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.persistence.RecoveryFailure;
  16 import akka.serialization.Serialization;
  17 import com.google.common.annotations.VisibleForTesting;
  18 import com.google.common.base.Optional;
  19 import com.google.common.base.Preconditions;
  20 import java.io.IOException;
  21 import java.util.Collections;
  22 import java.util.Map;
  23 import java.util.concurrent.TimeUnit;
  24 import javax.annotation.Nonnull;
  25 import org.opendaylight.controller.cluster.common.actor.CommonConfig;
  26 import org.opendaylight.controller.cluster.common.actor.MeteringBehavior;
  27 import org.opendaylight.controller.cluster.datastore.ShardCommitCoordinator.CohortEntry;
  28 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
  29 import org.opendaylight.controller.cluster.datastore.identifiers.ShardIdentifier;
  30 import org.opendaylight.controller.cluster.datastore.identifiers.ShardTransactionIdentifier;
  31 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardMBeanFactory;
  32 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardStats;
  33 import org.opendaylight.controller.cluster.datastore.messages.AbortTransaction;
  34 import org.opendaylight.controller.cluster.datastore.messages.ActorInitialized;
  35 import org.opendaylight.controller.cluster.datastore.messages.BatchedModifications;
  36 import org.opendaylight.controller.cluster.datastore.messages.CanCommitTransaction;
  37 import org.opendaylight.controller.cluster.datastore.messages.CloseTransactionChain;
  38 import org.opendaylight.controller.cluster.datastore.messages.CommitTransaction;
  39 import org.opendaylight.controller.cluster.datastore.messages.CommitTransactionReply;
  40 import org.opendaylight.controller.cluster.datastore.messages.CreateTransaction;
  41 import org.opendaylight.controller.cluster.datastore.messages.CreateTransactionReply;
  42 import org.opendaylight.controller.cluster.datastore.messages.DatastoreSnapshot;
  43 import org.opendaylight.controller.cluster.datastore.messages.DatastoreSnapshot.ShardSnapshot;
  44 import org.opendaylight.controller.cluster.datastore.messages.ForwardedReadyTransaction;
  45 import org.opendaylight.controller.cluster.datastore.messages.GetShardDataTree;
  46 import org.opendaylight.controller.cluster.datastore.messages.PeerAddressResolved;
  47 import org.opendaylight.controller.cluster.datastore.messages.ReadyLocalTransaction;
  48 import org.opendaylight.controller.cluster.datastore.messages.RegisterChangeListener;
  49 import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeChangeListener;
  50 import org.opendaylight.controller.cluster.datastore.messages.ShardLeaderStateChanged;
  51 import org.opendaylight.controller.cluster.datastore.messages.UpdateSchemaContext;
  52 import org.opendaylight.controller.cluster.datastore.modification.Modification;
  53 import org.opendaylight.controller.cluster.datastore.modification.ModificationPayload;
  54 import org.opendaylight.controller.cluster.datastore.modification.MutableCompositeModification;
  55 import org.opendaylight.controller.cluster.datastore.utils.Dispatchers;
  56 import org.opendaylight.controller.cluster.datastore.utils.MessageTracker;
  57 import org.opendaylight.controller.cluster.notifications.LeaderStateChanged;
  58 import org.opendaylight.controller.cluster.notifications.RegisterRoleChangeListener;
  59 import org.opendaylight.controller.cluster.notifications.RoleChangeNotifier;
  60 import org.opendaylight.controller.cluster.raft.RaftActor;
  61 import org.opendaylight.controller.cluster.raft.RaftActorRecoveryCohort;
  62 import org.opendaylight.controller.cluster.raft.RaftActorSnapshotCohort;
  63 import org.opendaylight.controller.cluster.raft.RaftState;
  64 import org.opendaylight.controller.cluster.raft.base.messages.FollowerInitialSyncUpStatus;
  65 import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply;
  66 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationByteStringPayload;
  67 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationPayload;
  68 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree;
  69 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  70 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
  71 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
  72 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  73 import scala.concurrent.duration.Duration;
  74 import scala.concurrent.duration.FiniteDuration;
  75
  76 /**
  77  * A Shard represents a portion of the logical data tree <br/>
  78  * <p>
  79  * Our Shard uses InMemoryDataTree as it's internal representation and delegates all requests it
  80  * </p>
  81  */
  82 public class Shard extends RaftActor {
  83
  84     protected static final Object TX_COMMIT_TIMEOUT_CHECK_MESSAGE = "txCommitTimeoutCheck";
  85
  86     @VisibleForTesting
  87     static final Object GET_SHARD_MBEAN_MESSAGE = "getShardMBeanMessage";
  88
  89     @VisibleForTesting
  90     static final String DEFAULT_NAME = "default";
  91
  92     // The state of this Shard
  93     private final ShardDataTree store;
  94
  95     /// The name of this shard
  96     private final String name;
  97
  98     private final ShardStats shardMBean;
  99
 100     private DatastoreContext datastoreContext;
 101
 102     private final ShardCommitCoordinator commitCoordinator;
 103
 104     private long transactionCommitTimeout;
 105
 106     private Cancellable txCommitTimeoutCheckSchedule;
 107
 108     private final Optional<ActorRef> roleChangeNotifier;
 109
 110     private final MessageTracker appendEntriesReplyTracker;
 111
 112     private final ShardTransactionActorFactory transactionActorFactory;
 113
 114     private final ShardSnapshotCohort snapshotCohort;
 115
 116     private final DataTreeChangeListenerSupport treeChangeSupport = new DataTreeChangeListenerSupport(this);
 117     private final DataChangeListenerSupport changeSupport = new DataChangeListenerSupport(this);
 118
 119     private ShardSnapshot restoreFromSnapshot;
 120
 121     protected Shard(AbstractBuilder<?, ?> builder) {
 122         super(builder.getId().toString(), builder.getPeerAddresses(),
 123                 Optional.of(builder.getDatastoreContext().getShardRaftConfig()), DataStoreVersions.CURRENT_VERSION);
 124
 125         this.name = builder.getId().toString();
 126         this.datastoreContext = builder.getDatastoreContext();
 127         this.restoreFromSnapshot = builder.getRestoreFromSnapshot();
 128
 129         setPersistence(datastoreContext.isPersistent());
 130
 131         LOG.info("Shard created : {}, persistent : {}", name, datastoreContext.isPersistent());
 132
 133         store = new ShardDataTree(builder.getSchemaContext());
 134
 135         shardMBean = ShardMBeanFactory.getShardStatsMBean(name.toString(),
 136                 datastoreContext.getDataStoreMXBeanType());
 137         shardMBean.setShard(this);
 138
 139         if (isMetricsCaptureEnabled()) {
 140             getContext().become(new MeteringBehavior(this));
 141         }
 142
 143         commitCoordinator = new ShardCommitCoordinator(store,
 144                 datastoreContext.getShardCommitQueueExpiryTimeoutInMillis(),
 145                 datastoreContext.getShardTransactionCommitQueueCapacity(), self(), LOG, this.name);
 146
 147         setTransactionCommitTimeout();
 148
 149         // create a notifier actor for each cluster member
 150         roleChangeNotifier = createRoleChangeNotifier(name.toString());
 151
 152         appendEntriesReplyTracker = new MessageTracker(AppendEntriesReply.class,
 153                 getRaftActorContext().getConfigParams().getIsolatedCheckIntervalInMillis());
 154
 155         transactionActorFactory = new ShardTransactionActorFactory(store, datastoreContext,
 156                 new Dispatchers(context().system().dispatchers()).getDispatcherPath(
 157                         Dispatchers.DispatcherType.Transaction), self(), getContext(), shardMBean);
 158
 159         snapshotCohort = new ShardSnapshotCohort(transactionActorFactory, store, LOG, this.name);
 160
 161
 162     }
 163
 164     private void setTransactionCommitTimeout() {
 165         transactionCommitTimeout = TimeUnit.MILLISECONDS.convert(
 166                 datastoreContext.getShardTransactionCommitTimeoutInSeconds(), TimeUnit.SECONDS) / 2;
 167     }
 168
 169     private Optional<ActorRef> createRoleChangeNotifier(String shardId) {
 170         ActorRef shardRoleChangeNotifier = this.getContext().actorOf(
 171             RoleChangeNotifier.getProps(shardId), shardId + "-notifier");
 172         return Optional.of(shardRoleChangeNotifier);
 173     }
 174
 175     @Override
 176     public void postStop() {
 177         LOG.info("Stopping Shard {}", persistenceId());
 178
 179         super.postStop();
 180
 181         if(txCommitTimeoutCheckSchedule != null) {
 182             txCommitTimeoutCheckSchedule.cancel();
 183         }
 184
 185         shardMBean.unregisterMBean();
 186     }
 187
 188     @Override
 189     public void onReceiveRecover(final Object message) throws Exception {
 190         if(LOG.isDebugEnabled()) {
 191             LOG.debug("{}: onReceiveRecover: Received message {} from {}", persistenceId(),
 192                 message.getClass().toString(), getSender());
 193         }
 194
 195         if (message instanceof RecoveryFailure){
 196             LOG.error("{}: Recovery failed because of this cause",
 197                     persistenceId(), ((RecoveryFailure) message).cause());
 198
 199             // Even though recovery failed, we still need to finish our recovery, eg send the
 200             // ActorInitialized message and start the txCommitTimeoutCheckSchedule.
 201             onRecoveryComplete();
 202         } else {
 203             super.onReceiveRecover(message);
 204             if(LOG.isTraceEnabled()) {
 205                 appendEntriesReplyTracker.begin();
 206             }
 207         }
 208     }
 209
 210     @Override
 211     public void onReceiveCommand(final Object message) throws Exception {
 212
 213         MessageTracker.Context context = appendEntriesReplyTracker.received(message);
 214
 215         if(context.error().isPresent()){
 216             LOG.trace("{} : AppendEntriesReply failed to arrive at the expected interval {}", persistenceId(),
 217                 context.error());
 218         }
 219
 220         try {
 221             if (CreateTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 222                 handleCreateTransaction(message);
 223             } else if (BatchedModifications.class.isInstance(message)) {
 224                 handleBatchedModifications((BatchedModifications)message);
 225             } else if (message instanceof ForwardedReadyTransaction) {
 226                 commitCoordinator.handleForwardedReadyTransaction((ForwardedReadyTransaction) message,
 227                         getSender(), this);
 228             } else if (message instanceof ReadyLocalTransaction) {
 229                 handleReadyLocalTransaction((ReadyLocalTransaction)message);
 230             } else if (CanCommitTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 231                 handleCanCommitTransaction(CanCommitTransaction.fromSerializable(message));
 232             } else if (CommitTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 233                 handleCommitTransaction(CommitTransaction.fromSerializable(message));
 234             } else if (AbortTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 235                 handleAbortTransaction(AbortTransaction.fromSerializable(message));
 236             } else if (CloseTransactionChain.SERIALIZABLE_CLASS.isInstance(message)) {
 237                 closeTransactionChain(CloseTransactionChain.fromSerializable(message));
 238             } else if (message instanceof RegisterChangeListener) {
 239                 changeSupport.onMessage((RegisterChangeListener) message, isLeader(), hasLeader());
 240             } else if (message instanceof RegisterDataTreeChangeListener) {
 241                 treeChangeSupport.onMessage((RegisterDataTreeChangeListener) message, isLeader(), hasLeader());
 242             } else if (message instanceof UpdateSchemaContext) {
 243                 updateSchemaContext((UpdateSchemaContext) message);
 244             } else if (message instanceof PeerAddressResolved) {
 245                 PeerAddressResolved resolved = (PeerAddressResolved) message;
 246                 setPeerAddress(resolved.getPeerId().toString(),
 247                         resolved.getPeerAddress());
 248             } else if (message.equals(TX_COMMIT_TIMEOUT_CHECK_MESSAGE)) {
 249                 handleTransactionCommitTimeoutCheck();
 250             } else if(message instanceof DatastoreContext) {
 251                 onDatastoreContext((DatastoreContext)message);
 252             } else if(message instanceof RegisterRoleChangeListener){
 253                 roleChangeNotifier.get().forward(message, context());
 254             } else if (message instanceof FollowerInitialSyncUpStatus) {
 255                 shardMBean.setFollowerInitialSyncStatus(((FollowerInitialSyncUpStatus) message).isInitialSyncDone());
 256                 context().parent().tell(message, self());
 257             } else if(GET_SHARD_MBEAN_MESSAGE.equals(message)){
 258                 sender().tell(getShardMBean(), self());
 259             } else if(message instanceof GetShardDataTree){
 260                 sender().tell(store.getDataTree(), self());
 261             } else {
 262                 super.onReceiveCommand(message);
 263             }
 264         } finally {
 265             context.done();
 266         }
 267     }
 268
 269     private boolean hasLeader() {
 270         return getLeaderId() != null;
 271     }
 272
 273     public int getPendingTxCommitQueueSize() {
 274         return commitCoordinator.getQueueSize();
 275     }
 276
 277     @Override
 278     protected Optional<ActorRef> getRoleChangeNotifier() {
 279         return roleChangeNotifier;
 280     }
 281
 282     @Override
 283     protected LeaderStateChanged newLeaderStateChanged(String memberId, String leaderId, short leaderPayloadVersion) {
 284         return new ShardLeaderStateChanged(memberId, leaderId,
 285                 isLeader() ? Optional.<DataTree>of(store.getDataTree()) : Optional.<DataTree>absent(),
 286                 leaderPayloadVersion);
 287     }
 288
 289     protected void onDatastoreContext(DatastoreContext context) {
 290         datastoreContext = context;
 291
 292         commitCoordinator.setQueueCapacity(datastoreContext.getShardTransactionCommitQueueCapacity());
 293
 294         setTransactionCommitTimeout();
 295
 296         if(datastoreContext.isPersistent() && !persistence().isRecoveryApplicable()) {
 297             setPersistence(true);
 298         } else if(!datastoreContext.isPersistent() && persistence().isRecoveryApplicable()) {
 299             setPersistence(false);
 300         }
 301
 302         updateConfigParams(datastoreContext.getShardRaftConfig());
 303     }
 304
 305     private void handleTransactionCommitTimeoutCheck() {
 306         CohortEntry cohortEntry = commitCoordinator.getCurrentCohortEntry();
 307         if(cohortEntry != null) {
 308             if(cohortEntry.isExpired(transactionCommitTimeout)) {
 309                 LOG.warn("{}: Current transaction {} has timed out after {} ms - aborting",
 310                         persistenceId(), cohortEntry.getTransactionID(), transactionCommitTimeout);
 311
 312                 doAbortTransaction(cohortEntry.getTransactionID(), null);
 313             }
 314         }
 315
 316         commitCoordinator.cleanupExpiredCohortEntries();
 317     }
 318
 319     private static boolean isEmptyCommit(final DataTreeCandidate candidate) {
 320         return ModificationType.UNMODIFIED.equals(candidate.getRootNode().getModificationType());
 321     }
 322
 323     void continueCommit(final CohortEntry cohortEntry) {
 324         final DataTreeCandidate candidate = cohortEntry.getCandidate();
 325
 326         // If we do not have any followers and we are not using persistence
 327         // or if cohortEntry has no modifications
 328         // we can apply modification to the state immediately
 329         if ((!hasFollowers() && !persistence().isRecoveryApplicable()) || isEmptyCommit(candidate)) {
 330             applyModificationToState(cohortEntry.getReplySender(), cohortEntry.getTransactionID(), candidate);
 331         } else {
 332             Shard.this.persistData(cohortEntry.getReplySender(), cohortEntry.getTransactionID(),
 333                 DataTreeCandidatePayload.create(candidate));
 334         }
 335     }
 336
 337     private void handleCommitTransaction(final CommitTransaction commit) {
 338         if(!commitCoordinator.handleCommit(commit.getTransactionID(), getSender(), this)) {
 339             shardMBean.incrementFailedTransactionsCount();
 340         }
 341     }
 342
 343     private void finishCommit(@Nonnull final ActorRef sender, @Nonnull final String transactionID, @Nonnull final CohortEntry cohortEntry) {
 344         LOG.debug("{}: Finishing commit for transaction {}", persistenceId(), cohortEntry.getTransactionID());
 345
 346         try {
 347             cohortEntry.commit();
 348
 349             sender.tell(CommitTransactionReply.INSTANCE.toSerializable(), getSelf());
 350
 351             shardMBean.incrementCommittedTransactionCount();
 352             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 353
 354         } catch (Exception e) {
 355             sender.tell(new akka.actor.Status.Failure(e), getSelf());
 356
 357             LOG.error("{}, An exception occurred while committing transaction {}", persistenceId(),
 358                     transactionID, e);
 359             shardMBean.incrementFailedTransactionsCount();
 360         } finally {
 361             commitCoordinator.currentTransactionComplete(transactionID, true);
 362         }
 363     }
 364
 365     private void finishCommit(@Nonnull final ActorRef sender, final @Nonnull String transactionID) {
 366         // With persistence enabled, this method is called via applyState by the leader strategy
 367         // after the commit has been replicated to a majority of the followers.
 368
 369         CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 370         if (cohortEntry == null) {
 371             // The transaction is no longer the current commit. This can happen if the transaction
 372             // was aborted prior, most likely due to timeout in the front-end. We need to finish
 373             // committing the transaction though since it was successfully persisted and replicated
 374             // however we can't use the original cohort b/c it was already preCommitted and may
 375             // conflict with the current commit or may have been aborted so we commit with a new
 376             // transaction.
 377             cohortEntry = commitCoordinator.getAndRemoveCohortEntry(transactionID);
 378             if(cohortEntry != null) {
 379                 try {
 380                     store.applyForeignCandidate(transactionID, cohortEntry.getCandidate());
 381                 } catch (DataValidationFailedException e) {
 382                     shardMBean.incrementFailedTransactionsCount();
 383                     LOG.error("{}: Failed to re-apply transaction {}", persistenceId(), transactionID, e);
 384                 }
 385
 386                 sender.tell(CommitTransactionReply.INSTANCE.toSerializable(), getSelf());
 387             } else {
 388                 // This really shouldn't happen - it likely means that persistence or replication
 389                 // took so long to complete such that the cohort entry was expired from the cache.
 390                 IllegalStateException ex = new IllegalStateException(
 391                         String.format("%s: Could not finish committing transaction %s - no CohortEntry found",
 392                                 persistenceId(), transactionID));
 393                 LOG.error(ex.getMessage());
 394                 sender.tell(new akka.actor.Status.Failure(ex), getSelf());
 395             }
 396         } else {
 397             finishCommit(sender, transactionID, cohortEntry);
 398         }
 399     }
 400
 401     private void handleCanCommitTransaction(final CanCommitTransaction canCommit) {
 402         LOG.debug("{}: Can committing transaction {}", persistenceId(), canCommit.getTransactionID());
 403         commitCoordinator.handleCanCommit(canCommit.getTransactionID(), getSender(), this);
 404     }
 405
 406     private void noLeaderError(String errMessage, Object message) {
 407         // TODO: rather than throwing an immediate exception, we could schedule a timer to try again to make
 408         // it more resilient in case we're in the process of electing a new leader.
 409         getSender().tell(new akka.actor.Status.Failure(new NoShardLeaderException(errMessage, persistenceId())), getSelf());
 410     }
 411
 412     protected void handleBatchedModificationsLocal(BatchedModifications batched, ActorRef sender) {
 413         try {
 414             commitCoordinator.handleBatchedModifications(batched, sender, this);
 415         } catch (Exception e) {
 416             LOG.error("{}: Error handling BatchedModifications for Tx {}", persistenceId(),
 417                     batched.getTransactionID(), e);
 418             sender.tell(new akka.actor.Status.Failure(e), getSelf());
 419         }
 420     }
 421
 422     private void handleBatchedModifications(BatchedModifications batched) {
 423         // This message is sent to prepare the modifications transaction directly on the Shard as an
 424         // optimization to avoid the extra overhead of a separate ShardTransaction actor. On the last
 425         // BatchedModifications message, the caller sets the ready flag in the message indicating
 426         // modifications are complete. The reply contains the cohort actor path (this actor) for the caller
 427         // to initiate the 3-phase commit. This also avoids the overhead of sending an additional
 428         // ReadyTransaction message.
 429
 430         // If we're not the leader then forward to the leader. This is a safety measure - we shouldn't
 431         // normally get here if we're not the leader as the front-end (TransactionProxy) should determine
 432         // the primary/leader shard. However with timing and caching on the front-end, there's a small
 433         // window where it could have a stale leader during leadership transitions.
 434         //
 435         if(isLeader()) {
 436             failIfIsolatedLeader(getSender());
 437
 438             handleBatchedModificationsLocal(batched, getSender());
 439         } else {
 440             ActorSelection leader = getLeader();
 441             if(leader != null) {
 442                 // TODO: what if this is not the first batch and leadership changed in between batched messages?
 443                 // We could check if the commitCoordinator already has a cached entry and forward all the previous
 444                 // batched modifications.
 445                 LOG.debug("{}: Forwarding BatchedModifications to leader {}", persistenceId(), leader);
 446                 leader.forward(batched, getContext());
 447             } else {
 448                 noLeaderError("Could not commit transaction " + batched.getTransactionID(), batched);
 449             }
 450         }
 451     }
 452
 453     private boolean failIfIsolatedLeader(ActorRef sender) {
 454         if(isIsolatedLeader()) {
 455             sender.tell(new akka.actor.Status.Failure(new NoShardLeaderException(String.format(
 456                     "Shard %s was the leader but has lost contact with all of its followers. Either all" +
 457                     " other follower nodes are down or this node is isolated by a network partition.",
 458                     persistenceId()))), getSelf());
 459             return true;
 460         }
 461
 462         return false;
 463     }
 464
 465     protected boolean isIsolatedLeader() {
 466         return getRaftState() == RaftState.IsolatedLeader;
 467     }
 468
 469     private void handleReadyLocalTransaction(final ReadyLocalTransaction message) {
 470         if (isLeader()) {
 471             failIfIsolatedLeader(getSender());
 472
 473             try {
 474                 commitCoordinator.handleReadyLocalTransaction(message, getSender(), this);
 475             } catch (Exception e) {
 476                 LOG.error("{}: Error handling ReadyLocalTransaction for Tx {}", persistenceId(),
 477                         message.getTransactionID(), e);
 478                 getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 479             }
 480         } else {
 481             ActorSelection leader = getLeader();
 482             if (leader != null) {
 483                 LOG.debug("{}: Forwarding ReadyLocalTransaction to leader {}", persistenceId(), leader);
 484                 message.setRemoteVersion(getCurrentBehavior().getLeaderPayloadVersion());
 485                 leader.forward(message, getContext());
 486             } else {
 487                 noLeaderError("Could not commit transaction " + message.getTransactionID(), message);
 488             }
 489         }
 490     }
 491
 492     private void handleAbortTransaction(final AbortTransaction abort) {
 493         doAbortTransaction(abort.getTransactionID(), getSender());
 494     }
 495
 496     void doAbortTransaction(final String transactionID, final ActorRef sender) {
 497         commitCoordinator.handleAbort(transactionID, sender, this);
 498     }
 499
 500     private void handleCreateTransaction(final Object message) {
 501         if (isLeader()) {
 502             createTransaction(CreateTransaction.fromSerializable(message));
 503         } else if (getLeader() != null) {
 504             getLeader().forward(message, getContext());
 505         } else {
 506             getSender().tell(new akka.actor.Status.Failure(new NoShardLeaderException(
 507                     "Could not create a shard transaction", persistenceId())), getSelf());
 508         }
 509     }
 510
 511     private void closeTransactionChain(final CloseTransactionChain closeTransactionChain) {
 512         store.closeTransactionChain(closeTransactionChain.getTransactionChainId());
 513     }
 514
 515     private ActorRef createTypedTransactionActor(int transactionType,
 516             ShardTransactionIdentifier transactionId, String transactionChainId,
 517             short clientVersion ) {
 518
 519         return transactionActorFactory.newShardTransaction(TransactionType.fromInt(transactionType),
 520                 transactionId, transactionChainId, clientVersion);
 521     }
 522
 523     private void createTransaction(CreateTransaction createTransaction) {
 524         try {
 525             if(TransactionType.fromInt(createTransaction.getTransactionType()) != TransactionType.READ_ONLY &&
 526                     failIfIsolatedLeader(getSender())) {
 527                 return;
 528             }
 529
 530             ActorRef transactionActor = createTransaction(createTransaction.getTransactionType(),
 531                 createTransaction.getTransactionId(), createTransaction.getTransactionChainId(),
 532                 createTransaction.getVersion());
 533
 534             getSender().tell(new CreateTransactionReply(Serialization.serializedActorPath(transactionActor),
 535                     createTransaction.getTransactionId()).toSerializable(), getSelf());
 536         } catch (Exception e) {
 537             getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 538         }
 539     }
 540
 541     private ActorRef createTransaction(int transactionType, String remoteTransactionId,
 542             String transactionChainId, short clientVersion) {
 543
 544
 545         ShardTransactionIdentifier transactionId = new ShardTransactionIdentifier(remoteTransactionId);
 546
 547         if(LOG.isDebugEnabled()) {
 548             LOG.debug("{}: Creating transaction : {} ", persistenceId(), transactionId);
 549         }
 550
 551         ActorRef transactionActor = createTypedTransactionActor(transactionType, transactionId,
 552                 transactionChainId, clientVersion);
 553
 554         return transactionActor;
 555     }
 556
 557     private void commitWithNewTransaction(final Modification modification) {
 558         ReadWriteShardDataTreeTransaction tx = store.newReadWriteTransaction(modification.toString(), null);
 559         modification.apply(tx.getSnapshot());
 560         try {
 561             snapshotCohort.syncCommitTransaction(tx);
 562             shardMBean.incrementCommittedTransactionCount();
 563             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 564         } catch (Exception e) {
 565             shardMBean.incrementFailedTransactionsCount();
 566             LOG.error("{}: Failed to commit", persistenceId(), e);
 567         }
 568     }
 569
 570     private void updateSchemaContext(final UpdateSchemaContext message) {
 571         updateSchemaContext(message.getSchemaContext());
 572     }
 573
 574     @VisibleForTesting
 575     void updateSchemaContext(final SchemaContext schemaContext) {
 576         store.updateSchemaContext(schemaContext);
 577     }
 578
 579     private boolean isMetricsCaptureEnabled() {
 580         CommonConfig config = new CommonConfig(getContext().system().settings().config());
 581         return config.isMetricCaptureEnabled();
 582     }
 583
 584     @Override
 585     @VisibleForTesting
 586     public RaftActorSnapshotCohort getRaftActorSnapshotCohort() {
 587         return snapshotCohort;
 588     }
 589
 590     @Override
 591     @Nonnull
 592     protected RaftActorRecoveryCohort getRaftActorRecoveryCohort() {
 593         return new ShardRecoveryCoordinator(store, store.getSchemaContext(),
 594                 restoreFromSnapshot != null ? restoreFromSnapshot.getSnapshot() : null, persistenceId(), LOG);
 595     }
 596
 597     @Override
 598     protected void onRecoveryComplete() {
 599         restoreFromSnapshot = null;
 600
 601         //notify shard manager
 602         getContext().parent().tell(new ActorInitialized(), getSelf());
 603
 604         // Being paranoid here - this method should only be called once but just in case...
 605         if(txCommitTimeoutCheckSchedule == null) {
 606             // Schedule a message to be periodically sent to check if the current in-progress
 607             // transaction should be expired and aborted.
 608             FiniteDuration period = Duration.create(transactionCommitTimeout / 3, TimeUnit.MILLISECONDS);
 609             txCommitTimeoutCheckSchedule = getContext().system().scheduler().schedule(
 610                     period, period, getSelf(),
 611                     TX_COMMIT_TIMEOUT_CHECK_MESSAGE, getContext().dispatcher(), ActorRef.noSender());
 612         }
 613     }
 614
 615     @Override
 616     protected void applyState(final ActorRef clientActor, final String identifier, final Object data) {
 617         if (data instanceof DataTreeCandidatePayload) {
 618             if (clientActor == null) {
 619                 // No clientActor indicates a replica coming from the leader
 620                 try {
 621                     store.applyForeignCandidate(identifier, ((DataTreeCandidatePayload)data).getCandidate());
 622                 } catch (DataValidationFailedException | IOException e) {
 623                     LOG.error("{}: Error applying replica {}", persistenceId(), identifier, e);
 624                 }
 625             } else {
 626                 // Replication consensus reached, proceed to commit
 627                 finishCommit(clientActor, identifier);
 628             }
 629         } else if (data instanceof ModificationPayload) {
 630             try {
 631                 applyModificationToState(clientActor, identifier, ((ModificationPayload) data).getModification());
 632             } catch (ClassNotFoundException | IOException e) {
 633                 LOG.error("{}: Error extracting ModificationPayload", persistenceId(), e);
 634             }
 635         } else if (data instanceof CompositeModificationPayload) {
 636             Object modification = ((CompositeModificationPayload) data).getModification();
 637
 638             applyModificationToState(clientActor, identifier, modification);
 639         } else if(data instanceof CompositeModificationByteStringPayload ){
 640             Object modification = ((CompositeModificationByteStringPayload) data).getModification();
 641
 642             applyModificationToState(clientActor, identifier, modification);
 643         } else {
 644             LOG.error("{}: Unknown state received {} Class loader = {} CompositeNodeMod.ClassLoader = {}",
 645                     persistenceId(), data, data.getClass().getClassLoader(),
 646                     CompositeModificationPayload.class.getClassLoader());
 647         }
 648     }
 649
 650     private void applyModificationToState(ActorRef clientActor, String identifier, Object modification) {
 651         if(modification == null) {
 652             LOG.error(
 653                     "{}: modification is null - this is very unexpected, clientActor = {}, identifier = {}",
 654                     persistenceId(), identifier, clientActor != null ? clientActor.path().toString() : null);
 655         } else if(clientActor == null) {
 656             // There's no clientActor to which to send a commit reply so we must be applying
 657             // replicated state from the leader.
 658             commitWithNewTransaction(MutableCompositeModification.fromSerializable(modification));
 659         } else {
 660             // This must be the OK to commit after replication consensus.
 661             finishCommit(clientActor, identifier);
 662         }
 663     }
 664
 665     @Override
 666     protected void onStateChanged() {
 667         boolean isLeader = isLeader();
 668         boolean hasLeader = hasLeader();
 669         changeSupport.onLeadershipChange(isLeader, hasLeader);
 670         treeChangeSupport.onLeadershipChange(isLeader, hasLeader);
 671
 672         // If this actor is no longer the leader close all the transaction chains
 673         if (!isLeader) {
 674             if(LOG.isDebugEnabled()) {
 675                 LOG.debug(
 676                     "{}: onStateChanged: Closing all transaction chains because shard {} is no longer the leader",
 677                     persistenceId(), getId());
 678             }
 679
 680             store.closeAllTransactionChains();
 681         }
 682     }
 683
 684     @Override
 685     protected void onLeaderChanged(String oldLeader, String newLeader) {
 686         shardMBean.incrementLeadershipChangeCount();
 687     }
 688
 689     @Override
 690     public String persistenceId() {
 691         return this.name;
 692     }
 693
 694     @VisibleForTesting
 695     ShardCommitCoordinator getCommitCoordinator() {
 696         return commitCoordinator;
 697     }
 698
 699     public DatastoreContext getDatastoreContext() {
 700         return datastoreContext;
 701     }
 702
 703     @VisibleForTesting
 704     public ShardDataTree getDataStore() {
 705         return store;
 706     }
 707
 708     @VisibleForTesting
 709     ShardStats getShardMBean() {
 710         return shardMBean;
 711     }
 712
 713     public static Builder builder() {
 714         return new Builder();
 715     }
 716
 717     public static abstract class AbstractBuilder<T extends AbstractBuilder<T, S>, S extends Shard> {
 718         private final Class<S> shardClass;
 719         private ShardIdentifier id;
 720         private Map<String, String> peerAddresses = Collections.emptyMap();
 721         private DatastoreContext datastoreContext;
 722         private SchemaContext schemaContext;
 723         private DatastoreSnapshot.ShardSnapshot restoreFromSnapshot;
 724         private volatile boolean sealed;
 725
 726         protected AbstractBuilder(Class<S> shardClass) {
 727             this.shardClass = shardClass;
 728         }
 729
 730         protected void checkSealed() {
 731             Preconditions.checkState(!sealed, "Builder isalready sealed - further modifications are not allowed");
 732         }
 733
 734         @SuppressWarnings("unchecked")
 735         private T self() {
 736             return (T) this;
 737         }
 738
 739         public T id(ShardIdentifier id) {
 740             checkSealed();
 741             this.id = id;
 742             return self();
 743         }
 744
 745         public T peerAddresses(Map<String, String> peerAddresses) {
 746             checkSealed();
 747             this.peerAddresses = peerAddresses;
 748             return self();
 749         }
 750
 751         public T datastoreContext(DatastoreContext datastoreContext) {
 752             checkSealed();
 753             this.datastoreContext = datastoreContext;
 754             return self();
 755         }
 756
 757         public T schemaContext(SchemaContext schemaContext) {
 758             checkSealed();
 759             this.schemaContext = schemaContext;
 760             return self();
 761         }
 762
 763         public T restoreFromSnapshot(DatastoreSnapshot.ShardSnapshot restoreFromSnapshot) {
 764             checkSealed();
 765             this.restoreFromSnapshot = restoreFromSnapshot;
 766             return self();
 767         }
 768
 769         public ShardIdentifier getId() {
 770             return id;
 771         }
 772
 773         public Map<String, String> getPeerAddresses() {
 774             return peerAddresses;
 775         }
 776
 777         public DatastoreContext getDatastoreContext() {
 778             return datastoreContext;
 779         }
 780
 781         public SchemaContext getSchemaContext() {
 782             return schemaContext;
 783         }
 784
 785         public DatastoreSnapshot.ShardSnapshot getRestoreFromSnapshot() {
 786             return restoreFromSnapshot;
 787         }
 788
 789         protected void verify() {
 790             Preconditions.checkNotNull(id, "id should not be null");
 791             Preconditions.checkNotNull(peerAddresses, "peerAddresses should not be null");
 792             Preconditions.checkNotNull(datastoreContext, "dataStoreContext should not be null");
 793             Preconditions.checkNotNull(schemaContext, "schemaContext should not be null");
 794         }
 795
 796         public Props props() {
 797             sealed = true;
 798             verify();
 799             return Props.create(shardClass, this);
 800         }
 801     }
 802
 803     public static class Builder extends AbstractBuilder<Builder, Shard> {
 804         private Builder() {
 805             super(Shard.class);
 806         }
 807     }
 808 }