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;
  16 import akka.actor.Status.Failure;
  17 import akka.serialization.Serialization;
  18 import com.google.common.annotations.VisibleForTesting;
  19 import com.google.common.base.Optional;
  20 import com.google.common.base.Preconditions;
  21 import com.google.common.base.Ticker;
  22 import com.google.common.base.Verify;
  23 import com.google.common.collect.ImmutableList;
  24 import com.google.common.collect.ImmutableMap;
  25 import com.google.common.collect.Range;
  26 import java.io.IOException;
  27 import java.util.Arrays;
  28 import java.util.Collection;
  29 import java.util.Collections;
  30 import java.util.Map;
  31 import java.util.concurrent.TimeUnit;
  32 import javax.annotation.Nonnull;
  33 import javax.annotation.Nullable;
  34 import org.opendaylight.controller.cluster.access.ABIVersion;
  35 import org.opendaylight.controller.cluster.access.commands.ConnectClientRequest;
  36 import org.opendaylight.controller.cluster.access.commands.ConnectClientSuccess;
  37 import org.opendaylight.controller.cluster.access.commands.LocalHistoryRequest;
  38 import org.opendaylight.controller.cluster.access.commands.NotLeaderException;
  39 import org.opendaylight.controller.cluster.access.commands.TransactionRequest;
  40 import org.opendaylight.controller.cluster.access.concepts.ClientIdentifier;
  41 import org.opendaylight.controller.cluster.access.concepts.FrontendIdentifier;
  42 import org.opendaylight.controller.cluster.access.concepts.LocalHistoryIdentifier;
  43 import org.opendaylight.controller.cluster.access.concepts.Request;
  44 import org.opendaylight.controller.cluster.access.concepts.RequestEnvelope;
  45 import org.opendaylight.controller.cluster.access.concepts.RequestException;
  46 import org.opendaylight.controller.cluster.access.concepts.RequestSuccess;
  47 import org.opendaylight.controller.cluster.access.concepts.RetiredGenerationException;
  48 import org.opendaylight.controller.cluster.access.concepts.RuntimeRequestException;
  49 import org.opendaylight.controller.cluster.access.concepts.SliceableMessage;
  50 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  51 import org.opendaylight.controller.cluster.access.concepts.UnsupportedRequestException;
  52 import org.opendaylight.controller.cluster.common.actor.CommonConfig;
  53 import org.opendaylight.controller.cluster.common.actor.Dispatchers;
  54 import org.opendaylight.controller.cluster.common.actor.Dispatchers.DispatcherType;
  55 import org.opendaylight.controller.cluster.common.actor.MessageTracker;
  56 import org.opendaylight.controller.cluster.common.actor.MessageTracker.Error;
  57 import org.opendaylight.controller.cluster.common.actor.MeteringBehavior;
  58 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
  59 import org.opendaylight.controller.cluster.datastore.identifiers.ShardIdentifier;
  60 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardMBeanFactory;
  61 import org.opendaylight.controller.cluster.datastore.jmx.mbeans.shard.ShardStats;
  62 import org.opendaylight.controller.cluster.datastore.messages.AbortTransaction;
  63 import org.opendaylight.controller.cluster.datastore.messages.ActorInitialized;
  64 import org.opendaylight.controller.cluster.datastore.messages.BatchedModifications;
  65 import org.opendaylight.controller.cluster.datastore.messages.CanCommitTransaction;
  66 import org.opendaylight.controller.cluster.datastore.messages.CloseTransactionChain;
  67 import org.opendaylight.controller.cluster.datastore.messages.CommitTransaction;
  68 import org.opendaylight.controller.cluster.datastore.messages.CreateTransaction;
  69 import org.opendaylight.controller.cluster.datastore.messages.CreateTransactionReply;
  70 import org.opendaylight.controller.cluster.datastore.messages.ForwardedReadyTransaction;
  71 import org.opendaylight.controller.cluster.datastore.messages.GetShardDataTree;
  72 import org.opendaylight.controller.cluster.datastore.messages.MakeLeaderLocal;
  73 import org.opendaylight.controller.cluster.datastore.messages.OnDemandShardState;
  74 import org.opendaylight.controller.cluster.datastore.messages.PeerAddressResolved;
  75 import org.opendaylight.controller.cluster.datastore.messages.PersistAbortTransactionPayload;
  76 import org.opendaylight.controller.cluster.datastore.messages.ReadyLocalTransaction;
  77 import org.opendaylight.controller.cluster.datastore.messages.RegisterChangeListener;
  78 import org.opendaylight.controller.cluster.datastore.messages.RegisterDataTreeChangeListener;
  79 import org.opendaylight.controller.cluster.datastore.messages.ShardLeaderStateChanged;
  80 import org.opendaylight.controller.cluster.datastore.messages.UpdateSchemaContext;
  81 import org.opendaylight.controller.cluster.datastore.persisted.AbortTransactionPayload;
  82 import org.opendaylight.controller.cluster.datastore.persisted.DatastoreSnapshot;
  83 import org.opendaylight.controller.cluster.datastore.persisted.DatastoreSnapshot.ShardSnapshot;
  84 import org.opendaylight.controller.cluster.messaging.MessageSlicer;
  85 import org.opendaylight.controller.cluster.messaging.SliceOptions;
  86 import org.opendaylight.controller.cluster.notifications.LeaderStateChanged;
  87 import org.opendaylight.controller.cluster.notifications.RegisterRoleChangeListener;
  88 import org.opendaylight.controller.cluster.notifications.RoleChangeNotifier;
  89 import org.opendaylight.controller.cluster.raft.LeadershipTransferFailedException;
  90 import org.opendaylight.controller.cluster.raft.RaftActor;
  91 import org.opendaylight.controller.cluster.raft.RaftActorRecoveryCohort;
  92 import org.opendaylight.controller.cluster.raft.RaftActorSnapshotCohort;
  93 import org.opendaylight.controller.cluster.raft.RaftState;
  94 import org.opendaylight.controller.cluster.raft.base.messages.FollowerInitialSyncUpStatus;
  95 import org.opendaylight.controller.cluster.raft.client.messages.OnDemandRaftState;
  96 import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply;
  97 import org.opendaylight.controller.cluster.raft.messages.RequestLeadership;
  98 import org.opendaylight.controller.cluster.raft.messages.ServerRemoved;
  99 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.Payload;
 100 import org.opendaylight.yangtools.concepts.Identifier;
 101 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
 102 import org.opendaylight.yangtools.yang.data.api.schema.tree.TipProducingDataTree;
 103 import org.opendaylight.yangtools.yang.data.api.schema.tree.TreeType;
 104 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
 105 import org.opendaylight.yangtools.yang.model.api.SchemaContextProvider;
 106 import scala.concurrent.duration.Duration;
 107 import scala.concurrent.duration.FiniteDuration;
 108
 109 /**
 110  * A Shard represents a portion of the logical data tree.
 111  *
 112  * <p>
 113  * Our Shard uses InMemoryDataTree as it's internal representation and delegates all requests it
 114  */
 115 public class Shard extends RaftActor {
 116
 117     @VisibleForTesting
 118     static final Object TX_COMMIT_TIMEOUT_CHECK_MESSAGE = new Object() {
 119         @Override
 120         public String toString() {
 121             return "txCommitTimeoutCheck";
 122         }
 123     };
 124
 125     @VisibleForTesting
 126     static final Object GET_SHARD_MBEAN_MESSAGE = new Object() {
 127         @Override
 128         public String toString() {
 129             return "getShardMBeanMessage";
 130         }
 131     };
 132
 133     static final Object RESUME_NEXT_PENDING_TRANSACTION = new Object() {
 134         @Override
 135         public String toString() {
 136             return "resumeNextPendingTransaction";
 137         }
 138     };
 139
 140     // FIXME: shard names should be encapsulated in their own class and this should be exposed as a constant.
 141     public static final String DEFAULT_NAME = "default";
 142
 143     private static final Collection<ABIVersion> SUPPORTED_ABIVERSIONS;
 144
 145     static {
 146         final ABIVersion[] values = ABIVersion.values();
 147         final ABIVersion[] real = Arrays.copyOfRange(values, 1, values.length - 1);
 148         SUPPORTED_ABIVERSIONS = ImmutableList.copyOf(real).reverse();
 149     }
 150
 151     // FIXME: make this a dynamic property based on mailbox size and maximum number of clients
 152     private static final int CLIENT_MAX_MESSAGES = 1000;
 153
 154     // The state of this Shard
 155     private final ShardDataTree store;
 156
 157     /// The name of this shard
 158     private final String name;
 159
 160     private final ShardStats shardMBean;
 161
 162     private DatastoreContext datastoreContext;
 163
 164     private final ShardCommitCoordinator commitCoordinator;
 165
 166     private long transactionCommitTimeout;
 167
 168     private Cancellable txCommitTimeoutCheckSchedule;
 169
 170     private final Optional<ActorRef> roleChangeNotifier;
 171
 172     private final MessageTracker appendEntriesReplyTracker;
 173
 174     private final ShardTransactionActorFactory transactionActorFactory;
 175
 176     private final ShardSnapshotCohort snapshotCohort;
 177
 178     private final DataTreeChangeListenerSupport treeChangeSupport = new DataTreeChangeListenerSupport(this);
 179     private final DataChangeListenerSupport changeSupport = new DataChangeListenerSupport(this);
 180
 181
 182     private ShardSnapshot restoreFromSnapshot;
 183
 184     private final ShardTransactionMessageRetrySupport messageRetrySupport;
 185
 186     private final FrontendMetadata frontendMetadata;
 187     private Map<FrontendIdentifier, LeaderFrontendState> knownFrontends = ImmutableMap.of();
 188
 189     private final MessageSlicer responseMessageSlicer;
 190     private final Dispatchers dispatchers;
 191
 192     protected Shard(final AbstractBuilder<?, ?> builder) {
 193         super(builder.getId().toString(), builder.getPeerAddresses(),
 194                 Optional.of(builder.getDatastoreContext().getShardRaftConfig()), DataStoreVersions.CURRENT_VERSION);
 195
 196         this.name = builder.getId().toString();
 197         this.datastoreContext = builder.getDatastoreContext();
 198         this.restoreFromSnapshot = builder.getRestoreFromSnapshot();
 199         this.frontendMetadata = new FrontendMetadata(name);
 200
 201         setPersistence(datastoreContext.isPersistent());
 202
 203         LOG.info("Shard created : {}, persistent : {}", name, datastoreContext.isPersistent());
 204
 205         ShardDataTreeChangeListenerPublisherActorProxy treeChangeListenerPublisher =
 206                 new ShardDataTreeChangeListenerPublisherActorProxy(getContext(), name + "-DTCL-publisher", name);
 207         ShardDataChangeListenerPublisherActorProxy dataChangeListenerPublisher =
 208                 new ShardDataChangeListenerPublisherActorProxy(getContext(), name + "-DCL-publisher", name);
 209         if (builder.getDataTree() != null) {
 210             store = new ShardDataTree(this, builder.getSchemaContext(), builder.getDataTree(),
 211                     treeChangeListenerPublisher, dataChangeListenerPublisher, name, frontendMetadata);
 212         } else {
 213             store = new ShardDataTree(this, builder.getSchemaContext(), builder.getTreeType(),
 214                     builder.getDatastoreContext().getStoreRoot(), treeChangeListenerPublisher,
 215                     dataChangeListenerPublisher, name, frontendMetadata);
 216         }
 217
 218         shardMBean = ShardMBeanFactory.getShardStatsMBean(name, datastoreContext.getDataStoreMXBeanType(), this);
 219
 220         if (isMetricsCaptureEnabled()) {
 221             getContext().become(new MeteringBehavior(this));
 222         }
 223
 224         commitCoordinator = new ShardCommitCoordinator(store, LOG, this.name);
 225
 226         setTransactionCommitTimeout();
 227
 228         // create a notifier actor for each cluster member
 229         roleChangeNotifier = createRoleChangeNotifier(name);
 230
 231         appendEntriesReplyTracker = new MessageTracker(AppendEntriesReply.class,
 232                 getRaftActorContext().getConfigParams().getIsolatedCheckIntervalInMillis());
 233
 234         dispatchers = new Dispatchers(context().system().dispatchers());
 235         transactionActorFactory = new ShardTransactionActorFactory(store, datastoreContext,
 236             dispatchers.getDispatcherPath(Dispatchers.DispatcherType.Transaction),
 237                 self(), getContext(), shardMBean, builder.getId().getShardName());
 238
 239         snapshotCohort = ShardSnapshotCohort.create(getContext(), builder.getId().getMemberName(), store, LOG,
 240             this.name);
 241
 242         messageRetrySupport = new ShardTransactionMessageRetrySupport(this);
 243
 244         responseMessageSlicer = MessageSlicer.builder().logContext(this.name)
 245                 .messageSliceSize(datastoreContext.getMaximumMessageSliceSize())
 246                 .fileBackedStreamFactory(getRaftActorContext().getFileBackedOutputStreamFactory())
 247                 .expireStateAfterInactivity(2, TimeUnit.MINUTES).build();
 248     }
 249
 250     private void setTransactionCommitTimeout() {
 251         transactionCommitTimeout = TimeUnit.MILLISECONDS.convert(
 252                 datastoreContext.getShardTransactionCommitTimeoutInSeconds(), TimeUnit.SECONDS) / 2;
 253     }
 254
 255     private Optional<ActorRef> createRoleChangeNotifier(final String shardId) {
 256         ActorRef shardRoleChangeNotifier = this.getContext().actorOf(
 257             RoleChangeNotifier.getProps(shardId), shardId + "-notifier");
 258         return Optional.of(shardRoleChangeNotifier);
 259     }
 260
 261     @Override
 262     public void postStop() {
 263         LOG.info("Stopping Shard {}", persistenceId());
 264
 265         super.postStop();
 266
 267         messageRetrySupport.close();
 268
 269         if (txCommitTimeoutCheckSchedule != null) {
 270             txCommitTimeoutCheckSchedule.cancel();
 271         }
 272
 273         commitCoordinator.abortPendingTransactions("Transaction aborted due to shutdown.", this);
 274
 275         shardMBean.unregisterMBean();
 276     }
 277
 278     @Override
 279     protected void handleRecover(final Object message) {
 280         LOG.debug("{}: onReceiveRecover: Received message {} from {}", persistenceId(), message.getClass(),
 281             getSender());
 282
 283         super.handleRecover(message);
 284         if (LOG.isTraceEnabled()) {
 285             appendEntriesReplyTracker.begin();
 286         }
 287     }
 288
 289     @Override
 290     protected void handleNonRaftCommand(final Object message) {
 291         try (MessageTracker.Context context = appendEntriesReplyTracker.received(message)) {
 292             final Optional<Error> maybeError = context.error();
 293             if (maybeError.isPresent()) {
 294                 LOG.trace("{} : AppendEntriesReply failed to arrive at the expected interval {}", persistenceId(),
 295                     maybeError.get());
 296             }
 297
 298             store.resetTransactionBatch();
 299
 300             if (message instanceof RequestEnvelope) {
 301                 handleRequestEnvelope((RequestEnvelope)message);
 302             } else if (message instanceof ConnectClientRequest) {
 303                 handleConnectClient((ConnectClientRequest)message);
 304             } else if (CreateTransaction.isSerializedType(message)) {
 305                 handleCreateTransaction(message);
 306             } else if (message instanceof BatchedModifications) {
 307                 handleBatchedModifications((BatchedModifications)message);
 308             } else if (message instanceof ForwardedReadyTransaction) {
 309                 handleForwardedReadyTransaction((ForwardedReadyTransaction) message);
 310             } else if (message instanceof ReadyLocalTransaction) {
 311                 handleReadyLocalTransaction((ReadyLocalTransaction)message);
 312             } else if (CanCommitTransaction.isSerializedType(message)) {
 313                 handleCanCommitTransaction(CanCommitTransaction.fromSerializable(message));
 314             } else if (CommitTransaction.isSerializedType(message)) {
 315                 handleCommitTransaction(CommitTransaction.fromSerializable(message));
 316             } else if (AbortTransaction.isSerializedType(message)) {
 317                 handleAbortTransaction(AbortTransaction.fromSerializable(message));
 318             } else if (CloseTransactionChain.isSerializedType(message)) {
 319                 closeTransactionChain(CloseTransactionChain.fromSerializable(message));
 320             } else if (message instanceof RegisterChangeListener) {
 321                 changeSupport.onMessage((RegisterChangeListener) message, isLeader(), hasLeader());
 322             } else if (message instanceof RegisterDataTreeChangeListener) {
 323                 treeChangeSupport.onMessage((RegisterDataTreeChangeListener) message, isLeader(), hasLeader());
 324             } else if (message instanceof UpdateSchemaContext) {
 325                 updateSchemaContext((UpdateSchemaContext) message);
 326             } else if (message instanceof PeerAddressResolved) {
 327                 PeerAddressResolved resolved = (PeerAddressResolved) message;
 328                 setPeerAddress(resolved.getPeerId(), resolved.getPeerAddress());
 329             } else if (TX_COMMIT_TIMEOUT_CHECK_MESSAGE.equals(message)) {
 330                 store.checkForExpiredTransactions(transactionCommitTimeout);
 331                 commitCoordinator.checkForExpiredTransactions(transactionCommitTimeout, this);
 332             } else if (message instanceof DatastoreContext) {
 333                 onDatastoreContext((DatastoreContext)message);
 334             } else if (message instanceof RegisterRoleChangeListener) {
 335                 roleChangeNotifier.get().forward(message, context());
 336             } else if (message instanceof FollowerInitialSyncUpStatus) {
 337                 shardMBean.setFollowerInitialSyncStatus(((FollowerInitialSyncUpStatus) message).isInitialSyncDone());
 338                 context().parent().tell(message, self());
 339             } else if (GET_SHARD_MBEAN_MESSAGE.equals(message)) {
 340                 sender().tell(getShardMBean(), self());
 341             } else if (message instanceof GetShardDataTree) {
 342                 sender().tell(store.getDataTree(), self());
 343             } else if (message instanceof ServerRemoved) {
 344                 context().parent().forward(message, context());
 345             } else if (ShardTransactionMessageRetrySupport.TIMER_MESSAGE_CLASS.isInstance(message)) {
 346                 messageRetrySupport.onTimerMessage(message);
 347             } else if (message instanceof DataTreeCohortActorRegistry.CohortRegistryCommand) {
 348                 store.processCohortRegistryCommand(getSender(),
 349                         (DataTreeCohortActorRegistry.CohortRegistryCommand) message);
 350             } else if (message instanceof PersistAbortTransactionPayload) {
 351                 final TransactionIdentifier txId = ((PersistAbortTransactionPayload) message).getTransactionId();
 352                 persistPayload(txId, AbortTransactionPayload.create(txId), true);
 353             } else if (message instanceof MakeLeaderLocal) {
 354                 onMakeLeaderLocal();
 355             } else if (RESUME_NEXT_PENDING_TRANSACTION.equals(message)) {
 356                 store.resumeNextPendingTransaction();
 357             } else if (!responseMessageSlicer.handleMessage(message)) {
 358                 super.handleNonRaftCommand(message);
 359             }
 360         }
 361     }
 362
 363     @SuppressWarnings("checkstyle:IllegalCatch")
 364     private void handleRequestEnvelope(final RequestEnvelope envelope) {
 365         final long now = ticker().read();
 366         try {
 367             final RequestSuccess<?, ?> success = handleRequest(envelope, now);
 368             if (success != null) {
 369                 final long executionTimeNanos = ticker().read() - now;
 370                 if (success instanceof SliceableMessage) {
 371                     dispatchers.getDispatcher(DispatcherType.Serialization).execute(() ->
 372                         responseMessageSlicer.slice(SliceOptions.builder().identifier(success.getTarget())
 373                             .message(envelope.newSuccessEnvelope(success, executionTimeNanos))
 374                             .sendTo(envelope.getMessage().getReplyTo()).replyTo(self())
 375                             .onFailureCallback(t -> {
 376                                 LOG.warn("Error slicing response {}", success, t);
 377                             }).build()));
 378                 } else {
 379                     envelope.sendSuccess(success, executionTimeNanos);
 380                 }
 381             }
 382         } catch (RequestException e) {
 383             LOG.debug("{}: request {} failed", persistenceId(), envelope, e);
 384             envelope.sendFailure(e, ticker().read() - now);
 385         } catch (Exception e) {
 386             LOG.debug("{}: request {} caused failure", persistenceId(), envelope, e);
 387             envelope.sendFailure(new RuntimeRequestException("Request failed to process", e),
 388                 ticker().read() - now);
 389         }
 390     }
 391
 392     private void onMakeLeaderLocal() {
 393         LOG.debug("{}: onMakeLeaderLocal received", persistenceId());
 394         if (isLeader()) {
 395             getSender().tell(new Status.Success(null), getSelf());
 396             return;
 397         }
 398
 399         final ActorSelection leader = getLeader();
 400
 401         if (leader == null) {
 402             // Leader is not present. The cluster is most likely trying to
 403             // elect a leader and we should let that run its normal course
 404
 405             // TODO we can wait for the election to complete and retry the
 406             // request. We can also let the caller retry by sending a flag
 407             // in the response indicating the request is "reTryable".
 408             getSender().tell(new Failure(
 409                     new LeadershipTransferFailedException("We cannot initiate leadership transfer to local node. "
 410                             + "Currently there is no leader for " + persistenceId())),
 411                     getSelf());
 412             return;
 413         }
 414
 415         leader.tell(new RequestLeadership(getId(), getSender()), getSelf());
 416     }
 417
 418     // Acquire our frontend tracking handle and verify generation matches
 419     private LeaderFrontendState getFrontend(final ClientIdentifier clientId) throws RequestException {
 420         final LeaderFrontendState existing = knownFrontends.get(clientId.getFrontendId());
 421         if (existing != null) {
 422             final int cmp = Long.compareUnsigned(existing.getIdentifier().getGeneration(), clientId.getGeneration());
 423             if (cmp == 0) {
 424                 return existing;
 425             }
 426             if (cmp > 0) {
 427                 LOG.debug("{}: rejecting request from outdated client {}", persistenceId(), clientId);
 428                 throw new RetiredGenerationException(existing.getIdentifier().getGeneration());
 429             }
 430
 431             LOG.info("{}: retiring state {}, outdated by request from client {}", persistenceId(), existing, clientId);
 432             existing.retire();
 433             knownFrontends.remove(clientId.getFrontendId());
 434         } else {
 435             LOG.debug("{}: client {} is not yet known", persistenceId(), clientId);
 436         }
 437
 438         final LeaderFrontendState ret = new LeaderFrontendState(persistenceId(), clientId, store);
 439         knownFrontends.put(clientId.getFrontendId(), ret);
 440         LOG.debug("{}: created state {} for client {}", persistenceId(), ret, clientId);
 441         return ret;
 442     }
 443
 444     private static @Nonnull ABIVersion selectVersion(final ConnectClientRequest message) {
 445         final Range<ABIVersion> clientRange = Range.closed(message.getMinVersion(), message.getMaxVersion());
 446         for (ABIVersion v : SUPPORTED_ABIVERSIONS) {
 447             if (clientRange.contains(v)) {
 448                 return v;
 449             }
 450         }
 451
 452         throw new IllegalArgumentException(String.format(
 453             "No common version between backend versions %s and client versions %s", SUPPORTED_ABIVERSIONS,
 454             clientRange));
 455     }
 456
 457     @SuppressWarnings("checkstyle:IllegalCatch")
 458     private void handleConnectClient(final ConnectClientRequest message) {
 459         try {
 460             if (!isLeader() || !isLeaderActive()) {
 461                 LOG.info("{}: not currently leader, rejecting request {}. isLeader: {}, isLeaderActive: {},"
 462                                 + "isLeadershipTransferInProgress: {}.",
 463                         persistenceId(), message, isLeader(), isLeaderActive(), isLeadershipTransferInProgress());
 464                 throw new NotLeaderException(getSelf());
 465             }
 466
 467             final ABIVersion selectedVersion = selectVersion(message);
 468             final LeaderFrontendState frontend = getFrontend(message.getTarget());
 469             frontend.reconnect();
 470             message.getReplyTo().tell(new ConnectClientSuccess(message.getTarget(), message.getSequence(), getSelf(),
 471                 ImmutableList.of(), store.getDataTree(), CLIENT_MAX_MESSAGES).toVersion(selectedVersion),
 472                 ActorRef.noSender());
 473         } catch (RequestException | RuntimeException e) {
 474             message.getReplyTo().tell(new Failure(e), ActorRef.noSender());
 475         }
 476     }
 477
 478     private @Nullable RequestSuccess<?, ?> handleRequest(final RequestEnvelope envelope, final long now)
 479             throws RequestException {
 480         // We are not the leader, hence we want to fail-fast.
 481         if (!isLeader() || !isLeaderActive()) {
 482             LOG.info("{}: not currently leader, rejecting request {}. isLeader: {}, isLeaderActive: {},"
 483                             + "isLeadershipTransferInProgress: {}.",
 484                     persistenceId(), envelope, isLeader(), isLeaderActive(), isLeadershipTransferInProgress());
 485             throw new NotLeaderException(getSelf());
 486         }
 487
 488         final Request<?, ?> request = envelope.getMessage();
 489         if (request instanceof TransactionRequest) {
 490             final TransactionRequest<?> txReq = (TransactionRequest<?>)request;
 491             final ClientIdentifier clientId = txReq.getTarget().getHistoryId().getClientId();
 492             return getFrontend(clientId).handleTransactionRequest(txReq, envelope, now);
 493         } else if (request instanceof LocalHistoryRequest) {
 494             final LocalHistoryRequest<?> lhReq = (LocalHistoryRequest<?>)request;
 495             final ClientIdentifier clientId = lhReq.getTarget().getClientId();
 496             return getFrontend(clientId).handleLocalHistoryRequest(lhReq, envelope, now);
 497         } else {
 498             LOG.warn("{}: rejecting unsupported request {}", persistenceId(), request);
 499             throw new UnsupportedRequestException(request);
 500         }
 501     }
 502
 503     private boolean hasLeader() {
 504         return getLeaderId() != null;
 505     }
 506
 507     public int getPendingTxCommitQueueSize() {
 508         return store.getQueueSize();
 509     }
 510
 511     public int getCohortCacheSize() {
 512         return commitCoordinator.getCohortCacheSize();
 513     }
 514
 515     @Override
 516     protected Optional<ActorRef> getRoleChangeNotifier() {
 517         return roleChangeNotifier;
 518     }
 519
 520     @Override
 521     protected LeaderStateChanged newLeaderStateChanged(final String memberId, final String leaderId,
 522             final short leaderPayloadVersion) {
 523         return isLeader() ? new ShardLeaderStateChanged(memberId, leaderId, store.getDataTree(), leaderPayloadVersion)
 524                 : new ShardLeaderStateChanged(memberId, leaderId, leaderPayloadVersion);
 525     }
 526
 527     protected void onDatastoreContext(final DatastoreContext context) {
 528         datastoreContext = context;
 529
 530         setTransactionCommitTimeout();
 531
 532         setPersistence(datastoreContext.isPersistent());
 533
 534         updateConfigParams(datastoreContext.getShardRaftConfig());
 535     }
 536
 537     // applyState() will be invoked once consensus is reached on the payload
 538     void persistPayload(final Identifier id, final Payload payload, final boolean batchHint) {
 539         boolean canSkipPayload = !hasFollowers() && !persistence().isRecoveryApplicable();
 540         if (canSkipPayload) {
 541             applyState(self(), id, payload);
 542         } else {
 543             // We are faking the sender
 544             persistData(self(), id, payload, batchHint);
 545         }
 546     }
 547
 548     private void handleCommitTransaction(final CommitTransaction commit) {
 549         if (isLeader()) {
 550             commitCoordinator.handleCommit(commit.getTransactionId(), getSender(), this);
 551         } else {
 552             ActorSelection leader = getLeader();
 553             if (leader == null) {
 554                 messageRetrySupport.addMessageToRetry(commit, getSender(),
 555                         "Could not commit transaction " + commit.getTransactionId());
 556             } else {
 557                 LOG.debug("{}: Forwarding CommitTransaction to leader {}", persistenceId(), leader);
 558                 leader.forward(commit, getContext());
 559             }
 560         }
 561     }
 562
 563     private void handleCanCommitTransaction(final CanCommitTransaction canCommit) {
 564         LOG.debug("{}: Can committing transaction {}", persistenceId(), canCommit.getTransactionId());
 565
 566         if (isLeader()) {
 567             commitCoordinator.handleCanCommit(canCommit.getTransactionId(), getSender(), this);
 568         } else {
 569             ActorSelection leader = getLeader();
 570             if (leader == null) {
 571                 messageRetrySupport.addMessageToRetry(canCommit, getSender(),
 572                         "Could not canCommit transaction " + canCommit.getTransactionId());
 573             } else {
 574                 LOG.debug("{}: Forwarding CanCommitTransaction to leader {}", persistenceId(), leader);
 575                 leader.forward(canCommit, getContext());
 576             }
 577         }
 578     }
 579
 580     @SuppressWarnings("checkstyle:IllegalCatch")
 581     protected void handleBatchedModificationsLocal(final BatchedModifications batched, final ActorRef sender) {
 582         try {
 583             commitCoordinator.handleBatchedModifications(batched, sender, this);
 584         } catch (Exception e) {
 585             LOG.error("{}: Error handling BatchedModifications for Tx {}", persistenceId(),
 586                     batched.getTransactionId(), e);
 587             sender.tell(new Failure(e), getSelf());
 588         }
 589     }
 590
 591     private void handleBatchedModifications(final BatchedModifications batched) {
 592         // This message is sent to prepare the modifications transaction directly on the Shard as an
 593         // optimization to avoid the extra overhead of a separate ShardTransaction actor. On the last
 594         // BatchedModifications message, the caller sets the ready flag in the message indicating
 595         // modifications are complete. The reply contains the cohort actor path (this actor) for the caller
 596         // to initiate the 3-phase commit. This also avoids the overhead of sending an additional
 597         // ReadyTransaction message.
 598
 599         // If we're not the leader then forward to the leader. This is a safety measure - we shouldn't
 600         // normally get here if we're not the leader as the front-end (TransactionProxy) should determine
 601         // the primary/leader shard. However with timing and caching on the front-end, there's a small
 602         // window where it could have a stale leader during leadership transitions.
 603         //
 604         boolean isLeaderActive = isLeaderActive();
 605         if (isLeader() && isLeaderActive) {
 606             handleBatchedModificationsLocal(batched, getSender());
 607         } else {
 608             ActorSelection leader = getLeader();
 609             if (!isLeaderActive || leader == null) {
 610                 messageRetrySupport.addMessageToRetry(batched, getSender(),
 611                         "Could not commit transaction " + batched.getTransactionId());
 612             } else {
 613                 // If this is not the first batch and leadership changed in between batched messages,
 614                 // we need to reconstruct previous BatchedModifications from the transaction
 615                 // DataTreeModification, honoring the max batched modification count, and forward all the
 616                 // previous BatchedModifications to the new leader.
 617                 Collection<BatchedModifications> newModifications = commitCoordinator
 618                         .createForwardedBatchedModifications(batched,
 619                                 datastoreContext.getShardBatchedModificationCount());
 620
 621                 LOG.debug("{}: Forwarding {} BatchedModifications to leader {}", persistenceId(),
 622                         newModifications.size(), leader);
 623
 624                 for (BatchedModifications bm : newModifications) {
 625                     leader.forward(bm, getContext());
 626                 }
 627             }
 628         }
 629     }
 630
 631     private boolean failIfIsolatedLeader(final ActorRef sender) {
 632         if (isIsolatedLeader()) {
 633             sender.tell(new Failure(new NoShardLeaderException(String.format(
 634                     "Shard %s was the leader but has lost contact with all of its followers. Either all"
 635                     + " other follower nodes are down or this node is isolated by a network partition.",
 636                     persistenceId()))), getSelf());
 637             return true;
 638         }
 639
 640         return false;
 641     }
 642
 643     protected boolean isIsolatedLeader() {
 644         return getRaftState() == RaftState.IsolatedLeader;
 645     }
 646
 647     @SuppressWarnings("checkstyle:IllegalCatch")
 648     private void handleReadyLocalTransaction(final ReadyLocalTransaction message) {
 649         LOG.debug("{}: handleReadyLocalTransaction for {}", persistenceId(), message.getTransactionId());
 650
 651         boolean isLeaderActive = isLeaderActive();
 652         if (isLeader() && isLeaderActive) {
 653             try {
 654                 commitCoordinator.handleReadyLocalTransaction(message, getSender(), this);
 655             } catch (Exception e) {
 656                 LOG.error("{}: Error handling ReadyLocalTransaction for Tx {}", persistenceId(),
 657                         message.getTransactionId(), e);
 658                 getSender().tell(new Failure(e), getSelf());
 659             }
 660         } else {
 661             ActorSelection leader = getLeader();
 662             if (!isLeaderActive || leader == null) {
 663                 messageRetrySupport.addMessageToRetry(message, getSender(),
 664                         "Could not commit transaction " + message.getTransactionId());
 665             } else {
 666                 LOG.debug("{}: Forwarding ReadyLocalTransaction to leader {}", persistenceId(), leader);
 667                 message.setRemoteVersion(getCurrentBehavior().getLeaderPayloadVersion());
 668                 leader.forward(message, getContext());
 669             }
 670         }
 671     }
 672
 673     private void handleForwardedReadyTransaction(final ForwardedReadyTransaction forwardedReady) {
 674         LOG.debug("{}: handleForwardedReadyTransaction for {}", persistenceId(), forwardedReady.getTransactionId());
 675
 676         boolean isLeaderActive = isLeaderActive();
 677         if (isLeader() && isLeaderActive) {
 678             commitCoordinator.handleForwardedReadyTransaction(forwardedReady, getSender(), this);
 679         } else {
 680             ActorSelection leader = getLeader();
 681             if (!isLeaderActive || leader == null) {
 682                 messageRetrySupport.addMessageToRetry(forwardedReady, getSender(),
 683                         "Could not commit transaction " + forwardedReady.getTransactionId());
 684             } else {
 685                 LOG.debug("{}: Forwarding ForwardedReadyTransaction to leader {}", persistenceId(), leader);
 686
 687                 ReadyLocalTransaction readyLocal = new ReadyLocalTransaction(forwardedReady.getTransactionId(),
 688                         forwardedReady.getTransaction().getSnapshot(), forwardedReady.isDoImmediateCommit());
 689                 readyLocal.setRemoteVersion(getCurrentBehavior().getLeaderPayloadVersion());
 690                 leader.forward(readyLocal, getContext());
 691             }
 692         }
 693     }
 694
 695     private void handleAbortTransaction(final AbortTransaction abort) {
 696         doAbortTransaction(abort.getTransactionId(), getSender());
 697     }
 698
 699     void doAbortTransaction(final Identifier transactionID, final ActorRef sender) {
 700         commitCoordinator.handleAbort(transactionID, sender, this);
 701     }
 702
 703     private void handleCreateTransaction(final Object message) {
 704         if (isLeader()) {
 705             createTransaction(CreateTransaction.fromSerializable(message));
 706         } else if (getLeader() != null) {
 707             getLeader().forward(message, getContext());
 708         } else {
 709             getSender().tell(new Failure(new NoShardLeaderException(
 710                     "Could not create a shard transaction", persistenceId())), getSelf());
 711         }
 712     }
 713
 714     private void closeTransactionChain(final CloseTransactionChain closeTransactionChain) {
 715         final LocalHistoryIdentifier id = closeTransactionChain.getIdentifier();
 716         store.closeTransactionChain(id, null);
 717         store.purgeTransactionChain(id, null);
 718     }
 719
 720     @SuppressWarnings("checkstyle:IllegalCatch")
 721     private void createTransaction(final CreateTransaction createTransaction) {
 722         try {
 723             if (TransactionType.fromInt(createTransaction.getTransactionType()) != TransactionType.READ_ONLY
 724                     && failIfIsolatedLeader(getSender())) {
 725                 return;
 726             }
 727
 728             ActorRef transactionActor = createTransaction(createTransaction.getTransactionType(),
 729                 createTransaction.getTransactionId());
 730
 731             getSender().tell(new CreateTransactionReply(Serialization.serializedActorPath(transactionActor),
 732                     createTransaction.getTransactionId(), createTransaction.getVersion()).toSerializable(), getSelf());
 733         } catch (Exception e) {
 734             getSender().tell(new Failure(e), getSelf());
 735         }
 736     }
 737
 738     private ActorRef createTransaction(final int transactionType, final TransactionIdentifier transactionId) {
 739         LOG.debug("{}: Creating transaction : {} ", persistenceId(), transactionId);
 740         return transactionActorFactory.newShardTransaction(TransactionType.fromInt(transactionType),
 741             transactionId);
 742     }
 743
 744     private void updateSchemaContext(final UpdateSchemaContext message) {
 745         updateSchemaContext(message.getSchemaContext());
 746     }
 747
 748     @VisibleForTesting
 749     void updateSchemaContext(final SchemaContext schemaContext) {
 750         store.updateSchemaContext(schemaContext);
 751     }
 752
 753     private boolean isMetricsCaptureEnabled() {
 754         CommonConfig config = new CommonConfig(getContext().system().settings().config());
 755         return config.isMetricCaptureEnabled();
 756     }
 757
 758     @Override
 759     @VisibleForTesting
 760     public RaftActorSnapshotCohort getRaftActorSnapshotCohort() {
 761         return snapshotCohort;
 762     }
 763
 764     @Override
 765     @Nonnull
 766     protected RaftActorRecoveryCohort getRaftActorRecoveryCohort() {
 767         return new ShardRecoveryCoordinator(store,
 768             restoreFromSnapshot != null ? restoreFromSnapshot.getSnapshot() : null, persistenceId(), LOG);
 769     }
 770
 771     @Override
 772     protected void onRecoveryComplete() {
 773         restoreFromSnapshot = null;
 774
 775         //notify shard manager
 776         getContext().parent().tell(new ActorInitialized(), getSelf());
 777
 778         // Being paranoid here - this method should only be called once but just in case...
 779         if (txCommitTimeoutCheckSchedule == null) {
 780             // Schedule a message to be periodically sent to check if the current in-progress
 781             // transaction should be expired and aborted.
 782             FiniteDuration period = Duration.create(transactionCommitTimeout / 3, TimeUnit.MILLISECONDS);
 783             txCommitTimeoutCheckSchedule = getContext().system().scheduler().schedule(
 784                     period, period, getSelf(),
 785                     TX_COMMIT_TIMEOUT_CHECK_MESSAGE, getContext().dispatcher(), ActorRef.noSender());
 786         }
 787     }
 788
 789     @Override
 790     protected void applyState(final ActorRef clientActor, final Identifier identifier, final Object data) {
 791         if (data instanceof Payload) {
 792             try {
 793                 store.applyReplicatedPayload(identifier, (Payload)data);
 794             } catch (DataValidationFailedException | IOException e) {
 795                 LOG.error("{}: Error applying replica {}", persistenceId(), identifier, e);
 796             }
 797         } else {
 798             LOG.error("{}: Unknown state for {} received {}", persistenceId(), identifier, data);
 799         }
 800     }
 801
 802     @Override
 803     protected void onStateChanged() {
 804         boolean isLeader = isLeader();
 805         boolean hasLeader = hasLeader();
 806         changeSupport.onLeadershipChange(isLeader, hasLeader);
 807         treeChangeSupport.onLeadershipChange(isLeader, hasLeader);
 808
 809         // If this actor is no longer the leader close all the transaction chains
 810         if (!isLeader) {
 811             if (LOG.isDebugEnabled()) {
 812                 LOG.debug(
 813                     "{}: onStateChanged: Closing all transaction chains because shard {} is no longer the leader",
 814                     persistenceId(), getId());
 815             }
 816
 817             store.purgeLeaderState();
 818         }
 819
 820         if (hasLeader && !isIsolatedLeader()) {
 821             messageRetrySupport.retryMessages();
 822         }
 823     }
 824
 825     @Override
 826     protected void onLeaderChanged(final String oldLeader, final String newLeader) {
 827         shardMBean.incrementLeadershipChangeCount();
 828
 829         final boolean hasLeader = hasLeader();
 830         if (!hasLeader) {
 831             // No leader implies we are not the leader, lose frontend state if we have any. This also places
 832             // an explicit guard so the map will not get modified accidentally.
 833             if (!knownFrontends.isEmpty()) {
 834                 LOG.debug("{}: removing frontend state for {}", persistenceId(), knownFrontends.keySet());
 835                 knownFrontends = ImmutableMap.of();
 836             }
 837             return;
 838         }
 839
 840         if (!isLeader()) {
 841             // Another leader was elected. If we were the previous leader and had pending transactions, convert
 842             // them to transaction messages and send to the new leader.
 843             ActorSelection leader = getLeader();
 844             if (leader != null) {
 845                 Collection<?> messagesToForward = convertPendingTransactionsToMessages();
 846
 847                 if (!messagesToForward.isEmpty()) {
 848                     LOG.debug("{}: Forwarding {} pending transaction messages to leader {}", persistenceId(),
 849                             messagesToForward.size(), leader);
 850
 851                     for (Object message : messagesToForward) {
 852                         leader.tell(message, self());
 853                     }
 854                 }
 855             } else {
 856                 commitCoordinator.abortPendingTransactions("The transacton was aborted due to inflight leadership "
 857                         + "change and the leader address isn't available.", this);
 858             }
 859         } else {
 860             // We have become the leader, we need to reconstruct frontend state
 861             knownFrontends = Verify.verifyNotNull(frontendMetadata.toLeaderState(this));
 862             LOG.debug("{}: became leader with frontend state for {}", persistenceId(), knownFrontends.keySet());
 863         }
 864
 865         if (!isIsolatedLeader()) {
 866             messageRetrySupport.retryMessages();
 867         }
 868     }
 869
 870     /**
 871      * Clears all pending transactions and converts them to messages to be forwarded to a new leader.
 872      *
 873      * @return the converted messages
 874      */
 875     public Collection<?> convertPendingTransactionsToMessages() {
 876         return commitCoordinator.convertPendingTransactionsToMessages(
 877                 datastoreContext.getShardBatchedModificationCount());
 878     }
 879
 880     @Override
 881     protected void pauseLeader(final Runnable operation) {
 882         LOG.debug("{}: In pauseLeader, operation: {}", persistenceId(), operation);
 883         store.setRunOnPendingTransactionsComplete(operation);
 884     }
 885
 886     @Override
 887     protected OnDemandRaftState.AbstractBuilder<?> newOnDemandRaftStateBuilder() {
 888         return OnDemandShardState.newBuilder().treeChangeListenerActors(treeChangeSupport.getListenerActors())
 889                 .dataChangeListenerActors(changeSupport.getListenerActors())
 890                 .commitCohortActors(store.getCohortActors());
 891     }
 892
 893     @Override
 894     public String persistenceId() {
 895         return this.name;
 896     }
 897
 898     @VisibleForTesting
 899     ShardCommitCoordinator getCommitCoordinator() {
 900         return commitCoordinator;
 901     }
 902
 903     public DatastoreContext getDatastoreContext() {
 904         return datastoreContext;
 905     }
 906
 907     @VisibleForTesting
 908     public ShardDataTree getDataStore() {
 909         return store;
 910     }
 911
 912     @VisibleForTesting
 913     ShardStats getShardMBean() {
 914         return shardMBean;
 915     }
 916
 917     public static Builder builder() {
 918         return new Builder();
 919     }
 920
 921     public abstract static class AbstractBuilder<T extends AbstractBuilder<T, S>, S extends Shard> {
 922         private final Class<S> shardClass;
 923         private ShardIdentifier id;
 924         private Map<String, String> peerAddresses = Collections.emptyMap();
 925         private DatastoreContext datastoreContext;
 926         private SchemaContextProvider schemaContextProvider;
 927         private DatastoreSnapshot.ShardSnapshot restoreFromSnapshot;
 928         private TipProducingDataTree dataTree;
 929         private volatile boolean sealed;
 930
 931         protected AbstractBuilder(final Class<S> shardClass) {
 932             this.shardClass = shardClass;
 933         }
 934
 935         protected void checkSealed() {
 936             Preconditions.checkState(!sealed, "Builder isalready sealed - further modifications are not allowed");
 937         }
 938
 939         @SuppressWarnings("unchecked")
 940         private T self() {
 941             return (T) this;
 942         }
 943
 944         public T id(final ShardIdentifier newId) {
 945             checkSealed();
 946             this.id = newId;
 947             return self();
 948         }
 949
 950         public T peerAddresses(final Map<String, String> newPeerAddresses) {
 951             checkSealed();
 952             this.peerAddresses = newPeerAddresses;
 953             return self();
 954         }
 955
 956         public T datastoreContext(final DatastoreContext newDatastoreContext) {
 957             checkSealed();
 958             this.datastoreContext = newDatastoreContext;
 959             return self();
 960         }
 961
 962         public T schemaContextProvider(final SchemaContextProvider schemaContextProvider) {
 963             checkSealed();
 964             this.schemaContextProvider = Preconditions.checkNotNull(schemaContextProvider);
 965             return self();
 966         }
 967
 968         public T restoreFromSnapshot(final DatastoreSnapshot.ShardSnapshot newRestoreFromSnapshot) {
 969             checkSealed();
 970             this.restoreFromSnapshot = newRestoreFromSnapshot;
 971             return self();
 972         }
 973
 974         public T dataTree(final TipProducingDataTree newDataTree) {
 975             checkSealed();
 976             this.dataTree = newDataTree;
 977             return self();
 978         }
 979
 980         public ShardIdentifier getId() {
 981             return id;
 982         }
 983
 984         public Map<String, String> getPeerAddresses() {
 985             return peerAddresses;
 986         }
 987
 988         public DatastoreContext getDatastoreContext() {
 989             return datastoreContext;
 990         }
 991
 992         public SchemaContext getSchemaContext() {
 993             return Verify.verifyNotNull(schemaContextProvider.getSchemaContext());
 994         }
 995
 996         public DatastoreSnapshot.ShardSnapshot getRestoreFromSnapshot() {
 997             return restoreFromSnapshot;
 998         }
 999
1000         public TipProducingDataTree getDataTree() {
1001             return dataTree;
1002         }
1003
1004         public TreeType getTreeType() {
1005             switch (datastoreContext.getLogicalStoreType()) {
1006                 case CONFIGURATION:
1007                     return TreeType.CONFIGURATION;
1008                 case OPERATIONAL:
1009                     return TreeType.OPERATIONAL;
1010                 default:
1011                     throw new IllegalStateException("Unhandled logical store type "
1012                             + datastoreContext.getLogicalStoreType());
1013             }
1014         }
1015
1016         protected void verify() {
1017             Preconditions.checkNotNull(id, "id should not be null");
1018             Preconditions.checkNotNull(peerAddresses, "peerAddresses should not be null");
1019             Preconditions.checkNotNull(datastoreContext, "dataStoreContext should not be null");
1020             Preconditions.checkNotNull(schemaContextProvider, "schemaContextProvider should not be null");
1021         }
1022
1023         public Props props() {
1024             sealed = true;
1025             verify();
1026             return Props.create(shardClass, this);
1027         }
1028     }
1029
1030     public static class Builder extends AbstractBuilder<Builder, Shard> {
1031         private Builder() {
1032             super(Shard.class);
1033         }
1034     }
1035
1036     Ticker ticker() {
1037         return Ticker.systemTicker();
1038     }
1039
1040     void scheduleNextPendingTransaction() {
1041         self().tell(RESUME_NEXT_PENDING_TRANSACTION, ActorRef.noSender());
1042     }
1043 }