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