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