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

   1 /*
   2  * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8
   9 package org.opendaylight.controller.cluster.datastore;
  10
  11 import akka.actor.ActorRef;
  12 import akka.actor.ActorSelection;
  13 import akka.actor.Cancellable;
  14 import akka.actor.PoisonPill;
  15 import akka.actor.Props;
  16 import akka.event.Logging;
  17 import akka.event.LoggingAdapter;
  18 import akka.japi.Creator;
  19 import akka.persistence.RecoveryFailure;
  20 import akka.serialization.Serialization;
  21 import com.google.common.annotations.VisibleForTesting;
  22 import com.google.common.base.Optional;
  23 import com.google.common.base.Preconditions;
  24 import com.google.common.collect.Lists;
  25 import com.google.common.util.concurrent.FutureCallback;
  26 import com.google.common.util.concurrent.Futures;
  27 import com.google.common.util.concurrent.ListenableFuture;
  28 import com.google.protobuf.ByteString;
  29 import com.google.protobuf.InvalidProtocolBufferException;
  30 import java.io.IOException;
  31 import java.util.Collection;
  32 import java.util.HashMap;
  33 import java.util.List;
  34 import java.util.Map;
  35 import java.util.concurrent.ExecutionException;
  36 import java.util.concurrent.TimeUnit;
  37 import javax.annotation.Nonnull;
  38 import org.opendaylight.controller.cluster.DataPersistenceProvider;
  39 import org.opendaylight.controller.cluster.common.actor.CommonConfig;
  40 import org.opendaylight.controller.cluster.common.actor.MeteringBehavior;
  41 import org.opendaylight.controller.cluster.datastore.ShardCommitCoordinator.CohortEntry;
  42 import org.opendaylight.controller.cluster.datastore.compat.BackwardsCompatibleThreePhaseCommitCohort;
  43 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
  44 import org.opendaylight.controller.cluster.datastore.identifiers.ShardIdentifier;
  45 import org.opendaylight.controller.cluster.datastore.identifiers.ShardTransactionIdentifier;
  46 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardMBeanFactory;
  47 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardStats;
  48 import org.opendaylight.controller.cluster.datastore.messages.AbortTransaction;
  49 import org.opendaylight.controller.cluster.datastore.messages.AbortTransactionReply;
  50 import org.opendaylight.controller.cluster.datastore.messages.ActorInitialized;
  51 import org.opendaylight.controller.cluster.datastore.messages.CanCommitTransaction;
  52 import org.opendaylight.controller.cluster.datastore.messages.CloseTransactionChain;
  53 import org.opendaylight.controller.cluster.datastore.messages.CommitTransaction;
  54 import org.opendaylight.controller.cluster.datastore.messages.CommitTransactionReply;
  55 import org.opendaylight.controller.cluster.datastore.messages.CreateTransaction;
  56 import org.opendaylight.controller.cluster.datastore.messages.CreateTransactionReply;
  57 import org.opendaylight.controller.cluster.datastore.messages.EnableNotification;
  58 import org.opendaylight.controller.cluster.datastore.messages.ForwardedReadyTransaction;
  59 import org.opendaylight.controller.cluster.datastore.messages.PeerAddressResolved;
  60 import org.opendaylight.controller.cluster.datastore.messages.ReadData;
  61 import org.opendaylight.controller.cluster.datastore.messages.ReadDataReply;
  62 import org.opendaylight.controller.cluster.datastore.messages.ReadyTransactionReply;
  63 import org.opendaylight.controller.cluster.datastore.messages.RegisterChangeListener;
  64 import org.opendaylight.controller.cluster.datastore.messages.RegisterChangeListenerReply;
  65 import org.opendaylight.controller.cluster.datastore.messages.UpdateSchemaContext;
  66 import org.opendaylight.controller.cluster.datastore.modification.Modification;
  67 import org.opendaylight.controller.cluster.datastore.modification.ModificationPayload;
  68 import org.opendaylight.controller.cluster.datastore.modification.MutableCompositeModification;
  69 import org.opendaylight.controller.cluster.datastore.node.NormalizedNodeToNodeCodec;
  70 import org.opendaylight.controller.cluster.notifications.RoleChangeNotifier;
  71 import org.opendaylight.controller.cluster.raft.RaftActor;
  72 import org.opendaylight.controller.cluster.raft.ReplicatedLogEntry;
  73 import org.opendaylight.controller.cluster.raft.base.messages.CaptureSnapshotReply;
  74 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationByteStringPayload;
  75 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationPayload;
  76 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.Payload;
  77 import org.opendaylight.controller.md.sal.common.api.data.AsyncDataChangeListener;
  78 import org.opendaylight.controller.md.sal.dom.store.impl.InMemoryDOMDataStore;
  79 import org.opendaylight.controller.md.sal.dom.store.impl.InMemoryDOMDataStoreFactory;
  80 import org.opendaylight.controller.protobuff.messages.common.NormalizedNodeMessages;
  81 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  82 import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransactionChain;
  83 import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransactionFactory;
  84 import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
  85 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  86 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  87 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  88 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  89 import scala.concurrent.duration.Duration;
  90 import scala.concurrent.duration.FiniteDuration;
  91
  92 /**
  93  * A Shard represents a portion of the logical data tree <br/>
  94  * <p>
  95  * Our Shard uses InMemoryDataStore as it's internal representation and delegates all requests it
  96  * </p>
  97  */
  98 public class Shard extends RaftActor {
  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     private final LoggingAdapter LOG =
 109         Logging.getLogger(getContext().system(), this);
 110
 111     /// The name of this shard
 112     private final ShardIdentifier name;
 113
 114     private final ShardStats shardMBean;
 115
 116     private final List<ActorSelection> dataChangeListeners =  Lists.newArrayList();
 117
 118     private final List<DelayedListenerRegistration> delayedListenerRegistrations =
 119                                                                        Lists.newArrayList();
 120
 121     private final DatastoreContext datastoreContext;
 122
 123     private final DataPersistenceProvider dataPersistenceProvider;
 124
 125     private SchemaContext schemaContext;
 126
 127     private ActorRef createSnapshotTransaction;
 128
 129     private int createSnapshotTransactionCounter;
 130
 131     private final ShardCommitCoordinator commitCoordinator;
 132
 133     private final long transactionCommitTimeout;
 134
 135     private Cancellable txCommitTimeoutCheckSchedule;
 136
 137     private final Optional<ActorRef> roleChangeNotifier;
 138
 139     /**
 140      * Coordinates persistence recovery on startup.
 141      */
 142     private ShardRecoveryCoordinator recoveryCoordinator;
 143     private List<Object> currentLogRecoveryBatch;
 144
 145     private final Map<String, DOMStoreTransactionChain> transactionChains = new HashMap<>();
 146
 147     protected Shard(final ShardIdentifier name, final Map<ShardIdentifier, String> peerAddresses,
 148             final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 149         super(name.toString(), mapPeerAddresses(peerAddresses),
 150                 Optional.of(datastoreContext.getShardRaftConfig()));
 151
 152         this.name = name;
 153         this.datastoreContext = datastoreContext;
 154         this.schemaContext = schemaContext;
 155         this.dataPersistenceProvider = (datastoreContext.isPersistent()) ? new PersistentDataProvider() : new NonPersistentRaftDataProvider();
 156
 157         LOG.info("Shard created : {} persistent : {}", name, datastoreContext.isPersistent());
 158
 159         store = InMemoryDOMDataStoreFactory.create(name.toString(), null,
 160                 datastoreContext.getDataStoreProperties());
 161
 162         if(schemaContext != null) {
 163             store.onGlobalContextUpdated(schemaContext);
 164         }
 165
 166         shardMBean = ShardMBeanFactory.getShardStatsMBean(name.toString(),
 167                 datastoreContext.getDataStoreMXBeanType());
 168         shardMBean.setNotificationManager(store.getDataChangeListenerNotificationManager());
 169
 170         if (isMetricsCaptureEnabled()) {
 171             getContext().become(new MeteringBehavior(this));
 172         }
 173
 174         commitCoordinator = new ShardCommitCoordinator(TimeUnit.SECONDS.convert(1, TimeUnit.MINUTES),
 175                 datastoreContext.getShardTransactionCommitQueueCapacity());
 176
 177         transactionCommitTimeout = TimeUnit.MILLISECONDS.convert(
 178                 datastoreContext.getShardTransactionCommitTimeoutInSeconds(), TimeUnit.SECONDS);
 179
 180         // create a notifier actor for each cluster member
 181         roleChangeNotifier = createRoleChangeNotifier(name.toString());
 182     }
 183
 184     private static Map<String, String> mapPeerAddresses(
 185         final Map<ShardIdentifier, String> peerAddresses) {
 186         Map<String, String> map = new HashMap<>();
 187
 188         for (Map.Entry<ShardIdentifier, String> entry : peerAddresses
 189             .entrySet()) {
 190             map.put(entry.getKey().toString(), entry.getValue());
 191         }
 192
 193         return map;
 194     }
 195
 196     public static Props props(final ShardIdentifier name,
 197         final Map<ShardIdentifier, String> peerAddresses,
 198         final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 199         Preconditions.checkNotNull(name, "name should not be null");
 200         Preconditions.checkNotNull(peerAddresses, "peerAddresses should not be null");
 201         Preconditions.checkNotNull(datastoreContext, "dataStoreContext should not be null");
 202         Preconditions.checkNotNull(schemaContext, "schemaContext should not be null");
 203
 204         return Props.create(new ShardCreator(name, peerAddresses, datastoreContext, schemaContext));
 205     }
 206
 207     private Optional<ActorRef> createRoleChangeNotifier(String shardId) {
 208         ActorRef shardRoleChangeNotifier = this.getContext().actorOf(
 209             RoleChangeNotifier.getProps(shardId), shardId + "-notifier");
 210         return Optional.<ActorRef>of(shardRoleChangeNotifier);
 211     }
 212
 213     @Override
 214     public void postStop() {
 215         super.postStop();
 216
 217         if(txCommitTimeoutCheckSchedule != null) {
 218             txCommitTimeoutCheckSchedule.cancel();
 219         }
 220     }
 221
 222     @Override
 223     public void onReceiveRecover(final Object message) throws Exception {
 224         if(LOG.isDebugEnabled()) {
 225             LOG.debug("onReceiveRecover: Received message {} from {}",
 226                 message.getClass().toString(),
 227                 getSender());
 228         }
 229
 230         if (message instanceof RecoveryFailure){
 231             LOG.error(((RecoveryFailure) message).cause(), "Recovery failed because of this cause");
 232
 233             // Even though recovery failed, we still need to finish our recovery, eg send the
 234             // ActorInitialized message and start the txCommitTimeoutCheckSchedule.
 235             onRecoveryComplete();
 236         } else {
 237             super.onReceiveRecover(message);
 238         }
 239     }
 240
 241     @Override
 242     public void onReceiveCommand(final Object message) throws Exception {
 243         if(LOG.isDebugEnabled()) {
 244             LOG.debug("onReceiveCommand: Received message {} from {}", message, getSender());
 245         }
 246
 247         if(message.getClass().equals(ReadDataReply.SERIALIZABLE_CLASS)) {
 248             handleReadDataReply(message);
 249         } else if (message.getClass().equals(CreateTransaction.SERIALIZABLE_CLASS)) {
 250             handleCreateTransaction(message);
 251         } else if(message instanceof ForwardedReadyTransaction) {
 252             handleForwardedReadyTransaction((ForwardedReadyTransaction)message);
 253         } else if(message.getClass().equals(CanCommitTransaction.SERIALIZABLE_CLASS)) {
 254             handleCanCommitTransaction(CanCommitTransaction.fromSerializable(message));
 255         } else if(message.getClass().equals(CommitTransaction.SERIALIZABLE_CLASS)) {
 256             handleCommitTransaction(CommitTransaction.fromSerializable(message));
 257         } else if(message.getClass().equals(AbortTransaction.SERIALIZABLE_CLASS)) {
 258             handleAbortTransaction(AbortTransaction.fromSerializable(message));
 259         } else if (message.getClass().equals(CloseTransactionChain.SERIALIZABLE_CLASS)){
 260             closeTransactionChain(CloseTransactionChain.fromSerializable(message));
 261         } else if (message instanceof RegisterChangeListener) {
 262             registerChangeListener((RegisterChangeListener) message);
 263         } else if (message instanceof UpdateSchemaContext) {
 264             updateSchemaContext((UpdateSchemaContext) message);
 265         } else if (message instanceof PeerAddressResolved) {
 266             PeerAddressResolved resolved = (PeerAddressResolved) message;
 267             setPeerAddress(resolved.getPeerId().toString(),
 268                 resolved.getPeerAddress());
 269         } else if(message.equals(TX_COMMIT_TIMEOUT_CHECK_MESSAGE)) {
 270             handleTransactionCommitTimeoutCheck();
 271         } else {
 272             super.onReceiveCommand(message);
 273         }
 274     }
 275
 276     @Override
 277     protected Optional<ActorRef> getRoleChangeNotifier() {
 278         return roleChangeNotifier;
 279     }
 280
 281     private void handleTransactionCommitTimeoutCheck() {
 282         CohortEntry cohortEntry = commitCoordinator.getCurrentCohortEntry();
 283         if(cohortEntry != null) {
 284             long elapsed = System.currentTimeMillis() - cohortEntry.getLastAccessTime();
 285             if(elapsed > transactionCommitTimeout) {
 286                 LOG.warning("Current transaction {} has timed out after {} ms - aborting",
 287                         cohortEntry.getTransactionID(), transactionCommitTimeout);
 288
 289                 doAbortTransaction(cohortEntry.getTransactionID(), null);
 290             }
 291         }
 292     }
 293
 294     private void handleCommitTransaction(final CommitTransaction commit) {
 295         final String transactionID = commit.getTransactionID();
 296
 297         LOG.debug("Committing transaction {}", transactionID);
 298
 299         // Get the current in-progress cohort entry in the commitCoordinator if it corresponds to
 300         // this transaction.
 301         final CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 302         if(cohortEntry == null) {
 303             // We're not the current Tx - the Tx was likely expired b/c it took too long in
 304             // between the canCommit and commit messages.
 305             IllegalStateException ex = new IllegalStateException(
 306                     String.format("Cannot commit transaction %s - it is not the current transaction",
 307                             transactionID));
 308             LOG.error(ex.getMessage());
 309             shardMBean.incrementFailedTransactionsCount();
 310             getSender().tell(new akka.actor.Status.Failure(ex), getSelf());
 311             return;
 312         }
 313
 314         // We perform the preCommit phase here atomically with the commit phase. This is an
 315         // optimization to eliminate the overhead of an extra preCommit message. We lose front-end
 316         // coordination of preCommit across shards in case of failure but preCommit should not
 317         // normally fail since we ensure only one concurrent 3-phase commit.
 318
 319         try {
 320             // We block on the future here so we don't have to worry about possibly accessing our
 321             // state on a different thread outside of our dispatcher. Also, the data store
 322             // currently uses a same thread executor anyway.
 323             cohortEntry.getCohort().preCommit().get();
 324
 325             // If we do not have any followers and we are not using persistence we can
 326             // apply modification to the state immediately
 327             if(!hasFollowers() && !persistence().isRecoveryApplicable()){
 328                 applyModificationToState(getSender(), transactionID, cohortEntry.getModification());
 329             } else {
 330                 Shard.this.persistData(getSender(), transactionID,
 331                         new ModificationPayload(cohortEntry.getModification()));
 332             }
 333         } catch (InterruptedException | ExecutionException | IOException e) {
 334             LOG.error(e, "An exception occurred while preCommitting transaction {}",
 335                     cohortEntry.getTransactionID());
 336             shardMBean.incrementFailedTransactionsCount();
 337             getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 338         }
 339
 340         cohortEntry.updateLastAccessTime();
 341     }
 342
 343     private void finishCommit(@Nonnull final ActorRef sender, final @Nonnull String transactionID) {
 344         // With persistence enabled, this method is called via applyState by the leader strategy
 345         // after the commit has been replicated to a majority of the followers.
 346
 347         CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 348         if(cohortEntry == null) {
 349             // The transaction is no longer the current commit. This can happen if the transaction
 350             // was aborted prior, most likely due to timeout in the front-end. We need to finish
 351             // committing the transaction though since it was successfully persisted and replicated
 352             // however we can't use the original cohort b/c it was already preCommitted and may
 353             // conflict with the current commit or may have been aborted so we commit with a new
 354             // transaction.
 355             cohortEntry = commitCoordinator.getAndRemoveCohortEntry(transactionID);
 356             if(cohortEntry != null) {
 357                 commitWithNewTransaction(cohortEntry.getModification());
 358                 sender.tell(CommitTransactionReply.INSTANCE.toSerializable(), getSelf());
 359             } else {
 360                 // This really shouldn't happen - it likely means that persistence or replication
 361                 // took so long to complete such that the cohort entry was expired from the cache.
 362                 IllegalStateException ex = new IllegalStateException(
 363                         String.format("Could not finish committing transaction %s - no CohortEntry found",
 364                                 transactionID));
 365                 LOG.error(ex.getMessage());
 366                 sender.tell(new akka.actor.Status.Failure(ex), getSelf());
 367             }
 368
 369             return;
 370         }
 371
 372         LOG.debug("Finishing commit for transaction {}", cohortEntry.getTransactionID());
 373
 374         try {
 375             // We block on the future here so we don't have to worry about possibly accessing our
 376             // state on a different thread outside of our dispatcher. Also, the data store
 377             // currently uses a same thread executor anyway.
 378             cohortEntry.getCohort().commit().get();
 379
 380             sender.tell(CommitTransactionReply.INSTANCE.toSerializable(), getSelf());
 381
 382             shardMBean.incrementCommittedTransactionCount();
 383             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 384
 385         } catch (InterruptedException | ExecutionException e) {
 386             sender.tell(new akka.actor.Status.Failure(e), getSelf());
 387
 388             LOG.error(e, "An exception occurred while committing transaction {}", transactionID);
 389             shardMBean.incrementFailedTransactionsCount();
 390         }
 391
 392         commitCoordinator.currentTransactionComplete(transactionID, true);
 393     }
 394
 395     private void handleCanCommitTransaction(final CanCommitTransaction canCommit) {
 396         LOG.debug("Can committing transaction {}", canCommit.getTransactionID());
 397         commitCoordinator.handleCanCommit(canCommit, getSender(), self());
 398     }
 399
 400     private void handleForwardedReadyTransaction(ForwardedReadyTransaction ready) {
 401         LOG.debug("Readying transaction {}, client version {}", ready.getTransactionID(),
 402                 ready.getTxnClientVersion());
 403
 404         // This message is forwarded by the ShardTransaction on ready. We cache the cohort in the
 405         // commitCoordinator in preparation for the subsequent three phase commit initiated by
 406         // the front-end.
 407         commitCoordinator.transactionReady(ready.getTransactionID(), ready.getCohort(),
 408                 ready.getModification());
 409
 410         // Return our actor path as we'll handle the three phase commit, except if the Tx client
 411         // version < 1 (Helium-1 version). This means the Tx was initiated by a base Helium version
 412         // node. In that case, the subsequent 3-phase commit messages won't contain the
 413         // transactionId so to maintain backwards compatibility, we create a separate cohort actor
 414         // to provide the compatible behavior.
 415         ActorRef replyActorPath = self();
 416         if(ready.getTxnClientVersion() < DataStoreVersions.HELIUM_1_VERSION) {
 417             LOG.debug("Creating BackwardsCompatibleThreePhaseCommitCohort");
 418             replyActorPath = getContext().actorOf(BackwardsCompatibleThreePhaseCommitCohort.props(
 419                     ready.getTransactionID()));
 420         }
 421
 422         ReadyTransactionReply readyTransactionReply = new ReadyTransactionReply(
 423                 Serialization.serializedActorPath(replyActorPath));
 424         getSender().tell(ready.isReturnSerialized() ? readyTransactionReply.toSerializable() :
 425                 readyTransactionReply, getSelf());
 426     }
 427
 428     private void handleAbortTransaction(final AbortTransaction abort) {
 429         doAbortTransaction(abort.getTransactionID(), getSender());
 430     }
 431
 432     void doAbortTransaction(final String transactionID, final ActorRef sender) {
 433         final CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 434         if(cohortEntry != null) {
 435             LOG.debug("Aborting transaction {}", transactionID);
 436
 437             // We don't remove the cached cohort entry here (ie pass false) in case the Tx was
 438             // aborted during replication in which case we may still commit locally if replication
 439             // succeeds.
 440             commitCoordinator.currentTransactionComplete(transactionID, false);
 441
 442             final ListenableFuture<Void> future = cohortEntry.getCohort().abort();
 443             final ActorRef self = getSelf();
 444
 445             Futures.addCallback(future, new FutureCallback<Void>() {
 446                 @Override
 447                 public void onSuccess(final Void v) {
 448                     shardMBean.incrementAbortTransactionsCount();
 449
 450                     if(sender != null) {
 451                         sender.tell(AbortTransactionReply.INSTANCE.toSerializable(), self);
 452                     }
 453                 }
 454
 455                 @Override
 456                 public void onFailure(final Throwable t) {
 457                     LOG.error(t, "An exception happened during abort");
 458
 459                     if(sender != null) {
 460                         sender.tell(new akka.actor.Status.Failure(t), self);
 461                     }
 462                 }
 463             });
 464         }
 465     }
 466
 467     private void handleCreateTransaction(final Object message) {
 468         if (isLeader()) {
 469             createTransaction(CreateTransaction.fromSerializable(message));
 470         } else if (getLeader() != null) {
 471             getLeader().forward(message, getContext());
 472         } else {
 473             getSender().tell(new akka.actor.Status.Failure(new NoShardLeaderException(
 474                 "Could not find shard leader so transaction cannot be created. This typically happens" +
 475                 " when the system is coming up or recovering and a leader is being elected. Try again" +
 476                 " later.")), getSelf());
 477         }
 478     }
 479
 480     private void handleReadDataReply(final Object message) {
 481         // This must be for install snapshot. Don't want to open this up and trigger
 482         // deSerialization
 483
 484         self().tell(new CaptureSnapshotReply(ReadDataReply.fromSerializableAsByteString(message)),
 485                 self());
 486
 487         createSnapshotTransaction = null;
 488
 489         // Send a PoisonPill instead of sending close transaction because we do not really need
 490         // a response
 491         getSender().tell(PoisonPill.getInstance(), self());
 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 getContext().actorOf(
 527                 ShardTransaction.props(factory.newReadOnlyTransaction(), getSelf(),
 528                         schemaContext,datastoreContext, shardMBean,
 529                         transactionId.getRemoteTransactionId(), clientVersion),
 530                         transactionId.toString());
 531
 532         } else if (transactionType == TransactionProxy.TransactionType.READ_WRITE.ordinal()) {
 533
 534             shardMBean.incrementReadWriteTransactionCount();
 535
 536             return getContext().actorOf(
 537                 ShardTransaction.props(factory.newReadWriteTransaction(), getSelf(),
 538                         schemaContext, datastoreContext, shardMBean,
 539                         transactionId.getRemoteTransactionId(), clientVersion),
 540                         transactionId.toString());
 541
 542
 543         } else if (transactionType == TransactionProxy.TransactionType.WRITE_ONLY.ordinal()) {
 544
 545             shardMBean.incrementWriteOnlyTransactionCount();
 546
 547             return getContext().actorOf(
 548                 ShardTransaction.props(factory.newWriteOnlyTransaction(), getSelf(),
 549                         schemaContext, datastoreContext, shardMBean,
 550                         transactionId.getRemoteTransactionId(), clientVersion),
 551                         transactionId.toString());
 552         } else {
 553             throw new IllegalArgumentException(
 554                 "Shard="+name + ":CreateTransaction message has unidentified transaction type="
 555                     + transactionType);
 556         }
 557     }
 558
 559     private void createTransaction(CreateTransaction createTransaction) {
 560         try {
 561             ActorRef transactionActor = createTransaction(createTransaction.getTransactionType(),
 562                 createTransaction.getTransactionId(), createTransaction.getTransactionChainId(),
 563                 createTransaction.getVersion());
 564
 565             getSender().tell(new CreateTransactionReply(Serialization.serializedActorPath(transactionActor),
 566                     createTransaction.getTransactionId()).toSerializable(), getSelf());
 567         } catch (Exception e) {
 568             getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 569         }
 570     }
 571
 572     private ActorRef createTransaction(int transactionType, String remoteTransactionId,
 573             String transactionChainId, short clientVersion) {
 574
 575         ShardTransactionIdentifier transactionId =
 576             ShardTransactionIdentifier.builder()
 577                 .remoteTransactionId(remoteTransactionId)
 578                 .build();
 579
 580         if(LOG.isDebugEnabled()) {
 581             LOG.debug("Creating transaction : {} ", transactionId);
 582         }
 583
 584         ActorRef transactionActor = createTypedTransactionActor(transactionType, transactionId,
 585                 transactionChainId, clientVersion);
 586
 587         return transactionActor;
 588     }
 589
 590     private void syncCommitTransaction(final DOMStoreWriteTransaction transaction)
 591         throws ExecutionException, InterruptedException {
 592         DOMStoreThreePhaseCommitCohort commitCohort = transaction.ready();
 593         commitCohort.preCommit().get();
 594         commitCohort.commit().get();
 595     }
 596
 597     private void commitWithNewTransaction(final Modification modification) {
 598         DOMStoreWriteTransaction tx = store.newWriteOnlyTransaction();
 599         modification.apply(tx);
 600         try {
 601             syncCommitTransaction(tx);
 602             shardMBean.incrementCommittedTransactionCount();
 603             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 604         } catch (InterruptedException | ExecutionException e) {
 605             shardMBean.incrementFailedTransactionsCount();
 606             LOG.error(e, "Failed to commit");
 607         }
 608     }
 609
 610     private void updateSchemaContext(final UpdateSchemaContext message) {
 611         this.schemaContext = message.getSchemaContext();
 612         updateSchemaContext(message.getSchemaContext());
 613         store.onGlobalContextUpdated(message.getSchemaContext());
 614     }
 615
 616     @VisibleForTesting
 617     void updateSchemaContext(final SchemaContext schemaContext) {
 618         store.onGlobalContextUpdated(schemaContext);
 619     }
 620
 621     private void registerChangeListener(final RegisterChangeListener registerChangeListener) {
 622
 623         LOG.debug("registerDataChangeListener for {}", registerChangeListener.getPath());
 624
 625         ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
 626                                                      NormalizedNode<?, ?>>> registration;
 627         if(isLeader()) {
 628             registration = doChangeListenerRegistration(registerChangeListener);
 629         } else {
 630             LOG.debug("Shard is not the leader - delaying registration");
 631
 632             DelayedListenerRegistration delayedReg =
 633                     new DelayedListenerRegistration(registerChangeListener);
 634             delayedListenerRegistrations.add(delayedReg);
 635             registration = delayedReg;
 636         }
 637
 638         ActorRef listenerRegistration = getContext().actorOf(
 639                 DataChangeListenerRegistration.props(registration));
 640
 641         LOG.debug("registerDataChangeListener sending reply, listenerRegistrationPath = {} ",
 642                     listenerRegistration.path());
 643
 644         getSender().tell(new RegisterChangeListenerReply(listenerRegistration.path()), getSelf());
 645     }
 646
 647     private ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
 648                                                NormalizedNode<?, ?>>> doChangeListenerRegistration(
 649             final RegisterChangeListener registerChangeListener) {
 650
 651         ActorSelection dataChangeListenerPath = getContext().system().actorSelection(
 652                 registerChangeListener.getDataChangeListenerPath());
 653
 654         // Notify the listener if notifications should be enabled or not
 655         // If this shard is the leader then it will enable notifications else
 656         // it will not
 657         dataChangeListenerPath.tell(new EnableNotification(true), getSelf());
 658
 659         // Now store a reference to the data change listener so it can be notified
 660         // at a later point if notifications should be enabled or disabled
 661         dataChangeListeners.add(dataChangeListenerPath);
 662
 663         AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>> listener =
 664                 new DataChangeListenerProxy(dataChangeListenerPath);
 665
 666         LOG.debug("Registering for path {}", registerChangeListener.getPath());
 667
 668         return store.registerChangeListener(registerChangeListener.getPath(), listener,
 669                 registerChangeListener.getScope());
 670     }
 671
 672     private boolean isMetricsCaptureEnabled(){
 673         CommonConfig config = new CommonConfig(getContext().system().settings().config());
 674         return config.isMetricCaptureEnabled();
 675     }
 676
 677     @Override
 678     protected
 679     void startLogRecoveryBatch(final int maxBatchSize) {
 680         currentLogRecoveryBatch = Lists.newArrayListWithCapacity(maxBatchSize);
 681
 682         if(LOG.isDebugEnabled()) {
 683             LOG.debug("{} : starting log recovery batch with max size {}", persistenceId(), maxBatchSize);
 684         }
 685     }
 686
 687     @Override
 688     protected void appendRecoveredLogEntry(final Payload data) {
 689         if(data instanceof ModificationPayload) {
 690             try {
 691                 currentLogRecoveryBatch.add(((ModificationPayload) data).getModification());
 692             } catch (ClassNotFoundException | IOException e) {
 693                 LOG.error(e, "Error extracting ModificationPayload");
 694             }
 695         } else if (data instanceof CompositeModificationPayload) {
 696             currentLogRecoveryBatch.add(((CompositeModificationPayload) data).getModification());
 697         } else if (data instanceof CompositeModificationByteStringPayload) {
 698             currentLogRecoveryBatch.add(((CompositeModificationByteStringPayload) data).getModification());
 699         } else {
 700             LOG.error("Unknown state received {} during recovery", data);
 701         }
 702     }
 703
 704     @Override
 705     protected void applyRecoverySnapshot(final ByteString snapshot) {
 706         if(recoveryCoordinator == null) {
 707             recoveryCoordinator = new ShardRecoveryCoordinator(persistenceId(), schemaContext);
 708         }
 709
 710         recoveryCoordinator.submit(snapshot, store.newWriteOnlyTransaction());
 711
 712         if(LOG.isDebugEnabled()) {
 713             LOG.debug("{} : submitted recovery sbapshot", persistenceId());
 714         }
 715     }
 716
 717     @Override
 718     protected void applyCurrentLogRecoveryBatch() {
 719         if(recoveryCoordinator == null) {
 720             recoveryCoordinator = new ShardRecoveryCoordinator(persistenceId(), schemaContext);
 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(e, "Failed to commit");
 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(e, "Error extracting ModificationPayload");
 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                     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                     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         if (createSnapshotTransaction == null) {
 828
 829             // Create a transaction. We are really going to treat the transaction as a worker
 830             // so that this actor does not get block building the snapshot
 831             createSnapshotTransaction = createTransaction(
 832                 TransactionProxy.TransactionType.READ_ONLY.ordinal(),
 833                 "createSnapshot" + ++createSnapshotTransactionCounter, "",
 834                 DataStoreVersions.CURRENT_VERSION);
 835
 836             createSnapshotTransaction.tell(
 837                 new ReadData(YangInstanceIdentifier.builder().build()).toSerializable(), self());
 838
 839         }
 840     }
 841
 842     @VisibleForTesting
 843     @Override
 844     protected void applySnapshot(final ByteString snapshot) {
 845         // Since this will be done only on Recovery or when this actor is a Follower
 846         // we can safely commit everything in here. We not need to worry about event notifications
 847         // as they would have already been disabled on the follower
 848
 849         LOG.info("Applying snapshot");
 850         try {
 851             DOMStoreWriteTransaction transaction = store.newWriteOnlyTransaction();
 852             NormalizedNodeMessages.Node serializedNode = NormalizedNodeMessages.Node.parseFrom(snapshot);
 853             NormalizedNode<?, ?> node = new NormalizedNodeToNodeCodec(schemaContext)
 854                 .decode(serializedNode);
 855
 856             // delete everything first
 857             transaction.delete(YangInstanceIdentifier.builder().build());
 858
 859             // Add everything from the remote node back
 860             transaction.write(YangInstanceIdentifier.builder().build(), node);
 861             syncCommitTransaction(transaction);
 862         } catch (InvalidProtocolBufferException | InterruptedException | ExecutionException e) {
 863             LOG.error(e, "An exception occurred when applying snapshot");
 864         } finally {
 865             LOG.info("Done applying snapshot");
 866         }
 867     }
 868
 869     @Override
 870     protected void onStateChanged() {
 871         boolean isLeader = isLeader();
 872         for (ActorSelection dataChangeListener : dataChangeListeners) {
 873             dataChangeListener.tell(new EnableNotification(isLeader), getSelf());
 874         }
 875
 876         if(isLeader) {
 877             for(DelayedListenerRegistration reg: delayedListenerRegistrations) {
 878                 if(!reg.isClosed()) {
 879                     reg.setDelegate(doChangeListenerRegistration(reg.getRegisterChangeListener()));
 880                 }
 881             }
 882
 883             delayedListenerRegistrations.clear();
 884         }
 885
 886         shardMBean.setRaftState(getRaftState().name());
 887         shardMBean.setCurrentTerm(getCurrentTerm());
 888
 889         // If this actor is no longer the leader close all the transaction chains
 890         if(!isLeader){
 891             for(Map.Entry<String, DOMStoreTransactionChain> entry : transactionChains.entrySet()){
 892                 if(LOG.isDebugEnabled()) {
 893                     LOG.debug(
 894                         "onStateChanged: Closing transaction chain {} because shard {} is no longer the leader",
 895                         entry.getKey(), getId());
 896                 }
 897                 entry.getValue().close();
 898             }
 899
 900             transactionChains.clear();
 901         }
 902     }
 903
 904     @Override
 905     protected DataPersistenceProvider persistence() {
 906         return dataPersistenceProvider;
 907     }
 908
 909     @Override protected void onLeaderChanged(final String oldLeader, final String newLeader) {
 910         shardMBean.setLeader(newLeader);
 911     }
 912
 913     @Override public String persistenceId() {
 914         return this.name.toString();
 915     }
 916
 917     @VisibleForTesting
 918     DataPersistenceProvider getDataPersistenceProvider() {
 919         return dataPersistenceProvider;
 920     }
 921
 922     private static class ShardCreator implements Creator<Shard> {
 923
 924         private static final long serialVersionUID = 1L;
 925
 926         final ShardIdentifier name;
 927         final Map<ShardIdentifier, String> peerAddresses;
 928         final DatastoreContext datastoreContext;
 929         final SchemaContext schemaContext;
 930
 931         ShardCreator(final ShardIdentifier name, final Map<ShardIdentifier, String> peerAddresses,
 932                 final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 933             this.name = name;
 934             this.peerAddresses = peerAddresses;
 935             this.datastoreContext = datastoreContext;
 936             this.schemaContext = schemaContext;
 937         }
 938
 939         @Override
 940         public Shard create() throws Exception {
 941             return new Shard(name, peerAddresses, datastoreContext, schemaContext);
 942         }
 943     }
 944
 945     @VisibleForTesting
 946     InMemoryDOMDataStore getDataStore() {
 947         return store;
 948     }
 949
 950     @VisibleForTesting
 951     ShardStats getShardMBean() {
 952         return shardMBean;
 953     }
 954
 955     private static class DelayedListenerRegistration implements
 956         ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>>> {
 957
 958         private volatile boolean closed;
 959
 960         private final RegisterChangeListener registerChangeListener;
 961
 962         private volatile ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
 963                                                              NormalizedNode<?, ?>>> delegate;
 964
 965         DelayedListenerRegistration(final RegisterChangeListener registerChangeListener) {
 966             this.registerChangeListener = registerChangeListener;
 967         }
 968
 969         void setDelegate( final ListenerRegistration<AsyncDataChangeListener<YangInstanceIdentifier,
 970                                             NormalizedNode<?, ?>>> registration) {
 971             this.delegate = registration;
 972         }
 973
 974         boolean isClosed() {
 975             return closed;
 976         }
 977
 978         RegisterChangeListener getRegisterChangeListener() {
 979             return registerChangeListener;
 980         }
 981
 982         @Override
 983         public AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>> getInstance() {
 984             return delegate != null ? delegate.getInstance() : null;
 985         }
 986
 987         @Override
 988         public void close() {
 989             closed = true;
 990             if(delegate != null) {
 991                 delegate.close();
 992             }
 993         }
 994     }
 995 }