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