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

   1 /*
   2  * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8
   9 package org.opendaylight.controller.cluster.datastore;
  10
  11 import akka.actor.ActorRef;
  12 import akka.actor.ActorSelection;
  13 import akka.actor.Cancellable;
  14 import akka.actor.Props;
  15 import akka.japi.Creator;
  16 import akka.persistence.RecoveryFailure;
  17 import akka.serialization.Serialization;
  18 import com.google.common.annotations.VisibleForTesting;
  19 import com.google.common.base.Optional;
  20 import com.google.common.base.Preconditions;
  21 import java.io.IOException;
  22 import java.util.HashMap;
  23 import java.util.Map;
  24 import java.util.concurrent.TimeUnit;
  25 import javax.annotation.Nonnull;
  26 import org.opendaylight.controller.cluster.common.actor.CommonConfig;
  27 import org.opendaylight.controller.cluster.common.actor.MeteringBehavior;
  28 import org.opendaylight.controller.cluster.datastore.ShardCommitCoordinator.CohortEntry;
  29 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
  30 import org.opendaylight.controller.cluster.datastore.identifiers.ShardIdentifier;
  31 import org.opendaylight.controller.cluster.datastore.identifiers.ShardTransactionIdentifier;
  32 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardMBeanFactory;
  33 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardStats;
  34 import org.opendaylight.controller.cluster.datastore.messages.AbortTransaction;
  35 import org.opendaylight.controller.cluster.datastore.messages.ActorInitialized;
  36 import org.opendaylight.controller.cluster.datastore.messages.BatchedModifications;
  37 import org.opendaylight.controller.cluster.datastore.messages.CanCommitTransaction;
  38 import org.opendaylight.controller.cluster.datastore.messages.CloseTransactionChain;
  39 import org.opendaylight.controller.cluster.datastore.messages.CommitTransaction;
  40 import org.opendaylight.controller.cluster.datastore.messages.CommitTransactionReply;
  41 import org.opendaylight.controller.cluster.datastore.messages.CreateTransaction;
  42 import org.opendaylight.controller.cluster.datastore.messages.CreateTransactionReply;
  43 import org.opendaylight.controller.cluster.datastore.messages.ForwardedReadyTransaction;
  44 import org.opendaylight.controller.cluster.datastore.messages.PeerAddressResolved;
  45 import org.opendaylight.controller.cluster.datastore.messages.ReadyLocalTransaction;
  46 import org.opendaylight.controller.cluster.datastore.messages.RegisterChangeListener;
  47 import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeChangeListener;
  48 import org.opendaylight.controller.cluster.datastore.messages.ShardLeaderStateChanged;
  49 import org.opendaylight.controller.cluster.datastore.messages.UpdateSchemaContext;
  50 import org.opendaylight.controller.cluster.datastore.modification.Modification;
  51 import org.opendaylight.controller.cluster.datastore.modification.ModificationPayload;
  52 import org.opendaylight.controller.cluster.datastore.modification.MutableCompositeModification;
  53 import org.opendaylight.controller.cluster.datastore.utils.Dispatchers;
  54 import org.opendaylight.controller.cluster.datastore.utils.MessageTracker;
  55 import org.opendaylight.controller.cluster.notifications.LeaderStateChanged;
  56 import org.opendaylight.controller.cluster.notifications.RegisterRoleChangeListener;
  57 import org.opendaylight.controller.cluster.notifications.RoleChangeNotifier;
  58 import org.opendaylight.controller.cluster.raft.RaftActor;
  59 import org.opendaylight.controller.cluster.raft.RaftActorRecoveryCohort;
  60 import org.opendaylight.controller.cluster.raft.RaftActorSnapshotCohort;
  61 import org.opendaylight.controller.cluster.raft.RaftState;
  62 import org.opendaylight.controller.cluster.raft.base.messages.FollowerInitialSyncUpStatus;
  63 import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply;
  64 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationByteStringPayload;
  65 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationPayload;
  66 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree;
  67 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  68 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
  69 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
  70 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  71 import scala.concurrent.duration.Duration;
  72 import scala.concurrent.duration.FiniteDuration;
  73
  74 /**
  75  * A Shard represents a portion of the logical data tree <br/>
  76  * <p>
  77  * Our Shard uses InMemoryDataTree as it's internal representation and delegates all requests it
  78  * </p>
  79  */
  80 public class Shard extends RaftActor {
  81
  82     protected static final Object TX_COMMIT_TIMEOUT_CHECK_MESSAGE = "txCommitTimeoutCheck";
  83
  84     @VisibleForTesting
  85     static final Object GET_SHARD_MBEAN_MESSAGE = "getShardMBeanMessage";
  86
  87     @VisibleForTesting
  88     static final String DEFAULT_NAME = "default";
  89
  90     // The state of this Shard
  91     private final ShardDataTree store;
  92
  93     /// The name of this shard
  94     private final String name;
  95
  96     private final ShardStats shardMBean;
  97
  98     private DatastoreContext datastoreContext;
  99
 100     private final ShardCommitCoordinator commitCoordinator;
 101
 102     private long transactionCommitTimeout;
 103
 104     private Cancellable txCommitTimeoutCheckSchedule;
 105
 106     private final Optional<ActorRef> roleChangeNotifier;
 107
 108     private final MessageTracker appendEntriesReplyTracker;
 109
 110     private final ShardTransactionActorFactory transactionActorFactory;
 111
 112     private final ShardSnapshotCohort snapshotCohort;
 113
 114     private final DataTreeChangeListenerSupport treeChangeSupport = new DataTreeChangeListenerSupport(this);
 115     private final DataChangeListenerSupport changeSupport = new DataChangeListenerSupport(this);
 116
 117     protected Shard(final ShardIdentifier name, final Map<String, String> peerAddresses,
 118             final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 119         super(name.toString(), new HashMap<>(peerAddresses), Optional.of(datastoreContext.getShardRaftConfig()),
 120                 DataStoreVersions.CURRENT_VERSION);
 121
 122         this.name = name.toString();
 123         this.datastoreContext = datastoreContext;
 124
 125         setPersistence(datastoreContext.isPersistent());
 126
 127         LOG.info("Shard created : {}, persistent : {}", name, datastoreContext.isPersistent());
 128
 129         store = new ShardDataTree(schemaContext);
 130
 131         shardMBean = ShardMBeanFactory.getShardStatsMBean(name.toString(),
 132                 datastoreContext.getDataStoreMXBeanType());
 133         shardMBean.setShard(this);
 134
 135         if (isMetricsCaptureEnabled()) {
 136             getContext().become(new MeteringBehavior(this));
 137         }
 138
 139         commitCoordinator = new ShardCommitCoordinator(store,
 140                 datastoreContext.getShardCommitQueueExpiryTimeoutInMillis(),
 141                 datastoreContext.getShardTransactionCommitQueueCapacity(), self(), LOG, this.name);
 142
 143         setTransactionCommitTimeout();
 144
 145         // create a notifier actor for each cluster member
 146         roleChangeNotifier = createRoleChangeNotifier(name.toString());
 147
 148         appendEntriesReplyTracker = new MessageTracker(AppendEntriesReply.class,
 149                 getRaftActorContext().getConfigParams().getIsolatedCheckIntervalInMillis());
 150
 151         transactionActorFactory = new ShardTransactionActorFactory(store, datastoreContext,
 152                 new Dispatchers(context().system().dispatchers()).getDispatcherPath(
 153                         Dispatchers.DispatcherType.Transaction), self(), getContext(), shardMBean);
 154
 155         snapshotCohort = new ShardSnapshotCohort(transactionActorFactory, store, LOG, this.name);
 156
 157
 158     }
 159
 160     private void setTransactionCommitTimeout() {
 161         transactionCommitTimeout = TimeUnit.MILLISECONDS.convert(
 162                 datastoreContext.getShardTransactionCommitTimeoutInSeconds(), TimeUnit.SECONDS) / 2;
 163     }
 164
 165     public static Props props(final ShardIdentifier name,
 166         final Map<String, String> peerAddresses,
 167         final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 168         Preconditions.checkNotNull(name, "name should not be null");
 169         Preconditions.checkNotNull(peerAddresses, "peerAddresses should not be null");
 170         Preconditions.checkNotNull(datastoreContext, "dataStoreContext should not be null");
 171         Preconditions.checkNotNull(schemaContext, "schemaContext should not be null");
 172
 173         return Props.create(new ShardCreator(name, peerAddresses, datastoreContext, schemaContext));
 174     }
 175
 176     private Optional<ActorRef> createRoleChangeNotifier(String shardId) {
 177         ActorRef shardRoleChangeNotifier = this.getContext().actorOf(
 178             RoleChangeNotifier.getProps(shardId), shardId + "-notifier");
 179         return Optional.of(shardRoleChangeNotifier);
 180     }
 181
 182     @Override
 183     public void postStop() {
 184         LOG.info("Stopping Shard {}", persistenceId());
 185
 186         super.postStop();
 187
 188         if(txCommitTimeoutCheckSchedule != null) {
 189             txCommitTimeoutCheckSchedule.cancel();
 190         }
 191
 192         shardMBean.unregisterMBean();
 193     }
 194
 195     @Override
 196     public void onReceiveRecover(final Object message) throws Exception {
 197         if(LOG.isDebugEnabled()) {
 198             LOG.debug("{}: onReceiveRecover: Received message {} from {}", persistenceId(),
 199                 message.getClass().toString(), getSender());
 200         }
 201
 202         if (message instanceof RecoveryFailure){
 203             LOG.error("{}: Recovery failed because of this cause",
 204                     persistenceId(), ((RecoveryFailure) message).cause());
 205
 206             // Even though recovery failed, we still need to finish our recovery, eg send the
 207             // ActorInitialized message and start the txCommitTimeoutCheckSchedule.
 208             onRecoveryComplete();
 209         } else {
 210             super.onReceiveRecover(message);
 211             if(LOG.isTraceEnabled()) {
 212                 appendEntriesReplyTracker.begin();
 213             }
 214         }
 215     }
 216
 217     @Override
 218     public void onReceiveCommand(final Object message) throws Exception {
 219
 220         MessageTracker.Context context = appendEntriesReplyTracker.received(message);
 221
 222         if(context.error().isPresent()){
 223             LOG.trace("{} : AppendEntriesReply failed to arrive at the expected interval {}", persistenceId(),
 224                 context.error());
 225         }
 226
 227         try {
 228             if (CreateTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 229                 handleCreateTransaction(message);
 230             } else if (BatchedModifications.class.isInstance(message)) {
 231                 handleBatchedModifications((BatchedModifications)message);
 232             } else if (message instanceof ForwardedReadyTransaction) {
 233                 commitCoordinator.handleForwardedReadyTransaction((ForwardedReadyTransaction) message,
 234                         getSender(), this);
 235             } else if (message instanceof ReadyLocalTransaction) {
 236                 handleReadyLocalTransaction((ReadyLocalTransaction)message);
 237             } else if (CanCommitTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 238                 handleCanCommitTransaction(CanCommitTransaction.fromSerializable(message));
 239             } else if (CommitTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 240                 handleCommitTransaction(CommitTransaction.fromSerializable(message));
 241             } else if (AbortTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 242                 handleAbortTransaction(AbortTransaction.fromSerializable(message));
 243             } else if (CloseTransactionChain.SERIALIZABLE_CLASS.isInstance(message)) {
 244                 closeTransactionChain(CloseTransactionChain.fromSerializable(message));
 245             } else if (message instanceof RegisterChangeListener) {
 246                 changeSupport.onMessage((RegisterChangeListener) message, isLeader(), hasLeader());
 247             } else if (message instanceof RegisterDataTreeChangeListener) {
 248                 treeChangeSupport.onMessage((RegisterDataTreeChangeListener) message, isLeader(), hasLeader());
 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 if(message instanceof DatastoreContext) {
 258                 onDatastoreContext((DatastoreContext)message);
 259             } else if(message instanceof RegisterRoleChangeListener){
 260                 roleChangeNotifier.get().forward(message, context());
 261             } else if (message instanceof FollowerInitialSyncUpStatus) {
 262                 shardMBean.setFollowerInitialSyncStatus(((FollowerInitialSyncUpStatus) message).isInitialSyncDone());
 263                 context().parent().tell(message, self());
 264             } else if(GET_SHARD_MBEAN_MESSAGE.equals(message)){
 265                 sender().tell(getShardMBean(), self());
 266             } else {
 267                 super.onReceiveCommand(message);
 268             }
 269         } finally {
 270             context.done();
 271         }
 272     }
 273
 274     private boolean hasLeader() {
 275         return getLeaderId() != null;
 276     }
 277
 278     public int getPendingTxCommitQueueSize() {
 279         return commitCoordinator.getQueueSize();
 280     }
 281
 282     @Override
 283     protected Optional<ActorRef> getRoleChangeNotifier() {
 284         return roleChangeNotifier;
 285     }
 286
 287     @Override
 288     protected LeaderStateChanged newLeaderStateChanged(String memberId, String leaderId, short leaderPayloadVersion) {
 289         return new ShardLeaderStateChanged(memberId, leaderId,
 290                 isLeader() ? Optional.<DataTree>of(store.getDataTree()) : Optional.<DataTree>absent(),
 291                 leaderPayloadVersion);
 292     }
 293
 294     private void onDatastoreContext(DatastoreContext context) {
 295         datastoreContext = context;
 296
 297         commitCoordinator.setQueueCapacity(datastoreContext.getShardTransactionCommitQueueCapacity());
 298
 299         setTransactionCommitTimeout();
 300
 301         if(datastoreContext.isPersistent() && !persistence().isRecoveryApplicable()) {
 302             setPersistence(true);
 303         } else if(!datastoreContext.isPersistent() && persistence().isRecoveryApplicable()) {
 304             setPersistence(false);
 305         }
 306
 307         updateConfigParams(datastoreContext.getShardRaftConfig());
 308     }
 309
 310     private void handleTransactionCommitTimeoutCheck() {
 311         CohortEntry cohortEntry = commitCoordinator.getCurrentCohortEntry();
 312         if(cohortEntry != null) {
 313             if(cohortEntry.isExpired(transactionCommitTimeout)) {
 314                 LOG.warn("{}: Current transaction {} has timed out after {} ms - aborting",
 315                         persistenceId(), cohortEntry.getTransactionID(), transactionCommitTimeout);
 316
 317                 doAbortTransaction(cohortEntry.getTransactionID(), null);
 318             }
 319         }
 320
 321         commitCoordinator.cleanupExpiredCohortEntries();
 322     }
 323
 324     private static boolean isEmptyCommit(final DataTreeCandidate candidate) {
 325         return ModificationType.UNMODIFIED.equals(candidate.getRootNode().getModificationType());
 326     }
 327
 328     void continueCommit(final CohortEntry cohortEntry) throws Exception {
 329         final DataTreeCandidate candidate = cohortEntry.getCandidate();
 330
 331         // If we do not have any followers and we are not using persistence
 332         // or if cohortEntry has no modifications
 333         // we can apply modification to the state immediately
 334         if ((!hasFollowers() && !persistence().isRecoveryApplicable()) || isEmptyCommit(candidate)) {
 335             applyModificationToState(cohortEntry.getReplySender(), cohortEntry.getTransactionID(), candidate);
 336         } else {
 337             Shard.this.persistData(cohortEntry.getReplySender(), cohortEntry.getTransactionID(),
 338                 DataTreeCandidatePayload.create(candidate));
 339         }
 340     }
 341
 342     private void handleCommitTransaction(final CommitTransaction commit) {
 343         if(!commitCoordinator.handleCommit(commit.getTransactionID(), getSender(), this)) {
 344             shardMBean.incrementFailedTransactionsCount();
 345         }
 346     }
 347
 348     private void finishCommit(@Nonnull final ActorRef sender, @Nonnull final String transactionID, @Nonnull final CohortEntry cohortEntry) {
 349         LOG.debug("{}: Finishing commit for transaction {}", persistenceId(), cohortEntry.getTransactionID());
 350
 351         try {
 352             cohortEntry.commit();
 353
 354             sender.tell(CommitTransactionReply.INSTANCE.toSerializable(), getSelf());
 355
 356             shardMBean.incrementCommittedTransactionCount();
 357             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 358
 359         } catch (Exception e) {
 360             sender.tell(new akka.actor.Status.Failure(e), getSelf());
 361
 362             LOG.error("{}, An exception occurred while committing transaction {}", persistenceId(),
 363                     transactionID, e);
 364             shardMBean.incrementFailedTransactionsCount();
 365         } finally {
 366             commitCoordinator.currentTransactionComplete(transactionID, true);
 367         }
 368     }
 369
 370     private void finishCommit(@Nonnull final ActorRef sender, final @Nonnull String transactionID) {
 371         // With persistence enabled, this method is called via applyState by the leader strategy
 372         // after the commit has been replicated to a majority of the followers.
 373
 374         CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 375         if (cohortEntry == null) {
 376             // The transaction is no longer the current commit. This can happen if the transaction
 377             // was aborted prior, most likely due to timeout in the front-end. We need to finish
 378             // committing the transaction though since it was successfully persisted and replicated
 379             // however we can't use the original cohort b/c it was already preCommitted and may
 380             // conflict with the current commit or may have been aborted so we commit with a new
 381             // transaction.
 382             cohortEntry = commitCoordinator.getAndRemoveCohortEntry(transactionID);
 383             if(cohortEntry != null) {
 384                 try {
 385                     store.applyForeignCandidate(transactionID, cohortEntry.getCandidate());
 386                 } catch (DataValidationFailedException e) {
 387                     shardMBean.incrementFailedTransactionsCount();
 388                     LOG.error("{}: Failed to re-apply transaction {}", persistenceId(), transactionID, e);
 389                 }
 390
 391                 sender.tell(CommitTransactionReply.INSTANCE.toSerializable(), getSelf());
 392             } else {
 393                 // This really shouldn't happen - it likely means that persistence or replication
 394                 // took so long to complete such that the cohort entry was expired from the cache.
 395                 IllegalStateException ex = new IllegalStateException(
 396                         String.format("%s: Could not finish committing transaction %s - no CohortEntry found",
 397                                 persistenceId(), transactionID));
 398                 LOG.error(ex.getMessage());
 399                 sender.tell(new akka.actor.Status.Failure(ex), getSelf());
 400             }
 401         } else {
 402             finishCommit(sender, transactionID, cohortEntry);
 403         }
 404     }
 405
 406     private void handleCanCommitTransaction(final CanCommitTransaction canCommit) {
 407         LOG.debug("{}: Can committing transaction {}", persistenceId(), canCommit.getTransactionID());
 408         commitCoordinator.handleCanCommit(canCommit.getTransactionID(), getSender(), this);
 409     }
 410
 411     private void noLeaderError(String errMessage, Object message) {
 412         // TODO: rather than throwing an immediate exception, we could schedule a timer to try again to make
 413         // it more resilient in case we're in the process of electing a new leader.
 414         getSender().tell(new akka.actor.Status.Failure(new NoShardLeaderException(errMessage, persistenceId())), getSelf());
 415     }
 416
 417     private void handleBatchedModifications(BatchedModifications batched) {
 418         // This message is sent to prepare the modifications transaction directly on the Shard as an
 419         // optimization to avoid the extra overhead of a separate ShardTransaction actor. On the last
 420         // BatchedModifications message, the caller sets the ready flag in the message indicating
 421         // modifications are complete. The reply contains the cohort actor path (this actor) for the caller
 422         // to initiate the 3-phase commit. This also avoids the overhead of sending an additional
 423         // ReadyTransaction message.
 424
 425         // If we're not the leader then forward to the leader. This is a safety measure - we shouldn't
 426         // normally get here if we're not the leader as the front-end (TransactionProxy) should determine
 427         // the primary/leader shard. However with timing and caching on the front-end, there's a small
 428         // window where it could have a stale leader during leadership transitions.
 429         //
 430         if(isLeader()) {
 431             failIfIsolatedLeader(getSender());
 432
 433             try {
 434                 commitCoordinator.handleBatchedModifications(batched, getSender(), this);
 435             } catch (Exception e) {
 436                 LOG.error("{}: Error handling BatchedModifications for Tx {}", persistenceId(),
 437                         batched.getTransactionID(), e);
 438                 getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 439             }
 440         } else {
 441             ActorSelection leader = getLeader();
 442             if(leader != null) {
 443                 // TODO: what if this is not the first batch and leadership changed in between batched messages?
 444                 // We could check if the commitCoordinator already has a cached entry and forward all the previous
 445                 // batched modifications.
 446                 LOG.debug("{}: Forwarding BatchedModifications to leader {}", persistenceId(), leader);
 447                 leader.forward(batched, getContext());
 448             } else {
 449                 noLeaderError("Could not commit transaction " + batched.getTransactionID(), batched);
 450             }
 451         }
 452     }
 453
 454     private boolean failIfIsolatedLeader(ActorRef sender) {
 455         if(getRaftState() == RaftState.IsolatedLeader) {
 456             sender.tell(new akka.actor.Status.Failure(new NoShardLeaderException(String.format(
 457                     "Shard %s was the leader but has lost contact with all of its followers. Either all" +
 458                     " other follower nodes are down or this node is isolated by a network partition.",
 459                     persistenceId()))), getSelf());
 460             return true;
 461         }
 462
 463         return false;
 464     }
 465
 466     private void handleReadyLocalTransaction(final ReadyLocalTransaction message) {
 467         if (isLeader()) {
 468             failIfIsolatedLeader(getSender());
 469
 470             try {
 471                 commitCoordinator.handleReadyLocalTransaction(message, getSender(), this);
 472             } catch (Exception e) {
 473                 LOG.error("{}: Error handling ReadyLocalTransaction for Tx {}", persistenceId(),
 474                         message.getTransactionID(), e);
 475                 getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 476             }
 477         } else {
 478             ActorSelection leader = getLeader();
 479             if (leader != null) {
 480                 LOG.debug("{}: Forwarding ReadyLocalTransaction to leader {}", persistenceId(), leader);
 481                 message.setRemoteVersion(getCurrentBehavior().getLeaderPayloadVersion());
 482                 leader.forward(message, getContext());
 483             } else {
 484                 noLeaderError("Could not commit transaction " + message.getTransactionID(), message);
 485             }
 486         }
 487     }
 488
 489     private void handleAbortTransaction(final AbortTransaction abort) {
 490         doAbortTransaction(abort.getTransactionID(), getSender());
 491     }
 492
 493     void doAbortTransaction(final String transactionID, final ActorRef sender) {
 494         commitCoordinator.handleAbort(transactionID, sender, this);
 495     }
 496
 497     private void handleCreateTransaction(final Object message) {
 498         if (isLeader()) {
 499             createTransaction(CreateTransaction.fromSerializable(message));
 500         } else if (getLeader() != null) {
 501             getLeader().forward(message, getContext());
 502         } else {
 503             getSender().tell(new akka.actor.Status.Failure(new NoShardLeaderException(
 504                     "Could not create a shard transaction", persistenceId())), getSelf());
 505         }
 506     }
 507
 508     private void closeTransactionChain(final CloseTransactionChain closeTransactionChain) {
 509         store.closeTransactionChain(closeTransactionChain.getTransactionChainId());
 510     }
 511
 512     private ActorRef createTypedTransactionActor(int transactionType,
 513             ShardTransactionIdentifier transactionId, String transactionChainId,
 514             short clientVersion ) {
 515
 516         return transactionActorFactory.newShardTransaction(TransactionType.fromInt(transactionType),
 517                 transactionId, transactionChainId, clientVersion);
 518     }
 519
 520     private void createTransaction(CreateTransaction createTransaction) {
 521         try {
 522             if(TransactionType.fromInt(createTransaction.getTransactionType()) != TransactionType.READ_ONLY &&
 523                     failIfIsolatedLeader(getSender())) {
 524                 return;
 525             }
 526
 527             ActorRef transactionActor = createTransaction(createTransaction.getTransactionType(),
 528                 createTransaction.getTransactionId(), createTransaction.getTransactionChainId(),
 529                 createTransaction.getVersion());
 530
 531             getSender().tell(new CreateTransactionReply(Serialization.serializedActorPath(transactionActor),
 532                     createTransaction.getTransactionId()).toSerializable(), getSelf());
 533         } catch (Exception e) {
 534             getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 535         }
 536     }
 537
 538     private ActorRef createTransaction(int transactionType, String remoteTransactionId,
 539             String transactionChainId, short clientVersion) {
 540
 541
 542         ShardTransactionIdentifier transactionId = new ShardTransactionIdentifier(remoteTransactionId);
 543
 544         if(LOG.isDebugEnabled()) {
 545             LOG.debug("{}: Creating transaction : {} ", persistenceId(), transactionId);
 546         }
 547
 548         ActorRef transactionActor = createTypedTransactionActor(transactionType, transactionId,
 549                 transactionChainId, clientVersion);
 550
 551         return transactionActor;
 552     }
 553
 554     private void commitWithNewTransaction(final Modification modification) {
 555         ReadWriteShardDataTreeTransaction tx = store.newReadWriteTransaction(modification.toString(), null);
 556         modification.apply(tx.getSnapshot());
 557         try {
 558             snapshotCohort.syncCommitTransaction(tx);
 559             shardMBean.incrementCommittedTransactionCount();
 560             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 561         } catch (Exception e) {
 562             shardMBean.incrementFailedTransactionsCount();
 563             LOG.error("{}: Failed to commit", persistenceId(), e);
 564         }
 565     }
 566
 567     private void updateSchemaContext(final UpdateSchemaContext message) {
 568         updateSchemaContext(message.getSchemaContext());
 569     }
 570
 571     @VisibleForTesting
 572     void updateSchemaContext(final SchemaContext schemaContext) {
 573         store.updateSchemaContext(schemaContext);
 574     }
 575
 576     private boolean isMetricsCaptureEnabled() {
 577         CommonConfig config = new CommonConfig(getContext().system().settings().config());
 578         return config.isMetricCaptureEnabled();
 579     }
 580
 581     @Override
 582     @VisibleForTesting
 583     public RaftActorSnapshotCohort getRaftActorSnapshotCohort() {
 584         return snapshotCohort;
 585     }
 586
 587     @Override
 588     @Nonnull
 589     protected RaftActorRecoveryCohort getRaftActorRecoveryCohort() {
 590         return new ShardRecoveryCoordinator(store, store.getSchemaContext(), persistenceId(), LOG);
 591     }
 592
 593     @Override
 594     protected void onRecoveryComplete() {
 595         //notify shard manager
 596         getContext().parent().tell(new ActorInitialized(), getSelf());
 597
 598         // Being paranoid here - this method should only be called once but just in case...
 599         if(txCommitTimeoutCheckSchedule == null) {
 600             // Schedule a message to be periodically sent to check if the current in-progress
 601             // transaction should be expired and aborted.
 602             FiniteDuration period = Duration.create(transactionCommitTimeout / 3, TimeUnit.MILLISECONDS);
 603             txCommitTimeoutCheckSchedule = getContext().system().scheduler().schedule(
 604                     period, period, getSelf(),
 605                     TX_COMMIT_TIMEOUT_CHECK_MESSAGE, getContext().dispatcher(), ActorRef.noSender());
 606         }
 607     }
 608
 609     @Override
 610     protected void applyState(final ActorRef clientActor, final String identifier, final Object data) {
 611         if (data instanceof DataTreeCandidatePayload) {
 612             if (clientActor == null) {
 613                 // No clientActor indicates a replica coming from the leader
 614                 try {
 615                     store.applyForeignCandidate(identifier, ((DataTreeCandidatePayload)data).getCandidate());
 616                 } catch (DataValidationFailedException | IOException e) {
 617                     LOG.error("{}: Error applying replica {}", persistenceId(), identifier, e);
 618                 }
 619             } else {
 620                 // Replication consensus reached, proceed to commit
 621                 finishCommit(clientActor, identifier);
 622             }
 623         } else if (data instanceof ModificationPayload) {
 624             try {
 625                 applyModificationToState(clientActor, identifier, ((ModificationPayload) data).getModification());
 626             } catch (ClassNotFoundException | IOException e) {
 627                 LOG.error("{}: Error extracting ModificationPayload", persistenceId(), e);
 628             }
 629         } else if (data instanceof CompositeModificationPayload) {
 630             Object modification = ((CompositeModificationPayload) data).getModification();
 631
 632             applyModificationToState(clientActor, identifier, modification);
 633         } else if(data instanceof CompositeModificationByteStringPayload ){
 634             Object modification = ((CompositeModificationByteStringPayload) data).getModification();
 635
 636             applyModificationToState(clientActor, identifier, modification);
 637         } else {
 638             LOG.error("{}: Unknown state received {} Class loader = {} CompositeNodeMod.ClassLoader = {}",
 639                     persistenceId(), data, data.getClass().getClassLoader(),
 640                     CompositeModificationPayload.class.getClassLoader());
 641         }
 642     }
 643
 644     private void applyModificationToState(ActorRef clientActor, String identifier, Object modification) {
 645         if(modification == null) {
 646             LOG.error(
 647                     "{}: modification is null - this is very unexpected, clientActor = {}, identifier = {}",
 648                     persistenceId(), identifier, clientActor != null ? clientActor.path().toString() : null);
 649         } else if(clientActor == null) {
 650             // There's no clientActor to which to send a commit reply so we must be applying
 651             // replicated state from the leader.
 652             commitWithNewTransaction(MutableCompositeModification.fromSerializable(modification));
 653         } else {
 654             // This must be the OK to commit after replication consensus.
 655             finishCommit(clientActor, identifier);
 656         }
 657     }
 658
 659     @Override
 660     protected void onStateChanged() {
 661         boolean isLeader = isLeader();
 662         boolean hasLeader = hasLeader();
 663         changeSupport.onLeadershipChange(isLeader, hasLeader);
 664         treeChangeSupport.onLeadershipChange(isLeader, hasLeader);
 665
 666         // If this actor is no longer the leader close all the transaction chains
 667         if (!isLeader) {
 668             if(LOG.isDebugEnabled()) {
 669                 LOG.debug(
 670                     "{}: onStateChanged: Closing all transaction chains because shard {} is no longer the leader",
 671                     persistenceId(), getId());
 672             }
 673
 674             store.closeAllTransactionChains();
 675         }
 676     }
 677
 678     @Override
 679     protected void onLeaderChanged(String oldLeader, String newLeader) {
 680         shardMBean.incrementLeadershipChangeCount();
 681     }
 682
 683     @Override
 684     public String persistenceId() {
 685         return this.name;
 686     }
 687
 688     @VisibleForTesting
 689     ShardCommitCoordinator getCommitCoordinator() {
 690         return commitCoordinator;
 691     }
 692
 693
 694     private static class ShardCreator implements Creator<Shard> {
 695
 696         private static final long serialVersionUID = 1L;
 697
 698         final ShardIdentifier name;
 699         final Map<String, String> peerAddresses;
 700         final DatastoreContext datastoreContext;
 701         final SchemaContext schemaContext;
 702
 703         ShardCreator(final ShardIdentifier name, final Map<String, String> peerAddresses,
 704                 final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 705             this.name = name;
 706             this.peerAddresses = peerAddresses;
 707             this.datastoreContext = datastoreContext;
 708             this.schemaContext = schemaContext;
 709         }
 710
 711         @Override
 712         public Shard create() throws Exception {
 713             return new Shard(name, peerAddresses, datastoreContext, schemaContext);
 714         }
 715     }
 716
 717     @VisibleForTesting
 718     public ShardDataTree getDataStore() {
 719         return store;
 720     }
 721
 722     @VisibleForTesting
 723     ShardStats getShardMBean() {
 724         return shardMBean;
 725     }
 726 }