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());
 247             } else if (message instanceof RegisterDataTreeChangeListener) {
 248                 treeChangeSupport.onMessage((RegisterDataTreeChangeListener) message, isLeader());
 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     public int getPendingTxCommitQueueSize() {
 275         return commitCoordinator.getQueueSize();
 276     }
 277
 278     @Override
 279     protected Optional<ActorRef> getRoleChangeNotifier() {
 280         return roleChangeNotifier;
 281     }
 282
 283     @Override
 284     protected LeaderStateChanged newLeaderStateChanged(String memberId, String leaderId, short leaderPayloadVersion) {
 285         return new ShardLeaderStateChanged(memberId, leaderId,
 286                 isLeader() ? Optional.<DataTree>of(store.getDataTree()) : Optional.<DataTree>absent(),
 287                 leaderPayloadVersion);
 288     }
 289
 290     private void onDatastoreContext(DatastoreContext context) {
 291         datastoreContext = context;
 292
 293         commitCoordinator.setQueueCapacity(datastoreContext.getShardTransactionCommitQueueCapacity());
 294
 295         setTransactionCommitTimeout();
 296
 297         if(datastoreContext.isPersistent() && !persistence().isRecoveryApplicable()) {
 298             setPersistence(true);
 299         } else if(!datastoreContext.isPersistent() && persistence().isRecoveryApplicable()) {
 300             setPersistence(false);
 301         }
 302
 303         updateConfigParams(datastoreContext.getShardRaftConfig());
 304     }
 305
 306     private void handleTransactionCommitTimeoutCheck() {
 307         CohortEntry cohortEntry = commitCoordinator.getCurrentCohortEntry();
 308         if(cohortEntry != null) {
 309             if(cohortEntry.isExpired(transactionCommitTimeout)) {
 310                 LOG.warn("{}: Current transaction {} has timed out after {} ms - aborting",
 311                         persistenceId(), cohortEntry.getTransactionID(), transactionCommitTimeout);
 312
 313                 doAbortTransaction(cohortEntry.getTransactionID(), null);
 314             }
 315         }
 316
 317         commitCoordinator.cleanupExpiredCohortEntries();
 318     }
 319
 320     private static boolean isEmptyCommit(final DataTreeCandidate candidate) {
 321         return ModificationType.UNMODIFIED.equals(candidate.getRootNode().getModificationType());
 322     }
 323
 324     void continueCommit(final CohortEntry cohortEntry) throws Exception {
 325         final DataTreeCandidate candidate = cohortEntry.getCandidate();
 326
 327         // If we do not have any followers and we are not using persistence
 328         // or if cohortEntry has no modifications
 329         // we can apply modification to the state immediately
 330         if ((!hasFollowers() && !persistence().isRecoveryApplicable()) || isEmptyCommit(candidate)) {
 331             applyModificationToState(cohortEntry.getReplySender(), cohortEntry.getTransactionID(), candidate);
 332         } else {
 333             Shard.this.persistData(cohortEntry.getReplySender(), cohortEntry.getTransactionID(),
 334                 DataTreeCandidatePayload.create(candidate));
 335         }
 336     }
 337
 338     private void handleCommitTransaction(final CommitTransaction commit) {
 339         if(!commitCoordinator.handleCommit(commit.getTransactionID(), getSender(), this)) {
 340             shardMBean.incrementFailedTransactionsCount();
 341         }
 342     }
 343
 344     private void finishCommit(@Nonnull final ActorRef sender, @Nonnull final String transactionID, @Nonnull final CohortEntry cohortEntry) {
 345         LOG.debug("{}: Finishing commit for transaction {}", persistenceId(), cohortEntry.getTransactionID());
 346
 347         try {
 348             cohortEntry.commit();
 349
 350             sender.tell(CommitTransactionReply.INSTANCE.toSerializable(), getSelf());
 351
 352             shardMBean.incrementCommittedTransactionCount();
 353             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 354
 355         } catch (Exception e) {
 356             sender.tell(new akka.actor.Status.Failure(e), getSelf());
 357
 358             LOG.error("{}, An exception occurred while committing transaction {}", persistenceId(),
 359                     transactionID, e);
 360             shardMBean.incrementFailedTransactionsCount();
 361         } finally {
 362             commitCoordinator.currentTransactionComplete(transactionID, true);
 363         }
 364     }
 365
 366     private void finishCommit(@Nonnull final ActorRef sender, final @Nonnull String transactionID) {
 367         // With persistence enabled, this method is called via applyState by the leader strategy
 368         // after the commit has been replicated to a majority of the followers.
 369
 370         CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 371         if (cohortEntry == null) {
 372             // The transaction is no longer the current commit. This can happen if the transaction
 373             // was aborted prior, most likely due to timeout in the front-end. We need to finish
 374             // committing the transaction though since it was successfully persisted and replicated
 375             // however we can't use the original cohort b/c it was already preCommitted and may
 376             // conflict with the current commit or may have been aborted so we commit with a new
 377             // transaction.
 378             cohortEntry = commitCoordinator.getAndRemoveCohortEntry(transactionID);
 379             if(cohortEntry != null) {
 380                 try {
 381                     store.applyForeignCandidate(transactionID, cohortEntry.getCandidate());
 382                 } catch (DataValidationFailedException e) {
 383                     shardMBean.incrementFailedTransactionsCount();
 384                     LOG.error("{}: Failed to re-apply transaction {}", persistenceId(), transactionID, e);
 385                 }
 386
 387                 sender.tell(CommitTransactionReply.INSTANCE.toSerializable(), getSelf());
 388             } else {
 389                 // This really shouldn't happen - it likely means that persistence or replication
 390                 // took so long to complete such that the cohort entry was expired from the cache.
 391                 IllegalStateException ex = new IllegalStateException(
 392                         String.format("%s: Could not finish committing transaction %s - no CohortEntry found",
 393                                 persistenceId(), transactionID));
 394                 LOG.error(ex.getMessage());
 395                 sender.tell(new akka.actor.Status.Failure(ex), getSelf());
 396             }
 397         } else {
 398             finishCommit(sender, transactionID, cohortEntry);
 399         }
 400     }
 401
 402     private void handleCanCommitTransaction(final CanCommitTransaction canCommit) {
 403         LOG.debug("{}: Can committing transaction {}", persistenceId(), canCommit.getTransactionID());
 404         commitCoordinator.handleCanCommit(canCommit.getTransactionID(), getSender(), this);
 405     }
 406
 407     private void noLeaderError(String errMessage, Object message) {
 408         // TODO: rather than throwing an immediate exception, we could schedule a timer to try again to make
 409         // it more resilient in case we're in the process of electing a new leader.
 410         getSender().tell(new akka.actor.Status.Failure(new NoShardLeaderException(errMessage, persistenceId())), getSelf());
 411     }
 412
 413     private void handleBatchedModifications(BatchedModifications batched) {
 414         // This message is sent to prepare the modifications transaction directly on the Shard as an
 415         // optimization to avoid the extra overhead of a separate ShardTransaction actor. On the last
 416         // BatchedModifications message, the caller sets the ready flag in the message indicating
 417         // modifications are complete. The reply contains the cohort actor path (this actor) for the caller
 418         // to initiate the 3-phase commit. This also avoids the overhead of sending an additional
 419         // ReadyTransaction message.
 420
 421         // If we're not the leader then forward to the leader. This is a safety measure - we shouldn't
 422         // normally get here if we're not the leader as the front-end (TransactionProxy) should determine
 423         // the primary/leader shard. However with timing and caching on the front-end, there's a small
 424         // window where it could have a stale leader during leadership transitions.
 425         //
 426         if(isLeader()) {
 427             failIfIsolatedLeader(getSender());
 428
 429             try {
 430                 commitCoordinator.handleBatchedModifications(batched, getSender(), this);
 431             } catch (Exception e) {
 432                 LOG.error("{}: Error handling BatchedModifications for Tx {}", persistenceId(),
 433                         batched.getTransactionID(), e);
 434                 getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 435             }
 436         } else {
 437             ActorSelection leader = getLeader();
 438             if(leader != null) {
 439                 // TODO: what if this is not the first batch and leadership changed in between batched messages?
 440                 // We could check if the commitCoordinator already has a cached entry and forward all the previous
 441                 // batched modifications.
 442                 LOG.debug("{}: Forwarding BatchedModifications to leader {}", persistenceId(), leader);
 443                 leader.forward(batched, getContext());
 444             } else {
 445                 noLeaderError("Could not commit transaction " + batched.getTransactionID(), batched);
 446             }
 447         }
 448     }
 449
 450     private boolean failIfIsolatedLeader(ActorRef sender) {
 451         if(getRaftState() == RaftState.IsolatedLeader) {
 452             sender.tell(new akka.actor.Status.Failure(new NoShardLeaderException(String.format(
 453                     "Shard %s was the leader but has lost contact with all of its followers. Either all" +
 454                     " other follower nodes are down or this node is isolated by a network partition.",
 455                     persistenceId()))), getSelf());
 456             return true;
 457         }
 458
 459         return false;
 460     }
 461
 462     private void handleReadyLocalTransaction(final ReadyLocalTransaction message) {
 463         if (isLeader()) {
 464             failIfIsolatedLeader(getSender());
 465
 466             try {
 467                 commitCoordinator.handleReadyLocalTransaction(message, getSender(), this);
 468             } catch (Exception e) {
 469                 LOG.error("{}: Error handling ReadyLocalTransaction for Tx {}", persistenceId(),
 470                         message.getTransactionID(), e);
 471                 getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 472             }
 473         } else {
 474             ActorSelection leader = getLeader();
 475             if (leader != null) {
 476                 LOG.debug("{}: Forwarding ReadyLocalTransaction to leader {}", persistenceId(), leader);
 477                 message.setRemoteVersion(getCurrentBehavior().getLeaderPayloadVersion());
 478                 leader.forward(message, getContext());
 479             } else {
 480                 noLeaderError("Could not commit transaction " + message.getTransactionID(), message);
 481             }
 482         }
 483     }
 484
 485     private void handleAbortTransaction(final AbortTransaction abort) {
 486         doAbortTransaction(abort.getTransactionID(), getSender());
 487     }
 488
 489     void doAbortTransaction(final String transactionID, final ActorRef sender) {
 490         commitCoordinator.handleAbort(transactionID, sender, this);
 491     }
 492
 493     private void handleCreateTransaction(final Object message) {
 494         if (isLeader()) {
 495             createTransaction(CreateTransaction.fromSerializable(message));
 496         } else if (getLeader() != null) {
 497             getLeader().forward(message, getContext());
 498         } else {
 499             getSender().tell(new akka.actor.Status.Failure(new NoShardLeaderException(
 500                     "Could not create a shard transaction", persistenceId())), getSelf());
 501         }
 502     }
 503
 504     private void closeTransactionChain(final CloseTransactionChain closeTransactionChain) {
 505         store.closeTransactionChain(closeTransactionChain.getTransactionChainId());
 506     }
 507
 508     private ActorRef createTypedTransactionActor(int transactionType,
 509             ShardTransactionIdentifier transactionId, String transactionChainId,
 510             short clientVersion ) {
 511
 512         return transactionActorFactory.newShardTransaction(TransactionType.fromInt(transactionType),
 513                 transactionId, transactionChainId, clientVersion);
 514     }
 515
 516     private void createTransaction(CreateTransaction createTransaction) {
 517         try {
 518             if(TransactionType.fromInt(createTransaction.getTransactionType()) != TransactionType.READ_ONLY &&
 519                     failIfIsolatedLeader(getSender())) {
 520                 return;
 521             }
 522
 523             ActorRef transactionActor = createTransaction(createTransaction.getTransactionType(),
 524                 createTransaction.getTransactionId(), createTransaction.getTransactionChainId(),
 525                 createTransaction.getVersion());
 526
 527             getSender().tell(new CreateTransactionReply(Serialization.serializedActorPath(transactionActor),
 528                     createTransaction.getTransactionId()).toSerializable(), getSelf());
 529         } catch (Exception e) {
 530             getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 531         }
 532     }
 533
 534     private ActorRef createTransaction(int transactionType, String remoteTransactionId,
 535             String transactionChainId, short clientVersion) {
 536
 537
 538         ShardTransactionIdentifier transactionId = new ShardTransactionIdentifier(remoteTransactionId);
 539
 540         if(LOG.isDebugEnabled()) {
 541             LOG.debug("{}: Creating transaction : {} ", persistenceId(), transactionId);
 542         }
 543
 544         ActorRef transactionActor = createTypedTransactionActor(transactionType, transactionId,
 545                 transactionChainId, clientVersion);
 546
 547         return transactionActor;
 548     }
 549
 550     private void commitWithNewTransaction(final Modification modification) {
 551         ReadWriteShardDataTreeTransaction tx = store.newReadWriteTransaction(modification.toString(), null);
 552         modification.apply(tx.getSnapshot());
 553         try {
 554             snapshotCohort.syncCommitTransaction(tx);
 555             shardMBean.incrementCommittedTransactionCount();
 556             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 557         } catch (Exception e) {
 558             shardMBean.incrementFailedTransactionsCount();
 559             LOG.error("{}: Failed to commit", persistenceId(), e);
 560         }
 561     }
 562
 563     private void updateSchemaContext(final UpdateSchemaContext message) {
 564         updateSchemaContext(message.getSchemaContext());
 565     }
 566
 567     @VisibleForTesting
 568     void updateSchemaContext(final SchemaContext schemaContext) {
 569         store.updateSchemaContext(schemaContext);
 570     }
 571
 572     private boolean isMetricsCaptureEnabled() {
 573         CommonConfig config = new CommonConfig(getContext().system().settings().config());
 574         return config.isMetricCaptureEnabled();
 575     }
 576
 577     @Override
 578     @VisibleForTesting
 579     public RaftActorSnapshotCohort getRaftActorSnapshotCohort() {
 580         return snapshotCohort;
 581     }
 582
 583     @Override
 584     @Nonnull
 585     protected RaftActorRecoveryCohort getRaftActorRecoveryCohort() {
 586         return new ShardRecoveryCoordinator(store, store.getSchemaContext(), persistenceId(), LOG);
 587     }
 588
 589     @Override
 590     protected void onRecoveryComplete() {
 591         //notify shard manager
 592         getContext().parent().tell(new ActorInitialized(), getSelf());
 593
 594         // Being paranoid here - this method should only be called once but just in case...
 595         if(txCommitTimeoutCheckSchedule == null) {
 596             // Schedule a message to be periodically sent to check if the current in-progress
 597             // transaction should be expired and aborted.
 598             FiniteDuration period = Duration.create(transactionCommitTimeout / 3, TimeUnit.MILLISECONDS);
 599             txCommitTimeoutCheckSchedule = getContext().system().scheduler().schedule(
 600                     period, period, getSelf(),
 601                     TX_COMMIT_TIMEOUT_CHECK_MESSAGE, getContext().dispatcher(), ActorRef.noSender());
 602         }
 603     }
 604
 605     @Override
 606     protected void applyState(final ActorRef clientActor, final String identifier, final Object data) {
 607         if (data instanceof DataTreeCandidatePayload) {
 608             if (clientActor == null) {
 609                 // No clientActor indicates a replica coming from the leader
 610                 try {
 611                     store.applyForeignCandidate(identifier, ((DataTreeCandidatePayload)data).getCandidate());
 612                 } catch (DataValidationFailedException | IOException e) {
 613                     LOG.error("{}: Error applying replica {}", persistenceId(), identifier, e);
 614                 }
 615             } else {
 616                 // Replication consensus reached, proceed to commit
 617                 finishCommit(clientActor, identifier);
 618             }
 619         } else if (data instanceof ModificationPayload) {
 620             try {
 621                 applyModificationToState(clientActor, identifier, ((ModificationPayload) data).getModification());
 622             } catch (ClassNotFoundException | IOException e) {
 623                 LOG.error("{}: Error extracting ModificationPayload", persistenceId(), e);
 624             }
 625         } else if (data instanceof CompositeModificationPayload) {
 626             Object modification = ((CompositeModificationPayload) data).getModification();
 627
 628             applyModificationToState(clientActor, identifier, modification);
 629         } else if(data instanceof CompositeModificationByteStringPayload ){
 630             Object modification = ((CompositeModificationByteStringPayload) data).getModification();
 631
 632             applyModificationToState(clientActor, identifier, modification);
 633         } else {
 634             LOG.error("{}: Unknown state received {} Class loader = {} CompositeNodeMod.ClassLoader = {}",
 635                     persistenceId(), data, data.getClass().getClassLoader(),
 636                     CompositeModificationPayload.class.getClassLoader());
 637         }
 638     }
 639
 640     private void applyModificationToState(ActorRef clientActor, String identifier, Object modification) {
 641         if(modification == null) {
 642             LOG.error(
 643                     "{}: modification is null - this is very unexpected, clientActor = {}, identifier = {}",
 644                     persistenceId(), identifier, clientActor != null ? clientActor.path().toString() : null);
 645         } else if(clientActor == null) {
 646             // There's no clientActor to which to send a commit reply so we must be applying
 647             // replicated state from the leader.
 648             commitWithNewTransaction(MutableCompositeModification.fromSerializable(modification));
 649         } else {
 650             // This must be the OK to commit after replication consensus.
 651             finishCommit(clientActor, identifier);
 652         }
 653     }
 654
 655     @Override
 656     protected void onStateChanged() {
 657         boolean isLeader = isLeader();
 658         changeSupport.onLeadershipChange(isLeader);
 659         treeChangeSupport.onLeadershipChange(isLeader);
 660
 661         // If this actor is no longer the leader close all the transaction chains
 662         if (!isLeader) {
 663             if(LOG.isDebugEnabled()) {
 664                 LOG.debug(
 665                     "{}: onStateChanged: Closing all transaction chains because shard {} is no longer the leader",
 666                     persistenceId(), getId());
 667             }
 668
 669             store.closeAllTransactionChains();
 670         }
 671     }
 672
 673     @Override
 674     protected void onLeaderChanged(String oldLeader, String newLeader) {
 675         shardMBean.incrementLeadershipChangeCount();
 676     }
 677
 678     @Override
 679     public String persistenceId() {
 680         return this.name;
 681     }
 682
 683     @VisibleForTesting
 684     ShardCommitCoordinator getCommitCoordinator() {
 685         return commitCoordinator;
 686     }
 687
 688
 689     private static class ShardCreator implements Creator<Shard> {
 690
 691         private static final long serialVersionUID = 1L;
 692
 693         final ShardIdentifier name;
 694         final Map<String, String> peerAddresses;
 695         final DatastoreContext datastoreContext;
 696         final SchemaContext schemaContext;
 697
 698         ShardCreator(final ShardIdentifier name, final Map<String, String> peerAddresses,
 699                 final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 700             this.name = name;
 701             this.peerAddresses = peerAddresses;
 702             this.datastoreContext = datastoreContext;
 703             this.schemaContext = schemaContext;
 704         }
 705
 706         @Override
 707         public Shard create() throws Exception {
 708             return new Shard(name, peerAddresses, datastoreContext, schemaContext);
 709         }
 710     }
 711
 712     @VisibleForTesting
 713     public ShardDataTree getDataStore() {
 714         return store;
 715     }
 716
 717     @VisibleForTesting
 718     ShardStats getShardMBean() {
 719         return shardMBean;
 720     }
 721 }