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