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