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.exceptions.NoShardLeaderException;
  31 import org.opendaylight.controller.cluster.datastore.identifiers.ShardIdentifier;
  32 import org.opendaylight.controller.cluster.datastore.identifiers.ShardTransactionIdentifier;
  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.CommitTransactionReply;
  42 import org.opendaylight.controller.cluster.datastore.messages.CreateTransaction;
  43 import org.opendaylight.controller.cluster.datastore.messages.CreateTransactionReply;
  44 import org.opendaylight.controller.cluster.datastore.messages.DatastoreSnapshot;
  45 import org.opendaylight.controller.cluster.datastore.messages.DatastoreSnapshot.ShardSnapshot;
  46 import org.opendaylight.controller.cluster.datastore.messages.ForwardedReadyTransaction;
  47 import org.opendaylight.controller.cluster.datastore.messages.GetShardDataTree;
  48 import org.opendaylight.controller.cluster.datastore.messages.PeerAddressResolved;
  49 import org.opendaylight.controller.cluster.datastore.messages.ReadyLocalTransaction;
  50 import org.opendaylight.controller.cluster.datastore.messages.RegisterChangeListener;
  51 import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeChangeListener;
  52 import org.opendaylight.controller.cluster.datastore.messages.ShardLeaderStateChanged;
  53 import org.opendaylight.controller.cluster.datastore.messages.UpdateSchemaContext;
  54 import org.opendaylight.controller.cluster.datastore.modification.Modification;
  55 import org.opendaylight.controller.cluster.datastore.modification.MutableCompositeModification;
  56 import org.opendaylight.controller.cluster.datastore.utils.Dispatchers;
  57 import org.opendaylight.controller.cluster.notifications.LeaderStateChanged;
  58 import org.opendaylight.controller.cluster.notifications.RegisterRoleChangeListener;
  59 import org.opendaylight.controller.cluster.notifications.RoleChangeNotifier;
  60 import org.opendaylight.controller.cluster.raft.RaftActor;
  61 import org.opendaylight.controller.cluster.raft.RaftActorRecoveryCohort;
  62 import org.opendaylight.controller.cluster.raft.RaftActorSnapshotCohort;
  63 import org.opendaylight.controller.cluster.raft.RaftState;
  64 import org.opendaylight.controller.cluster.raft.base.messages.FollowerInitialSyncUpStatus;
  65 import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply;
  66 import org.opendaylight.controller.cluster.raft.messages.ServerRemoved;
  67 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationByteStringPayload;
  68 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationPayload;
  69 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  70 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
  71 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
  72 import org.opendaylight.yangtools.yang.data.api.schema.tree.TreeType;
  73 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  74 import scala.concurrent.duration.Duration;
  75 import scala.concurrent.duration.FiniteDuration;
  76
  77 /**
  78  * A Shard represents a portion of the logical data tree <br/>
  79  * <p>
  80  * Our Shard uses InMemoryDataTree as it's internal representation and delegates all requests it
  81  * </p>
  82  */
  83 public class Shard extends RaftActor {
  84
  85     @VisibleForTesting
  86     static final Object TX_COMMIT_TIMEOUT_CHECK_MESSAGE = new Object() {
  87         @Override
  88         public String toString() {
  89             return "txCommitTimeoutCheck";
  90         }
  91     };
  92
  93     @VisibleForTesting
  94     static final Object GET_SHARD_MBEAN_MESSAGE = new Object() {
  95         @Override
  96         public String toString() {
  97             return "getShardMBeanMessage";
  98         }
  99     };
 100
 101     // FIXME: shard names should be encapsulated in their own class and this should be exposed as a constant.
 102     public static final String DEFAULT_NAME = "default";
 103
 104     // The state of this Shard
 105     private final ShardDataTree store;
 106
 107     /// The name of this shard
 108     private final String name;
 109
 110     private final ShardStats shardMBean;
 111
 112     private DatastoreContext datastoreContext;
 113
 114     private final ShardCommitCoordinator commitCoordinator;
 115
 116     private long transactionCommitTimeout;
 117
 118     private Cancellable txCommitTimeoutCheckSchedule;
 119
 120     private final Optional<ActorRef> roleChangeNotifier;
 121
 122     private final MessageTracker appendEntriesReplyTracker;
 123
 124     private final ShardTransactionActorFactory transactionActorFactory;
 125
 126     private final ShardSnapshotCohort snapshotCohort;
 127
 128     private final DataTreeChangeListenerSupport treeChangeSupport = new DataTreeChangeListenerSupport(this);
 129     private final DataChangeListenerSupport changeSupport = new DataChangeListenerSupport(this);
 130
 131
 132     private ShardSnapshot restoreFromSnapshot;
 133
 134     private final ShardTransactionMessageRetrySupport messageRetrySupport;
 135
 136     protected Shard(AbstractBuilder<?, ?> builder) {
 137         super(builder.getId().toString(), builder.getPeerAddresses(),
 138                 Optional.of(builder.getDatastoreContext().getShardRaftConfig()), DataStoreVersions.CURRENT_VERSION);
 139
 140         this.name = builder.getId().toString();
 141         this.datastoreContext = builder.getDatastoreContext();
 142         this.restoreFromSnapshot = builder.getRestoreFromSnapshot();
 143
 144         setPersistence(datastoreContext.isPersistent());
 145
 146         LOG.info("Shard created : {}, persistent : {}", name, datastoreContext.isPersistent());
 147
 148         store = new ShardDataTree(builder.getSchemaContext(), builder.getTreeType(),
 149                 new ShardDataTreeChangeListenerPublisherActorProxy(getContext(), name + "-DTCL-publisher"),
 150                 new ShardDataChangeListenerPublisherActorProxy(getContext(), name + "-DCL-publisher"), name);
 151
 152         shardMBean = ShardMBeanFactory.getShardStatsMBean(name.toString(),
 153                 datastoreContext.getDataStoreMXBeanType());
 154         shardMBean.setShard(this);
 155
 156         if (isMetricsCaptureEnabled()) {
 157             getContext().become(new MeteringBehavior(this));
 158         }
 159
 160         commitCoordinator = new ShardCommitCoordinator(store,
 161                 datastoreContext.getShardCommitQueueExpiryTimeoutInMillis(),
 162                 datastoreContext.getShardTransactionCommitQueueCapacity(), LOG, this.name);
 163
 164         setTransactionCommitTimeout();
 165
 166         // create a notifier actor for each cluster member
 167         roleChangeNotifier = createRoleChangeNotifier(name.toString());
 168
 169         appendEntriesReplyTracker = new MessageTracker(AppendEntriesReply.class,
 170                 getRaftActorContext().getConfigParams().getIsolatedCheckIntervalInMillis());
 171
 172         transactionActorFactory = new ShardTransactionActorFactory(store, datastoreContext,
 173                 new Dispatchers(context().system().dispatchers()).getDispatcherPath(
 174                         Dispatchers.DispatcherType.Transaction), self(), getContext(), shardMBean);
 175
 176         snapshotCohort = new ShardSnapshotCohort(transactionActorFactory, store, LOG, this.name);
 177
 178         messageRetrySupport = new ShardTransactionMessageRetrySupport(this);
 179     }
 180
 181     private void setTransactionCommitTimeout() {
 182         transactionCommitTimeout = TimeUnit.MILLISECONDS.convert(
 183                 datastoreContext.getShardTransactionCommitTimeoutInSeconds(), TimeUnit.SECONDS) / 2;
 184     }
 185
 186     private Optional<ActorRef> createRoleChangeNotifier(String shardId) {
 187         ActorRef shardRoleChangeNotifier = this.getContext().actorOf(
 188             RoleChangeNotifier.getProps(shardId), shardId + "-notifier");
 189         return Optional.of(shardRoleChangeNotifier);
 190     }
 191
 192     @Override
 193     public void postStop() {
 194         LOG.info("Stopping Shard {}", persistenceId());
 195
 196         super.postStop();
 197
 198         messageRetrySupport.close();
 199
 200         if(txCommitTimeoutCheckSchedule != null) {
 201             txCommitTimeoutCheckSchedule.cancel();
 202         }
 203
 204         commitCoordinator.abortPendingTransactions("Transaction aborted due to shutdown.", this);
 205
 206         shardMBean.unregisterMBean();
 207     }
 208
 209     @Override
 210     protected void handleRecover(final Object message) {
 211         LOG.debug("{}: onReceiveRecover: Received message {} from {}", persistenceId(), message.getClass(),
 212             getSender());
 213
 214         super.handleRecover(message);
 215         if (LOG.isTraceEnabled()) {
 216             appendEntriesReplyTracker.begin();
 217         }
 218     }
 219
 220     @Override
 221     protected void handleNonRaftCommand(final Object message) {
 222         try (final MessageTracker.Context context = appendEntriesReplyTracker.received(message)) {
 223             final Optional<Error> maybeError = context.error();
 224             if (maybeError.isPresent()) {
 225                 LOG.trace("{} : AppendEntriesReply failed to arrive at the expected interval {}", persistenceId(),
 226                     maybeError.get());
 227             }
 228
 229             if (CreateTransaction.isSerializedType(message)) {
 230                 handleCreateTransaction(message);
 231             } else if (message instanceof BatchedModifications) {
 232                 handleBatchedModifications((BatchedModifications)message);
 233             } else if (message instanceof ForwardedReadyTransaction) {
 234                 handleForwardedReadyTransaction((ForwardedReadyTransaction) message);
 235             } else if (message instanceof ReadyLocalTransaction) {
 236                 handleReadyLocalTransaction((ReadyLocalTransaction)message);
 237             } else if (CanCommitTransaction.isSerializedType(message)) {
 238                 handleCanCommitTransaction(CanCommitTransaction.fromSerializable(message));
 239             } else if (CommitTransaction.isSerializedType(message)) {
 240                 handleCommitTransaction(CommitTransaction.fromSerializable(message));
 241             } else if (AbortTransaction.isSerializedType(message)) {
 242                 handleAbortTransaction(AbortTransaction.fromSerializable(message));
 243             } else if (CloseTransactionChain.isSerializedType(message)) {
 244                 closeTransactionChain(CloseTransactionChain.fromSerializable(message));
 245             } else if (message instanceof RegisterChangeListener) {
 246                 changeSupport.onMessage((RegisterChangeListener) message, isLeader(), hasLeader());
 247             } else if (message instanceof RegisterDataTreeChangeListener) {
 248                 treeChangeSupport.onMessage((RegisterDataTreeChangeListener) message, isLeader(), hasLeader());
 249             } else if (message instanceof UpdateSchemaContext) {
 250                 updateSchemaContext((UpdateSchemaContext) message);
 251             } else if (message instanceof PeerAddressResolved) {
 252                 PeerAddressResolved resolved = (PeerAddressResolved) message;
 253                 setPeerAddress(resolved.getPeerId().toString(),
 254                         resolved.getPeerAddress());
 255             } else if (TX_COMMIT_TIMEOUT_CHECK_MESSAGE.equals(message)) {
 256                 commitCoordinator.checkForExpiredTransactions(transactionCommitTimeout, this);
 257             } else if(message instanceof DatastoreContext) {
 258                 onDatastoreContext((DatastoreContext)message);
 259             } else if(message instanceof RegisterRoleChangeListener){
 260                 roleChangeNotifier.get().forward(message, context());
 261             } else if (message instanceof FollowerInitialSyncUpStatus) {
 262                 shardMBean.setFollowerInitialSyncStatus(((FollowerInitialSyncUpStatus) message).isInitialSyncDone());
 263                 context().parent().tell(message, self());
 264             } else if(GET_SHARD_MBEAN_MESSAGE.equals(message)){
 265                 sender().tell(getShardMBean(), self());
 266             } else if(message instanceof GetShardDataTree) {
 267                 sender().tell(store.getDataTree(), self());
 268             } else if(message instanceof ServerRemoved){
 269                 context().parent().forward(message, context());
 270             } else if(ShardTransactionMessageRetrySupport.TIMER_MESSAGE_CLASS.isInstance(message)) {
 271                 messageRetrySupport.onTimerMessage(message);
 272             } else if (message instanceof DataTreeCohortActorRegistry.CohortRegistryCommand) {
 273                 commitCoordinator.processCohortRegistryCommand(getSender(),
 274                         (DataTreeCohortActorRegistry.CohortRegistryCommand) message);
 275             } else {
 276                 super.handleNonRaftCommand(message);
 277             }
 278         }
 279     }
 280
 281     private boolean hasLeader() {
 282         return getLeaderId() != null;
 283     }
 284
 285     public int getPendingTxCommitQueueSize() {
 286         return commitCoordinator.getQueueSize();
 287     }
 288
 289     public int getCohortCacheSize() {
 290         return commitCoordinator.getCohortCacheSize();
 291     }
 292
 293     @Override
 294     protected Optional<ActorRef> getRoleChangeNotifier() {
 295         return roleChangeNotifier;
 296     }
 297
 298     @Override
 299     protected LeaderStateChanged newLeaderStateChanged(String memberId, String leaderId, short leaderPayloadVersion) {
 300         return isLeader() ? new ShardLeaderStateChanged(memberId, leaderId, store.getDataTree(), leaderPayloadVersion)
 301                 : new ShardLeaderStateChanged(memberId, leaderId, leaderPayloadVersion);
 302     }
 303
 304     protected void onDatastoreContext(DatastoreContext context) {
 305         datastoreContext = context;
 306
 307         commitCoordinator.setQueueCapacity(datastoreContext.getShardTransactionCommitQueueCapacity());
 308
 309         setTransactionCommitTimeout();
 310
 311         if(datastoreContext.isPersistent() && !persistence().isRecoveryApplicable()) {
 312             setPersistence(true);
 313         } else if(!datastoreContext.isPersistent() && persistence().isRecoveryApplicable()) {
 314             setPersistence(false);
 315         }
 316
 317         updateConfigParams(datastoreContext.getShardRaftConfig());
 318     }
 319
 320     private static boolean isEmptyCommit(final DataTreeCandidate candidate) {
 321         return ModificationType.UNMODIFIED.equals(candidate.getRootNode().getModificationType());
 322     }
 323
 324     void continueCommit(final CohortEntry cohortEntry) {
 325         final DataTreeCandidate candidate = cohortEntry.getCandidate();
 326
 327         // If we do not have any followers and we are not using persistence
 328         // or if cohortEntry has no modifications
 329         // we can apply modification to the state immediately
 330         if ((!hasFollowers() && !persistence().isRecoveryApplicable()) || isEmptyCommit(candidate)) {
 331             applyModificationToState(cohortEntry.getReplySender(), cohortEntry.getTransactionID(), candidate);
 332         } else {
 333             Shard.this.persistData(cohortEntry.getReplySender(), cohortEntry.getTransactionID(),
 334                     DataTreeCandidatePayload.create(candidate));
 335         }
 336     }
 337
 338     private void handleCommitTransaction(final CommitTransaction commit) {
 339         if (isLeader()) {
 340         if(!commitCoordinator.handleCommit(commit.getTransactionID(), getSender(), this)) {
 341             shardMBean.incrementFailedTransactionsCount();
 342         }
 343         } else {
 344             ActorSelection leader = getLeader();
 345             if (leader == null) {
 346                 messageRetrySupport.addMessageToRetry(commit, getSender(),
 347                         "Could not commit transaction " + commit.getTransactionID());
 348             } else {
 349                 LOG.debug("{}: Forwarding CommitTransaction to leader {}", persistenceId(), leader);
 350                 leader.forward(commit, getContext());
 351             }
 352         }
 353     }
 354
 355     private void finishCommit(@Nonnull final ActorRef sender, @Nonnull final String transactionID, @Nonnull final CohortEntry cohortEntry) {
 356         LOG.debug("{}: Finishing commit for transaction {}", persistenceId(), cohortEntry.getTransactionID());
 357
 358         try {
 359             try {
 360             cohortEntry.commit();
 361             } catch(ExecutionException e) {
 362                 // We may get a "store tree and candidate base differ" IllegalStateException from commit under
 363                 // certain edge case scenarios so we'll try to re-apply the candidate from scratch as a last
 364                 // resort. Eg, we're a follower and a tx payload is replicated but the leader goes down before
 365                 // applying it to the state. We then become the leader and a second tx is pre-committed and
 366                 // replicated. When consensus occurs, this will cause the first tx to be applied as a foreign
 367                 // candidate via applyState prior to the second tx. Since the second tx has already been
 368                 // pre-committed, when it gets here to commit it will get an IllegalStateException.
 369
 370                 // FIXME - this is not an ideal way to handle this scenario. This is temporary - a cleaner
 371                 // solution will be forthcoming.
 372                 if(e.getCause() instanceof IllegalStateException) {
 373                     LOG.debug("{}: commit failed for transaction {} - retrying as foreign candidate", persistenceId(),
 374                             transactionID, e);
 375                     store.applyForeignCandidate(transactionID, cohortEntry.getCandidate());
 376                 } else {
 377                     throw e;
 378                 }
 379             }
 380
 381             sender.tell(CommitTransactionReply.instance(cohortEntry.getClientVersion()).toSerializable(), getSelf());
 382
 383             shardMBean.incrementCommittedTransactionCount();
 384             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 385
 386         } catch (Exception e) {
 387             sender.tell(new akka.actor.Status.Failure(e), getSelf());
 388
 389             LOG.error("{}, An exception occurred while committing transaction {}", persistenceId(),
 390                     transactionID, e);
 391             shardMBean.incrementFailedTransactionsCount();
 392         } finally {
 393             commitCoordinator.currentTransactionComplete(transactionID, true);
 394         }
 395     }
 396
 397     private void finishCommit(@Nonnull final ActorRef sender, final @Nonnull String transactionID) {
 398         // With persistence enabled, this method is called via applyState by the leader strategy
 399         // after the commit has been replicated to a majority of the followers.
 400
 401         CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 402         if (cohortEntry == null) {
 403             // The transaction is no longer the current commit. This can happen if the transaction
 404             // was aborted prior, most likely due to timeout in the front-end. We need to finish
 405             // committing the transaction though since it was successfully persisted and replicated
 406             // however we can't use the original cohort b/c it was already preCommitted and may
 407             // conflict with the current commit or may have been aborted so we commit with a new
 408             // transaction.
 409             cohortEntry = commitCoordinator.getAndRemoveCohortEntry(transactionID);
 410             if(cohortEntry != null) {
 411                 try {
 412                     store.applyForeignCandidate(transactionID, cohortEntry.getCandidate());
 413                 } catch (DataValidationFailedException e) {
 414                     shardMBean.incrementFailedTransactionsCount();
 415                     LOG.error("{}: Failed to re-apply transaction {}", persistenceId(), transactionID, e);
 416                 }
 417
 418                 sender.tell(CommitTransactionReply.instance(cohortEntry.getClientVersion()).toSerializable(),
 419                         getSelf());
 420             } else {
 421                 // This really shouldn't happen - it likely means that persistence or replication
 422                 // took so long to complete such that the cohort entry was expired from the cache.
 423                 IllegalStateException ex = new IllegalStateException(
 424                         String.format("%s: Could not finish committing transaction %s - no CohortEntry found",
 425                                 persistenceId(), transactionID));
 426                 LOG.error(ex.getMessage());
 427                 sender.tell(new akka.actor.Status.Failure(ex), getSelf());
 428             }
 429         } else {
 430             finishCommit(sender, transactionID, cohortEntry);
 431         }
 432     }
 433
 434     private void handleCanCommitTransaction(final CanCommitTransaction canCommit) {
 435         LOG.debug("{}: Can committing transaction {}", persistenceId(), canCommit.getTransactionID());
 436
 437         if (isLeader()) {
 438         commitCoordinator.handleCanCommit(canCommit.getTransactionID(), getSender(), this);
 439         } else {
 440             ActorSelection leader = getLeader();
 441             if (leader == null) {
 442                 messageRetrySupport.addMessageToRetry(canCommit, getSender(),
 443                         "Could not canCommit transaction " + canCommit.getTransactionID());
 444             } else {
 445                 LOG.debug("{}: Forwarding CanCommitTransaction to leader {}", persistenceId(), leader);
 446                 leader.forward(canCommit, getContext());
 447             }
 448         }
 449     }
 450
 451     protected void handleBatchedModificationsLocal(BatchedModifications batched, ActorRef sender) {
 452         try {
 453             commitCoordinator.handleBatchedModifications(batched, sender, this, store.getSchemaContext());
 454         } catch (Exception e) {
 455             LOG.error("{}: Error handling BatchedModifications for Tx {}", persistenceId(),
 456                     batched.getTransactionID(), e);
 457             sender.tell(new akka.actor.Status.Failure(e), getSelf());
 458         }
 459     }
 460
 461     private void handleBatchedModifications(BatchedModifications batched) {
 462         // This message is sent to prepare the modifications transaction directly on the Shard as an
 463         // optimization to avoid the extra overhead of a separate ShardTransaction actor. On the last
 464         // BatchedModifications message, the caller sets the ready flag in the message indicating
 465         // modifications are complete. The reply contains the cohort actor path (this actor) for the caller
 466         // to initiate the 3-phase commit. This also avoids the overhead of sending an additional
 467         // ReadyTransaction message.
 468
 469         // If we're not the leader then forward to the leader. This is a safety measure - we shouldn't
 470         // normally get here if we're not the leader as the front-end (TransactionProxy) should determine
 471         // the primary/leader shard. However with timing and caching on the front-end, there's a small
 472         // window where it could have a stale leader during leadership transitions.
 473         //
 474         boolean isLeaderActive = isLeaderActive();
 475         if (isLeader() && isLeaderActive) {
 476             handleBatchedModificationsLocal(batched, getSender());
 477         } else {
 478             ActorSelection leader = getLeader();
 479             if (!isLeaderActive || leader == null) {
 480                 messageRetrySupport.addMessageToRetry(batched, getSender(),
 481                         "Could not commit transaction " + batched.getTransactionID());
 482             } else {
 483                 // If this is not the first batch and leadership changed in between batched messages,
 484                 // we need to reconstruct previous BatchedModifications from the transaction
 485                 // DataTreeModification, honoring the max batched modification count, and forward all the
 486                 // previous BatchedModifications to the new leader.
 487                 Collection<BatchedModifications> newModifications = commitCoordinator.createForwardedBatchedModifications(
 488                         batched, datastoreContext.getShardBatchedModificationCount());
 489
 490                 LOG.debug("{}: Forwarding {} BatchedModifications to leader {}", persistenceId(),
 491                         newModifications.size(), leader);
 492
 493                 for(BatchedModifications bm: newModifications) {
 494                     leader.forward(bm, getContext());
 495                 }
 496             }
 497         }
 498     }
 499
 500     private boolean failIfIsolatedLeader(ActorRef sender) {
 501         if(isIsolatedLeader()) {
 502             sender.tell(new akka.actor.Status.Failure(new NoShardLeaderException(String.format(
 503                     "Shard %s was the leader but has lost contact with all of its followers. Either all" +
 504                     " other follower nodes are down or this node is isolated by a network partition.",
 505                     persistenceId()))), getSelf());
 506             return true;
 507         }
 508
 509         return false;
 510     }
 511
 512     protected boolean isIsolatedLeader() {
 513         return getRaftState() == RaftState.IsolatedLeader;
 514     }
 515
 516     private void handleReadyLocalTransaction(final ReadyLocalTransaction message) {
 517         LOG.debug("{}: handleReadyLocalTransaction for {}", persistenceId(), message.getTransactionID());
 518
 519         boolean isLeaderActive = isLeaderActive();
 520         if (isLeader() && isLeaderActive) {
 521             try {
 522                 commitCoordinator.handleReadyLocalTransaction(message, getSender(), this, store.getSchemaContext());
 523             } catch (Exception e) {
 524                 LOG.error("{}: Error handling ReadyLocalTransaction for Tx {}", persistenceId(),
 525                         message.getTransactionID(), e);
 526                 getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 527             }
 528         } else {
 529             ActorSelection leader = getLeader();
 530             if (!isLeaderActive || leader == null) {
 531                 messageRetrySupport.addMessageToRetry(message, getSender(),
 532                         "Could not commit transaction " + message.getTransactionID());
 533             } else {
 534                 LOG.debug("{}: Forwarding ReadyLocalTransaction to leader {}", persistenceId(), leader);
 535                 message.setRemoteVersion(getCurrentBehavior().getLeaderPayloadVersion());
 536                 leader.forward(message, getContext());
 537             }
 538         }
 539     }
 540
 541     private void handleForwardedReadyTransaction(ForwardedReadyTransaction forwardedReady) {
 542         LOG.debug("{}: handleForwardedReadyTransaction for {}", persistenceId(), forwardedReady.getTransactionID());
 543
 544         boolean isLeaderActive = isLeaderActive();
 545         if (isLeader() && isLeaderActive) {
 546             commitCoordinator.handleForwardedReadyTransaction(forwardedReady, getSender(), this,
 547                     store.getSchemaContext());
 548         } else {
 549             ActorSelection leader = getLeader();
 550             if (!isLeaderActive || leader == null) {
 551                 messageRetrySupport.addMessageToRetry(forwardedReady, getSender(),
 552                         "Could not commit transaction " + forwardedReady.getTransactionID());
 553             } else {
 554                 LOG.debug("{}: Forwarding ForwardedReadyTransaction to leader {}", persistenceId(), leader);
 555
 556                 ReadyLocalTransaction readyLocal = new ReadyLocalTransaction(forwardedReady.getTransactionID(),
 557                         forwardedReady.getTransaction().getSnapshot(), forwardedReady.isDoImmediateCommit());
 558                 readyLocal.setRemoteVersion(getCurrentBehavior().getLeaderPayloadVersion());
 559                 leader.forward(readyLocal, getContext());
 560             }
 561         }
 562     }
 563
 564     private void handleAbortTransaction(final AbortTransaction abort) {
 565         doAbortTransaction(abort.getTransactionID(), getSender());
 566     }
 567
 568     void doAbortTransaction(final String transactionID, final ActorRef sender) {
 569         commitCoordinator.handleAbort(transactionID, sender, this);
 570     }
 571
 572     private void handleCreateTransaction(final Object message) {
 573         if (isLeader()) {
 574             createTransaction(CreateTransaction.fromSerializable(message));
 575         } else if (getLeader() != null) {
 576             getLeader().forward(message, getContext());
 577         } else {
 578             getSender().tell(new akka.actor.Status.Failure(new NoShardLeaderException(
 579                     "Could not create a shard transaction", persistenceId())), getSelf());
 580         }
 581     }
 582
 583     private void closeTransactionChain(final CloseTransactionChain closeTransactionChain) {
 584         store.closeTransactionChain(closeTransactionChain.getTransactionChainId());
 585     }
 586
 587     private ActorRef createTypedTransactionActor(int transactionType,
 588             ShardTransactionIdentifier transactionId, String transactionChainId) {
 589
 590         return transactionActorFactory.newShardTransaction(TransactionType.fromInt(transactionType),
 591                 transactionId, transactionChainId);
 592     }
 593
 594     private void createTransaction(CreateTransaction createTransaction) {
 595         try {
 596             if(TransactionType.fromInt(createTransaction.getTransactionType()) != TransactionType.READ_ONLY &&
 597                     failIfIsolatedLeader(getSender())) {
 598                 return;
 599             }
 600
 601             ActorRef transactionActor = createTransaction(createTransaction.getTransactionType(),
 602                 createTransaction.getTransactionId(), createTransaction.getTransactionChainId());
 603
 604             getSender().tell(new CreateTransactionReply(Serialization.serializedActorPath(transactionActor),
 605                     createTransaction.getTransactionId(), createTransaction.getVersion()).toSerializable(), getSelf());
 606         } catch (Exception e) {
 607             getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 608         }
 609     }
 610
 611     private ActorRef createTransaction(int transactionType, String remoteTransactionId,
 612             String transactionChainId) {
 613
 614
 615         ShardTransactionIdentifier transactionId = new ShardTransactionIdentifier(remoteTransactionId);
 616
 617         if(LOG.isDebugEnabled()) {
 618             LOG.debug("{}: Creating transaction : {} ", persistenceId(), transactionId);
 619         }
 620
 621         ActorRef transactionActor = createTypedTransactionActor(transactionType, transactionId,
 622                 transactionChainId);
 623
 624         return transactionActor;
 625     }
 626
 627     private void commitWithNewTransaction(final Modification modification) {
 628         ReadWriteShardDataTreeTransaction tx = store.newReadWriteTransaction(modification.toString(), null);
 629         modification.apply(tx.getSnapshot());
 630         try {
 631             snapshotCohort.syncCommitTransaction(tx);
 632             shardMBean.incrementCommittedTransactionCount();
 633             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 634         } catch (Exception e) {
 635             shardMBean.incrementFailedTransactionsCount();
 636             LOG.error("{}: Failed to commit", persistenceId(), e);
 637         }
 638     }
 639
 640     private void updateSchemaContext(final UpdateSchemaContext message) {
 641         updateSchemaContext(message.getSchemaContext());
 642     }
 643
 644     @VisibleForTesting
 645     void updateSchemaContext(final SchemaContext schemaContext) {
 646         store.updateSchemaContext(schemaContext);
 647     }
 648
 649     private boolean isMetricsCaptureEnabled() {
 650         CommonConfig config = new CommonConfig(getContext().system().settings().config());
 651         return config.isMetricCaptureEnabled();
 652     }
 653
 654     @Override
 655     @VisibleForTesting
 656     public RaftActorSnapshotCohort getRaftActorSnapshotCohort() {
 657         return snapshotCohort;
 658     }
 659
 660     @Override
 661     @Nonnull
 662     protected RaftActorRecoveryCohort getRaftActorRecoveryCohort() {
 663         return new ShardRecoveryCoordinator(store, store.getSchemaContext(),
 664                 restoreFromSnapshot != null ? restoreFromSnapshot.getSnapshot() : null, persistenceId(), LOG);
 665     }
 666
 667     @Override
 668     protected void onRecoveryComplete() {
 669         restoreFromSnapshot = null;
 670
 671         //notify shard manager
 672         getContext().parent().tell(new ActorInitialized(), getSelf());
 673
 674         // Being paranoid here - this method should only be called once but just in case...
 675         if(txCommitTimeoutCheckSchedule == null) {
 676             // Schedule a message to be periodically sent to check if the current in-progress
 677             // transaction should be expired and aborted.
 678             FiniteDuration period = Duration.create(transactionCommitTimeout / 3, TimeUnit.MILLISECONDS);
 679             txCommitTimeoutCheckSchedule = getContext().system().scheduler().schedule(
 680                     period, period, getSelf(),
 681                     TX_COMMIT_TIMEOUT_CHECK_MESSAGE, getContext().dispatcher(), ActorRef.noSender());
 682         }
 683     }
 684
 685     @Override
 686     protected void applyState(final ActorRef clientActor, final String identifier, final Object data) {
 687         if (data instanceof DataTreeCandidatePayload) {
 688             if (clientActor == null) {
 689                 // No clientActor indicates a replica coming from the leader
 690                 try {
 691                     store.applyForeignCandidate(identifier, ((DataTreeCandidatePayload)data).getCandidate());
 692                 } catch (DataValidationFailedException | IOException e) {
 693                     LOG.error("{}: Error applying replica {}", persistenceId(), identifier, e);
 694                 }
 695             } else {
 696                 // Replication consensus reached, proceed to commit
 697                 finishCommit(clientActor, identifier);
 698             }
 699         } else if (data instanceof CompositeModificationPayload) {
 700             Object modification = ((CompositeModificationPayload) data).getModification();
 701
 702             applyModificationToState(clientActor, identifier, modification);
 703         } else if(data instanceof CompositeModificationByteStringPayload ){
 704             Object modification = ((CompositeModificationByteStringPayload) data).getModification();
 705
 706             applyModificationToState(clientActor, identifier, modification);
 707         } else {
 708             LOG.error("{}: Unknown state received {} Class loader = {} CompositeNodeMod.ClassLoader = {}",
 709                     persistenceId(), data, data.getClass().getClassLoader(),
 710                     CompositeModificationPayload.class.getClassLoader());
 711         }
 712     }
 713
 714     private void applyModificationToState(ActorRef clientActor, String identifier, Object modification) {
 715         if(modification == null) {
 716             LOG.error(
 717                     "{}: modification is null - this is very unexpected, clientActor = {}, identifier = {}",
 718                     persistenceId(), identifier, clientActor != null ? clientActor.path().toString() : null);
 719         } else if(clientActor == null) {
 720             // There's no clientActor to which to send a commit reply so we must be applying
 721             // replicated state from the leader.
 722             commitWithNewTransaction(MutableCompositeModification.fromSerializable(modification));
 723         } else {
 724             // This must be the OK to commit after replication consensus.
 725             finishCommit(clientActor, identifier);
 726         }
 727     }
 728
 729     @Override
 730     protected void onStateChanged() {
 731         boolean isLeader = isLeader();
 732         boolean hasLeader = hasLeader();
 733         changeSupport.onLeadershipChange(isLeader, hasLeader);
 734         treeChangeSupport.onLeadershipChange(isLeader, hasLeader);
 735
 736         // If this actor is no longer the leader close all the transaction chains
 737         if (!isLeader) {
 738             if(LOG.isDebugEnabled()) {
 739                 LOG.debug(
 740                     "{}: onStateChanged: Closing all transaction chains because shard {} is no longer the leader",
 741                     persistenceId(), getId());
 742             }
 743
 744             store.closeAllTransactionChains();
 745         }
 746
 747         if(hasLeader && !isIsolatedLeader()) {
 748             messageRetrySupport.retryMessages();
 749         }
 750     }
 751
 752     @Override
 753     protected void onLeaderChanged(String oldLeader, String newLeader) {
 754         shardMBean.incrementLeadershipChangeCount();
 755
 756         boolean hasLeader = hasLeader();
 757         if(hasLeader && !isLeader()) {
 758             // Another leader was elected. If we were the previous leader and had pending transactions, convert
 759             // them to transaction messages and send to the new leader.
 760             ActorSelection leader = getLeader();
 761             if(leader != null) {
 762                 Collection<Object> messagesToForward = commitCoordinator.convertPendingTransactionsToMessages(
 763                         datastoreContext.getShardBatchedModificationCount());
 764
 765                 if(!messagesToForward.isEmpty()) {
 766                     LOG.debug("{}: Forwarding {} pending transaction messages to leader {}", persistenceId(),
 767                             messagesToForward.size(), leader);
 768
 769                     for(Object message: messagesToForward) {
 770                         leader.tell(message, self());
 771                     }
 772                 }
 773             } else {
 774                 commitCoordinator.abortPendingTransactions(
 775                         "The transacton was aborted due to inflight leadership change and the leader address isn't available.",
 776                         this);
 777             }
 778         }
 779
 780         if(hasLeader && !isIsolatedLeader()) {
 781             messageRetrySupport.retryMessages();
 782         }
 783     }
 784
 785     @Override
 786     protected void pauseLeader(Runnable operation) {
 787         LOG.debug("{}: In pauseLeader, operation: {}", persistenceId(), operation);
 788         commitCoordinator.setRunOnPendingTransactionsComplete(operation);
 789     }
 790
 791     @Override
 792     public String persistenceId() {
 793         return this.name;
 794     }
 795
 796     @VisibleForTesting
 797     ShardCommitCoordinator getCommitCoordinator() {
 798         return commitCoordinator;
 799     }
 800
 801     public DatastoreContext getDatastoreContext() {
 802         return datastoreContext;
 803     }
 804
 805     @VisibleForTesting
 806     public ShardDataTree getDataStore() {
 807         return store;
 808     }
 809
 810     @VisibleForTesting
 811     ShardStats getShardMBean() {
 812         return shardMBean;
 813     }
 814
 815     public static Builder builder() {
 816         return new Builder();
 817     }
 818
 819     public static abstract class AbstractBuilder<T extends AbstractBuilder<T, S>, S extends Shard> {
 820         private final Class<S> shardClass;
 821         private ShardIdentifier id;
 822         private Map<String, String> peerAddresses = Collections.emptyMap();
 823         private DatastoreContext datastoreContext;
 824         private SchemaContext schemaContext;
 825         private DatastoreSnapshot.ShardSnapshot restoreFromSnapshot;
 826         private volatile boolean sealed;
 827
 828         protected AbstractBuilder(Class<S> shardClass) {
 829             this.shardClass = shardClass;
 830         }
 831
 832         protected void checkSealed() {
 833             Preconditions.checkState(!sealed, "Builder isalready sealed - further modifications are not allowed");
 834         }
 835
 836         @SuppressWarnings("unchecked")
 837         private T self() {
 838             return (T) this;
 839         }
 840
 841         public T id(ShardIdentifier id) {
 842             checkSealed();
 843             this.id = id;
 844             return self();
 845         }
 846
 847         public T peerAddresses(Map<String, String> peerAddresses) {
 848             checkSealed();
 849             this.peerAddresses = peerAddresses;
 850             return self();
 851         }
 852
 853         public T datastoreContext(DatastoreContext datastoreContext) {
 854             checkSealed();
 855             this.datastoreContext = datastoreContext;
 856             return self();
 857         }
 858
 859         public T schemaContext(SchemaContext schemaContext) {
 860             checkSealed();
 861             this.schemaContext = schemaContext;
 862             return self();
 863         }
 864
 865         public T restoreFromSnapshot(DatastoreSnapshot.ShardSnapshot restoreFromSnapshot) {
 866             checkSealed();
 867             this.restoreFromSnapshot = restoreFromSnapshot;
 868             return self();
 869         }
 870
 871         public ShardIdentifier getId() {
 872             return id;
 873         }
 874
 875         public Map<String, String> getPeerAddresses() {
 876             return peerAddresses;
 877         }
 878
 879         public DatastoreContext getDatastoreContext() {
 880             return datastoreContext;
 881         }
 882
 883         public SchemaContext getSchemaContext() {
 884             return schemaContext;
 885         }
 886
 887         public DatastoreSnapshot.ShardSnapshot getRestoreFromSnapshot() {
 888             return restoreFromSnapshot;
 889         }
 890
 891         public TreeType getTreeType() {
 892             switch (datastoreContext.getLogicalStoreType()) {
 893             case CONFIGURATION:
 894                 return TreeType.CONFIGURATION;
 895             case OPERATIONAL:
 896                 return TreeType.OPERATIONAL;
 897             }
 898
 899             throw new IllegalStateException("Unhandled logical store type " + datastoreContext.getLogicalStoreType());
 900         }
 901
 902         protected void verify() {
 903             Preconditions.checkNotNull(id, "id should not be null");
 904             Preconditions.checkNotNull(peerAddresses, "peerAddresses should not be null");
 905             Preconditions.checkNotNull(datastoreContext, "dataStoreContext should not be null");
 906             Preconditions.checkNotNull(schemaContext, "schemaContext should not be null");
 907         }
 908
 909         public Props props() {
 910             sealed = true;
 911             verify();
 912             return Props.create(shardClass, this);
 913         }
 914     }
 915
 916     public static class Builder extends AbstractBuilder<Builder, Shard> {
 917         private Builder() {
 918             super(Shard.class);
 919         }
 920     }
 921 }