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