939
 940     @Override protected void onLeaderChanged(final String oldLeader, final String newLeader) {
 941         shardMBean.setLeader(newLeader);
 942     }
 943
 944     @Override public String persistenceId() {
 945         return this.name.toString();
 946     }
 947
 948     @VisibleForTesting
 949     DataPersistenceProvider getDataPersistenceProvider() {
 950         return dataPersistenceProvider;
 951     }
 952
 953     private static class ShardCreator implements Creator<Shard> {
 954
 955         private static final long serialVersionUID = 1L;
 956
 957         final ShardIdentifier name;
 958         final Map<ShardIdentifier, String> peerAddresses;
 959         final DatastoreContext datastoreContext;
 960         final SchemaContext schemaContext;
 961
 962         ShardCreator(final ShardIdentifier name, final Map<ShardIdentifier, String> peerAddresses,
 963                 final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 964             this.name = name;
 965             this.peerAddresses = peerAddresses;
 966             this.datastoreContext = datastoreContext;
 967             this.schemaContext = schemaContext;
 968         }
 969
 970         @Override
 971         public Shard create() throws Exception {
 972             return new Shard(name, peerAddresses, datastoreContext, schemaContext);
 973         }
 974     }
 975
 976     @VisibleForTesting
 977     InMemoryDOMDataStore getDataStore() {
 978         return store;
 979     }
 980
 981     @VisibleForTesting
 982     ShardStats getShardMBean() {
 983         return shardMBean;
 984     }
 985
 986     private static class DelayedListenerRegistration implements
 987         ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>>> {
 988
 989         private volatile boolean closed;
 990
 991         private final RegisterChangeListener registerChangeListener;
 992
 993         private volatile ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
 994                                                              NormalizedNode<?, ?>>> delegate;
 995
 996         DelayedListenerRegistration(final RegisterChangeListener registerChangeListener) {
 997             this.registerChangeListener = registerChangeListener;
 998         }
 999
1000         void setDelegate( final ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
1001                                             NormalizedNode<?, ?>>> registration) {
1002             this.delegate = registration;
1003         }
1004
1005         boolean isClosed() {
1006             return closed;
1007         }
1008
1009         RegisterChangeListener getRegisterChangeListener() {
1010             return registerChangeListener;
1011         }
1012
1013         @Override
1014         public AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>> getInstance() {
1015             return delegate != null ? delegate.getInstance() : null;
1016         }
1017
1018         @Override
1019         public void close() {
1020             closed = true;
1021             if(delegate != null) {
1022                 delegate.close();
1023             }
1024         }
1025     }
1026 }