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