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.messages.ServerRemoved;
  67 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationByteStringPayload;
  68 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationPayload;
  69 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree;
  70 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  71 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
  72 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
  73 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  74 import scala.concurrent.duration.Duration;
  75 import scala.concurrent.duration.FiniteDuration;
  76
  77 /**
  78  * A Shard represents a portion of the logical data tree <br/>
  79  * <p>
  80  * Our Shard uses InMemoryDataTree as it's internal representation and delegates all requests it
  81  * </p>
  82  */
  83 public class Shard extends RaftActor {
  84
  85     protected static final Object TX_COMMIT_TIMEOUT_CHECK_MESSAGE = "txCommitTimeoutCheck";
  86
  87     @VisibleForTesting
  88     static final Object GET_SHARD_MBEAN_MESSAGE = "getShardMBeanMessage";
  89
  90     @VisibleForTesting
  91     static final String DEFAULT_NAME = "default";
  92
  93     // The state of this Shard
  94     private final ShardDataTree store;
  95
  96     /// The name of this shard
  97     private final String name;
  98
  99     private final ShardStats shardMBean;
 100
 101     private DatastoreContext datastoreContext;
 102
 103     private final ShardCommitCoordinator commitCoordinator;
 104
 105     private long transactionCommitTimeout;
 106
 107     private Cancellable txCommitTimeoutCheckSchedule;
 108
 109     private final Optional<ActorRef> roleChangeNotifier;
 110
 111     private final MessageTracker appendEntriesReplyTracker;
 112
 113     private final ShardTransactionActorFactory transactionActorFactory;
 114
 115     private final ShardSnapshotCohort snapshotCohort;
 116
 117     private final DataTreeChangeListenerSupport treeChangeSupport = new DataTreeChangeListenerSupport(this);
 118     private final DataChangeListenerSupport changeSupport = new DataChangeListenerSupport(this);
 119
 120
 121     private ShardSnapshot restoreFromSnapshot;
 122
 123
 124
 125     protected Shard(AbstractBuilder<?, ?> builder) {
 126         super(builder.getId().toString(), builder.getPeerAddresses(),
 127                 Optional.of(builder.getDatastoreContext().getShardRaftConfig()), DataStoreVersions.CURRENT_VERSION);
 128
 129         this.name = builder.getId().toString();
 130         this.datastoreContext = builder.getDatastoreContext();
 131         this.restoreFromSnapshot = builder.getRestoreFromSnapshot();
 132
 133         setPersistence(datastoreContext.isPersistent());
 134
 135         LOG.info("Shard created : {}, persistent : {}", name, datastoreContext.isPersistent());
 136
 137         store = new ShardDataTree(builder.getSchemaContext());
 138
 139         shardMBean = ShardMBeanFactory.getShardStatsMBean(name.toString(),
 140                 datastoreContext.getDataStoreMXBeanType());
 141         shardMBean.setShard(this);
 142
 143         if (isMetricsCaptureEnabled()) {
 144             getContext().become(new MeteringBehavior(this));
 145         }
 146
 147         commitCoordinator = new ShardCommitCoordinator(store,
 148                 datastoreContext.getShardCommitQueueExpiryTimeoutInMillis(),
 149                 datastoreContext.getShardTransactionCommitQueueCapacity(), LOG, this.name);
 150
 151         setTransactionCommitTimeout();
 152
 153         // create a notifier actor for each cluster member
 154         roleChangeNotifier = createRoleChangeNotifier(name.toString());
 155
 156         appendEntriesReplyTracker = new MessageTracker(AppendEntriesReply.class,
 157                 getRaftActorContext().getConfigParams().getIsolatedCheckIntervalInMillis());
 158
 159         transactionActorFactory = new ShardTransactionActorFactory(store, datastoreContext,
 160                 new Dispatchers(context().system().dispatchers()).getDispatcherPath(
 161                         Dispatchers.DispatcherType.Transaction), self(), getContext(), shardMBean);
 162
 163         snapshotCohort = new ShardSnapshotCohort(transactionActorFactory, store, LOG, this.name);
 164
 165
 166
 167     }
 168
 169     private void setTransactionCommitTimeout() {
 170         transactionCommitTimeout = TimeUnit.MILLISECONDS.convert(
 171                 datastoreContext.getShardTransactionCommitTimeoutInSeconds(), TimeUnit.SECONDS) / 2;
 172     }
 173
 174     private Optional<ActorRef> createRoleChangeNotifier(String shardId) {
 175         ActorRef shardRoleChangeNotifier = this.getContext().actorOf(
 176             RoleChangeNotifier.getProps(shardId), shardId + "-notifier");
 177         return Optional.of(shardRoleChangeNotifier);
 178     }
 179
 180     @Override
 181     public void postStop() {
 182         LOG.info("Stopping Shard {}", persistenceId());
 183
 184         super.postStop();
 185
 186         if(txCommitTimeoutCheckSchedule != null) {
 187             txCommitTimeoutCheckSchedule.cancel();
 188         }
 189
 190         shardMBean.unregisterMBean();
 191     }
 192
 193     @Override
 194     public void onReceiveRecover(final Object message) throws Exception {
 195         if(LOG.isDebugEnabled()) {
 196             LOG.debug("{}: onReceiveRecover: Received message {} from {}", persistenceId(),
 197                 message.getClass().toString(), getSender());
 198         }
 199
 200         if (message instanceof RecoveryFailure){
 201             LOG.error("{}: Recovery failed because of this cause",
 202                     persistenceId(), ((RecoveryFailure) message).cause());
 203
 204             // Even though recovery failed, we still need to finish our recovery, eg send the
 205             // ActorInitialized message and start the txCommitTimeoutCheckSchedule.
 206             onRecoveryComplete();
 207         } else {
 208             super.onReceiveRecover(message);
 209             if(LOG.isTraceEnabled()) {
 210                 appendEntriesReplyTracker.begin();
 211             }
 212         }
 213     }
 214
 215     @Override
 216     public void onReceiveCommand(final Object message) throws Exception {
 217
 218         MessageTracker.Context context = appendEntriesReplyTracker.received(message);
 219
 220         if(context.error().isPresent()){
 221             LOG.trace("{} : AppendEntriesReply failed to arrive at the expected interval {}", persistenceId(),
 222                 context.error());
 223         }
 224
 225         try {
 226             if (CreateTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 227                 handleCreateTransaction(message);
 228             } else if (BatchedModifications.class.isInstance(message)) {
 229                 handleBatchedModifications((BatchedModifications)message);
 230             } else if (message instanceof ForwardedReadyTransaction) {
 231                 commitCoordinator.handleForwardedReadyTransaction((ForwardedReadyTransaction) message,
 232                         getSender(), this);
 233             } else if (message instanceof ReadyLocalTransaction) {
 234                 handleReadyLocalTransaction((ReadyLocalTransaction)message);
 235             } else if (CanCommitTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 236                 handleCanCommitTransaction(CanCommitTransaction.fromSerializable(message));
 237             } else if (CommitTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 238                 handleCommitTransaction(CommitTransaction.fromSerializable(message));
 239             } else if (AbortTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 240                 handleAbortTransaction(AbortTransaction.fromSerializable(message));
 241             } else if (CloseTransactionChain.SERIALIZABLE_CLASS.isInstance(message)) {
 242                 closeTransactionChain(CloseTransactionChain.fromSerializable(message));
 243             } else if (message instanceof RegisterChangeListener) {
 244                 changeSupport.onMessage((RegisterChangeListener) message, isLeader(), hasLeader());
 245             } else if (message instanceof RegisterDataTreeChangeListener) {
 246                 treeChangeSupport.onMessage((RegisterDataTreeChangeListener) message, isLeader(), hasLeader());
 247             } else if (message instanceof UpdateSchemaContext) {
 248                 updateSchemaContext((UpdateSchemaContext) message);
 249             } else if (message instanceof PeerAddressResolved) {
 250                 PeerAddressResolved resolved = (PeerAddressResolved) message;
 251                 setPeerAddress(resolved.getPeerId().toString(),
 252                         resolved.getPeerAddress());
 253             } else if (message.equals(TX_COMMIT_TIMEOUT_CHECK_MESSAGE)) {
 254                 handleTransactionCommitTimeoutCheck();
 255             } else if(message instanceof DatastoreContext) {
 256                 onDatastoreContext((DatastoreContext)message);
 257             } else if(message instanceof RegisterRoleChangeListener){
 258                 roleChangeNotifier.get().forward(message, context());
 259             } else if (message instanceof FollowerInitialSyncUpStatus) {
 260                 shardMBean.setFollowerInitialSyncStatus(((FollowerInitialSyncUpStatus) message).isInitialSyncDone());
 261                 context().parent().tell(message, self());
 262             } else if(GET_SHARD_MBEAN_MESSAGE.equals(message)){
 263                 sender().tell(getShardMBean(), self());
 264             } else if(message instanceof GetShardDataTree) {
 265                 sender().tell(store.getDataTree(), self());
 266             } else if(message instanceof ServerRemoved){
 267                 context().parent().forward(message, context());
 268             } else {
 269                 super.onReceiveCommand(message);
 270             }
 271         } finally {
 272             context.done();
 273         }
 274     }
 275
 276     private boolean hasLeader() {
 277         return getLeaderId() != null;
 278     }
 279
 280     public int getPendingTxCommitQueueSize() {
 281         return commitCoordinator.getQueueSize();
 282     }
 283
 284     @Override
 285     protected Optional<ActorRef> getRoleChangeNotifier() {
 286         return roleChangeNotifier;
 287     }
 288
 289     @Override
 290     protected LeaderStateChanged newLeaderStateChanged(String memberId, String leaderId, short leaderPayloadVersion) {
 291         return new ShardLeaderStateChanged(memberId, leaderId,
 292                 isLeader() ? Optional.<DataTree>of(store.getDataTree()) : Optional.<DataTree>absent(),
 293                 leaderPayloadVersion);
 294     }
 295
 296     protected void onDatastoreContext(DatastoreContext context) {
 297         datastoreContext = context;
 298
 299         commitCoordinator.setQueueCapacity(datastoreContext.getShardTransactionCommitQueueCapacity());
 300
 301         setTransactionCommitTimeout();
 302
 303         if(datastoreContext.isPersistent() && !persistence().isRecoveryApplicable()) {
 304             setPersistence(true);
 305         } else if(!datastoreContext.isPersistent() && persistence().isRecoveryApplicable()) {
 306             setPersistence(false);
 307         }
 308
 309         updateConfigParams(datastoreContext.getShardRaftConfig());
 310     }
 311
 312     private void handleTransactionCommitTimeoutCheck() {
 313         CohortEntry cohortEntry = commitCoordinator.getCurrentCohortEntry();
 314         if(cohortEntry != null) {
 315             if(cohortEntry.isExpired(transactionCommitTimeout)) {
 316                 LOG.warn("{}: Current transaction {} has timed out after {} ms - aborting",
 317                         persistenceId(), cohortEntry.getTransactionID(), transactionCommitTimeout);
 318
 319                 doAbortTransaction(cohortEntry.getTransactionID(), null);
 320             }
 321         }
 322
 323         commitCoordinator.cleanupExpiredCohortEntries();
 324     }
 325
 326     private static boolean isEmptyCommit(final DataTreeCandidate candidate) {
 327         return ModificationType.UNMODIFIED.equals(candidate.getRootNode().getModificationType());
 328     }
 329
 330     void continueCommit(final CohortEntry cohortEntry) {
 331         final DataTreeCandidate candidate = cohortEntry.getCandidate();
 332
 333         // If we do not have any followers and we are not using persistence
 334         // or if cohortEntry has no modifications
 335         // we can apply modification to the state immediately
 336         if ((!hasFollowers() && !persistence().isRecoveryApplicable()) || isEmptyCommit(candidate)) {
 337             applyModificationToState(cohortEntry.getReplySender(), cohortEntry.getTransactionID(), candidate);
 338         } else {
 339             Shard.this.persistData(cohortEntry.getReplySender(), cohortEntry.getTransactionID(),
 340                     DataTreeCandidatePayload.create(candidate));
 341         }
 342     }
 343
 344     private void handleCommitTransaction(final CommitTransaction commit) {
 345         if(!commitCoordinator.handleCommit(commit.getTransactionID(), getSender(), this)) {
 346             shardMBean.incrementFailedTransactionsCount();
 347         }
 348     }
 349
 350     private void finishCommit(@Nonnull final ActorRef sender, @Nonnull final String transactionID, @Nonnull final CohortEntry cohortEntry) {
 351         LOG.debug("{}: Finishing commit for transaction {}", persistenceId(), cohortEntry.getTransactionID());
 352
 353         try {
 354             cohortEntry.commit();
 355
 356             sender.tell(CommitTransactionReply.INSTANCE.toSerializable(), getSelf());
 357
 358             shardMBean.incrementCommittedTransactionCount();
 359             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 360
 361         } catch (Exception e) {
 362             sender.tell(new akka.actor.Status.Failure(e), getSelf());
 363
 364             LOG.error("{}, An exception occurred while committing transaction {}", persistenceId(),
 365                     transactionID, e);
 366             shardMBean.incrementFailedTransactionsCount();
 367         } finally {
 368             commitCoordinator.currentTransactionComplete(transactionID, true);
 369         }
 370     }
 371
 372     private void finishCommit(@Nonnull final ActorRef sender, final @Nonnull String transactionID) {
 373         // With persistence enabled, this method is called via applyState by the leader strategy
 374         // after the commit has been replicated to a majority of the followers.
 375
 376         CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 377         if (cohortEntry == null) {
 378             // The transaction is no longer the current commit. This can happen if the transaction
 379             // was aborted prior, most likely due to timeout in the front-end. We need to finish
 380             // committing the transaction though since it was successfully persisted and replicated
 381             // however we can't use the original cohort b/c it was already preCommitted and may
 382             // conflict with the current commit or may have been aborted so we commit with a new
 383             // transaction.
 384             cohortEntry = commitCoordinator.getAndRemoveCohortEntry(transactionID);
 385             if(cohortEntry != null) {
 386                 try {
 387                     store.applyForeignCandidate(transactionID, cohortEntry.getCandidate());
 388                 } catch (DataValidationFailedException e) {
 389                     shardMBean.incrementFailedTransactionsCount();
 390                     LOG.error("{}: Failed to re-apply transaction {}", persistenceId(), transactionID, e);
 391                 }
 392
 393                 sender.tell(CommitTransactionReply.INSTANCE.toSerializable(), getSelf());
 394             } else {
 395                 // This really shouldn't happen - it likely means that persistence or replication
 396                 // took so long to complete such that the cohort entry was expired from the cache.
 397                 IllegalStateException ex = new IllegalStateException(
 398                         String.format("%s: Could not finish committing transaction %s - no CohortEntry found",
 399                                 persistenceId(), transactionID));
 400                 LOG.error(ex.getMessage());
 401                 sender.tell(new akka.actor.Status.Failure(ex), getSelf());
 402             }
 403         } else {
 404             finishCommit(sender, transactionID, cohortEntry);
 405         }
 406     }
 407
 408     private void handleCanCommitTransaction(final CanCommitTransaction canCommit) {
 409         LOG.debug("{}: Can committing transaction {}", persistenceId(), canCommit.getTransactionID());
 410         commitCoordinator.handleCanCommit(canCommit.getTransactionID(), getSender(), this);
 411     }
 412
 413     private void noLeaderError(String errMessage, Object message) {
 414         // TODO: rather than throwing an immediate exception, we could schedule a timer to try again to make
 415         // it more resilient in case we're in the process of electing a new leader.
 416         getSender().tell(new akka.actor.Status.Failure(new NoShardLeaderException(errMessage, persistenceId())), getSelf());
 417     }
 418
 419     protected void handleBatchedModificationsLocal(BatchedModifications batched, ActorRef sender) {
 420         try {
 421             commitCoordinator.handleBatchedModifications(batched, sender, this);
 422         } catch (Exception e) {
 423             LOG.error("{}: Error handling BatchedModifications for Tx {}", persistenceId(),
 424                     batched.getTransactionID(), e);
 425             sender.tell(new akka.actor.Status.Failure(e), getSelf());
 426         }
 427     }
 428
 429     private void handleBatchedModifications(BatchedModifications batched) {
 430         // This message is sent to prepare the modifications transaction directly on the Shard as an
 431         // optimization to avoid the extra overhead of a separate ShardTransaction actor. On the last
 432         // BatchedModifications message, the caller sets the ready flag in the message indicating
 433         // modifications are complete. The reply contains the cohort actor path (this actor) for the caller
 434         // to initiate the 3-phase commit. This also avoids the overhead of sending an additional
 435         // ReadyTransaction message.
 436
 437         // If we're not the leader then forward to the leader. This is a safety measure - we shouldn't
 438         // normally get here if we're not the leader as the front-end (TransactionProxy) should determine
 439         // the primary/leader shard. However with timing and caching on the front-end, there's a small
 440         // window where it could have a stale leader during leadership transitions.
 441         //
 442         if(isLeader()) {
 443             failIfIsolatedLeader(getSender());
 444
 445             handleBatchedModificationsLocal(batched, getSender());
 446         } else {
 447             ActorSelection leader = getLeader();
 448             if(leader != null) {
 449                 // TODO: what if this is not the first batch and leadership changed in between batched messages?
 450                 // We could check if the commitCoordinator already has a cached entry and forward all the previous
 451                 // batched modifications.
 452                 LOG.debug("{}: Forwarding BatchedModifications to leader {}", persistenceId(), leader);
 453                 leader.forward(batched, getContext());
 454             } else {
 455                 noLeaderError("Could not commit transaction " + batched.getTransactionID(), batched);
 456             }
 457         }
 458     }
 459
 460     private boolean failIfIsolatedLeader(ActorRef sender) {
 461         if(isIsolatedLeader()) {
 462             sender.tell(new akka.actor.Status.Failure(new NoShardLeaderException(String.format(
 463                     "Shard %s was the leader but has lost contact with all of its followers. Either all" +
 464                     " other follower nodes are down or this node is isolated by a network partition.",
 465                     persistenceId()))), getSelf());
 466             return true;
 467         }
 468
 469         return false;
 470     }
 471
 472     protected boolean isIsolatedLeader() {
 473         return getRaftState() == RaftState.IsolatedLeader;
 474     }
 475
 476     private void handleReadyLocalTransaction(final ReadyLocalTransaction message) {
 477         if (isLeader()) {
 478             failIfIsolatedLeader(getSender());
 479
 480             try {
 481                 commitCoordinator.handleReadyLocalTransaction(message, getSender(), this);
 482             } catch (Exception e) {
 483                 LOG.error("{}: Error handling ReadyLocalTransaction for Tx {}", persistenceId(),
 484                         message.getTransactionID(), e);
 485                 getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 486             }
 487         } else {
 488             ActorSelection leader = getLeader();
 489             if (leader != null) {
 490                 LOG.debug("{}: Forwarding ReadyLocalTransaction to leader {}", persistenceId(), leader);
 491                 message.setRemoteVersion(getCurrentBehavior().getLeaderPayloadVersion());
 492                 leader.forward(message, getContext());
 493             } else {
 494                 noLeaderError("Could not commit transaction " + message.getTransactionID(), message);
 495             }
 496         }
 497     }
 498
 499     private void handleAbortTransaction(final AbortTransaction abort) {
 500         doAbortTransaction(abort.getTransactionID(), getSender());
 501     }
 502
 503     void doAbortTransaction(final String transactionID, final ActorRef sender) {
 504         commitCoordinator.handleAbort(transactionID, sender, this);
 505     }
 506
 507     private void handleCreateTransaction(final Object message) {
 508         if (isLeader()) {
 509             createTransaction(CreateTransaction.fromSerializable(message));
 510         } else if (getLeader() != null) {
 511             getLeader().forward(message, getContext());
 512         } else {
 513             getSender().tell(new akka.actor.Status.Failure(new NoShardLeaderException(
 514                     "Could not create a shard transaction", persistenceId())), getSelf());
 515         }
 516     }
 517
 518     private void closeTransactionChain(final CloseTransactionChain closeTransactionChain) {
 519         store.closeTransactionChain(closeTransactionChain.getTransactionChainId());
 520     }
 521
 522     private ActorRef createTypedTransactionActor(int transactionType,
 523             ShardTransactionIdentifier transactionId, String transactionChainId,
 524             short clientVersion ) {
 525
 526         return transactionActorFactory.newShardTransaction(TransactionType.fromInt(transactionType),
 527                 transactionId, transactionChainId, clientVersion);
 528     }
 529
 530     private void createTransaction(CreateTransaction createTransaction) {
 531         try {
 532             if(TransactionType.fromInt(createTransaction.getTransactionType()) != TransactionType.READ_ONLY &&
 533                     failIfIsolatedLeader(getSender())) {
 534                 return;
 535             }
 536
 537             ActorRef transactionActor = createTransaction(createTransaction.getTransactionType(),
 538                 createTransaction.getTransactionId(), createTransaction.getTransactionChainId(),
 539                 createTransaction.getVersion());
 540
 541             getSender().tell(new CreateTransactionReply(Serialization.serializedActorPath(transactionActor),
 542                     createTransaction.getTransactionId()).toSerializable(), getSelf());
 543         } catch (Exception e) {
 544             getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 545         }
 546     }
 547
 548     private ActorRef createTransaction(int transactionType, String remoteTransactionId,
 549             String transactionChainId, short clientVersion) {
 550
 551
 552         ShardTransactionIdentifier transactionId = new ShardTransactionIdentifier(remoteTransactionId);
 553
 554         if(LOG.isDebugEnabled()) {
 555             LOG.debug("{}: Creating transaction : {} ", persistenceId(), transactionId);
 556         }
 557
 558         ActorRef transactionActor = createTypedTransactionActor(transactionType, transactionId,
 559                 transactionChainId, clientVersion);
 560
 561         return transactionActor;
 562     }
 563
 564     private void commitWithNewTransaction(final Modification modification) {
 565         ReadWriteShardDataTreeTransaction tx = store.newReadWriteTransaction(modification.toString(), null);
 566         modification.apply(tx.getSnapshot());
 567         try {
 568             snapshotCohort.syncCommitTransaction(tx);
 569             shardMBean.incrementCommittedTransactionCount();
 570             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 571         } catch (Exception e) {
 572             shardMBean.incrementFailedTransactionsCount();
 573             LOG.error("{}: Failed to commit", persistenceId(), e);
 574         }
 575     }
 576
 577     private void updateSchemaContext(final UpdateSchemaContext message) {
 578         updateSchemaContext(message.getSchemaContext());
 579     }
 580
 581     @VisibleForTesting
 582     void updateSchemaContext(final SchemaContext schemaContext) {
 583         store.updateSchemaContext(schemaContext);
 584     }
 585
 586     private boolean isMetricsCaptureEnabled() {
 587         CommonConfig config = new CommonConfig(getContext().system().settings().config());
 588         return config.isMetricCaptureEnabled();
 589     }
 590
 591     @Override
 592     @VisibleForTesting
 593     public RaftActorSnapshotCohort getRaftActorSnapshotCohort() {
 594         return snapshotCohort;
 595     }
 596
 597     @Override
 598     @Nonnull
 599     protected RaftActorRecoveryCohort getRaftActorRecoveryCohort() {
 600         return new ShardRecoveryCoordinator(store, store.getSchemaContext(),
 601                 restoreFromSnapshot != null ? restoreFromSnapshot.getSnapshot() : null, persistenceId(), LOG);
 602     }
 603
 604     @Override
 605     protected void onRecoveryComplete() {
 606         restoreFromSnapshot = null;
 607
 608         //notify shard manager
 609         getContext().parent().tell(new ActorInitialized(), getSelf());
 610
 611         // Being paranoid here - this method should only be called once but just in case...
 612         if(txCommitTimeoutCheckSchedule == null) {
 613             // Schedule a message to be periodically sent to check if the current in-progress
 614             // transaction should be expired and aborted.
 615             FiniteDuration period = Duration.create(transactionCommitTimeout / 3, TimeUnit.MILLISECONDS);
 616             txCommitTimeoutCheckSchedule = getContext().system().scheduler().schedule(
 617                     period, period, getSelf(),
 618                     TX_COMMIT_TIMEOUT_CHECK_MESSAGE, getContext().dispatcher(), ActorRef.noSender());
 619         }
 620     }
 621
 622     @Override
 623     protected void applyState(final ActorRef clientActor, final String identifier, final Object data) {
 624         if (data instanceof DataTreeCandidatePayload) {
 625             if (clientActor == null) {
 626                 // No clientActor indicates a replica coming from the leader
 627                 try {
 628                     store.applyForeignCandidate(identifier, ((DataTreeCandidatePayload)data).getCandidate());
 629                 } catch (DataValidationFailedException | IOException e) {
 630                     LOG.error("{}: Error applying replica {}", persistenceId(), identifier, e);
 631                 }
 632             } else {
 633                 // Replication consensus reached, proceed to commit
 634                 finishCommit(clientActor, identifier);
 635             }
 636         } else if (data instanceof ModificationPayload) {
 637             try {
 638                 applyModificationToState(clientActor, identifier, ((ModificationPayload) data).getModification());
 639             } catch (ClassNotFoundException | IOException e) {
 640                 LOG.error("{}: Error extracting ModificationPayload", persistenceId(), e);
 641             }
 642         } else if (data instanceof CompositeModificationPayload) {
 643             Object modification = ((CompositeModificationPayload) data).getModification();
 644
 645             applyModificationToState(clientActor, identifier, modification);
 646         } else if(data instanceof CompositeModificationByteStringPayload ){
 647             Object modification = ((CompositeModificationByteStringPayload) data).getModification();
 648
 649             applyModificationToState(clientActor, identifier, modification);
 650         } else {
 651             LOG.error("{}: Unknown state received {} Class loader = {} CompositeNodeMod.ClassLoader = {}",
 652                     persistenceId(), data, data.getClass().getClassLoader(),
 653                     CompositeModificationPayload.class.getClassLoader());
 654         }
 655     }
 656
 657     private void applyModificationToState(ActorRef clientActor, String identifier, Object modification) {
 658         if(modification == null) {
 659             LOG.error(
 660                     "{}: modification is null - this is very unexpected, clientActor = {}, identifier = {}",
 661                     persistenceId(), identifier, clientActor != null ? clientActor.path().toString() : null);
 662         } else if(clientActor == null) {
 663             // There's no clientActor to which to send a commit reply so we must be applying
 664             // replicated state from the leader.
 665             commitWithNewTransaction(MutableCompositeModification.fromSerializable(modification));
 666         } else {
 667             // This must be the OK to commit after replication consensus.
 668             finishCommit(clientActor, identifier);
 669         }
 670     }
 671
 672     @Override
 673     protected void onStateChanged() {
 674         boolean isLeader = isLeader();
 675         boolean hasLeader = hasLeader();
 676         changeSupport.onLeadershipChange(isLeader, hasLeader);
 677         treeChangeSupport.onLeadershipChange(isLeader, hasLeader);
 678
 679         // If this actor is no longer the leader close all the transaction chains
 680         if (!isLeader) {
 681             if(LOG.isDebugEnabled()) {
 682                 LOG.debug(
 683                     "{}: onStateChanged: Closing all transaction chains because shard {} is no longer the leader",
 684                     persistenceId(), getId());
 685             }
 686
 687             store.closeAllTransactionChains();
 688         }
 689     }
 690
 691     @Override
 692     protected void onLeaderChanged(String oldLeader, String newLeader) {
 693         shardMBean.incrementLeadershipChangeCount();
 694     }
 695
 696     @Override
 697     public String persistenceId() {
 698         return this.name;
 699     }
 700
 701     @VisibleForTesting
 702     ShardCommitCoordinator getCommitCoordinator() {
 703         return commitCoordinator;
 704     }
 705
 706     public DatastoreContext getDatastoreContext() {
 707         return datastoreContext;
 708     }
 709
 710     @VisibleForTesting
 711     public ShardDataTree getDataStore() {
 712         return store;
 713     }
 714
 715     @VisibleForTesting
 716     ShardStats getShardMBean() {
 717         return shardMBean;
 718     }
 719
 720     public static Builder builder() {
 721         return new Builder();
 722     }
 723
 724     public static abstract class AbstractBuilder<T extends AbstractBuilder<T, S>, S extends Shard> {
 725         private final Class<S> shardClass;
 726         private ShardIdentifier id;
 727         private Map<String, String> peerAddresses = Collections.emptyMap();
 728         private DatastoreContext datastoreContext;
 729         private SchemaContext schemaContext;
 730         private DatastoreSnapshot.ShardSnapshot restoreFromSnapshot;
 731         private volatile boolean sealed;
 732
 733         protected AbstractBuilder(Class<S> shardClass) {
 734             this.shardClass = shardClass;
 735         }
 736
 737         protected void checkSealed() {
 738             Preconditions.checkState(!sealed, "Builder isalready sealed - further modifications are not allowed");
 739         }
 740
 741         @SuppressWarnings("unchecked")
 742         private T self() {
 743             return (T) this;
 744         }
 745
 746         public T id(ShardIdentifier id) {
 747             checkSealed();
 748             this.id = id;
 749             return self();
 750         }
 751
 752         public T peerAddresses(Map<String, String> peerAddresses) {
 753             checkSealed();
 754             this.peerAddresses = peerAddresses;
 755             return self();
 756         }
 757
 758         public T datastoreContext(DatastoreContext datastoreContext) {
 759             checkSealed();
 760             this.datastoreContext = datastoreContext;
 761             return self();
 762         }
 763
 764         public T schemaContext(SchemaContext schemaContext) {
 765             checkSealed();
 766             this.schemaContext = schemaContext;
 767             return self();
 768         }
 769
 770         public T restoreFromSnapshot(DatastoreSnapshot.ShardSnapshot restoreFromSnapshot) {
 771             checkSealed();
 772             this.restoreFromSnapshot = restoreFromSnapshot;
 773             return self();
 774         }
 775
 776         public ShardIdentifier getId() {
 777             return id;
 778         }
 779
 780         public Map<String, String> getPeerAddresses() {
 781             return peerAddresses;
 782         }
 783
 784         public DatastoreContext getDatastoreContext() {
 785             return datastoreContext;
 786         }
 787
 788         public SchemaContext getSchemaContext() {
 789             return schemaContext;
 790         }
 791
 792         public DatastoreSnapshot.ShardSnapshot getRestoreFromSnapshot() {
 793             return restoreFromSnapshot;
 794         }
 795
 796         protected void verify() {
 797             Preconditions.checkNotNull(id, "id should not be null");
 798             Preconditions.checkNotNull(peerAddresses, "peerAddresses should not be null");
 799             Preconditions.checkNotNull(datastoreContext, "dataStoreContext should not be null");
 800             Preconditions.checkNotNull(schemaContext, "schemaContext should not be null");
 801         }
 802
 803         public Props props() {
 804             sealed = true;
 805             verify();
 806             return Props.create(shardClass, this);
 807         }
 808     }
 809
 810     public static class Builder extends AbstractBuilder<Builder, Shard> {
 811         private Builder() {
 812             super(Shard.class);
 813         }
 814     }
 815 }