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         // FIXME: BUG-1014: pass down the proper TreeType
 138         store = new ShardDataTree(builder.getSchemaContext());
 139
 140         shardMBean = ShardMBeanFactory.getShardStatsMBean(name.toString(),
 141                 datastoreContext.getDataStoreMXBeanType());
 142         shardMBean.setShard(this);
 143
 144         if (isMetricsCaptureEnabled()) {
 145             getContext().become(new MeteringBehavior(this));
 146         }
 147
 148         commitCoordinator = new ShardCommitCoordinator(store,
 149                 datastoreContext.getShardCommitQueueExpiryTimeoutInMillis(),
 150                 datastoreContext.getShardTransactionCommitQueueCapacity(), LOG, this.name);
 151
 152         setTransactionCommitTimeout();
 153
 154         // create a notifier actor for each cluster member
 155         roleChangeNotifier = createRoleChangeNotifier(name.toString());
 156
 157         appendEntriesReplyTracker = new MessageTracker(AppendEntriesReply.class,
 158                 getRaftActorContext().getConfigParams().getIsolatedCheckIntervalInMillis());
 159
 160         transactionActorFactory = new ShardTransactionActorFactory(store, datastoreContext,
 161                 new Dispatchers(context().system().dispatchers()).getDispatcherPath(
 162                         Dispatchers.DispatcherType.Transaction), self(), getContext(), shardMBean);
 163
 164         snapshotCohort = new ShardSnapshotCohort(transactionActorFactory, store, LOG, this.name);
 165
 166
 167
 168     }
 169
 170     private void setTransactionCommitTimeout() {
 171         transactionCommitTimeout = TimeUnit.MILLISECONDS.convert(
 172                 datastoreContext.getShardTransactionCommitTimeoutInSeconds(), TimeUnit.SECONDS) / 2;
 173     }
 174
 175     private Optional<ActorRef> createRoleChangeNotifier(String shardId) {
 176         ActorRef shardRoleChangeNotifier = this.getContext().actorOf(
 177             RoleChangeNotifier.getProps(shardId), shardId + "-notifier");
 178         return Optional.of(shardRoleChangeNotifier);
 179     }
 180
 181     @Override
 182     public void postStop() {
 183         LOG.info("Stopping Shard {}", persistenceId());
 184
 185         super.postStop();
 186
 187         if(txCommitTimeoutCheckSchedule != null) {
 188             txCommitTimeoutCheckSchedule.cancel();
 189         }
 190
 191         shardMBean.unregisterMBean();
 192     }
 193
 194     @Override
 195     public void onReceiveRecover(final Object message) throws Exception {
 196         if(LOG.isDebugEnabled()) {
 197             LOG.debug("{}: onReceiveRecover: Received message {} from {}", persistenceId(),
 198                 message.getClass().toString(), getSender());
 199         }
 200
 201         if (message instanceof RecoveryFailure){
 202             LOG.error("{}: Recovery failed because of this cause",
 203                     persistenceId(), ((RecoveryFailure) message).cause());
 204
 205             // Even though recovery failed, we still need to finish our recovery, eg send the
 206             // ActorInitialized message and start the txCommitTimeoutCheckSchedule.
 207             onRecoveryComplete();
 208         } else {
 209             super.onReceiveRecover(message);
 210             if(LOG.isTraceEnabled()) {
 211                 appendEntriesReplyTracker.begin();
 212             }
 213         }
 214     }
 215
 216     @Override
 217     public void onReceiveCommand(final Object message) throws Exception {
 218
 219         MessageTracker.Context context = appendEntriesReplyTracker.received(message);
 220
 221         if(context.error().isPresent()){
 222             LOG.trace("{} : AppendEntriesReply failed to arrive at the expected interval {}", persistenceId(),
 223                 context.error());
 224         }
 225
 226         try {
 227             if (CreateTransaction.SERIALIZABLE_CLASS.isInstance(message)) {
 228                 handleCreateTransaction(message);
 229             } else if (BatchedModifications.class.isInstance(message)) {
 230                 handleBatchedModifications((BatchedModifications)message);
 231             } else if (message instanceof ForwardedReadyTransaction) {
 232                 handleForwardedReadyTransaction((ForwardedReadyTransaction) message);
 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) {
 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());
 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());
 495             }
 496         }
 497     }
 498
 499     private void handleForwardedReadyTransaction(ForwardedReadyTransaction forwardedReady) {
 500         if (isLeader()) {
 501             failIfIsolatedLeader(getSender());
 502
 503             commitCoordinator.handleForwardedReadyTransaction(forwardedReady, getSender(), this);
 504         } else {
 505             ActorSelection leader = getLeader();
 506             if (leader != null) {
 507                 LOG.debug("{}: Forwarding ForwardedReadyTransaction to leader {}", persistenceId(), leader);
 508
 509                 ReadyLocalTransaction readyLocal = new ReadyLocalTransaction(forwardedReady.getTransactionID(),
 510                         forwardedReady.getTransaction().getSnapshot(), forwardedReady.isDoImmediateCommit());
 511                 readyLocal.setRemoteVersion(getCurrentBehavior().getLeaderPayloadVersion());
 512                 leader.forward(readyLocal, getContext());
 513             } else {
 514                 noLeaderError("Could not commit transaction " + forwardedReady.getTransactionID());
 515             }
 516         }
 517     }
 518
 519     private void handleAbortTransaction(final AbortTransaction abort) {
 520         doAbortTransaction(abort.getTransactionID(), getSender());
 521     }
 522
 523     void doAbortTransaction(final String transactionID, final ActorRef sender) {
 524         commitCoordinator.handleAbort(transactionID, sender, this);
 525     }
 526
 527     private void handleCreateTransaction(final Object message) {
 528         if (isLeader()) {
 529             createTransaction(CreateTransaction.fromSerializable(message));
 530         } else if (getLeader() != null) {
 531             getLeader().forward(message, getContext());
 532         } else {
 533             getSender().tell(new akka.actor.Status.Failure(new NoShardLeaderException(
 534                     "Could not create a shard transaction", persistenceId())), getSelf());
 535         }
 536     }
 537
 538     private void closeTransactionChain(final CloseTransactionChain closeTransactionChain) {
 539         store.closeTransactionChain(closeTransactionChain.getTransactionChainId());
 540     }
 541
 542     private ActorRef createTypedTransactionActor(int transactionType,
 543             ShardTransactionIdentifier transactionId, String transactionChainId,
 544             short clientVersion ) {
 545
 546         return transactionActorFactory.newShardTransaction(TransactionType.fromInt(transactionType),
 547                 transactionId, transactionChainId, clientVersion);
 548     }
 549
 550     private void createTransaction(CreateTransaction createTransaction) {
 551         try {
 552             if(TransactionType.fromInt(createTransaction.getTransactionType()) != TransactionType.READ_ONLY &&
 553                     failIfIsolatedLeader(getSender())) {
 554                 return;
 555             }
 556
 557             ActorRef transactionActor = createTransaction(createTransaction.getTransactionType(),
 558                 createTransaction.getTransactionId(), createTransaction.getTransactionChainId(),
 559                 createTransaction.getVersion());
 560
 561             getSender().tell(new CreateTransactionReply(Serialization.serializedActorPath(transactionActor),
 562                     createTransaction.getTransactionId()).toSerializable(), getSelf());
 563         } catch (Exception e) {
 564             getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 565         }
 566     }
 567
 568     private ActorRef createTransaction(int transactionType, String remoteTransactionId,
 569             String transactionChainId, short clientVersion) {
 570
 571
 572         ShardTransactionIdentifier transactionId = new ShardTransactionIdentifier(remoteTransactionId);
 573
 574         if(LOG.isDebugEnabled()) {
 575             LOG.debug("{}: Creating transaction : {} ", persistenceId(), transactionId);
 576         }
 577
 578         ActorRef transactionActor = createTypedTransactionActor(transactionType, transactionId,
 579                 transactionChainId, clientVersion);
 580
 581         return transactionActor;
 582     }
 583
 584     private void commitWithNewTransaction(final Modification modification) {
 585         ReadWriteShardDataTreeTransaction tx = store.newReadWriteTransaction(modification.toString(), null);
 586         modification.apply(tx.getSnapshot());
 587         try {
 588             snapshotCohort.syncCommitTransaction(tx);
 589             shardMBean.incrementCommittedTransactionCount();
 590             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 591         } catch (Exception e) {
 592             shardMBean.incrementFailedTransactionsCount();
 593             LOG.error("{}: Failed to commit", persistenceId(), e);
 594         }
 595     }
 596
 597     private void updateSchemaContext(final UpdateSchemaContext message) {
 598         updateSchemaContext(message.getSchemaContext());
 599     }
 600
 601     @VisibleForTesting
 602     void updateSchemaContext(final SchemaContext schemaContext) {
 603         store.updateSchemaContext(schemaContext);
 604     }
 605
 606     private boolean isMetricsCaptureEnabled() {
 607         CommonConfig config = new CommonConfig(getContext().system().settings().config());
 608         return config.isMetricCaptureEnabled();
 609     }
 610
 611     @Override
 612     @VisibleForTesting
 613     public RaftActorSnapshotCohort getRaftActorSnapshotCohort() {
 614         return snapshotCohort;
 615     }
 616
 617     @Override
 618     @Nonnull
 619     protected RaftActorRecoveryCohort getRaftActorRecoveryCohort() {
 620         return new ShardRecoveryCoordinator(store, store.getSchemaContext(),
 621                 restoreFromSnapshot != null ? restoreFromSnapshot.getSnapshot() : null, persistenceId(), LOG);
 622     }
 623
 624     @Override
 625     protected void onRecoveryComplete() {
 626         restoreFromSnapshot = null;
 627
 628         //notify shard manager
 629         getContext().parent().tell(new ActorInitialized(), getSelf());
 630
 631         // Being paranoid here - this method should only be called once but just in case...
 632         if(txCommitTimeoutCheckSchedule == null) {
 633             // Schedule a message to be periodically sent to check if the current in-progress
 634             // transaction should be expired and aborted.
 635             FiniteDuration period = Duration.create(transactionCommitTimeout / 3, TimeUnit.MILLISECONDS);
 636             txCommitTimeoutCheckSchedule = getContext().system().scheduler().schedule(
 637                     period, period, getSelf(),
 638                     TX_COMMIT_TIMEOUT_CHECK_MESSAGE, getContext().dispatcher(), ActorRef.noSender());
 639         }
 640     }
 641
 642     @Override
 643     protected void applyState(final ActorRef clientActor, final String identifier, final Object data) {
 644         if (data instanceof DataTreeCandidatePayload) {
 645             if (clientActor == null) {
 646                 // No clientActor indicates a replica coming from the leader
 647                 try {
 648                     store.applyForeignCandidate(identifier, ((DataTreeCandidatePayload)data).getCandidate());
 649                 } catch (DataValidationFailedException | IOException e) {
 650                     LOG.error("{}: Error applying replica {}", persistenceId(), identifier, e);
 651                 }
 652             } else {
 653                 // Replication consensus reached, proceed to commit
 654                 finishCommit(clientActor, identifier);
 655             }
 656         } else if (data instanceof ModificationPayload) {
 657             try {
 658                 applyModificationToState(clientActor, identifier, ((ModificationPayload) data).getModification());
 659             } catch (ClassNotFoundException | IOException e) {
 660                 LOG.error("{}: Error extracting ModificationPayload", persistenceId(), e);
 661             }
 662         } else if (data instanceof CompositeModificationPayload) {
 663             Object modification = ((CompositeModificationPayload) data).getModification();
 664
 665             applyModificationToState(clientActor, identifier, modification);
 666         } else if(data instanceof CompositeModificationByteStringPayload ){
 667             Object modification = ((CompositeModificationByteStringPayload) data).getModification();
 668
 669             applyModificationToState(clientActor, identifier, modification);
 670         } else {
 671             LOG.error("{}: Unknown state received {} Class loader = {} CompositeNodeMod.ClassLoader = {}",
 672                     persistenceId(), data, data.getClass().getClassLoader(),
 673                     CompositeModificationPayload.class.getClassLoader());
 674         }
 675     }
 676
 677     private void applyModificationToState(ActorRef clientActor, String identifier, Object modification) {
 678         if(modification == null) {
 679             LOG.error(
 680                     "{}: modification is null - this is very unexpected, clientActor = {}, identifier = {}",
 681                     persistenceId(), identifier, clientActor != null ? clientActor.path().toString() : null);
 682         } else if(clientActor == null) {
 683             // There's no clientActor to which to send a commit reply so we must be applying
 684             // replicated state from the leader.
 685             commitWithNewTransaction(MutableCompositeModification.fromSerializable(modification));
 686         } else {
 687             // This must be the OK to commit after replication consensus.
 688             finishCommit(clientActor, identifier);
 689         }
 690     }
 691
 692     @Override
 693     protected void onStateChanged() {
 694         boolean isLeader = isLeader();
 695         boolean hasLeader = hasLeader();
 696         changeSupport.onLeadershipChange(isLeader, hasLeader);
 697         treeChangeSupport.onLeadershipChange(isLeader, hasLeader);
 698
 699         // If this actor is no longer the leader close all the transaction chains
 700         if (!isLeader) {
 701             if(LOG.isDebugEnabled()) {
 702                 LOG.debug(
 703                     "{}: onStateChanged: Closing all transaction chains because shard {} is no longer the leader",
 704                     persistenceId(), getId());
 705             }
 706
 707             store.closeAllTransactionChains();
 708         }
 709     }
 710
 711     @Override
 712     protected void onLeaderChanged(String oldLeader, String newLeader) {
 713         shardMBean.incrementLeadershipChangeCount();
 714     }
 715
 716     @Override
 717     public String persistenceId() {
 718         return this.name;
 719     }
 720
 721     @VisibleForTesting
 722     ShardCommitCoordinator getCommitCoordinator() {
 723         return commitCoordinator;
 724     }
 725
 726     public DatastoreContext getDatastoreContext() {
 727         return datastoreContext;
 728     }
 729
 730     @VisibleForTesting
 731     public ShardDataTree getDataStore() {
 732         return store;
 733     }
 734
 735     @VisibleForTesting
 736     ShardStats getShardMBean() {
 737         return shardMBean;
 738     }
 739
 740     public static Builder builder() {
 741         return new Builder();
 742     }
 743
 744     public static abstract class AbstractBuilder<T extends AbstractBuilder<T, S>, S extends Shard> {
 745         private final Class<S> shardClass;
 746         private ShardIdentifier id;
 747         private Map<String, String> peerAddresses = Collections.emptyMap();
 748         private DatastoreContext datastoreContext;
 749         private SchemaContext schemaContext;
 750         private DatastoreSnapshot.ShardSnapshot restoreFromSnapshot;
 751         private volatile boolean sealed;
 752
 753         protected AbstractBuilder(Class<S> shardClass) {
 754             this.shardClass = shardClass;
 755         }
 756
 757         protected void checkSealed() {
 758             Preconditions.checkState(!sealed, "Builder isalready sealed - further modifications are not allowed");
 759         }
 760
 761         @SuppressWarnings("unchecked")
 762         private T self() {
 763             return (T) this;
 764         }
 765
 766         public T id(ShardIdentifier id) {
 767             checkSealed();
 768             this.id = id;
 769             return self();
 770         }
 771
 772         public T peerAddresses(Map<String, String> peerAddresses) {
 773             checkSealed();
 774             this.peerAddresses = peerAddresses;
 775             return self();
 776         }
 777
 778         public T datastoreContext(DatastoreContext datastoreContext) {
 779             checkSealed();
 780             this.datastoreContext = datastoreContext;
 781             return self();
 782         }
 783
 784         public T schemaContext(SchemaContext schemaContext) {
 785             checkSealed();
 786             this.schemaContext = schemaContext;
 787             return self();
 788         }
 789
 790         public T restoreFromSnapshot(DatastoreSnapshot.ShardSnapshot restoreFromSnapshot) {
 791             checkSealed();
 792             this.restoreFromSnapshot = restoreFromSnapshot;
 793             return self();
 794         }
 795
 796         public ShardIdentifier getId() {
 797             return id;
 798         }
 799
 800         public Map<String, String> getPeerAddresses() {
 801             return peerAddresses;
 802         }
 803
 804         public DatastoreContext getDatastoreContext() {
 805             return datastoreContext;
 806         }
 807
 808         public SchemaContext getSchemaContext() {
 809             return schemaContext;
 810         }
 811
 812         public DatastoreSnapshot.ShardSnapshot getRestoreFromSnapshot() {
 813             return restoreFromSnapshot;
 814         }
 815
 816         protected void verify() {
 817             Preconditions.checkNotNull(id, "id should not be null");
 818             Preconditions.checkNotNull(peerAddresses, "peerAddresses should not be null");
 819             Preconditions.checkNotNull(datastoreContext, "dataStoreContext should not be null");
 820             Preconditions.checkNotNull(schemaContext, "schemaContext should not be null");
 821         }
 822
 823         public Props props() {
 824             sealed = true;
 825             verify();
 826             return Props.create(shardClass, this);
 827         }
 828     }
 829
 830     public static class Builder extends AbstractBuilder<Builder, Shard> {
 831         private Builder() {
 832             super(Shard.class);
 833         }
 834     }
 835 }