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.actor.Status.Failure;
  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 com.google.common.base.Ticker;
  21 import com.google.common.base.Verify;
  22 import com.google.common.collect.ImmutableList;
  23 import com.google.common.collect.ImmutableMap;
  24 import com.google.common.collect.Range;
  25 import java.io.IOException;
  26 import java.util.Arrays;
  27 import java.util.Collection;
  28 import java.util.Collections;
  29 import java.util.Map;
  30 import java.util.concurrent.TimeUnit;
  31 import javax.annotation.Nonnull;
  32 import javax.annotation.Nullable;
  33 import org.opendaylight.controller.cluster.access.ABIVersion;
  34 import org.opendaylight.controller.cluster.access.commands.ConnectClientRequest;
  35 import org.opendaylight.controller.cluster.access.commands.ConnectClientSuccess;
  36 import org.opendaylight.controller.cluster.access.commands.LocalHistoryRequest;
  37 import org.opendaylight.controller.cluster.access.commands.NotLeaderException;
  38 import org.opendaylight.controller.cluster.access.commands.TransactionRequest;
  39 import org.opendaylight.controller.cluster.access.concepts.ClientIdentifier;
  40 import org.opendaylight.controller.cluster.access.concepts.FrontendIdentifier;
  41 import org.opendaylight.controller.cluster.access.concepts.LocalHistoryIdentifier;
  42 import org.opendaylight.controller.cluster.access.concepts.Request;
  43 import org.opendaylight.controller.cluster.access.concepts.RequestEnvelope;
  44 import org.opendaylight.controller.cluster.access.concepts.RequestException;
  45 import org.opendaylight.controller.cluster.access.concepts.RequestSuccess;
  46 import org.opendaylight.controller.cluster.access.concepts.RetiredGenerationException;
  47 import org.opendaylight.controller.cluster.access.concepts.RuntimeRequestException;
  48 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  49 import org.opendaylight.controller.cluster.access.concepts.UnsupportedRequestException;
  50 import org.opendaylight.controller.cluster.common.actor.CommonConfig;
  51 import org.opendaylight.controller.cluster.common.actor.MessageTracker;
  52 import org.opendaylight.controller.cluster.common.actor.MessageTracker.Error;
  53 import org.opendaylight.controller.cluster.common.actor.MeteringBehavior;
  54 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
  55 import org.opendaylight.controller.cluster.datastore.identifiers.ShardIdentifier;
  56 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardMBeanFactory;
  57 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardStats;
  58 import org.opendaylight.controller.cluster.datastore.messages.AbortTransaction;
  59 import org.opendaylight.controller.cluster.datastore.messages.ActorInitialized;
  60 import org.opendaylight.controller.cluster.datastore.messages.BatchedModifications;
  61 import org.opendaylight.controller.cluster.datastore.messages.CanCommitTransaction;
  62 import org.opendaylight.controller.cluster.datastore.messages.CloseTransactionChain;
  63 import org.opendaylight.controller.cluster.datastore.messages.CommitTransaction;
  64 import org.opendaylight.controller.cluster.datastore.messages.CreateTransaction;
  65 import org.opendaylight.controller.cluster.datastore.messages.CreateTransactionReply;
  66 import org.opendaylight.controller.cluster.datastore.messages.ForwardedReadyTransaction;
  67 import org.opendaylight.controller.cluster.datastore.messages.GetShardDataTree;
  68 import org.opendaylight.controller.cluster.datastore.messages.OnDemandShardState;
  69 import org.opendaylight.controller.cluster.datastore.messages.PeerAddressResolved;
  70 import org.opendaylight.controller.cluster.datastore.messages.PersistAbortTransactionPayload;
  71 import org.opendaylight.controller.cluster.datastore.messages.ReadyLocalTransaction;
  72 import org.opendaylight.controller.cluster.datastore.messages.RegisterChangeListener;
  73 import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeChangeListener;
  74 import org.opendaylight.controller.cluster.datastore.messages.ShardLeaderStateChanged;
  75 import org.opendaylight.controller.cluster.datastore.messages.UpdateSchemaContext;
  76 import org.opendaylight.controller.cluster.datastore.persisted.AbortTransactionPayload;
  77 import org.opendaylight.controller.cluster.datastore.persisted.DatastoreSnapshot;
  78 import org.opendaylight.controller.cluster.datastore.persisted.DatastoreSnapshot.ShardSnapshot;
  79 import org.opendaylight.controller.cluster.datastore.utils.Dispatchers;
  80 import org.opendaylight.controller.cluster.notifications.LeaderStateChanged;
  81 import org.opendaylight.controller.cluster.notifications.RegisterRoleChangeListener;
  82 import org.opendaylight.controller.cluster.notifications.RoleChangeNotifier;
  83 import org.opendaylight.controller.cluster.raft.RaftActor;
  84 import org.opendaylight.controller.cluster.raft.RaftActorRecoveryCohort;
  85 import org.opendaylight.controller.cluster.raft.RaftActorSnapshotCohort;
  86 import org.opendaylight.controller.cluster.raft.RaftState;
  87 import org.opendaylight.controller.cluster.raft.base.messages.FollowerInitialSyncUpStatus;
  88 import org.opendaylight.controller.cluster.raft.client.messages.OnDemandRaftState;
  89 import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply;
  90 import org.opendaylight.controller.cluster.raft.messages.ServerRemoved;
  91 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.Payload;
  92 import org.opendaylight.yangtools.concepts.Identifier;
  93 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
  94 import org.opendaylight.yangtools.yang.data.api.schema.tree.TipProducingDataTree;
  95 import org.opendaylight.yangtools.yang.data.api.schema.tree.TreeType;
  96 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  97 import scala.concurrent.duration.Duration;
  98 import scala.concurrent.duration.FiniteDuration;
  99
 100 /**
 101  * A Shard represents a portion of the logical data tree.
 102  *
 103  * <p>
 104  * Our Shard uses InMemoryDataTree as it's internal representation and delegates all requests it
 105  */
 106 public class Shard extends RaftActor {
 107
 108     @VisibleForTesting
 109     static final Object TX_COMMIT_TIMEOUT_CHECK_MESSAGE = new Object() {
 110         @Override
 111         public String toString() {
 112             return "txCommitTimeoutCheck";
 113         }
 114     };
 115
 116     @VisibleForTesting
 117     static final Object GET_SHARD_MBEAN_MESSAGE = new Object() {
 118         @Override
 119         public String toString() {
 120             return "getShardMBeanMessage";
 121         }
 122     };
 123
 124     // FIXME: shard names should be encapsulated in their own class and this should be exposed as a constant.
 125     public static final String DEFAULT_NAME = "default";
 126
 127     private static final Collection<ABIVersion> SUPPORTED_ABIVERSIONS;
 128
 129     static {
 130         final ABIVersion[] values = ABIVersion.values();
 131         final ABIVersion[] real = Arrays.copyOfRange(values, 1, values.length - 1);
 132         SUPPORTED_ABIVERSIONS = ImmutableList.copyOf(real).reverse();
 133     }
 134
 135     // FIXME: make this a dynamic property based on mailbox size and maximum number of clients
 136     private static final int CLIENT_MAX_MESSAGES = 1000;
 137
 138     // The state of this Shard
 139     private final ShardDataTree store;
 140
 141     /// The name of this shard
 142     private final String name;
 143
 144     private final ShardStats shardMBean;
 145
 146     private DatastoreContext datastoreContext;
 147
 148     private final ShardCommitCoordinator commitCoordinator;
 149
 150     private long transactionCommitTimeout;
 151
 152     private Cancellable txCommitTimeoutCheckSchedule;
 153
 154     private final Optional<ActorRef> roleChangeNotifier;
 155
 156     private final MessageTracker appendEntriesReplyTracker;
 157
 158     private final ShardTransactionActorFactory transactionActorFactory;
 159
 160     private final ShardSnapshotCohort snapshotCohort;
 161
 162     private final DataTreeChangeListenerSupport treeChangeSupport = new DataTreeChangeListenerSupport(this);
 163     private final DataChangeListenerSupport changeSupport = new DataChangeListenerSupport(this);
 164
 165
 166     private ShardSnapshot restoreFromSnapshot;
 167
 168     private final ShardTransactionMessageRetrySupport messageRetrySupport;
 169
 170     private final FrontendMetadata frontendMetadata;
 171     private Map<FrontendIdentifier, LeaderFrontendState> knownFrontends = ImmutableMap.of();
 172
 173     protected Shard(final AbstractBuilder<?, ?> builder) {
 174         super(builder.getId().toString(), builder.getPeerAddresses(),
 175                 Optional.of(builder.getDatastoreContext().getShardRaftConfig()), DataStoreVersions.CURRENT_VERSION);
 176
 177         this.name = builder.getId().toString();
 178         this.datastoreContext = builder.getDatastoreContext();
 179         this.restoreFromSnapshot = builder.getRestoreFromSnapshot();
 180         this.frontendMetadata = new FrontendMetadata(name);
 181
 182         setPersistence(datastoreContext.isPersistent());
 183
 184         LOG.info("Shard created : {}, persistent : {}", name, datastoreContext.isPersistent());
 185
 186         ShardDataTreeChangeListenerPublisherActorProxy treeChangeListenerPublisher =
 187                 new ShardDataTreeChangeListenerPublisherActorProxy(getContext(), name + "-DTCL-publisher");
 188         ShardDataChangeListenerPublisherActorProxy dataChangeListenerPublisher =
 189                 new ShardDataChangeListenerPublisherActorProxy(getContext(), name + "-DCL-publisher");
 190         if (builder.getDataTree() != null) {
 191             store = new ShardDataTree(this, builder.getSchemaContext(), builder.getDataTree(),
 192                     treeChangeListenerPublisher, dataChangeListenerPublisher, name, frontendMetadata);
 193         } else {
 194             store = new ShardDataTree(this, builder.getSchemaContext(), builder.getTreeType(),
 195                     builder.getDatastoreContext().getStoreRoot(), treeChangeListenerPublisher,
 196                     dataChangeListenerPublisher, name, frontendMetadata);
 197         }
 198
 199         shardMBean = ShardMBeanFactory.getShardStatsMBean(name, datastoreContext.getDataStoreMXBeanType(), this);
 200
 201         if (isMetricsCaptureEnabled()) {
 202             getContext().become(new MeteringBehavior(this));
 203         }
 204
 205         commitCoordinator = new ShardCommitCoordinator(store, LOG, this.name);
 206
 207         setTransactionCommitTimeout();
 208
 209         // create a notifier actor for each cluster member
 210         roleChangeNotifier = createRoleChangeNotifier(name);
 211
 212         appendEntriesReplyTracker = new MessageTracker(AppendEntriesReply.class,
 213                 getRaftActorContext().getConfigParams().getIsolatedCheckIntervalInMillis());
 214
 215         transactionActorFactory = new ShardTransactionActorFactory(store, datastoreContext,
 216             new Dispatchers(context().system().dispatchers()).getDispatcherPath(Dispatchers.DispatcherType.Transaction),
 217                 self(), getContext(), shardMBean, builder.getId().getShardName());
 218
 219         snapshotCohort = ShardSnapshotCohort.create(getContext(), builder.getId().getMemberName(), store, LOG,
 220             this.name);
 221
 222         messageRetrySupport = new ShardTransactionMessageRetrySupport(this);
 223     }
 224
 225     private void setTransactionCommitTimeout() {
 226         transactionCommitTimeout = TimeUnit.MILLISECONDS.convert(
 227                 datastoreContext.getShardTransactionCommitTimeoutInSeconds(), TimeUnit.SECONDS) / 2;
 228     }
 229
 230     private Optional<ActorRef> createRoleChangeNotifier(final String shardId) {
 231         ActorRef shardRoleChangeNotifier = this.getContext().actorOf(
 232             RoleChangeNotifier.getProps(shardId), shardId + "-notifier");
 233         return Optional.of(shardRoleChangeNotifier);
 234     }
 235
 236     @Override
 237     public void postStop() {
 238         LOG.info("Stopping Shard {}", persistenceId());
 239
 240         super.postStop();
 241
 242         messageRetrySupport.close();
 243
 244         if (txCommitTimeoutCheckSchedule != null) {
 245             txCommitTimeoutCheckSchedule.cancel();
 246         }
 247
 248         commitCoordinator.abortPendingTransactions("Transaction aborted due to shutdown.", this);
 249
 250         shardMBean.unregisterMBean();
 251     }
 252
 253     @Override
 254     protected void handleRecover(final Object message) {
 255         LOG.debug("{}: onReceiveRecover: Received message {} from {}", persistenceId(), message.getClass(),
 256             getSender());
 257
 258         super.handleRecover(message);
 259         if (LOG.isTraceEnabled()) {
 260             appendEntriesReplyTracker.begin();
 261         }
 262     }
 263
 264     @SuppressWarnings("checkstyle:IllegalCatch")
 265     @Override
 266     protected void handleNonRaftCommand(final Object message) {
 267         try (MessageTracker.Context context = appendEntriesReplyTracker.received(message)) {
 268             final Optional<Error> maybeError = context.error();
 269             if (maybeError.isPresent()) {
 270                 LOG.trace("{} : AppendEntriesReply failed to arrive at the expected interval {}", persistenceId(),
 271                     maybeError.get());
 272             }
 273
 274             if (message instanceof RequestEnvelope) {
 275                 final long now = ticker().read();
 276                 final RequestEnvelope envelope = (RequestEnvelope)message;
 277
 278                 try {
 279                     final RequestSuccess<?, ?> success = handleRequest(envelope, now);
 280                     if (success != null) {
 281                         envelope.sendSuccess(success, ticker().read() - now);
 282                     }
 283                 } catch (RequestException e) {
 284                     LOG.debug("{}: request {} failed", persistenceId(), envelope, e);
 285                     envelope.sendFailure(e, ticker().read() - now);
 286                 } catch (Exception e) {
 287                     LOG.debug("{}: request {} caused failure", persistenceId(), envelope, e);
 288                     envelope.sendFailure(new RuntimeRequestException("Request failed to process", e),
 289                         ticker().read() - now);
 290                 }
 291             } else if (message instanceof ConnectClientRequest) {
 292                 handleConnectClient((ConnectClientRequest)message);
 293             } else if (CreateTransaction.isSerializedType(message)) {
 294                 handleCreateTransaction(message);
 295             } else if (message instanceof BatchedModifications) {
 296                 handleBatchedModifications((BatchedModifications)message);
 297             } else if (message instanceof ForwardedReadyTransaction) {
 298                 handleForwardedReadyTransaction((ForwardedReadyTransaction) message);
 299             } else if (message instanceof ReadyLocalTransaction) {
 300                 handleReadyLocalTransaction((ReadyLocalTransaction)message);
 301             } else if (CanCommitTransaction.isSerializedType(message)) {
 302                 handleCanCommitTransaction(CanCommitTransaction.fromSerializable(message));
 303             } else if (CommitTransaction.isSerializedType(message)) {
 304                 handleCommitTransaction(CommitTransaction.fromSerializable(message));
 305             } else if (AbortTransaction.isSerializedType(message)) {
 306                 handleAbortTransaction(AbortTransaction.fromSerializable(message));
 307             } else if (CloseTransactionChain.isSerializedType(message)) {
 308                 closeTransactionChain(CloseTransactionChain.fromSerializable(message));
 309             } else if (message instanceof RegisterChangeListener) {
 310                 changeSupport.onMessage((RegisterChangeListener) message, isLeader(), hasLeader());
 311             } else if (message instanceof RegisterDataTreeChangeListener) {
 312                 treeChangeSupport.onMessage((RegisterDataTreeChangeListener) message, isLeader(), hasLeader());
 313             } else if (message instanceof UpdateSchemaContext) {
 314                 updateSchemaContext((UpdateSchemaContext) message);
 315             } else if (message instanceof PeerAddressResolved) {
 316                 PeerAddressResolved resolved = (PeerAddressResolved) message;
 317                 setPeerAddress(resolved.getPeerId(), resolved.getPeerAddress());
 318             } else if (TX_COMMIT_TIMEOUT_CHECK_MESSAGE.equals(message)) {
 319                 store.checkForExpiredTransactions(transactionCommitTimeout);
 320                 commitCoordinator.checkForExpiredTransactions(transactionCommitTimeout, this);
 321             } else if (message instanceof DatastoreContext) {
 322                 onDatastoreContext((DatastoreContext)message);
 323             } else if (message instanceof RegisterRoleChangeListener) {
 324                 roleChangeNotifier.get().forward(message, context());
 325             } else if (message instanceof FollowerInitialSyncUpStatus) {
 326                 shardMBean.setFollowerInitialSyncStatus(((FollowerInitialSyncUpStatus) message).isInitialSyncDone());
 327                 context().parent().tell(message, self());
 328             } else if (GET_SHARD_MBEAN_MESSAGE.equals(message)) {
 329                 sender().tell(getShardMBean(), self());
 330             } else if (message instanceof GetShardDataTree) {
 331                 sender().tell(store.getDataTree(), self());
 332             } else if (message instanceof ServerRemoved) {
 333                 context().parent().forward(message, context());
 334             } else if (ShardTransactionMessageRetrySupport.TIMER_MESSAGE_CLASS.isInstance(message)) {
 335                 messageRetrySupport.onTimerMessage(message);
 336             } else if (message instanceof DataTreeCohortActorRegistry.CohortRegistryCommand) {
 337                 store.processCohortRegistryCommand(getSender(),
 338                         (DataTreeCohortActorRegistry.CohortRegistryCommand) message);
 339             } else if (message instanceof PersistAbortTransactionPayload) {
 340                 final TransactionIdentifier txId = ((PersistAbortTransactionPayload) message).getTransactionId();
 341                 persistPayload(txId, AbortTransactionPayload.create(txId), true);
 342             } else {
 343                 super.handleNonRaftCommand(message);
 344             }
 345         }
 346     }
 347
 348     // Acquire our frontend tracking handle and verify generation matches
 349     private LeaderFrontendState getFrontend(final ClientIdentifier clientId) throws RequestException {
 350         final LeaderFrontendState existing = knownFrontends.get(clientId.getFrontendId());
 351         if (existing != null) {
 352             final int cmp = Long.compareUnsigned(existing.getIdentifier().getGeneration(), clientId.getGeneration());
 353             if (cmp == 0) {
 354                 return existing;
 355             }
 356             if (cmp > 0) {
 357                 LOG.debug("{}: rejecting request from outdated client {}", persistenceId(), clientId);
 358                 throw new RetiredGenerationException(existing.getIdentifier().getGeneration());
 359             }
 360
 361             LOG.info("{}: retiring state {}, outdated by request from client {}", persistenceId(), existing, clientId);
 362             existing.retire();
 363             knownFrontends.remove(clientId.getFrontendId());
 364         } else {
 365             LOG.debug("{}: client {} is not yet known", persistenceId(), clientId);
 366         }
 367
 368         final LeaderFrontendState ret = new LeaderFrontendState(persistenceId(), clientId, store);
 369         knownFrontends.put(clientId.getFrontendId(), ret);
 370         LOG.debug("{}: created state {} for client {}", persistenceId(), ret, clientId);
 371         return ret;
 372     }
 373
 374     private static @Nonnull ABIVersion selectVersion(final ConnectClientRequest message) {
 375         final Range<ABIVersion> clientRange = Range.closed(message.getMinVersion(), message.getMaxVersion());
 376         for (ABIVersion v : SUPPORTED_ABIVERSIONS) {
 377             if (clientRange.contains(v)) {
 378                 return v;
 379             }
 380         }
 381
 382         throw new IllegalArgumentException(String.format(
 383             "No common version between backend versions %s and client versions %s", SUPPORTED_ABIVERSIONS,
 384             clientRange));
 385     }
 386
 387     @SuppressWarnings("checkstyle:IllegalCatch")
 388     private void handleConnectClient(final ConnectClientRequest message) {
 389         try {
 390             if (!isLeader() || !isLeaderActive()) {
 391                 LOG.debug("{}: not currently leader, rejecting request {}", persistenceId(), message);
 392                 throw new NotLeaderException(getSelf());
 393             }
 394
 395             final ABIVersion selectedVersion = selectVersion(message);
 396             final LeaderFrontendState frontend = getFrontend(message.getTarget());
 397             frontend.reconnect();
 398             message.getReplyTo().tell(new ConnectClientSuccess(message.getTarget(), message.getSequence(), getSelf(),
 399                 ImmutableList.of(), store.getDataTree(), CLIENT_MAX_MESSAGES).toVersion(selectedVersion),
 400                 ActorRef.noSender());
 401         } catch (RequestException | RuntimeException e) {
 402             message.getReplyTo().tell(new Failure(e), ActorRef.noSender());
 403         }
 404     }
 405
 406     private @Nullable RequestSuccess<?, ?> handleRequest(final RequestEnvelope envelope, final long now)
 407             throws RequestException {
 408         // We are not the leader, hence we want to fail-fast.
 409         if (!isLeader() || !isLeaderActive()) {
 410             LOG.debug("{}: not currently leader, rejecting request {}", persistenceId(), envelope);
 411             throw new NotLeaderException(getSelf());
 412         }
 413
 414         final Request<?, ?> request = envelope.getMessage();
 415         if (request instanceof TransactionRequest) {
 416             final TransactionRequest<?> txReq = (TransactionRequest<?>)request;
 417             final ClientIdentifier clientId = txReq.getTarget().getHistoryId().getClientId();
 418             return getFrontend(clientId).handleTransactionRequest(txReq, envelope, now);
 419         } else if (request instanceof LocalHistoryRequest) {
 420             final LocalHistoryRequest<?> lhReq = (LocalHistoryRequest<?>)request;
 421             final ClientIdentifier clientId = lhReq.getTarget().getClientId();
 422             return getFrontend(clientId).handleLocalHistoryRequest(lhReq, envelope, now);
 423         } else {
 424             LOG.debug("{}: rejecting unsupported request {}", persistenceId(), request);
 425             throw new UnsupportedRequestException(request);
 426         }
 427     }
 428
 429     private boolean hasLeader() {
 430         return getLeaderId() != null;
 431     }
 432
 433     public int getPendingTxCommitQueueSize() {
 434         return store.getQueueSize();
 435     }
 436
 437     public int getCohortCacheSize() {
 438         return commitCoordinator.getCohortCacheSize();
 439     }
 440
 441     @Override
 442     protected Optional<ActorRef> getRoleChangeNotifier() {
 443         return roleChangeNotifier;
 444     }
 445
 446     @Override
 447     protected LeaderStateChanged newLeaderStateChanged(final String memberId, final String leaderId,
 448             final short leaderPayloadVersion) {
 449         return isLeader() ? new ShardLeaderStateChanged(memberId, leaderId, store.getDataTree(), leaderPayloadVersion)
 450                 : new ShardLeaderStateChanged(memberId, leaderId, leaderPayloadVersion);
 451     }
 452
 453     protected void onDatastoreContext(final DatastoreContext context) {
 454         datastoreContext = context;
 455
 456         setTransactionCommitTimeout();
 457
 458         setPersistence(datastoreContext.isPersistent());
 459
 460         updateConfigParams(datastoreContext.getShardRaftConfig());
 461     }
 462
 463     // applyState() will be invoked once consensus is reached on the payload
 464     void persistPayload(final Identifier id, final Payload payload, final boolean batchHint) {
 465         boolean canSkipPayload = !hasFollowers() && !persistence().isRecoveryApplicable();
 466         if (canSkipPayload) {
 467             applyState(self(), id, payload);
 468         } else {
 469             // We are faking the sender
 470             persistData(self(), id, payload, batchHint);
 471         }
 472     }
 473
 474     private void handleCommitTransaction(final CommitTransaction commit) {
 475         if (isLeader()) {
 476             commitCoordinator.handleCommit(commit.getTransactionId(), getSender(), this);
 477         } else {
 478             ActorSelection leader = getLeader();
 479             if (leader == null) {
 480                 messageRetrySupport.addMessageToRetry(commit, getSender(),
 481                         "Could not commit transaction " + commit.getTransactionId());
 482             } else {
 483                 LOG.debug("{}: Forwarding CommitTransaction to leader {}", persistenceId(), leader);
 484                 leader.forward(commit, getContext());
 485             }
 486         }
 487     }
 488
 489     private void handleCanCommitTransaction(final CanCommitTransaction canCommit) {
 490         LOG.debug("{}: Can committing transaction {}", persistenceId(), canCommit.getTransactionId());
 491
 492         if (isLeader()) {
 493             commitCoordinator.handleCanCommit(canCommit.getTransactionId(), getSender(), this);
 494         } else {
 495             ActorSelection leader = getLeader();
 496             if (leader == null) {
 497                 messageRetrySupport.addMessageToRetry(canCommit, getSender(),
 498                         "Could not canCommit transaction " + canCommit.getTransactionId());
 499             } else {
 500                 LOG.debug("{}: Forwarding CanCommitTransaction to leader {}", persistenceId(), leader);
 501                 leader.forward(canCommit, getContext());
 502             }
 503         }
 504     }
 505
 506     @SuppressWarnings("checkstyle:IllegalCatch")
 507     protected void handleBatchedModificationsLocal(final BatchedModifications batched, final ActorRef sender) {
 508         try {
 509             commitCoordinator.handleBatchedModifications(batched, sender, this);
 510         } catch (Exception e) {
 511             LOG.error("{}: Error handling BatchedModifications for Tx {}", persistenceId(),
 512                     batched.getTransactionId(), e);
 513             sender.tell(new Failure(e), getSelf());
 514         }
 515     }
 516
 517     private void handleBatchedModifications(final BatchedModifications batched) {
 518         // This message is sent to prepare the modifications transaction directly on the Shard as an
 519         // optimization to avoid the extra overhead of a separate ShardTransaction actor. On the last
 520         // BatchedModifications message, the caller sets the ready flag in the message indicating
 521         // modifications are complete. The reply contains the cohort actor path (this actor) for the caller
 522         // to initiate the 3-phase commit. This also avoids the overhead of sending an additional
 523         // ReadyTransaction message.
 524
 525         // If we're not the leader then forward to the leader. This is a safety measure - we shouldn't
 526         // normally get here if we're not the leader as the front-end (TransactionProxy) should determine
 527         // the primary/leader shard. However with timing and caching on the front-end, there's a small
 528         // window where it could have a stale leader during leadership transitions.
 529         //
 530         boolean isLeaderActive = isLeaderActive();
 531         if (isLeader() && isLeaderActive) {
 532             handleBatchedModificationsLocal(batched, getSender());
 533         } else {
 534             ActorSelection leader = getLeader();
 535             if (!isLeaderActive || leader == null) {
 536                 messageRetrySupport.addMessageToRetry(batched, getSender(),
 537                         "Could not commit transaction " + batched.getTransactionId());
 538             } else {
 539                 // If this is not the first batch and leadership changed in between batched messages,
 540                 // we need to reconstruct previous BatchedModifications from the transaction
 541                 // DataTreeModification, honoring the max batched modification count, and forward all the
 542                 // previous BatchedModifications to the new leader.
 543                 Collection<BatchedModifications> newModifications = commitCoordinator
 544                         .createForwardedBatchedModifications(batched,
 545                                 datastoreContext.getShardBatchedModificationCount());
 546
 547                 LOG.debug("{}: Forwarding {} BatchedModifications to leader {}", persistenceId(),
 548                         newModifications.size(), leader);
 549
 550                 for (BatchedModifications bm : newModifications) {
 551                     leader.forward(bm, getContext());
 552                 }
 553             }
 554         }
 555     }
 556
 557     private boolean failIfIsolatedLeader(final ActorRef sender) {
 558         if (isIsolatedLeader()) {
 559             sender.tell(new Failure(new NoShardLeaderException(String.format(
 560                     "Shard %s was the leader but has lost contact with all of its followers. Either all"
 561                     + " other follower nodes are down or this node is isolated by a network partition.",
 562                     persistenceId()))), getSelf());
 563             return true;
 564         }
 565
 566         return false;
 567     }
 568
 569     protected boolean isIsolatedLeader() {
 570         return getRaftState() == RaftState.IsolatedLeader;
 571     }
 572
 573     @SuppressWarnings("checkstyle:IllegalCatch")
 574     private void handleReadyLocalTransaction(final ReadyLocalTransaction message) {
 575         LOG.debug("{}: handleReadyLocalTransaction for {}", persistenceId(), message.getTransactionId());
 576
 577         boolean isLeaderActive = isLeaderActive();
 578         if (isLeader() && isLeaderActive) {
 579             try {
 580                 commitCoordinator.handleReadyLocalTransaction(message, getSender(), this);
 581             } catch (Exception e) {
 582                 LOG.error("{}: Error handling ReadyLocalTransaction for Tx {}", persistenceId(),
 583                         message.getTransactionId(), e);
 584                 getSender().tell(new Failure(e), getSelf());
 585             }
 586         } else {
 587             ActorSelection leader = getLeader();
 588             if (!isLeaderActive || leader == null) {
 589                 messageRetrySupport.addMessageToRetry(message, getSender(),
 590                         "Could not commit transaction " + message.getTransactionId());
 591             } else {
 592                 LOG.debug("{}: Forwarding ReadyLocalTransaction to leader {}", persistenceId(), leader);
 593                 message.setRemoteVersion(getCurrentBehavior().getLeaderPayloadVersion());
 594                 leader.forward(message, getContext());
 595             }
 596         }
 597     }
 598
 599     private void handleForwardedReadyTransaction(final ForwardedReadyTransaction forwardedReady) {
 600         LOG.debug("{}: handleForwardedReadyTransaction for {}", persistenceId(), forwardedReady.getTransactionId());
 601
 602         boolean isLeaderActive = isLeaderActive();
 603         if (isLeader() && isLeaderActive) {
 604             commitCoordinator.handleForwardedReadyTransaction(forwardedReady, getSender(), this);
 605         } else {
 606             ActorSelection leader = getLeader();
 607             if (!isLeaderActive || leader == null) {
 608                 messageRetrySupport.addMessageToRetry(forwardedReady, getSender(),
 609                         "Could not commit transaction " + forwardedReady.getTransactionId());
 610             } else {
 611                 LOG.debug("{}: Forwarding ForwardedReadyTransaction to leader {}", persistenceId(), leader);
 612
 613                 ReadyLocalTransaction readyLocal = new ReadyLocalTransaction(forwardedReady.getTransactionId(),
 614                         forwardedReady.getTransaction().getSnapshot(), forwardedReady.isDoImmediateCommit());
 615                 readyLocal.setRemoteVersion(getCurrentBehavior().getLeaderPayloadVersion());
 616                 leader.forward(readyLocal, getContext());
 617             }
 618         }
 619     }
 620
 621     private void handleAbortTransaction(final AbortTransaction abort) {
 622         doAbortTransaction(abort.getTransactionId(), getSender());
 623     }
 624
 625     void doAbortTransaction(final Identifier transactionID, final ActorRef sender) {
 626         commitCoordinator.handleAbort(transactionID, sender, this);
 627     }
 628
 629     private void handleCreateTransaction(final Object message) {
 630         if (isLeader()) {
 631             createTransaction(CreateTransaction.fromSerializable(message));
 632         } else if (getLeader() != null) {
 633             getLeader().forward(message, getContext());
 634         } else {
 635             getSender().tell(new Failure(new NoShardLeaderException(
 636                     "Could not create a shard transaction", persistenceId())), getSelf());
 637         }
 638     }
 639
 640     private void closeTransactionChain(final CloseTransactionChain closeTransactionChain) {
 641         final LocalHistoryIdentifier id = closeTransactionChain.getIdentifier();
 642         store.closeTransactionChain(id, null);
 643         store.purgeTransactionChain(id, null);
 644     }
 645
 646     @SuppressWarnings("checkstyle:IllegalCatch")
 647     private void createTransaction(final CreateTransaction createTransaction) {
 648         try {
 649             if (TransactionType.fromInt(createTransaction.getTransactionType()) != TransactionType.READ_ONLY
 650                     && failIfIsolatedLeader(getSender())) {
 651                 return;
 652             }
 653
 654             ActorRef transactionActor = createTransaction(createTransaction.getTransactionType(),
 655                 createTransaction.getTransactionId());
 656
 657             getSender().tell(new CreateTransactionReply(Serialization.serializedActorPath(transactionActor),
 658                     createTransaction.getTransactionId(), createTransaction.getVersion()).toSerializable(), getSelf());
 659         } catch (Exception e) {
 660             getSender().tell(new Failure(e), getSelf());
 661         }
 662     }
 663
 664     private ActorRef createTransaction(final int transactionType, final TransactionIdentifier transactionId) {
 665         LOG.debug("{}: Creating transaction : {} ", persistenceId(), transactionId);
 666         return transactionActorFactory.newShardTransaction(TransactionType.fromInt(transactionType),
 667             transactionId);
 668     }
 669
 670     private void updateSchemaContext(final UpdateSchemaContext message) {
 671         updateSchemaContext(message.getSchemaContext());
 672     }
 673
 674     @VisibleForTesting
 675     void updateSchemaContext(final SchemaContext schemaContext) {
 676         store.updateSchemaContext(schemaContext);
 677     }
 678
 679     private boolean isMetricsCaptureEnabled() {
 680         CommonConfig config = new CommonConfig(getContext().system().settings().config());
 681         return config.isMetricCaptureEnabled();
 682     }
 683
 684     @Override
 685     @VisibleForTesting
 686     public RaftActorSnapshotCohort getRaftActorSnapshotCohort() {
 687         return snapshotCohort;
 688     }
 689
 690     @Override
 691     @Nonnull
 692     protected RaftActorRecoveryCohort getRaftActorRecoveryCohort() {
 693         return new ShardRecoveryCoordinator(store,
 694             restoreFromSnapshot != null ? restoreFromSnapshot.getSnapshot() : null, persistenceId(), LOG);
 695     }
 696
 697     @Override
 698     protected void onRecoveryComplete() {
 699         restoreFromSnapshot = null;
 700
 701         //notify shard manager
 702         getContext().parent().tell(new ActorInitialized(), getSelf());
 703
 704         // Being paranoid here - this method should only be called once but just in case...
 705         if (txCommitTimeoutCheckSchedule == null) {
 706             // Schedule a message to be periodically sent to check if the current in-progress
 707             // transaction should be expired and aborted.
 708             FiniteDuration period = Duration.create(transactionCommitTimeout / 3, TimeUnit.MILLISECONDS);
 709             txCommitTimeoutCheckSchedule = getContext().system().scheduler().schedule(
 710                     period, period, getSelf(),
 711                     TX_COMMIT_TIMEOUT_CHECK_MESSAGE, getContext().dispatcher(), ActorRef.noSender());
 712         }
 713     }
 714
 715     @Override
 716     protected void applyState(final ActorRef clientActor, final Identifier identifier, final Object data) {
 717         if (data instanceof Payload) {
 718             try {
 719                 store.applyReplicatedPayload(identifier, (Payload)data);
 720             } catch (DataValidationFailedException | IOException e) {
 721                 LOG.error("{}: Error applying replica {}", persistenceId(), identifier, e);
 722             }
 723         } else {
 724             LOG.error("{}: Unknown state for {} received {}", persistenceId(), identifier, data);
 725         }
 726     }
 727
 728     @Override
 729     protected void onStateChanged() {
 730         boolean isLeader = isLeader();
 731         boolean hasLeader = hasLeader();
 732         changeSupport.onLeadershipChange(isLeader, hasLeader);
 733         treeChangeSupport.onLeadershipChange(isLeader, hasLeader);
 734
 735         // If this actor is no longer the leader close all the transaction chains
 736         if (!isLeader) {
 737             if (LOG.isDebugEnabled()) {
 738                 LOG.debug(
 739                     "{}: onStateChanged: Closing all transaction chains because shard {} is no longer the leader",
 740                     persistenceId(), getId());
 741             }
 742
 743             store.purgeLeaderState();
 744         }
 745
 746         if (hasLeader && !isIsolatedLeader()) {
 747             messageRetrySupport.retryMessages();
 748         }
 749     }
 750
 751     @Override
 752     protected void onLeaderChanged(final String oldLeader, final String newLeader) {
 753         shardMBean.incrementLeadershipChangeCount();
 754
 755         final boolean hasLeader = hasLeader();
 756         if (!hasLeader) {
 757             // No leader implies we are not the leader, lose frontend state if we have any. This also places
 758             // an explicit guard so the map will not get modified accidentally.
 759             if (!knownFrontends.isEmpty()) {
 760                 LOG.debug("{}: removing frontend state for {}", persistenceId(), knownFrontends.keySet());
 761                 knownFrontends = ImmutableMap.of();
 762             }
 763             return;
 764         }
 765
 766         if (!isLeader()) {
 767             // Another leader was elected. If we were the previous leader and had pending transactions, convert
 768             // them to transaction messages and send to the new leader.
 769             ActorSelection leader = getLeader();
 770             if (leader != null) {
 771                 Collection<?> messagesToForward = convertPendingTransactionsToMessages();
 772
 773                 if (!messagesToForward.isEmpty()) {
 774                     LOG.debug("{}: Forwarding {} pending transaction messages to leader {}", persistenceId(),
 775                             messagesToForward.size(), leader);
 776
 777                     for (Object message : messagesToForward) {
 778                         leader.tell(message, self());
 779                     }
 780                 }
 781             } else {
 782                 commitCoordinator.abortPendingTransactions("The transacton was aborted due to inflight leadership "
 783                         + "change and the leader address isn't available.", this);
 784             }
 785         } else {
 786             // We have become the leader, we need to reconstruct frontend state
 787             knownFrontends = Verify.verifyNotNull(frontendMetadata.toLeaderState(this));
 788             LOG.debug("{}: became leader with frontend state for {}", persistenceId(), knownFrontends.keySet());
 789         }
 790
 791         if (!isIsolatedLeader()) {
 792             messageRetrySupport.retryMessages();
 793         }
 794     }
 795
 796     /**
 797      * Clears all pending transactions and converts them to messages to be forwarded to a new leader.
 798      *
 799      * @return the converted messages
 800      */
 801     public Collection<?> convertPendingTransactionsToMessages() {
 802         return commitCoordinator.convertPendingTransactionsToMessages(
 803                 datastoreContext.getShardBatchedModificationCount());
 804     }
 805
 806     @Override
 807     protected void pauseLeader(final Runnable operation) {
 808         LOG.debug("{}: In pauseLeader, operation: {}", persistenceId(), operation);
 809         store.setRunOnPendingTransactionsComplete(operation);
 810     }
 811
 812     @Override
 813     protected OnDemandRaftState.AbstractBuilder<?> newOnDemandRaftStateBuilder() {
 814         return OnDemandShardState.newBuilder().treeChangeListenerActors(treeChangeSupport.getListenerActors())
 815                 .dataChangeListenerActors(changeSupport.getListenerActors())
 816                 .commitCohortActors(store.getCohortActors());
 817     }
 818
 819     @Override
 820     public String persistenceId() {
 821         return this.name;
 822     }
 823
 824     @VisibleForTesting
 825     ShardCommitCoordinator getCommitCoordinator() {
 826         return commitCoordinator;
 827     }
 828
 829     public DatastoreContext getDatastoreContext() {
 830         return datastoreContext;
 831     }
 832
 833     @VisibleForTesting
 834     public ShardDataTree getDataStore() {
 835         return store;
 836     }
 837
 838     @VisibleForTesting
 839     ShardStats getShardMBean() {
 840         return shardMBean;
 841     }
 842
 843     public static Builder builder() {
 844         return new Builder();
 845     }
 846
 847     public abstract static class AbstractBuilder<T extends AbstractBuilder<T, S>, S extends Shard> {
 848         private final Class<S> shardClass;
 849         private ShardIdentifier id;
 850         private Map<String, String> peerAddresses = Collections.emptyMap();
 851         private DatastoreContext datastoreContext;
 852         private SchemaContext schemaContext;
 853         private DatastoreSnapshot.ShardSnapshot restoreFromSnapshot;
 854         private TipProducingDataTree dataTree;
 855         private volatile boolean sealed;
 856
 857         protected AbstractBuilder(final Class<S> shardClass) {
 858             this.shardClass = shardClass;
 859         }
 860
 861         protected void checkSealed() {
 862             Preconditions.checkState(!sealed, "Builder isalready sealed - further modifications are not allowed");
 863         }
 864
 865         @SuppressWarnings("unchecked")
 866         private T self() {
 867             return (T) this;
 868         }
 869
 870         public T id(final ShardIdentifier newId) {
 871             checkSealed();
 872             this.id = newId;
 873             return self();
 874         }
 875
 876         public T peerAddresses(final Map<String, String> newPeerAddresses) {
 877             checkSealed();
 878             this.peerAddresses = newPeerAddresses;
 879             return self();
 880         }
 881
 882         public T datastoreContext(final DatastoreContext newDatastoreContext) {
 883             checkSealed();
 884             this.datastoreContext = newDatastoreContext;
 885             return self();
 886         }
 887
 888         public T schemaContext(final SchemaContext newSchemaContext) {
 889             checkSealed();
 890             this.schemaContext = newSchemaContext;
 891             return self();
 892         }
 893
 894         public T restoreFromSnapshot(final DatastoreSnapshot.ShardSnapshot newRestoreFromSnapshot) {
 895             checkSealed();
 896             this.restoreFromSnapshot = newRestoreFromSnapshot;
 897             return self();
 898         }
 899
 900         public T dataTree(final TipProducingDataTree newDataTree) {
 901             checkSealed();
 902             this.dataTree = newDataTree;
 903             return self();
 904         }
 905
 906         public ShardIdentifier getId() {
 907             return id;
 908         }
 909
 910         public Map<String, String> getPeerAddresses() {
 911             return peerAddresses;
 912         }
 913
 914         public DatastoreContext getDatastoreContext() {
 915             return datastoreContext;
 916         }
 917
 918         public SchemaContext getSchemaContext() {
 919             return schemaContext;
 920         }
 921
 922         public DatastoreSnapshot.ShardSnapshot getRestoreFromSnapshot() {
 923             return restoreFromSnapshot;
 924         }
 925
 926         public TipProducingDataTree getDataTree() {
 927             return dataTree;
 928         }
 929
 930         public TreeType getTreeType() {
 931             switch (datastoreContext.getLogicalStoreType()) {
 932                 case CONFIGURATION:
 933                     return TreeType.CONFIGURATION;
 934                 case OPERATIONAL:
 935                     return TreeType.OPERATIONAL;
 936                 default:
 937                     throw new IllegalStateException("Unhandled logical store type "
 938                             + datastoreContext.getLogicalStoreType());
 939             }
 940         }
 941
 942         protected void verify() {
 943             Preconditions.checkNotNull(id, "id should not be null");
 944             Preconditions.checkNotNull(peerAddresses, "peerAddresses should not be null");
 945             Preconditions.checkNotNull(datastoreContext, "dataStoreContext should not be null");
 946             Preconditions.checkNotNull(schemaContext, "schemaContext should not be null");
 947         }
 948
 949         public Props props() {
 950             sealed = true;
 951             verify();
 952             return Props.create(shardClass, this);
 953         }
 954     }
 955
 956     public static class Builder extends AbstractBuilder<Builder, Shard> {
 957         private Builder() {
 958             super(Shard.class);
 959         }
 960     }
 961
 962     Ticker ticker() {
 963         return Ticker.systemTicker();
 964     }
 965 }