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     @Override
 288     protected Optional<ActorRef> getRoleChangeNotifier() {
 289         return roleChangeNotifier;
 290     }
 291
 292     @Override
 293     protected LeaderStateChanged newLeaderStateChanged(String memberId, String leaderId, short leaderPayloadVersion) {
 294         return new ShardLeaderStateChanged(memberId, leaderId,
 295                 isLeader() ? Optional.<DataTree>of(store.getDataTree()) : Optional.<DataTree>absent(),
 296                 leaderPayloadVersion);
 297     }
 298
 299     protected void onDatastoreContext(DatastoreContext context) {
 300         datastoreContext = context;
 301
 302         commitCoordinator.setQueueCapacity(datastoreContext.getShardTransactionCommitQueueCapacity());
 303
 304         setTransactionCommitTimeout();
 305
 306         if(datastoreContext.isPersistent() && !persistence().isRecoveryApplicable()) {
 307             setPersistence(true);
 308         } else if(!datastoreContext.isPersistent() && persistence().isRecoveryApplicable()) {
 309             setPersistence(false);
 310         }
 311
 312         updateConfigParams(datastoreContext.getShardRaftConfig());
 313     }
 314
 315     private void handleTransactionCommitTimeoutCheck() {
 316         CohortEntry cohortEntry = commitCoordinator.getCurrentCohortEntry();
 317         if(cohortEntry != null) {
 318             if(cohortEntry.isExpired(transactionCommitTimeout)) {
 319                 LOG.warn("{}: Current transaction {} has timed out after {} ms - aborting",
 320                         persistenceId(), cohortEntry.getTransactionID(), transactionCommitTimeout);
 321
 322                 doAbortTransaction(cohortEntry.getTransactionID(), null);
 323             }
 324         }
 325
 326         commitCoordinator.cleanupExpiredCohortEntries();
 327     }
 328
 329     private static boolean isEmptyCommit(final DataTreeCandidate candidate) {
 330         return ModificationType.UNMODIFIED.equals(candidate.getRootNode().getModificationType());
 331     }
 332
 333     void continueCommit(final CohortEntry cohortEntry) {
 334         final DataTreeCandidate candidate = cohortEntry.getCandidate();
 335
 336         // If we do not have any followers and we are not using persistence
 337         // or if cohortEntry has no modifications
 338         // we can apply modification to the state immediately
 339         if ((!hasFollowers() && !persistence().isRecoveryApplicable()) || isEmptyCommit(candidate)) {
 340             applyModificationToState(cohortEntry.getReplySender(), cohortEntry.getTransactionID(), candidate);
 341         } else {
 342             Shard.this.persistData(cohortEntry.getReplySender(), cohortEntry.getTransactionID(),
 343                     DataTreeCandidatePayload.create(candidate));
 344         }
 345     }
 346
 347     private void handleCommitTransaction(final CommitTransaction commit) {
 348         if(!commitCoordinator.handleCommit(commit.getTransactionID(), getSender(), this)) {
 349             shardMBean.incrementFailedTransactionsCount();
 350         }
 351     }
 352
 353     private void finishCommit(@Nonnull final ActorRef sender, @Nonnull final String transactionID, @Nonnull final CohortEntry cohortEntry) {
 354         LOG.debug("{}: Finishing commit for transaction {}", persistenceId(), cohortEntry.getTransactionID());
 355
 356         try {
 357             cohortEntry.commit();
 358
 359             sender.tell(CommitTransactionReply.INSTANCE.toSerializable(), getSelf());
 360
 361             shardMBean.incrementCommittedTransactionCount();
 362             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 363
 364         } catch (Exception e) {
 365             sender.tell(new akka.actor.Status.Failure(e), getSelf());
 366
 367             LOG.error("{}, An exception occurred while committing transaction {}", persistenceId(),
 368                     transactionID, e);
 369             shardMBean.incrementFailedTransactionsCount();
 370         } finally {
 371             commitCoordinator.currentTransactionComplete(transactionID, true);
 372         }
 373     }
 374
 375     private void finishCommit(@Nonnull final ActorRef sender, final @Nonnull String transactionID) {
 376         // With persistence enabled, this method is called via applyState by the leader strategy
 377         // after the commit has been replicated to a majority of the followers.
 378
 379         CohortEntry cohortEntry = commitCoordinator.getCohortEntryIfCurrent(transactionID);
 380         if (cohortEntry == null) {
 381             // The transaction is no longer the current commit. This can happen if the transaction
 382             // was aborted prior, most likely due to timeout in the front-end. We need to finish
 383             // committing the transaction though since it was successfully persisted and replicated
 384             // however we can't use the original cohort b/c it was already preCommitted and may
 385             // conflict with the current commit or may have been aborted so we commit with a new
 386             // transaction.
 387             cohortEntry = commitCoordinator.getAndRemoveCohortEntry(transactionID);
 388             if(cohortEntry != null) {
 389                 try {
 390                     store.applyForeignCandidate(transactionID, cohortEntry.getCandidate());
 391                 } catch (DataValidationFailedException e) {
 392                     shardMBean.incrementFailedTransactionsCount();
 393                     LOG.error("{}: Failed to re-apply transaction {}", persistenceId(), transactionID, e);
 394                 }
 395
 396                 sender.tell(CommitTransactionReply.INSTANCE.toSerializable(), getSelf());
 397             } else {
 398                 // This really shouldn't happen - it likely means that persistence or replication
 399                 // took so long to complete such that the cohort entry was expired from the cache.
 400                 IllegalStateException ex = new IllegalStateException(
 401                         String.format("%s: Could not finish committing transaction %s - no CohortEntry found",
 402                                 persistenceId(), transactionID));
 403                 LOG.error(ex.getMessage());
 404                 sender.tell(new akka.actor.Status.Failure(ex), getSelf());
 405             }
 406         } else {
 407             finishCommit(sender, transactionID, cohortEntry);
 408         }
 409     }
 410
 411     private void handleCanCommitTransaction(final CanCommitTransaction canCommit) {
 412         LOG.debug("{}: Can committing transaction {}", persistenceId(), canCommit.getTransactionID());
 413         commitCoordinator.handleCanCommit(canCommit.getTransactionID(), getSender(), this);
 414     }
 415
 416     protected void handleBatchedModificationsLocal(BatchedModifications batched, ActorRef sender) {
 417         try {
 418             commitCoordinator.handleBatchedModifications(batched, sender, this);
 419         } catch (Exception e) {
 420             LOG.error("{}: Error handling BatchedModifications for Tx {}", persistenceId(),
 421                     batched.getTransactionID(), e);
 422             sender.tell(new akka.actor.Status.Failure(e), getSelf());
 423         }
 424     }
 425
 426     private void handleBatchedModifications(BatchedModifications batched) {
 427         // This message is sent to prepare the modifications transaction directly on the Shard as an
 428         // optimization to avoid the extra overhead of a separate ShardTransaction actor. On the last
 429         // BatchedModifications message, the caller sets the ready flag in the message indicating
 430         // modifications are complete. The reply contains the cohort actor path (this actor) for the caller
 431         // to initiate the 3-phase commit. This also avoids the overhead of sending an additional
 432         // ReadyTransaction message.
 433
 434         // If we're not the leader then forward to the leader. This is a safety measure - we shouldn't
 435         // normally get here if we're not the leader as the front-end (TransactionProxy) should determine
 436         // the primary/leader shard. However with timing and caching on the front-end, there's a small
 437         // window where it could have a stale leader during leadership transitions.
 438         //
 439         if(isLeader()) {
 440             failIfIsolatedLeader(getSender());
 441
 442             handleBatchedModificationsLocal(batched, getSender());
 443         } else {
 444             ActorSelection leader = getLeader();
 445             if(leader != null) {
 446                 // TODO: what if this is not the first batch and leadership changed in between batched messages?
 447                 // We could check if the commitCoordinator already has a cached entry and forward all the previous
 448                 // batched modifications.
 449                 LOG.debug("{}: Forwarding BatchedModifications to leader {}", persistenceId(), leader);
 450                 leader.forward(batched, getContext());
 451             } else {
 452                 messageRetrySupport.addMessageToRetry(batched, getSender(),
 453                         "Could not commit transaction " + batched.getTransactionID());
 454             }
 455         }
 456     }
 457
 458     private boolean failIfIsolatedLeader(ActorRef sender) {
 459         if(isIsolatedLeader()) {
 460             sender.tell(new akka.actor.Status.Failure(new NoShardLeaderException(String.format(
 461                     "Shard %s was the leader but has lost contact with all of its followers. Either all" +
 462                     " other follower nodes are down or this node is isolated by a network partition.",
 463                     persistenceId()))), getSelf());
 464             return true;
 465         }
 466
 467         return false;
 468     }
 469
 470     protected boolean isIsolatedLeader() {
 471         return getRaftState() == RaftState.IsolatedLeader;
 472     }
 473
 474     private void handleReadyLocalTransaction(final ReadyLocalTransaction message) {
 475         if (isLeader()) {
 476             failIfIsolatedLeader(getSender());
 477
 478             try {
 479                 commitCoordinator.handleReadyLocalTransaction(message, getSender(), this);
 480             } catch (Exception e) {
 481                 LOG.error("{}: Error handling ReadyLocalTransaction for Tx {}", persistenceId(),
 482                         message.getTransactionID(), e);
 483                 getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 484             }
 485         } else {
 486             ActorSelection leader = getLeader();
 487             if (leader != null) {
 488                 LOG.debug("{}: Forwarding ReadyLocalTransaction to leader {}", persistenceId(), leader);
 489                 message.setRemoteVersion(getCurrentBehavior().getLeaderPayloadVersion());
 490                 leader.forward(message, getContext());
 491             } else {
 492                 messageRetrySupport.addMessageToRetry(message, getSender(),
 493                         "Could not commit transaction " + message.getTransactionID());
 494             }
 495         }
 496     }
 497
 498     private void handleForwardedReadyTransaction(ForwardedReadyTransaction forwardedReady) {
 499         if (isLeader()) {
 500             failIfIsolatedLeader(getSender());
 501
 502             commitCoordinator.handleForwardedReadyTransaction(forwardedReady, getSender(), this);
 503         } else {
 504             ActorSelection leader = getLeader();
 505             if (leader != null) {
 506                 LOG.debug("{}: Forwarding ForwardedReadyTransaction to leader {}", persistenceId(), leader);
 507
 508                 ReadyLocalTransaction readyLocal = new ReadyLocalTransaction(forwardedReady.getTransactionID(),
 509                         forwardedReady.getTransaction().getSnapshot(), forwardedReady.isDoImmediateCommit());
 510                 readyLocal.setRemoteVersion(getCurrentBehavior().getLeaderPayloadVersion());
 511                 leader.forward(readyLocal, getContext());
 512             } else {
 513                 messageRetrySupport.addMessageToRetry(forwardedReady, getSender(),
 514                         "Could not commit transaction " + forwardedReady.getTransactionID());
 515             }
 516         }
 517     }
 518
 519     private void handleAbortTransaction(final AbortTransaction abort) {
 520         doAbortTransaction(abort.getTransactionID(), getSender());
 521     }
 522
 523     void doAbortTransaction(final String transactionID, final ActorRef sender) {
 524         commitCoordinator.handleAbort(transactionID, sender, this);
 525     }
 526
 527     private void handleCreateTransaction(final Object message) {
 528         if (isLeader()) {
 529             createTransaction(CreateTransaction.fromSerializable(message));
 530         } else if (getLeader() != null) {
 531             getLeader().forward(message, getContext());
 532         } else {
 533             getSender().tell(new akka.actor.Status.Failure(new NoShardLeaderException(
 534                     "Could not create a shard transaction", persistenceId())), getSelf());
 535         }
 536     }
 537
 538     private void closeTransactionChain(final CloseTransactionChain closeTransactionChain) {
 539         store.closeTransactionChain(closeTransactionChain.getTransactionChainId());
 540     }
 541
 542     private ActorRef createTypedTransactionActor(int transactionType,
 543             ShardTransactionIdentifier transactionId, String transactionChainId,
 544             short clientVersion ) {
 545
 546         return transactionActorFactory.newShardTransaction(TransactionType.fromInt(transactionType),
 547                 transactionId, transactionChainId, clientVersion);
 548     }
 549
 550     private void createTransaction(CreateTransaction createTransaction) {
 551         try {
 552             if(TransactionType.fromInt(createTransaction.getTransactionType()) != TransactionType.READ_ONLY &&
 553                     failIfIsolatedLeader(getSender())) {
 554                 return;
 555             }
 556
 557             ActorRef transactionActor = createTransaction(createTransaction.getTransactionType(),
 558                 createTransaction.getTransactionId(), createTransaction.getTransactionChainId(),
 559                 createTransaction.getVersion());
 560
 561             getSender().tell(new CreateTransactionReply(Serialization.serializedActorPath(transactionActor),
 562                     createTransaction.getTransactionId()).toSerializable(), getSelf());
 563         } catch (Exception e) {
 564             getSender().tell(new akka.actor.Status.Failure(e), getSelf());
 565         }
 566     }
 567
 568     private ActorRef createTransaction(int transactionType, String remoteTransactionId,
 569             String transactionChainId, short clientVersion) {
 570
 571
 572         ShardTransactionIdentifier transactionId = new ShardTransactionIdentifier(remoteTransactionId);
 573
 574         if(LOG.isDebugEnabled()) {
 575             LOG.debug("{}: Creating transaction : {} ", persistenceId(), transactionId);
 576         }
 577
 578         ActorRef transactionActor = createTypedTransactionActor(transactionType, transactionId,
 579                 transactionChainId, clientVersion);
 580
 581         return transactionActor;
 582     }
 583
 584     private void commitWithNewTransaction(final Modification modification) {
 585         ReadWriteShardDataTreeTransaction tx = store.newReadWriteTransaction(modification.toString(), null);
 586         modification.apply(tx.getSnapshot());
 587         try {
 588             snapshotCohort.syncCommitTransaction(tx);
 589             shardMBean.incrementCommittedTransactionCount();
 590             shardMBean.setLastCommittedTransactionTime(System.currentTimeMillis());
 591         } catch (Exception e) {
 592             shardMBean.incrementFailedTransactionsCount();
 593             LOG.error("{}: Failed to commit", persistenceId(), e);
 594         }
 595     }
 596
 597     private void updateSchemaContext(final UpdateSchemaContext message) {
 598         updateSchemaContext(message.getSchemaContext());
 599     }
 600
 601     @VisibleForTesting
 602     void updateSchemaContext(final SchemaContext schemaContext) {
 603         store.updateSchemaContext(schemaContext);
 604     }
 605
 606     private boolean isMetricsCaptureEnabled() {
 607         CommonConfig config = new CommonConfig(getContext().system().settings().config());
 608         return config.isMetricCaptureEnabled();
 609     }
 610
 611     @Override
 612     @VisibleForTesting
 613     public RaftActorSnapshotCohort getRaftActorSnapshotCohort() {
 614         return snapshotCohort;
 615     }
 616
 617     @Override
 618     @Nonnull
 619     protected RaftActorRecoveryCohort getRaftActorRecoveryCohort() {
 620         return new ShardRecoveryCoordinator(store, store.getSchemaContext(),
 621                 restoreFromSnapshot != null ? restoreFromSnapshot.getSnapshot() : null, persistenceId(), LOG);
 622     }
 623
 624     @Override
 625     protected void onRecoveryComplete() {
 626         restoreFromSnapshot = null;
 627
 628         //notify shard manager
 629         getContext().parent().tell(new ActorInitialized(), getSelf());
 630
 631         // Being paranoid here - this method should only be called once but just in case...
 632         if(txCommitTimeoutCheckSchedule == null) {
 633             // Schedule a message to be periodically sent to check if the current in-progress
 634             // transaction should be expired and aborted.
 635             FiniteDuration period = Duration.create(transactionCommitTimeout / 3, TimeUnit.MILLISECONDS);
 636             txCommitTimeoutCheckSchedule = getContext().system().scheduler().schedule(
 637                     period, period, getSelf(),
 638                     TX_COMMIT_TIMEOUT_CHECK_MESSAGE, getContext().dispatcher(), ActorRef.noSender());
 639         }
 640     }
 641
 642     @Override
 643     protected void applyState(final ActorRef clientActor, final String identifier, final Object data) {
 644         if (data instanceof DataTreeCandidatePayload) {
 645             if (clientActor == null) {
 646                 // No clientActor indicates a replica coming from the leader
 647                 try {
 648                     store.applyForeignCandidate(identifier, ((DataTreeCandidatePayload)data).getCandidate());
 649                 } catch (DataValidationFailedException | IOException e) {
 650                     LOG.error("{}: Error applying replica {}", persistenceId(), identifier, e);
 651                 }
 652             } else {
 653                 // Replication consensus reached, proceed to commit
 654                 finishCommit(clientActor, identifier);
 655             }
 656         } else if (data instanceof ModificationPayload) {
 657             try {
 658                 applyModificationToState(clientActor, identifier, ((ModificationPayload) data).getModification());
 659             } catch (ClassNotFoundException | IOException e) {
 660                 LOG.error("{}: Error extracting ModificationPayload", persistenceId(), e);
 661             }
 662         } else if (data instanceof CompositeModificationPayload) {
 663             Object modification = ((CompositeModificationPayload) data).getModification();
 664
 665             applyModificationToState(clientActor, identifier, modification);
 666         } else if(data instanceof CompositeModificationByteStringPayload ){
 667             Object modification = ((CompositeModificationByteStringPayload) data).getModification();
 668
 669             applyModificationToState(clientActor, identifier, modification);
 670         } else {
 671             LOG.error("{}: Unknown state received {} Class loader = {} CompositeNodeMod.ClassLoader = {}",
 672                     persistenceId(), data, data.getClass().getClassLoader(),
 673                     CompositeModificationPayload.class.getClassLoader());
 674         }
 675     }
 676
 677     private void applyModificationToState(ActorRef clientActor, String identifier, Object modification) {
 678         if(modification == null) {
 679             LOG.error(
 680                     "{}: modification is null - this is very unexpected, clientActor = {}, identifier = {}",
 681                     persistenceId(), identifier, clientActor != null ? clientActor.path().toString() : null);
 682         } else if(clientActor == null) {
 683             // There's no clientActor to which to send a commit reply so we must be applying
 684             // replicated state from the leader.
 685             commitWithNewTransaction(MutableCompositeModification.fromSerializable(modification));
 686         } else {
 687             // This must be the OK to commit after replication consensus.
 688             finishCommit(clientActor, identifier);
 689         }
 690     }
 691
 692     @Override
 693     protected void onStateChanged() {
 694         boolean isLeader = isLeader();
 695         boolean hasLeader = hasLeader();
 696         changeSupport.onLeadershipChange(isLeader, hasLeader);
 697         treeChangeSupport.onLeadershipChange(isLeader, hasLeader);
 698
 699         // If this actor is no longer the leader close all the transaction chains
 700         if (!isLeader) {
 701             if(LOG.isDebugEnabled()) {
 702                 LOG.debug(
 703                     "{}: onStateChanged: Closing all transaction chains because shard {} is no longer the leader",
 704                     persistenceId(), getId());
 705             }
 706
 707             store.closeAllTransactionChains();
 708         }
 709     }
 710
 711     @Override
 712     protected void onLeaderChanged(String oldLeader, String newLeader) {
 713         shardMBean.incrementLeadershipChangeCount();
 714
 715         if(hasLeader()) {
 716             messageRetrySupport.retryMessages();
 717         }
 718     }
 719
 720     @Override
 721     public String persistenceId() {
 722         return this.name;
 723     }
 724
 725     @VisibleForTesting
 726     ShardCommitCoordinator getCommitCoordinator() {
 727         return commitCoordinator;
 728     }
 729
 730     public DatastoreContext getDatastoreContext() {
 731         return datastoreContext;
 732     }
 733
 734     @VisibleForTesting
 735     public ShardDataTree getDataStore() {
 736         return store;
 737     }
 738
 739     @VisibleForTesting
 740     ShardStats getShardMBean() {
 741         return shardMBean;
 742     }
 743
 744     public static Builder builder() {
 745         return new Builder();
 746     }
 747
 748     public static abstract class AbstractBuilder<T extends AbstractBuilder<T, S>, S extends Shard> {
 749         private final Class<S> shardClass;
 750         private ShardIdentifier id;
 751         private Map<String, String> peerAddresses = Collections.emptyMap();
 752         private DatastoreContext datastoreContext;
 753         private SchemaContext schemaContext;
 754         private DatastoreSnapshot.ShardSnapshot restoreFromSnapshot;
 755         private volatile boolean sealed;
 756
 757         protected AbstractBuilder(Class<S> shardClass) {
 758             this.shardClass = shardClass;
 759         }
 760
 761         protected void checkSealed() {
 762             Preconditions.checkState(!sealed, "Builder isalready sealed - further modifications are not allowed");
 763         }
 764
 765         @SuppressWarnings("unchecked")
 766         private T self() {
 767             return (T) this;
 768         }
 769
 770         public T id(ShardIdentifier id) {
 771             checkSealed();
 772             this.id = id;
 773             return self();
 774         }
 775
 776         public T peerAddresses(Map<String, String> peerAddresses) {
 777             checkSealed();
 778             this.peerAddresses = peerAddresses;
 779             return self();
 780         }
 781
 782         public T datastoreContext(DatastoreContext datastoreContext) {
 783             checkSealed();
 784             this.datastoreContext = datastoreContext;
 785             return self();
 786         }
 787
 788         public T schemaContext(SchemaContext schemaContext) {
 789             checkSealed();
 790             this.schemaContext = schemaContext;
 791             return self();
 792         }
 793
 794         public T restoreFromSnapshot(DatastoreSnapshot.ShardSnapshot restoreFromSnapshot) {
 795             checkSealed();
 796             this.restoreFromSnapshot = restoreFromSnapshot;
 797             return self();
 798         }
 799
 800         public ShardIdentifier getId() {
 801             return id;
 802         }
 803
 804         public Map<String, String> getPeerAddresses() {
 805             return peerAddresses;
 806         }
 807
 808         public DatastoreContext getDatastoreContext() {
 809             return datastoreContext;
 810         }
 811
 812         public SchemaContext getSchemaContext() {
 813             return schemaContext;
 814         }
 815
 816         public DatastoreSnapshot.ShardSnapshot getRestoreFromSnapshot() {
 817             return restoreFromSnapshot;
 818         }
 819
 820         public TreeType getTreeType() {
 821             switch (datastoreContext.getLogicalStoreType()) {
 822             case CONFIGURATION:
 823                 return TreeType.CONFIGURATION;
 824             case OPERATIONAL:
 825                 return TreeType.OPERATIONAL;
 826             }
 827
 828             throw new IllegalStateException("Unhandled logical store type " + datastoreContext.getLogicalStoreType());
 829         }
 830
 831         protected void verify() {
 832             Preconditions.checkNotNull(id, "id should not be null");
 833             Preconditions.checkNotNull(peerAddresses, "peerAddresses should not be null");
 834             Preconditions.checkNotNull(datastoreContext, "dataStoreContext should not be null");
 835             Preconditions.checkNotNull(schemaContext, "schemaContext should not be null");
 836         }
 837
 838         public Props props() {
 839             sealed = true;
 840             verify();
 841             return Props.create(shardClass, this);
 842         }
 843     }
 844
 845     public static class Builder extends AbstractBuilder<Builder, Shard> {
 846         private Builder() {
 847             super(Shard.class);
 848         }
 849     }
 850 }