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 java.io.IOException;
  20 import java.util.Collection;
  21 import java.util.Collections;
  22 import java.util.Map;
  23 import java.util.concurrent.ExecutionException;
  24 import java.util.concurrent.TimeUnit;
  25 import javax.annotation.Nonnull;
  26 import org.opendaylight.controller.cluster.common.actor.CommonConfig;
  27 import org.opendaylight.controller.cluster.common.actor.MessageTracker;
  28 import org.opendaylight.controller.cluster.common.actor.MessageTracker.Error;
  29 import org.opendaylight.controller.cluster.common.actor.MeteringBehavior;
  30 import org.opendaylight.controller.cluster.datastore.ShardCommitCoordinator.CohortEntry;
  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.identifiers.ShardTransactionIdentifier;
  34 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardMBeanFactory;
  35 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardStats;
  36 import org.opendaylight.controller.cluster.datastore.messages.AbortTransaction;
  37 import org.opendaylight.controller.cluster.datastore.messages.ActorInitialized;
  38 import org.opendaylight.controller.cluster.datastore.messages.BatchedModifications;
  39 import org.opendaylight.controller.cluster.datastore.messages.CanCommitTransaction;
  40 import org.opendaylight.controller.cluster.datastore.messages.CloseTransactionChain;
  41 import org.opendaylight.controller.cluster.datastore.messages.CommitTransaction;
  42 import org.opendaylight.controller.cluster.datastore.messages.CommitTransactionReply;
  43 import org.opendaylight.controller.cluster.datastore.messages.CreateTransaction;
  44 import org.opendaylight.controller.cluster.datastore.messages.CreateTransactionReply;
  45 import org.opendaylight.controller.cluster.datastore.messages.DatastoreSnapshot;
  46 import org.opendaylight.controller.cluster.datastore.messages.DatastoreSnapshot.ShardSnapshot;
  47 import org.opendaylight.controller.cluster.datastore.messages.ForwardedReadyTransaction;
  48 import org.opendaylight.controller.cluster.datastore.messages.GetShardDataTree;
  49 import org.opendaylight.controller.cluster.datastore.messages.PeerAddressResolved;
  50 import org.opendaylight.controller.cluster.datastore.messages.ReadyLocalTransaction;
  51 import org.opendaylight.controller.cluster.datastore.messages.RegisterChangeListener;
  52 import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeChangeListener;
  53 import org.opendaylight.controller.cluster.datastore.messages.ShardLeaderStateChanged;
  54 import org.opendaylight.controller.cluster.datastore.messages.UpdateSchemaContext;
  55 import org.opendaylight.controller.cluster.datastore.modification.Modification;
  56 import org.opendaylight.controller.cluster.datastore.modification.MutableCompositeModification;
  57 import org.opendaylight.controller.cluster.datastore.utils.Dispatchers;
  58 import org.opendaylight.controller.cluster.notifications.LeaderStateChanged;
  59 import org.opendaylight.controller.cluster.notifications.RegisterRoleChangeListener;
  60 import org.opendaylight.controller.cluster.notifications.RoleChangeNotifier;
  61 import org.opendaylight.controller.cluster.raft.RaftActor;
  62 import org.opendaylight.controller.cluster.raft.RaftActorRecoveryCohort;
  63 import org.opendaylight.controller.cluster.raft.RaftActorSnapshotCohort;
  64 import org.opendaylight.controller.cluster.raft.RaftState;
  65 import org.opendaylight.controller.cluster.raft.base.messages.FollowerInitialSyncUpStatus;
  66 import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply;
  67 import org.opendaylight.controller.cluster.raft.messages.ServerRemoved;
  68 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationByteStringPayload;
  69 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationPayload;
  70 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree;
  71 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  72 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
  73 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
  74 import org.opendaylight.yangtools.yang.data.api.schema.tree.TreeType;
  75 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  76 import scala.concurrent.duration.Duration;
  77 import scala.concurrent.duration.FiniteDuration;
  78
  79 /**
  80  * A Shard represents a portion of the logical data tree <br/>
  81  * <p>
  82  * Our Shard uses InMemoryDataTree as it's internal representation and delegates all requests it
  83  * </p>
  84  */
  85 public class Shard extends RaftActor {
  86
  87     protected static final Object TX_COMMIT_TIMEOUT_CHECK_MESSAGE = "txCommitTimeoutCheck";
  88
  89     @VisibleForTesting
  90     static final Object GET_SHARD_MBEAN_MESSAGE = "getShardMBeanMessage";
  91
  92     // FIXME: shard names should be encapsulated in their own class and this should be exposed as a constant.
  93     public static final String DEFAULT_NAME = "default";
  94
  95     // The state of this Shard
  96     private final ShardDataTree store;
  97
  98     /// The name of this shard
  99     private final String name;
 100
 101     private final ShardStats shardMBean;
 102
 103     private DatastoreContext datastoreContext;
 104
 105     private final ShardCommitCoordinator commitCoordinator;
 106
 107     private long transactionCommitTimeout;
 108
 109     private Cancellable txCommitTimeoutCheckSchedule;
 110
 111     private final Optional<ActorRef> roleChangeNotifier;
 112
 113     private final MessageTracker appendEntriesReplyTracker;
 114
 115     private final ShardTransactionActorFactory transactionActorFactory;
 116
 117     private final ShardSnapshotCohort snapshotCohort;
 118
 119     private final DataTreeChangeListenerSupport treeChangeSupport = new DataTreeChangeListenerSupport(this);
 120     private final DataChangeListenerSupport changeSupport = new DataChangeListenerSupport(this);
 121
 122
 123     private ShardSnapshot restoreFromSnapshot;
 124
 125     private final ShardTransactionMessageRetrySupport messageRetrySupport;
 126
 127     protected Shard(AbstractBuilder<?, ?> builder) {
 128         super(builder.getId().toString(), builder.getPeerAddresses(),
 129                 Optional.of(builder.getDatastoreContext().getShardRaftConfig()), DataStoreVersions.CURRENT_VERSION);
 130
 131         this.name = builder.getId().toString();
 132         this.datastoreContext = builder.getDatastoreContext();
 133         this.restoreFromSnapshot = builder.getRestoreFromSnapshot();
 134
 135         setPersistence(datastoreContext.isPersistent());
 136
 137         LOG.info("Shard created : {}, persistent : {}", name, datastoreContext.isPersistent());
 138
 139         store = new ShardDataTree(builder.getSchemaContext(), builder.getTreeType(),
 140                 new ShardDataTreeChangeListenerPublisherActorProxy(getContext(), name + "-DTCL-publisher"),
 141                 new ShardDataChangeListenerPublisherActorProxy(getContext(), name + "-DCL-publisher"), name);
 142
 143         shardMBean = ShardMBeanFactory.getShardStatsMBean(name.toString(),
 144                 datastoreContext.getDataStoreMXBeanType());
 145         shardMBean.setShard(this);
 146
 147         if (isMetricsCaptureEnabled()) {
 148             getContext().become(new MeteringBehavior(this));
 149         }
 150
 151         commitCoordinator = new ShardCommitCoordinator(store,
 152                 datastoreContext.getShardCommitQueueExpiryTimeoutInMillis(),
 153                 datastoreContext.getShardTransactionCommitQueueCapacity(), LOG, this.name);
 154
 155         setTransactionCommitTimeout();
 156
 157         // create a notifier actor for each cluster member
 158         roleChangeNotifier = createRoleChangeNotifier(name.toString());
 159
 160         appendEntriesReplyTracker = new MessageTracker(AppendEntriesReply.class,
 161                 getRaftActorContext().getConfigParams().getIsolatedCheckIntervalInMillis());
 162
 163         transactionActorFactory = new ShardTransactionActorFactory(store, datastoreContext,
 164                 new Dispatchers(context().system().dispatchers()).getDispatcherPath(
 165                         Dispatchers.DispatcherType.Transaction), self(), getContext(), shardMBean);
 166
 167         snapshotCohort = new ShardSnapshotCohort(transactionActorFactory, store, LOG, this.name);
 168
 169         messageRetrySupport = new ShardTransactionMessageRetrySupport(this);
 170     }
 171
 172     private void setTransactionCommitTimeout() {
 173         transactionCommitTimeout = TimeUnit.MILLISECONDS.convert(
 174                 datastoreContext.getShardTransactionCommitTimeoutInSeconds(), TimeUnit.SECONDS) / 2;
 175     }
 176
 177     private Optional<ActorRef> createRoleChangeNotifier(String shardId) {
 178         ActorRef shardRoleChangeNotifier = this.getContext().actorOf(
 179             RoleChangeNotifier.getProps(shardId), shardId + "-notifier");
 180         return Optional.of(shardRoleChangeNotifier);
 181     }
 182
 183     @Override
 184     public void postStop() {
 185         LOG.info("Stopping Shard {}", persistenceId());
 186
 187         super.postStop();
 188
 189         messageRetrySupport.close();
 190
 191         if(txCommitTimeoutCheckSchedule != null) {
 192             txCommitTimeoutCheckSchedule.cancel();
 193         }
 194
 195         commitCoordinator.abortPendingTransactions("Transaction aborted due to shutdown.", this);
 196
 197         shardMBean.unregisterMBean();
 198     }
 199
 200     @Override
 201     protected void handleRecover(final Object message) {
 202         LOG.debug("{}: onReceiveRecover: Received message {} from {}", persistenceId(), message.getClass(),
 203             getSender());
 204
 205         super.handleRecover(message);
 206         if (LOG.isTraceEnabled()) {
 207             appendEntriesReplyTracker.begin();
 208         }
 209     }
 210
 211     @Override
 212     protected void handleCommand(final Object message) {
 213
 214         final MessageTracker.Context context = appendEntriesReplyTracker.received(message);
 215         final Optional<Error> maybeError = context.error();
 216         if (maybeError.isPresent()) {
 217             LOG.trace("{} : AppendEntriesReply failed to arrive at the expected interval {}", persistenceId(),
 218                 maybeError.get());
 219         }
 220
 221         try {
 222             if (CreateTransaction.isSerializedType(message)) {
 223                 handleCreateTransaction(message);
 224             } else if (message instanceof BatchedModifications) {
 225                 handleBatchedModifications((BatchedModifications)message);
 226             } else if (message instanceof ForwardedReadyTransaction) {
 227                 handleForwardedReadyTransaction((ForwardedReadyTransaction) message);
 228             } else if (message instanceof ReadyLocalTransaction) {
 229                 handleReadyLocalTransaction((ReadyLocalTransaction)message);
 230             } else if (CanCommitTransaction.isSerializedType(message)) {
 231                 handleCanCommitTransaction(CanCommitTransaction.fromSerializable(message));
 232             } else if (CommitTransaction.isSerializedType(message)) {
 233                 handleCommitTransaction(CommitTransaction.fromSerializable(message));
 234             } else if (AbortTransaction.isSerializedType(message)) {
 235                 handleAbortTransaction(AbortTransaction.fromSerializable(message));
 236             } else if (CloseTransactionChain.isSerializedType(message)) {
 237                 closeTransactionChain(CloseTransactionChain.fromSerializable(message));
 238             } else if (message instanceof RegisterChangeListener) {
 239                 changeSupport.onMessage((RegisterChangeListener) message, isLeader(), hasLeader());
 240             } else if (message instanceof RegisterDataTreeChangeListener) {
 241                 treeChangeSupport.onMessage((RegisterDataTreeChangeListener) message, isLeader(), hasLeader());
 242             } else if (message instanceof UpdateSchemaContext) {
 243                 updateSchemaContext((UpdateSchemaContext) message);
 244             } else if (message instanceof PeerAddressResolved) {
 245                 PeerAddressResolved resolved = (PeerAddressResolved) message;
 246                 setPeerAddress(resolved.getPeerId().toString(),
 247                         resolved.getPeerAddress());
 248             } else if (message.equals(TX_COMMIT_TIMEOUT_CHECK_MESSAGE)) {
 249                 commitCoordinator.checkForExpiredTransactions(transactionCommitTimeout, this);
 250             } else if(message instanceof DatastoreContext) {
 251                 onDatastoreContext((DatastoreContext)message);
 252             } else if(message instanceof RegisterRoleChangeListener){
 253                 roleChangeNotifier.get().forward(message, context());
 254             } else if (message instanceof FollowerInitialSyncUpStatus) {
 255                 shardMBean.setFollowerInitialSyncStatus(((FollowerInitialSyncUpStatus) message).isInitialSyncDone());
 256                 context().parent().tell(message, self());
 257             } else if(GET_SHARD_MBEAN_MESSAGE.equals(message)){
 258                 sender().tell(getShardMBean(), self());
 259             } else if(message instanceof GetShardDataTree) {
 260                 sender().tell(store.getDataTree(), self());
 261             } else if(message instanceof ServerRemoved){
 262                 context().parent().forward(message, context());
 263             } else if(ShardTransactionMessageRetrySupport.TIMER_MESSAGE_CLASS.isInstance(message)) {
 264                 messageRetrySupport.onTimerMessage(message);
 265             } else {
 266                 super.handleCommand(message);
 267             }
 268         } finally {
 269             context.done();
 270         }
 271     }
 272
 273     private boolean hasLeader() {
 274         return getLeaderId() != null;
 275     }
 276
 277     public int getPendingTxCommitQueueSize() {
 278         return commitCoordinator.getQueueSize();
 279     }
 280
 281     public int getCohortCacheSize() {
 282         return commitCoordinator.getCohortCacheSize();
 283     }
 284
 285     @Override
 286     protected Optional<ActorRef> getRoleChangeNotifier() {
 287         return roleChangeNotifier;
 288     }
 289
 290     @Override
 291     protected LeaderStateChanged newLeaderStateChanged(String memberId, String leaderId, short leaderPayloadVersion) {
 292         return new ShardLeaderStateChanged(memberId, leaderId,
 293                 isLeader() ? Optional.<DataTree>of(store.getDataTree()) : Optional.<DataTree>absent(),
 294                 leaderPayloadVersion);
 295     }
 296
 297     protected void onDatastoreContext(DatastoreContext context) {
 298         datastoreContext = context;
 299
 300         commitCoordinator.setQueueCapacity(datastoreContext.getShardTransactionCommitQueueCapacity());
 301
 302         setTransactionCommitTimeout();
 303
 304         if(datastoreContext.isPersistent() && !persistence().isRecoveryApplicable()) {
 305             setPersistence(true);
 306         } else if(!datastoreContext.isPersistent() && persistence().isRecoveryApplicable()) {
 307             setPersistence(false);
 308         }
 309
 310         updateConfigParams(datastoreContext.getShardRaftConfig());
 311     }
 312
 313     private static boolean isEmptyCommit(final DataTreeCandidate candidate) {
 314         return ModificationType.UNMODIFIED.equals(candidate.getRootNode().getModificationType());
 315     }
 316
 317     void continueCommit(final CohortEntry cohortEntry) {
 318         final DataTreeCandidate candidate = cohortEntry.getCandidate();
 319
 320         // If we do not have any followers and we are not using persistence
 321         // or if cohortEntry has no modifications
 322         // we can apply modification to the state immediately
 323         if ((!hasFollowers() && !persistence().isRecoveryApplicable()) || isEmptyCommit(candidate)) {
 324             applyModificationToState(cohortEntry.getReplySender(), cohortEntry.getTransactionID(), candidate);
 325         } else {
 326             Shard.this.persistData(cohortEntry.getReplySender(), cohortEntry.getTransactionID(),
 327                     DataTreeCandidatePayload.create(candidate));
 328         }
 329     }
 330
 331     private void handleCommitTransaction(final CommitTransaction commit) {
 332         if (isLeader()) {
 333             if(!commitCoordinator.handleCommit(commit.getTransactionID(), getSender(), this)) {
 334                 shardMBean.incrementFailedTransactionsCount();
 335             }
 336         } else {
 337             ActorSelection leader = getLeader();
 338             if (leader == null) {
 339                 messageRetrySupport.addMessageToRetry(commit, getSender(),
 340                         "Could not commit transaction " + commit.getTransactionID());
 341             } else {
 342                 LOG.debug("{}: Forwarding CommitTransaction to leader {}", persistenceId(), leader);
 343                 leader.forward(commit, getContext());
 344             }
 345         }
 346     }
 347
 348     private void finishCommit(@Nonnull final ActorRef sender, @Nonnull final String transactionID, @Nonnull final CohortEntry cohortEntry) {
 349         LOG.debug("{}: Finishing commit for transaction {}", persistenceId(), cohortEntry.getTransactionID());
 350
 351         try {
 352             try {
 353                 cohortEntry.commit();
 354             } catch(ExecutionException e) {
 355                 // We may get a "store tree and candidate base differ" IllegalStateException from commit under
 356                 // certain edge case scenarios so we'll try to re-apply the candidate from scratch as a last
 357                 // resort. Eg, we're a follower and a tx payload is replicated but the leader goes down before
 358                 // applying it to the state. We then become the leader and a second tx is pre-committed and
 359                 // replicated. When consensus occurs, this will cause the first tx to be applied as a foreign
 360                 // candidate via applyState prior to the second tx. Since the second tx has already been
 361                 // pre-committed, when it gets here to commit it will get an IllegalStateException.
 362
 363                 // FIXME - this is not an ideal way to handle this scenario. This is temporary - a cleaner
 364                 // solution will be forthcoming.
 365                 if(e.getCause() instanceof IllegalStateException) {
 366                     LOG.debug("{}: commit failed for transaction {} - retrying as foreign candidate", persistenceId(),
 367                             transactionID, e);
 368                     store.applyForeignCandidate(transactionID, cohortEntry.getCandidate());
 369                 } else {
 370                     throw e;
 371                 }
 372             }
 373
 374             sender.tell(CommitTransactionReply.instance(cohortEntry.getClientVersion()).toSerializable(), getSelf());
 375
 376             shardMBean.incrementCommittedTransactionCount();
 377             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 378
 379         } catch (Exception e) {
 380             sender.tell(new akka.actor.Status.Failure(e), getSelf());
 381
 382             LOG.error("{}, An exception occurred while committing transaction {}", persistenceId(),
 383                     transactionID, e);
 384             shardMBean.incrementFailedTransactionsCount();
 385         } finally {
 386             commitCoordinator.currentTransactionComplete(transactionID, true);
 387         }
 388     }
 389
 390     private void finishCommit(@Nonnull final ActorRef sender, final @Nonnull String transactionID) {
 391         // With persistence enabled, this method is called via applyState by the leader strategy
 392         // after the commit has been replicated to a majority of the followers.
 393
 394         CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 395         if (cohortEntry == null) {
 396             // The transaction is no longer the current commit. This can happen if the transaction
 397             // was aborted prior, most likely due to timeout in the front-end. We need to finish
 398             // committing the transaction though since it was successfully persisted and replicated
 399             // however we can't use the original cohort b/c it was already preCommitted and may
 400             // conflict with the current commit or may have been aborted so we commit with a new
 401             // transaction.
 402             cohortEntry = commitCoordinator.getAndRemoveCohortEntry(transactionID);
 403             if(cohortEntry != null) {
 404                 try {
 405                     store.applyForeignCandidate(transactionID, cohortEntry.getCandidate());
 406                 } catch (DataValidationFailedException e) {
 407                     shardMBean.incrementFailedTransactionsCount();
 408                     LOG.error("{}: Failed to re-apply transaction {}", persistenceId(), transactionID, e);
 409                 }
 410
 411                 sender.tell(CommitTransactionReply.instance(cohortEntry.getClientVersion()).toSerializable(),
 412                         getSelf());
 413             } else {
 414                 // This really shouldn't happen - it likely means that persistence or replication
 415                 // took so long to complete such that the cohort entry was expired from the cache.
 416                 IllegalStateException ex = new IllegalStateException(
 417                         String.format("%s: Could not finish committing transaction %s - no CohortEntry found",
 418                                 persistenceId(), transactionID));
 419                 LOG.error(ex.getMessage());
 420                 sender.tell(new akka.actor.Status.Failure(ex), getSelf());
 421             }
 422         } else {
 423             finishCommit(sender, transactionID, cohortEntry);
 424         }
 425     }
 426
 427     private void handleCanCommitTransaction(final CanCommitTransaction canCommit) {
 428         LOG.debug("{}: Can committing transaction {}", persistenceId(), canCommit.getTransactionID());
 429
 430         if (isLeader()) {
 431             commitCoordinator.handleCanCommit(canCommit.getTransactionID(), getSender(), this);
 432         } else {
 433             ActorSelection leader = getLeader();
 434             if (leader == null) {
 435                 messageRetrySupport.addMessageToRetry(canCommit, getSender(),
 436                         "Could not canCommit transaction " + canCommit.getTransactionID());
 437             } else {
 438                 LOG.debug("{}: Forwarding CanCommitTransaction to leader {}", persistenceId(), leader);
 439                 leader.forward(canCommit, getContext());
 440             }
 441         }
 442     }
 443
 444     protected void handleBatchedModificationsLocal(BatchedModifications batched, ActorRef sender) {
 445         try {
 446             commitCoordinator.handleBatchedModifications(batched, sender, this);
 447         } catch (Exception e) {
 448             LOG.error("{}: Error handling BatchedModifications for Tx {}", persistenceId(),
 449                     batched.getTransactionID(), e);
 450             sender.tell(new akka.actor.Status.Failure(e), getSelf());
 451         }
 452     }
 453
 454     private void handleBatchedModifications(BatchedModifications batched) {
 455         // This message is sent to prepare the modifications transaction directly on the Shard as an
 456         // optimization to avoid the extra overhead of a separate ShardTransaction actor. On the last
 457         // BatchedModifications message, the caller sets the ready flag in the message indicating
 458         // modifications are complete. The reply contains the cohort actor path (this actor) for the caller
 459         // to initiate the 3-phase commit. This also avoids the overhead of sending an additional
 460         // ReadyTransaction message.
 461
 462         // If we're not the leader then forward to the leader. This is a safety measure - we shouldn't
 463         // normally get here if we're not the leader as the front-end (TransactionProxy) should determine
 464         // the primary/leader shard. However with timing and caching on the front-end, there's a small
 465         // window where it could have a stale leader during leadership transitions.
 466         //
 467         boolean isLeaderActive = isLeaderActive();
 468         if (isLeader() && isLeaderActive) {
 469             handleBatchedModificationsLocal(batched, getSender());
 470         } else {
 471             ActorSelection leader = getLeader();
 472             if (!isLeaderActive || leader == null) {
 473                 messageRetrySupport.addMessageToRetry(batched, getSender(),
 474                         "Could not commit transaction " + batched.getTransactionID());
 475             } else {
 476                 // If this is not the first batch and leadership changed in between batched messages,
 477                 // we need to reconstruct previous BatchedModifications from the transaction
 478                 // DataTreeModification, honoring the max batched modification count, and forward all the
 479                 // previous BatchedModifications to the new leader.
 480                 Collection<BatchedModifications> newModifications = commitCoordinator.createForwardedBatchedModifications(
 481                         batched, datastoreContext.getShardBatchedModificationCount());
 482
 483                 LOG.debug("{}: Forwarding {} BatchedModifications to leader {}", persistenceId(),
 484                         newModifications.size(), leader);
 485
 486                 for(BatchedModifications bm: newModifications) {
 487                     leader.forward(bm, getContext());
 488                 }
 489             }
 490         }
 491     }
 492
 493     private boolean failIfIsolatedLeader(ActorRef sender) {
 494         if(isIsolatedLeader()) {
 495             sender.tell(new akka.actor.Status.Failure(new NoShardLeaderException(String.format(
 496                     "Shard %s was the leader but has lost contact with all of its followers. Either all" +
 497                     " other follower nodes are down or this node is isolated by a network partition.",
 498                     persistenceId()))), getSelf());
 499             return true;
 500         }
 501
 502         return false;
 503     }
 504
 505     protected boolean isIsolatedLeader() {
 506         return getRaftState() == RaftState.IsolatedLeader;
 507     }
 508
 509     private void handleReadyLocalTransaction(final ReadyLocalTransaction message) {
 510         LOG.debug("{}: handleReadyLocalTransaction for {}", persistenceId(), message.getTransactionID());
 511
 512         boolean isLeaderActive = isLeaderActive();
 513         if (isLeader() && isLeaderActive) {
 514             try {
 515                 commitCoordinator.handleReadyLocalTransaction(message, getSender(), this);
 516             } catch (Exception e) {
 517                 LOG.error("{}: Error handling ReadyLocalTransaction for Tx {}", persistenceId(),
 518                         message.getTransactionID(), e);
 519                 getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 520             }
 521         } else {
 522             ActorSelection leader = getLeader();
 523             if (!isLeaderActive || leader == null) {
 524                 messageRetrySupport.addMessageToRetry(message, getSender(),
 525                         "Could not commit transaction " + message.getTransactionID());
 526             } else {
 527                 LOG.debug("{}: Forwarding ReadyLocalTransaction to leader {}", persistenceId(), leader);
 528                 message.setRemoteVersion(getCurrentBehavior().getLeaderPayloadVersion());
 529                 leader.forward(message, getContext());
 530             }
 531         }
 532     }
 533
 534     private void handleForwardedReadyTransaction(ForwardedReadyTransaction forwardedReady) {
 535         LOG.debug("{}: handleForwardedReadyTransaction for {}", persistenceId(), forwardedReady.getTransactionID());
 536
 537         boolean isLeaderActive = isLeaderActive();
 538         if (isLeader() && isLeaderActive) {
 539             commitCoordinator.handleForwardedReadyTransaction(forwardedReady, getSender(), this);
 540         } else {
 541             ActorSelection leader = getLeader();
 542             if (!isLeaderActive || leader == null) {
 543                 messageRetrySupport.addMessageToRetry(forwardedReady, getSender(),
 544                         "Could not commit transaction " + forwardedReady.getTransactionID());
 545             } else {
 546                 LOG.debug("{}: Forwarding ForwardedReadyTransaction to leader {}", persistenceId(), leader);
 547
 548                 ReadyLocalTransaction readyLocal = new ReadyLocalTransaction(forwardedReady.getTransactionID(),
 549                         forwardedReady.getTransaction().getSnapshot(), forwardedReady.isDoImmediateCommit());
 550                 readyLocal.setRemoteVersion(getCurrentBehavior().getLeaderPayloadVersion());
 551                 leader.forward(readyLocal, getContext());
 552             }
 553         }
 554     }
 555
 556     private void handleAbortTransaction(final AbortTransaction abort) {
 557         doAbortTransaction(abort.getTransactionID(), getSender());
 558     }
 559
 560     void doAbortTransaction(final String transactionID, final ActorRef sender) {
 561         commitCoordinator.handleAbort(transactionID, sender, this);
 562     }
 563
 564     private void handleCreateTransaction(final Object message) {
 565         if (isLeader()) {
 566             createTransaction(CreateTransaction.fromSerializable(message));
 567         } else if (getLeader() != null) {
 568             getLeader().forward(message, getContext());
 569         } else {
 570             getSender().tell(new akka.actor.Status.Failure(new NoShardLeaderException(
 571                     "Could not create a shard transaction", persistenceId())), getSelf());
 572         }
 573     }
 574
 575     private void closeTransactionChain(final CloseTransactionChain closeTransactionChain) {
 576         store.closeTransactionChain(closeTransactionChain.getTransactionChainId());
 577     }
 578
 579     private ActorRef createTypedTransactionActor(int transactionType,
 580             ShardTransactionIdentifier transactionId, String transactionChainId) {
 581
 582         return transactionActorFactory.newShardTransaction(TransactionType.fromInt(transactionType),
 583                 transactionId, transactionChainId);
 584     }
 585
 586     private void createTransaction(CreateTransaction createTransaction) {
 587         try {
 588             if(TransactionType.fromInt(createTransaction.getTransactionType()) != TransactionType.READ_ONLY &&
 589                     failIfIsolatedLeader(getSender())) {
 590                 return;
 591             }
 592
 593             ActorRef transactionActor = createTransaction(createTransaction.getTransactionType(),
 594                 createTransaction.getTransactionId(), createTransaction.getTransactionChainId());
 595
 596             getSender().tell(new CreateTransactionReply(Serialization.serializedActorPath(transactionActor),
 597                     createTransaction.getTransactionId(), createTransaction.getVersion()).toSerializable(), getSelf());
 598         } catch (Exception e) {
 599             getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 600         }
 601     }
 602
 603     private ActorRef createTransaction(int transactionType, String remoteTransactionId,
 604             String transactionChainId) {
 605
 606
 607         ShardTransactionIdentifier transactionId = new ShardTransactionIdentifier(remoteTransactionId);
 608
 609         if(LOG.isDebugEnabled()) {
 610             LOG.debug("{}: Creating transaction : {} ", persistenceId(), transactionId);
 611         }
 612
 613         ActorRef transactionActor = createTypedTransactionActor(transactionType, transactionId,
 614                 transactionChainId);
 615
 616         return transactionActor;
 617     }
 618
 619     private void commitWithNewTransaction(final Modification modification) {
 620         ReadWriteShardDataTreeTransaction tx = store.newReadWriteTransaction(modification.toString(), null);
 621         modification.apply(tx.getSnapshot());
 622         try {
 623             snapshotCohort.syncCommitTransaction(tx);
 624             shardMBean.incrementCommittedTransactionCount();
 625             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 626         } catch (Exception e) {
 627             shardMBean.incrementFailedTransactionsCount();
 628             LOG.error("{}: Failed to commit", persistenceId(), e);
 629         }
 630     }
 631
 632     private void updateSchemaContext(final UpdateSchemaContext message) {
 633         updateSchemaContext(message.getSchemaContext());
 634     }
 635
 636     @VisibleForTesting
 637     void updateSchemaContext(final SchemaContext schemaContext) {
 638         store.updateSchemaContext(schemaContext);
 639     }
 640
 641     private boolean isMetricsCaptureEnabled() {
 642         CommonConfig config = new CommonConfig(getContext().system().settings().config());
 643         return config.isMetricCaptureEnabled();
 644     }
 645
 646     @Override
 647     @VisibleForTesting
 648     public RaftActorSnapshotCohort getRaftActorSnapshotCohort() {
 649         return snapshotCohort;
 650     }
 651
 652     @Override
 653     @Nonnull
 654     protected RaftActorRecoveryCohort getRaftActorRecoveryCohort() {
 655         return new ShardRecoveryCoordinator(store, store.getSchemaContext(),
 656                 restoreFromSnapshot != null ? restoreFromSnapshot.getSnapshot() : null, persistenceId(), LOG);
 657     }
 658
 659     @Override
 660     protected void onRecoveryComplete() {
 661         restoreFromSnapshot = null;
 662
 663         //notify shard manager
 664         getContext().parent().tell(new ActorInitialized(), getSelf());
 665
 666         // Being paranoid here - this method should only be called once but just in case...
 667         if(txCommitTimeoutCheckSchedule == null) {
 668             // Schedule a message to be periodically sent to check if the current in-progress
 669             // transaction should be expired and aborted.
 670             FiniteDuration period = Duration.create(transactionCommitTimeout / 3, TimeUnit.MILLISECONDS);
 671             txCommitTimeoutCheckSchedule = getContext().system().scheduler().schedule(
 672                     period, period, getSelf(),
 673                     TX_COMMIT_TIMEOUT_CHECK_MESSAGE, getContext().dispatcher(), ActorRef.noSender());
 674         }
 675     }
 676
 677     @Override
 678     protected void applyState(final ActorRef clientActor, final String identifier, final Object data) {
 679         if (data instanceof DataTreeCandidatePayload) {
 680             if (clientActor == null) {
 681                 // No clientActor indicates a replica coming from the leader
 682                 try {
 683                     store.applyForeignCandidate(identifier, ((DataTreeCandidatePayload)data).getCandidate());
 684                 } catch (DataValidationFailedException | IOException e) {
 685                     LOG.error("{}: Error applying replica {}", persistenceId(), identifier, e);
 686                 }
 687             } else {
 688                 // Replication consensus reached, proceed to commit
 689                 finishCommit(clientActor, identifier);
 690             }
 691         } else if (data instanceof CompositeModificationPayload) {
 692             Object modification = ((CompositeModificationPayload) data).getModification();
 693
 694             applyModificationToState(clientActor, identifier, modification);
 695         } else if(data instanceof CompositeModificationByteStringPayload ){
 696             Object modification = ((CompositeModificationByteStringPayload) data).getModification();
 697
 698             applyModificationToState(clientActor, identifier, modification);
 699         } else {
 700             LOG.error("{}: Unknown state received {} Class loader = {} CompositeNodeMod.ClassLoader = {}",
 701                     persistenceId(), data, data.getClass().getClassLoader(),
 702                     CompositeModificationPayload.class.getClassLoader());
 703         }
 704     }
 705
 706     private void applyModificationToState(ActorRef clientActor, String identifier, Object modification) {
 707         if(modification == null) {
 708             LOG.error(
 709                     "{}: modification is null - this is very unexpected, clientActor = {}, identifier = {}",
 710                     persistenceId(), identifier, clientActor != null ? clientActor.path().toString() : null);
 711         } else if(clientActor == null) {
 712             // There's no clientActor to which to send a commit reply so we must be applying
 713             // replicated state from the leader.
 714             commitWithNewTransaction(MutableCompositeModification.fromSerializable(modification));
 715         } else {
 716             // This must be the OK to commit after replication consensus.
 717             finishCommit(clientActor, identifier);
 718         }
 719     }
 720
 721     @Override
 722     protected void onStateChanged() {
 723         boolean isLeader = isLeader();
 724         boolean hasLeader = hasLeader();
 725         changeSupport.onLeadershipChange(isLeader, hasLeader);
 726         treeChangeSupport.onLeadershipChange(isLeader, hasLeader);
 727
 728         // If this actor is no longer the leader close all the transaction chains
 729         if (!isLeader) {
 730             if(LOG.isDebugEnabled()) {
 731                 LOG.debug(
 732                     "{}: onStateChanged: Closing all transaction chains because shard {} is no longer the leader",
 733                     persistenceId(), getId());
 734             }
 735
 736             store.closeAllTransactionChains();
 737         }
 738
 739         if(hasLeader && !isIsolatedLeader()) {
 740             messageRetrySupport.retryMessages();
 741         }
 742     }
 743
 744     @Override
 745     protected void onLeaderChanged(String oldLeader, String newLeader) {
 746         shardMBean.incrementLeadershipChangeCount();
 747
 748         boolean hasLeader = hasLeader();
 749         if(hasLeader && !isLeader()) {
 750             // Another leader was elected. If we were the previous leader and had pending transactions, convert
 751             // them to transaction messages and send to the new leader.
 752             ActorSelection leader = getLeader();
 753             if(leader != null) {
 754                 Collection<Object> messagesToForward = commitCoordinator.convertPendingTransactionsToMessages(
 755                         datastoreContext.getShardBatchedModificationCount());
 756
 757                 if(!messagesToForward.isEmpty()) {
 758                     LOG.debug("{}: Forwarding {} pending transaction messages to leader {}", persistenceId(),
 759                             messagesToForward.size(), leader);
 760
 761                     for(Object message: messagesToForward) {
 762                         leader.tell(message, self());
 763                     }
 764                 }
 765             } else {
 766                 commitCoordinator.abortPendingTransactions(
 767                         "The transacton was aborted due to inflight leadership change and the leader address isn't available.",
 768                         this);
 769             }
 770         }
 771
 772         if(hasLeader && !isIsolatedLeader()) {
 773             messageRetrySupport.retryMessages();
 774         }
 775     }
 776
 777     @Override
 778     protected void pauseLeader(Runnable operation) {
 779         LOG.debug("{}: In pauseLeader, operation: {}", persistenceId(), operation);
 780         commitCoordinator.setRunOnPendingTransactionsComplete(operation);
 781     }
 782
 783     @Override
 784     public String persistenceId() {
 785         return this.name;
 786     }
 787
 788     @VisibleForTesting
 789     ShardCommitCoordinator getCommitCoordinator() {
 790         return commitCoordinator;
 791     }
 792
 793     public DatastoreContext getDatastoreContext() {
 794         return datastoreContext;
 795     }
 796
 797     @VisibleForTesting
 798     public ShardDataTree getDataStore() {
 799         return store;
 800     }
 801
 802     @VisibleForTesting
 803     ShardStats getShardMBean() {
 804         return shardMBean;
 805     }
 806
 807     public static Builder builder() {
 808         return new Builder();
 809     }
 810
 811     public static abstract class AbstractBuilder<T extends AbstractBuilder<T, S>, S extends Shard> {
 812         private final Class<S> shardClass;
 813         private ShardIdentifier id;
 814         private Map<String, String> peerAddresses = Collections.emptyMap();
 815         private DatastoreContext datastoreContext;
 816         private SchemaContext schemaContext;
 817         private DatastoreSnapshot.ShardSnapshot restoreFromSnapshot;
 818         private volatile boolean sealed;
 819
 820         protected AbstractBuilder(Class<S> shardClass) {
 821             this.shardClass = shardClass;
 822         }
 823
 824         protected void checkSealed() {
 825             Preconditions.checkState(!sealed, "Builder isalready sealed - further modifications are not allowed");
 826         }
 827
 828         @SuppressWarnings("unchecked")
 829         private T self() {
 830             return (T) this;
 831         }
 832
 833         public T id(ShardIdentifier id) {
 834             checkSealed();
 835             this.id = id;
 836             return self();
 837         }
 838
 839         public T peerAddresses(Map<String, String> peerAddresses) {
 840             checkSealed();
 841             this.peerAddresses = peerAddresses;
 842             return self();
 843         }
 844
 845         public T datastoreContext(DatastoreContext datastoreContext) {
 846             checkSealed();
 847             this.datastoreContext = datastoreContext;
 848             return self();
 849         }
 850
 851         public T schemaContext(SchemaContext schemaContext) {
 852             checkSealed();
 853             this.schemaContext = schemaContext;
 854             return self();
 855         }
 856
 857         public T restoreFromSnapshot(DatastoreSnapshot.ShardSnapshot restoreFromSnapshot) {
 858             checkSealed();
 859             this.restoreFromSnapshot = restoreFromSnapshot;
 860             return self();
 861         }
 862
 863         public ShardIdentifier getId() {
 864             return id;
 865         }
 866
 867         public Map<String, String> getPeerAddresses() {
 868             return peerAddresses;
 869         }
 870
 871         public DatastoreContext getDatastoreContext() {
 872             return datastoreContext;
 873         }
 874
 875         public SchemaContext getSchemaContext() {
 876             return schemaContext;
 877         }
 878
 879         public DatastoreSnapshot.ShardSnapshot getRestoreFromSnapshot() {
 880             return restoreFromSnapshot;
 881         }
 882
 883         public TreeType getTreeType() {
 884             switch (datastoreContext.getLogicalStoreType()) {
 885             case CONFIGURATION:
 886                 return TreeType.CONFIGURATION;
 887             case OPERATIONAL:
 888                 return TreeType.OPERATIONAL;
 889             }
 890
 891             throw new IllegalStateException("Unhandled logical store type " + datastoreContext.getLogicalStoreType());
 892         }
 893
 894         protected void verify() {
 895             Preconditions.checkNotNull(id, "id should not be null");
 896             Preconditions.checkNotNull(peerAddresses, "peerAddresses should not be null");
 897             Preconditions.checkNotNull(datastoreContext, "dataStoreContext should not be null");
 898             Preconditions.checkNotNull(schemaContext, "schemaContext should not be null");
 899         }
 900
 901         public Props props() {
 902             sealed = true;
 903             verify();
 904             return Props.create(shardClass, this);
 905         }
 906     }
 907
 908     public static class Builder extends AbstractBuilder<Builder, Shard> {
 909         private Builder() {
 910             super(Shard.class);
 911         }
 912     }
 913 }