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