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