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.GetShardDataTree;
  45 import org.opendaylight.controller.cluster.datastore.messages.PeerAddressResolved;
  46 import org.opendaylight.controller.cluster.datastore.messages.ReadyLocalTransaction;
  47 import org.opendaylight.controller.cluster.datastore.messages.RegisterChangeListener;
  48 import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeChangeListener;
  49 import org.opendaylight.controller.cluster.datastore.messages.ShardLeaderStateChanged;
  50 import org.opendaylight.controller.cluster.datastore.messages.UpdateSchemaContext;
  51 import org.opendaylight.controller.cluster.datastore.modification.Modification;
  52 import org.opendaylight.controller.cluster.datastore.modification.ModificationPayload;
  53 import org.opendaylight.controller.cluster.datastore.modification.MutableCompositeModification;
  54 import org.opendaylight.controller.cluster.datastore.utils.Dispatchers;
  55 import org.opendaylight.controller.cluster.datastore.utils.MessageTracker;
  56 import org.opendaylight.controller.cluster.notifications.LeaderStateChanged;
  57 import org.opendaylight.controller.cluster.notifications.RegisterRoleChangeListener;
  58 import org.opendaylight.controller.cluster.notifications.RoleChangeNotifier;
  59 import org.opendaylight.controller.cluster.raft.RaftActor;
  60 import org.opendaylight.controller.cluster.raft.RaftActorRecoveryCohort;
  61 import org.opendaylight.controller.cluster.raft.RaftActorSnapshotCohort;
  62 import org.opendaylight.controller.cluster.raft.RaftState;
  63 import org.opendaylight.controller.cluster.raft.base.messages.FollowerInitialSyncUpStatus;
  64 import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply;
  65 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationByteStringPayload;
  66 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationPayload;
  67 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree;
  68 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  69 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
  70 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
  71 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  72 import scala.concurrent.duration.Duration;
  73 import scala.concurrent.duration.FiniteDuration;
  74
  75 /**
  76  * A Shard represents a portion of the logical data tree <br/>
  77  * <p>
  78  * Our Shard uses InMemoryDataTree as it's internal representation and delegates all requests it
  79  * </p>
  80  */
  81 public class Shard extends RaftActor {
  82
  83     protected static final Object TX_COMMIT_TIMEOUT_CHECK_MESSAGE = "txCommitTimeoutCheck";
  84
  85     @VisibleForTesting
  86     static final Object GET_SHARD_MBEAN_MESSAGE = "getShardMBeanMessage";
  87
  88     @VisibleForTesting
  89     static final String DEFAULT_NAME = "default";
  90
  91     // The state of this Shard
  92     private final ShardDataTree store;
  93
  94     /// The name of this shard
  95     private final String name;
  96
  97     private final ShardStats shardMBean;
  98
  99     private DatastoreContext datastoreContext;
 100
 101     private final ShardCommitCoordinator commitCoordinator;
 102
 103     private long transactionCommitTimeout;
 104
 105     private Cancellable txCommitTimeoutCheckSchedule;
 106
 107     private final Optional<ActorRef> roleChangeNotifier;
 108
 109     private final MessageTracker appendEntriesReplyTracker;
 110
 111     private final ShardTransactionActorFactory transactionActorFactory;
 112
 113     private final ShardSnapshotCohort snapshotCohort;
 114
 115     private final DataTreeChangeListenerSupport treeChangeSupport = new DataTreeChangeListenerSupport(this);
 116     private final DataChangeListenerSupport changeSupport = new DataChangeListenerSupport(this);
 117
 118     protected Shard(final ShardIdentifier name, final Map<String, String> peerAddresses,
 119             final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 120         super(name.toString(), new HashMap<>(peerAddresses), Optional.of(datastoreContext.getShardRaftConfig()),
 121                 DataStoreVersions.CURRENT_VERSION);
 122
 123         this.name = name.toString();
 124         this.datastoreContext = datastoreContext;
 125
 126         setPersistence(datastoreContext.isPersistent());
 127
 128         LOG.info("Shard created : {}, persistent : {}", name, datastoreContext.isPersistent());
 129
 130         store = new ShardDataTree(schemaContext);
 131
 132         shardMBean = ShardMBeanFactory.getShardStatsMBean(name.toString(),
 133                 datastoreContext.getDataStoreMXBeanType());
 134         shardMBean.setShard(this);
 135
 136         if (isMetricsCaptureEnabled()) {
 137             getContext().become(new MeteringBehavior(this));
 138         }
 139
 140         commitCoordinator = new ShardCommitCoordinator(store,
 141                 datastoreContext.getShardCommitQueueExpiryTimeoutInMillis(),
 142                 datastoreContext.getShardTransactionCommitQueueCapacity(), self(), LOG, this.name);
 143
 144         setTransactionCommitTimeout();
 145
 146         // create a notifier actor for each cluster member
 147         roleChangeNotifier = createRoleChangeNotifier(name.toString());
 148
 149         appendEntriesReplyTracker = new MessageTracker(AppendEntriesReply.class,
 150                 getRaftActorContext().getConfigParams().getIsolatedCheckIntervalInMillis());
 151
 152         transactionActorFactory = new ShardTransactionActorFactory(store, datastoreContext,
 153                 new Dispatchers(context().system().dispatchers()).getDispatcherPath(
 154                         Dispatchers.DispatcherType.Transaction), self(), getContext(), shardMBean);
 155
 156         snapshotCohort = new ShardSnapshotCohort(transactionActorFactory, store, LOG, this.name);
 157
 158
 159     }
 160
 161     private void setTransactionCommitTimeout() {
 162         transactionCommitTimeout = TimeUnit.MILLISECONDS.convert(
 163                 datastoreContext.getShardTransactionCommitTimeoutInSeconds(), TimeUnit.SECONDS) / 2;
 164     }
 165
 166     public static Props props(final ShardIdentifier name, final Map<String, String> peerAddresses,
 167             final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 168         return Props.create(new ShardCreator(name, peerAddresses, datastoreContext, schemaContext));
 169     }
 170
 171     private Optional<ActorRef> createRoleChangeNotifier(String shardId) {
 172         ActorRef shardRoleChangeNotifier = this.getContext().actorOf(
 173             RoleChangeNotifier.getProps(shardId), shardId + "-notifier");
 174         return Optional.of(shardRoleChangeNotifier);
 175     }
 176
 177     @Override
 178     public void postStop() {
 179         LOG.info("Stopping Shard {}", persistenceId());
 180
 181         super.postStop();
 182
 183         if(txCommitTimeoutCheckSchedule != null) {
 184             txCommitTimeoutCheckSchedule.cancel();
 185         }
 186
 187         shardMBean.unregisterMBean();
 188     }
 189
 190     @Override
 191     public void onReceiveRecover(final Object message) throws Exception {
 192         if(LOG.isDebugEnabled()) {
 193             LOG.debug("{}: onReceiveRecover: Received message {} from {}", persistenceId(),
 194                 message.getClass().toString(), getSender());
 195         }
 196
 197         if (message instanceof RecoveryFailure){
 198             LOG.error("{}: Recovery failed because of this cause",
 199                     persistenceId(), ((RecoveryFailure) message).cause());
 200
 201             // Even though recovery failed, we still need to finish our recovery, eg send the
 202             // ActorInitialized message and start the txCommitTimeoutCheckSchedule.
 203             onRecoveryComplete();
 204         } else {
 205             super.onReceiveRecover(message);
 206             if(LOG.isTraceEnabled()) {
 207                 appendEntriesReplyTracker.begin();
 208             }
 209         }
 210     }
 211
 212     @Override
 213     public void onReceiveCommand(final Object message) throws Exception {
 214
 215         MessageTracker.Context context = appendEntriesReplyTracker.received(message);
 216
 217         if(context.error().isPresent()){
 218             LOG.trace("{} : AppendEntriesReply failed to arrive at the expected interval {}", persistenceId(),
 219                 context.error());
 220         }
 221
 222         try {
 223             if (CreateTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 224                 handleCreateTransaction(message);
 225             } else if (BatchedModifications.class.isInstance(message)) {
 226                 handleBatchedModifications((BatchedModifications)message);
 227             } else if (message instanceof ForwardedReadyTransaction) {
 228                 commitCoordinator.handleForwardedReadyTransaction((ForwardedReadyTransaction) message,
 229                         getSender(), this);
 230             } else if (message instanceof ReadyLocalTransaction) {
 231                 handleReadyLocalTransaction((ReadyLocalTransaction)message);
 232             } else if (CanCommitTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 233                 handleCanCommitTransaction(CanCommitTransaction.fromSerializable(message));
 234             } else if (CommitTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 235                 handleCommitTransaction(CommitTransaction.fromSerializable(message));
 236             } else if (AbortTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 237                 handleAbortTransaction(AbortTransaction.fromSerializable(message));
 238             } else if (CloseTransactionChain.SERIALIZABLE_CLASS.isInstance(message)) {
 239                 closeTransactionChain(CloseTransactionChain.fromSerializable(message));
 240             } else if (message instanceof RegisterChangeListener) {
 241                 changeSupport.onMessage((RegisterChangeListener) message, isLeader(), hasLeader());
 242             } else if (message instanceof RegisterDataTreeChangeListener) {
 243                 treeChangeSupport.onMessage((RegisterDataTreeChangeListener) message, isLeader(), hasLeader());
 244             } else if (message instanceof UpdateSchemaContext) {
 245                 updateSchemaContext((UpdateSchemaContext) message);
 246             } else if (message instanceof PeerAddressResolved) {
 247                 PeerAddressResolved resolved = (PeerAddressResolved) message;
 248                 setPeerAddress(resolved.getPeerId().toString(),
 249                         resolved.getPeerAddress());
 250             } else if (message.equals(TX_COMMIT_TIMEOUT_CHECK_MESSAGE)) {
 251                 handleTransactionCommitTimeoutCheck();
 252             } else if(message instanceof DatastoreContext) {
 253                 onDatastoreContext((DatastoreContext)message);
 254             } else if(message instanceof RegisterRoleChangeListener){
 255                 roleChangeNotifier.get().forward(message, context());
 256             } else if (message instanceof FollowerInitialSyncUpStatus) {
 257                 shardMBean.setFollowerInitialSyncStatus(((FollowerInitialSyncUpStatus) message).isInitialSyncDone());
 258                 context().parent().tell(message, self());
 259             } else if(GET_SHARD_MBEAN_MESSAGE.equals(message)){
 260                 sender().tell(getShardMBean(), self());
 261             } else if(message instanceof GetShardDataTree){
 262                 sender().tell(store.getDataTree(), self());
 263             } else {
 264                 super.onReceiveCommand(message);
 265             }
 266         } finally {
 267             context.done();
 268         }
 269     }
 270
 271     private boolean hasLeader() {
 272         return getLeaderId() != null;
 273     }
 274
 275     public int getPendingTxCommitQueueSize() {
 276         return commitCoordinator.getQueueSize();
 277     }
 278
 279     @Override
 280     protected Optional<ActorRef> getRoleChangeNotifier() {
 281         return roleChangeNotifier;
 282     }
 283
 284     @Override
 285     protected LeaderStateChanged newLeaderStateChanged(String memberId, String leaderId, short leaderPayloadVersion) {
 286         return new ShardLeaderStateChanged(memberId, leaderId,
 287                 isLeader() ? Optional.<DataTree>of(store.getDataTree()) : Optional.<DataTree>absent(),
 288                 leaderPayloadVersion);
 289     }
 290
 291     protected void onDatastoreContext(DatastoreContext context) {
 292         datastoreContext = context;
 293
 294         commitCoordinator.setQueueCapacity(datastoreContext.getShardTransactionCommitQueueCapacity());
 295
 296         setTransactionCommitTimeout();
 297
 298         if(datastoreContext.isPersistent() && !persistence().isRecoveryApplicable()) {
 299             setPersistence(true);
 300         } else if(!datastoreContext.isPersistent() && persistence().isRecoveryApplicable()) {
 301             setPersistence(false);
 302         }
 303
 304         updateConfigParams(datastoreContext.getShardRaftConfig());
 305     }
 306
 307     private void handleTransactionCommitTimeoutCheck() {
 308         CohortEntry cohortEntry = commitCoordinator.getCurrentCohortEntry();
 309         if(cohortEntry != null) {
 310             if(cohortEntry.isExpired(transactionCommitTimeout)) {
 311                 LOG.warn("{}: Current transaction {} has timed out after {} ms - aborting",
 312                         persistenceId(), cohortEntry.getTransactionID(), transactionCommitTimeout);
 313
 314                 doAbortTransaction(cohortEntry.getTransactionID(), null);
 315             }
 316         }
 317
 318         commitCoordinator.cleanupExpiredCohortEntries();
 319     }
 320
 321     private static boolean isEmptyCommit(final DataTreeCandidate candidate) {
 322         return ModificationType.UNMODIFIED.equals(candidate.getRootNode().getModificationType());
 323     }
 324
 325     void continueCommit(final CohortEntry cohortEntry) throws Exception {
 326         final DataTreeCandidate candidate = cohortEntry.getCandidate();
 327
 328         // If we do not have any followers and we are not using persistence
 329         // or if cohortEntry has no modifications
 330         // we can apply modification to the state immediately
 331         if ((!hasFollowers() && !persistence().isRecoveryApplicable()) || isEmptyCommit(candidate)) {
 332             applyModificationToState(cohortEntry.getReplySender(), cohortEntry.getTransactionID(), candidate);
 333         } else {
 334             Shard.this.persistData(cohortEntry.getReplySender(), cohortEntry.getTransactionID(),
 335                 DataTreeCandidatePayload.create(candidate));
 336         }
 337     }
 338
 339     private void handleCommitTransaction(final CommitTransaction commit) {
 340         if(!commitCoordinator.handleCommit(commit.getTransactionID(), getSender(), this)) {
 341             shardMBean.incrementFailedTransactionsCount();
 342         }
 343     }
 344
 345     private void finishCommit(@Nonnull final ActorRef sender, @Nonnull final String transactionID, @Nonnull final CohortEntry cohortEntry) {
 346         LOG.debug("{}: Finishing commit for transaction {}", persistenceId(), cohortEntry.getTransactionID());
 347
 348         try {
 349             cohortEntry.commit();
 350
 351             sender.tell(CommitTransactionReply.INSTANCE.toSerializable(), getSelf());
 352
 353             shardMBean.incrementCommittedTransactionCount();
 354             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 355
 356         } catch (Exception e) {
 357             sender.tell(new akka.actor.Status.Failure(e), getSelf());
 358
 359             LOG.error("{}, An exception occurred while committing transaction {}", persistenceId(),
 360                     transactionID, e);
 361             shardMBean.incrementFailedTransactionsCount();
 362         } finally {
 363             commitCoordinator.currentTransactionComplete(transactionID, true);
 364         }
 365     }
 366
 367     private void finishCommit(@Nonnull final ActorRef sender, final @Nonnull String transactionID) {
 368         // With persistence enabled, this method is called via applyState by the leader strategy
 369         // after the commit has been replicated to a majority of the followers.
 370
 371         CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 372         if (cohortEntry == null) {
 373             // The transaction is no longer the current commit. This can happen if the transaction
 374             // was aborted prior, most likely due to timeout in the front-end. We need to finish
 375             // committing the transaction though since it was successfully persisted and replicated
 376             // however we can't use the original cohort b/c it was already preCommitted and may
 377             // conflict with the current commit or may have been aborted so we commit with a new
 378             // transaction.
 379             cohortEntry = commitCoordinator.getAndRemoveCohortEntry(transactionID);
 380             if(cohortEntry != null) {
 381                 try {
 382                     store.applyForeignCandidate(transactionID, cohortEntry.getCandidate());
 383                 } catch (DataValidationFailedException e) {
 384                     shardMBean.incrementFailedTransactionsCount();
 385                     LOG.error("{}: Failed to re-apply transaction {}", persistenceId(), transactionID, e);
 386                 }
 387
 388                 sender.tell(CommitTransactionReply.INSTANCE.toSerializable(), getSelf());
 389             } else {
 390                 // This really shouldn't happen - it likely means that persistence or replication
 391                 // took so long to complete such that the cohort entry was expired from the cache.
 392                 IllegalStateException ex = new IllegalStateException(
 393                         String.format("%s: Could not finish committing transaction %s - no CohortEntry found",
 394                                 persistenceId(), transactionID));
 395                 LOG.error(ex.getMessage());
 396                 sender.tell(new akka.actor.Status.Failure(ex), getSelf());
 397             }
 398         } else {
 399             finishCommit(sender, transactionID, cohortEntry);
 400         }
 401     }
 402
 403     private void handleCanCommitTransaction(final CanCommitTransaction canCommit) {
 404         LOG.debug("{}: Can committing transaction {}", persistenceId(), canCommit.getTransactionID());
 405         commitCoordinator.handleCanCommit(canCommit.getTransactionID(), getSender(), this);
 406     }
 407
 408     private void noLeaderError(String errMessage, Object message) {
 409         // TODO: rather than throwing an immediate exception, we could schedule a timer to try again to make
 410         // it more resilient in case we're in the process of electing a new leader.
 411         getSender().tell(new akka.actor.Status.Failure(new NoShardLeaderException(errMessage, persistenceId())), getSelf());
 412     }
 413
 414     protected void handleBatchedModificationsLocal(BatchedModifications batched, ActorRef sender) {
 415         try {
 416             commitCoordinator.handleBatchedModifications(batched, sender, this);
 417         } catch (Exception e) {
 418             LOG.error("{}: Error handling BatchedModifications for Tx {}", persistenceId(),
 419                     batched.getTransactionID(), e);
 420             sender.tell(new akka.actor.Status.Failure(e), getSelf());
 421         }
 422     }
 423
 424     private void handleBatchedModifications(BatchedModifications batched) {
 425         // This message is sent to prepare the modifications transaction directly on the Shard as an
 426         // optimization to avoid the extra overhead of a separate ShardTransaction actor. On the last
 427         // BatchedModifications message, the caller sets the ready flag in the message indicating
 428         // modifications are complete. The reply contains the cohort actor path (this actor) for the caller
 429         // to initiate the 3-phase commit. This also avoids the overhead of sending an additional
 430         // ReadyTransaction message.
 431
 432         // If we're not the leader then forward to the leader. This is a safety measure - we shouldn't
 433         // normally get here if we're not the leader as the front-end (TransactionProxy) should determine
 434         // the primary/leader shard. However with timing and caching on the front-end, there's a small
 435         // window where it could have a stale leader during leadership transitions.
 436         //
 437         if(isLeader()) {
 438             failIfIsolatedLeader(getSender());
 439
 440             handleBatchedModificationsLocal(batched, getSender());
 441         } else {
 442             ActorSelection leader = getLeader();
 443             if(leader != null) {
 444                 // TODO: what if this is not the first batch and leadership changed in between batched messages?
 445                 // We could check if the commitCoordinator already has a cached entry and forward all the previous
 446                 // batched modifications.
 447                 LOG.debug("{}: Forwarding BatchedModifications to leader {}", persistenceId(), leader);
 448                 leader.forward(batched, getContext());
 449             } else {
 450                 noLeaderError("Could not commit transaction " + batched.getTransactionID(), batched);
 451             }
 452         }
 453     }
 454
 455     private boolean failIfIsolatedLeader(ActorRef sender) {
 456         if(isIsolatedLeader()) {
 457             sender.tell(new akka.actor.Status.Failure(new NoShardLeaderException(String.format(
 458                     "Shard %s was the leader but has lost contact with all of its followers. Either all" +
 459                     " other follower nodes are down or this node is isolated by a network partition.",
 460                     persistenceId()))), getSelf());
 461             return true;
 462         }
 463
 464         return false;
 465     }
 466
 467     protected boolean isIsolatedLeader() {
 468         return getRaftState() == RaftState.IsolatedLeader;
 469     }
 470
 471     private void handleReadyLocalTransaction(final ReadyLocalTransaction message) {
 472         if (isLeader()) {
 473             failIfIsolatedLeader(getSender());
 474
 475             try {
 476                 commitCoordinator.handleReadyLocalTransaction(message, getSender(), this);
 477             } catch (Exception e) {
 478                 LOG.error("{}: Error handling ReadyLocalTransaction for Tx {}", persistenceId(),
 479                         message.getTransactionID(), e);
 480                 getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 481             }
 482         } else {
 483             ActorSelection leader = getLeader();
 484             if (leader != null) {
 485                 LOG.debug("{}: Forwarding ReadyLocalTransaction to leader {}", persistenceId(), leader);
 486                 message.setRemoteVersion(getCurrentBehavior().getLeaderPayloadVersion());
 487                 leader.forward(message, getContext());
 488             } else {
 489                 noLeaderError("Could not commit transaction " + message.getTransactionID(), message);
 490             }
 491         }
 492     }
 493
 494     private void handleAbortTransaction(final AbortTransaction abort) {
 495         doAbortTransaction(abort.getTransactionID(), getSender());
 496     }
 497
 498     void doAbortTransaction(final String transactionID, final ActorRef sender) {
 499         commitCoordinator.handleAbort(transactionID, sender, this);
 500     }
 501
 502     private void handleCreateTransaction(final Object message) {
 503         if (isLeader()) {
 504             createTransaction(CreateTransaction.fromSerializable(message));
 505         } else if (getLeader() != null) {
 506             getLeader().forward(message, getContext());
 507         } else {
 508             getSender().tell(new akka.actor.Status.Failure(new NoShardLeaderException(
 509                     "Could not create a shard transaction", persistenceId())), getSelf());
 510         }
 511     }
 512
 513     private void closeTransactionChain(final CloseTransactionChain closeTransactionChain) {
 514         store.closeTransactionChain(closeTransactionChain.getTransactionChainId());
 515     }
 516
 517     private ActorRef createTypedTransactionActor(int transactionType,
 518             ShardTransactionIdentifier transactionId, String transactionChainId,
 519             short clientVersion ) {
 520
 521         return transactionActorFactory.newShardTransaction(TransactionType.fromInt(transactionType),
 522                 transactionId, transactionChainId, clientVersion);
 523     }
 524
 525     private void createTransaction(CreateTransaction createTransaction) {
 526         try {
 527             if(TransactionType.fromInt(createTransaction.getTransactionType()) != TransactionType.READ_ONLY &&
 528                     failIfIsolatedLeader(getSender())) {
 529                 return;
 530             }
 531
 532             ActorRef transactionActor = createTransaction(createTransaction.getTransactionType(),
 533                 createTransaction.getTransactionId(), createTransaction.getTransactionChainId(),
 534                 createTransaction.getVersion());
 535
 536             getSender().tell(new CreateTransactionReply(Serialization.serializedActorPath(transactionActor),
 537                     createTransaction.getTransactionId()).toSerializable(), getSelf());
 538         } catch (Exception e) {
 539             getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 540         }
 541     }
 542
 543     private ActorRef createTransaction(int transactionType, String remoteTransactionId,
 544             String transactionChainId, short clientVersion) {
 545
 546
 547         ShardTransactionIdentifier transactionId = new ShardTransactionIdentifier(remoteTransactionId);
 548
 549         if(LOG.isDebugEnabled()) {
 550             LOG.debug("{}: Creating transaction : {} ", persistenceId(), transactionId);
 551         }
 552
 553         ActorRef transactionActor = createTypedTransactionActor(transactionType, transactionId,
 554                 transactionChainId, clientVersion);
 555
 556         return transactionActor;
 557     }
 558
 559     private void commitWithNewTransaction(final Modification modification) {
 560         ReadWriteShardDataTreeTransaction tx = store.newReadWriteTransaction(modification.toString(), null);
 561         modification.apply(tx.getSnapshot());
 562         try {
 563             snapshotCohort.syncCommitTransaction(tx);
 564             shardMBean.incrementCommittedTransactionCount();
 565             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 566         } catch (Exception e) {
 567             shardMBean.incrementFailedTransactionsCount();
 568             LOG.error("{}: Failed to commit", persistenceId(), e);
 569         }
 570     }
 571
 572     private void updateSchemaContext(final UpdateSchemaContext message) {
 573         updateSchemaContext(message.getSchemaContext());
 574     }
 575
 576     @VisibleForTesting
 577     void updateSchemaContext(final SchemaContext schemaContext) {
 578         store.updateSchemaContext(schemaContext);
 579     }
 580
 581     private boolean isMetricsCaptureEnabled() {
 582         CommonConfig config = new CommonConfig(getContext().system().settings().config());
 583         return config.isMetricCaptureEnabled();
 584     }
 585
 586     @Override
 587     @VisibleForTesting
 588     public RaftActorSnapshotCohort getRaftActorSnapshotCohort() {
 589         return snapshotCohort;
 590     }
 591
 592     @Override
 593     @Nonnull
 594     protected RaftActorRecoveryCohort getRaftActorRecoveryCohort() {
 595         return new ShardRecoveryCoordinator(store, store.getSchemaContext(), persistenceId(), LOG);
 596     }
 597
 598     @Override
 599     protected void onRecoveryComplete() {
 600         //notify shard manager
 601         getContext().parent().tell(new ActorInitialized(), getSelf());
 602
 603         // Being paranoid here - this method should only be called once but just in case...
 604         if(txCommitTimeoutCheckSchedule == null) {
 605             // Schedule a message to be periodically sent to check if the current in-progress
 606             // transaction should be expired and aborted.
 607             FiniteDuration period = Duration.create(transactionCommitTimeout / 3, TimeUnit.MILLISECONDS);
 608             txCommitTimeoutCheckSchedule = getContext().system().scheduler().schedule(
 609                     period, period, getSelf(),
 610                     TX_COMMIT_TIMEOUT_CHECK_MESSAGE, getContext().dispatcher(), ActorRef.noSender());
 611         }
 612     }
 613
 614     @Override
 615     protected void applyState(final ActorRef clientActor, final String identifier, final Object data) {
 616         if (data instanceof DataTreeCandidatePayload) {
 617             if (clientActor == null) {
 618                 // No clientActor indicates a replica coming from the leader
 619                 try {
 620                     store.applyForeignCandidate(identifier, ((DataTreeCandidatePayload)data).getCandidate());
 621                 } catch (DataValidationFailedException | IOException e) {
 622                     LOG.error("{}: Error applying replica {}", persistenceId(), identifier, e);
 623                 }
 624             } else {
 625                 // Replication consensus reached, proceed to commit
 626                 finishCommit(clientActor, identifier);
 627             }
 628         } else if (data instanceof ModificationPayload) {
 629             try {
 630                 applyModificationToState(clientActor, identifier, ((ModificationPayload) data).getModification());
 631             } catch (ClassNotFoundException | IOException e) {
 632                 LOG.error("{}: Error extracting ModificationPayload", persistenceId(), e);
 633             }
 634         } else if (data instanceof CompositeModificationPayload) {
 635             Object modification = ((CompositeModificationPayload) data).getModification();
 636
 637             applyModificationToState(clientActor, identifier, modification);
 638         } else if(data instanceof CompositeModificationByteStringPayload ){
 639             Object modification = ((CompositeModificationByteStringPayload) data).getModification();
 640
 641             applyModificationToState(clientActor, identifier, modification);
 642         } else {
 643             LOG.error("{}: Unknown state received {} Class loader = {} CompositeNodeMod.ClassLoader = {}",
 644                     persistenceId(), data, data.getClass().getClassLoader(),
 645                     CompositeModificationPayload.class.getClassLoader());
 646         }
 647     }
 648
 649     private void applyModificationToState(ActorRef clientActor, String identifier, Object modification) {
 650         if(modification == null) {
 651             LOG.error(
 652                     "{}: modification is null - this is very unexpected, clientActor = {}, identifier = {}",
 653                     persistenceId(), identifier, clientActor != null ? clientActor.path().toString() : null);
 654         } else if(clientActor == null) {
 655             // There's no clientActor to which to send a commit reply so we must be applying
 656             // replicated state from the leader.
 657             commitWithNewTransaction(MutableCompositeModification.fromSerializable(modification));
 658         } else {
 659             // This must be the OK to commit after replication consensus.
 660             finishCommit(clientActor, identifier);
 661         }
 662     }
 663
 664     @Override
 665     protected void onStateChanged() {
 666         boolean isLeader = isLeader();
 667         boolean hasLeader = hasLeader();
 668         changeSupport.onLeadershipChange(isLeader, hasLeader);
 669         treeChangeSupport.onLeadershipChange(isLeader, hasLeader);
 670
 671         // If this actor is no longer the leader close all the transaction chains
 672         if (!isLeader) {
 673             if(LOG.isDebugEnabled()) {
 674                 LOG.debug(
 675                     "{}: onStateChanged: Closing all transaction chains because shard {} is no longer the leader",
 676                     persistenceId(), getId());
 677             }
 678
 679             store.closeAllTransactionChains();
 680         }
 681     }
 682
 683     @Override
 684     protected void onLeaderChanged(String oldLeader, String newLeader) {
 685         shardMBean.incrementLeadershipChangeCount();
 686     }
 687
 688     @Override
 689     public String persistenceId() {
 690         return this.name;
 691     }
 692
 693     @VisibleForTesting
 694     ShardCommitCoordinator getCommitCoordinator() {
 695         return commitCoordinator;
 696     }
 697
 698     public DatastoreContext getDatastoreContext() {
 699         return datastoreContext;
 700     }
 701
 702     protected abstract static class AbstractShardCreator implements Creator<Shard> {
 703         private static final long serialVersionUID = 1L;
 704
 705         protected final ShardIdentifier name;
 706         protected final Map<String, String> peerAddresses;
 707         protected final DatastoreContext datastoreContext;
 708         protected final SchemaContext schemaContext;
 709
 710         protected AbstractShardCreator(final ShardIdentifier name, final Map<String, String> peerAddresses,
 711                 final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 712             this.name = Preconditions.checkNotNull(name, "name should not be null");
 713             this.peerAddresses = Preconditions.checkNotNull(peerAddresses, "peerAddresses should not be null");
 714             this.datastoreContext = Preconditions.checkNotNull(datastoreContext, "dataStoreContext should not be null");
 715             this.schemaContext = Preconditions.checkNotNull(schemaContext, "schemaContext should not be null");
 716         }
 717     }
 718
 719     private static class ShardCreator extends AbstractShardCreator {
 720         private static final long serialVersionUID = 1L;
 721
 722         ShardCreator(final ShardIdentifier name, final Map<String, String> peerAddresses,
 723                 final DatastoreContext datastoreContext, final SchemaContext schemaContext) {
 724             super(name, peerAddresses, datastoreContext, schemaContext);
 725         }
 726
 727         @Override
 728         public Shard create() throws Exception {
 729             return new Shard(name, peerAddresses, datastoreContext, schemaContext);
 730         }
 731     }
 732
 733     @VisibleForTesting
 734     public ShardDataTree getDataStore() {
 735         return store;
 736     }
 737
 738     @VisibleForTesting
 739     ShardStats getShardMBean() {
 740         return shardMBean;
 741     }
 742 }