opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/RemoteTransactionContext.java

   1 /*
   2  * Copyright (c) 2015 Cisco Systems, Inc. and others.  All rights reserved.
   3  * Copyright (c) 2015 Brocade Communications Systems, Inc. and others.  All rights reserved.
   4  *
   5  * This program and the accompanying materials are made available under the
   6  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   7  * and is available at http://www.eclipse.org/legal/epl-v10.html
   8  */
   9 package org.opendaylight.controller.cluster.datastore;
  10
  11 import static com.google.common.base.Preconditions.checkState;
  12 import static java.util.Objects.requireNonNull;
  13
  14 import akka.actor.ActorSelection;
  15 import akka.dispatch.Futures;
  16 import akka.dispatch.OnComplete;
  17 import com.google.common.util.concurrent.SettableFuture;
  18 import java.util.Optional;
  19 import java.util.SortedSet;
  20 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  21 import org.opendaylight.controller.cluster.datastore.messages.AbstractRead;
  22 import org.opendaylight.controller.cluster.datastore.messages.BatchedModifications;
  23 import org.opendaylight.controller.cluster.datastore.messages.CloseTransaction;
  24 import org.opendaylight.controller.cluster.datastore.modification.AbstractModification;
  25 import org.opendaylight.controller.cluster.datastore.modification.DeleteModification;
  26 import org.opendaylight.controller.cluster.datastore.modification.MergeModification;
  27 import org.opendaylight.controller.cluster.datastore.modification.Modification;
  28 import org.opendaylight.controller.cluster.datastore.modification.WriteModification;
  29 import org.opendaylight.controller.cluster.datastore.utils.ActorUtils;
  30 import org.opendaylight.mdsal.common.api.ReadFailedException;
  31 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  32 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  33 import org.slf4j.Logger;
  34 import org.slf4j.LoggerFactory;
  35 import scala.concurrent.Future;
  36
  37 /**
  38  * Redirects front-end transaction operations to a shard for processing. Instances of this class are used
  39  * when the destination shard is remote to the caller.
  40  *
  41  * @author Thomas Pantelis
  42  */
  43 public class RemoteTransactionContext extends AbstractTransactionContext {
  44     private static final Logger LOG = LoggerFactory.getLogger(RemoteTransactionContext.class);
  45
  46     private final ActorUtils actorUtils;
  47     private final ActorSelection actor;
  48     private final OperationLimiter limiter;
  49
  50     private BatchedModifications batchedModifications;
  51     private int totalBatchedModificationsSent;
  52     private int batchPermits;
  53
  54     /**
  55      * We have observed a failed modification batch. This transaction context is effectively doomed, as the backend
  56      * does not have a correct view of the world. If this happens, we do not limit operations but rather short-cut them
  57      * to a either a no-op (modifications) or a failure (reads). Once the transaction is ready, though, we send the
  58      * message to resynchronize with the backend, sharing a 'lost message' failure path.
  59      */
  60     private volatile Throwable failedModification;
  61
  62     protected RemoteTransactionContext(final TransactionIdentifier identifier, final ActorSelection actor,
  63             final ActorUtils actorUtils, final short remoteTransactionVersion, final OperationLimiter limiter) {
  64         super(identifier, remoteTransactionVersion);
  65         this.limiter = requireNonNull(limiter);
  66         this.actor = actor;
  67         this.actorUtils = actorUtils;
  68     }
  69
  70     private ActorSelection getActor() {
  71         return actor;
  72     }
  73
  74     protected ActorUtils getActorUtils() {
  75         return actorUtils;
  76     }
  77
  78     @Override
  79     public void closeTransaction() {
  80         LOG.debug("Tx {} closeTransaction called", getIdentifier());
  81         TransactionContextCleanup.untrack(this);
  82
  83         actorUtils.sendOperationAsync(getActor(), new CloseTransaction(getTransactionVersion()).toSerializable());
  84     }
  85
  86     @Override
  87     public Future<Object> directCommit(final Boolean havePermit) {
  88         LOG.debug("Tx {} directCommit called", getIdentifier());
  89
  90         // Send the remaining batched modifications, if any, with the ready flag set.
  91         bumpPermits(havePermit);
  92         return sendBatchedModifications(true, true, Optional.empty());
  93     }
  94
  95     @Override
  96     public Future<ActorSelection> readyTransaction(final Boolean havePermit,
  97             final Optional<SortedSet<String>> participatingShardNames) {
  98         logModificationCount();
  99
 100         LOG.debug("Tx {} readyTransaction called", getIdentifier());
 101
 102         // Send the remaining batched modifications, if any, with the ready flag set.
 103
 104         bumpPermits(havePermit);
 105         Future<Object> lastModificationsFuture = sendBatchedModifications(true, false, participatingShardNames);
 106
 107         return transformReadyReply(lastModificationsFuture);
 108     }
 109
 110     private void bumpPermits(final Boolean havePermit) {
 111         if (Boolean.TRUE.equals(havePermit)) {
 112             ++batchPermits;
 113         }
 114     }
 115
 116     protected Future<ActorSelection> transformReadyReply(final Future<Object> readyReplyFuture) {
 117         // Transform the last reply Future into a Future that returns the cohort actor path from
 118         // the last reply message. That's the end result of the ready operation.
 119
 120         return TransactionReadyReplyMapper.transform(readyReplyFuture, actorUtils, getIdentifier());
 121     }
 122
 123     private BatchedModifications newBatchedModifications() {
 124         return new BatchedModifications(getIdentifier(), getTransactionVersion());
 125     }
 126
 127     private void batchModification(final Modification modification, final boolean havePermit) {
 128         incrementModificationCount();
 129         if (havePermit) {
 130             ++batchPermits;
 131         }
 132
 133         if (batchedModifications == null) {
 134             batchedModifications = newBatchedModifications();
 135         }
 136
 137         batchedModifications.addModification(modification);
 138
 139         if (batchedModifications.getModifications().size()
 140                 >= actorUtils.getDatastoreContext().getShardBatchedModificationCount()) {
 141             sendBatchedModifications();
 142         }
 143     }
 144
 145     protected Future<Object> sendBatchedModifications() {
 146         return sendBatchedModifications(false, false, Optional.empty());
 147     }
 148
 149     protected Future<Object> sendBatchedModifications(final boolean ready, final boolean doCommitOnReady,
 150             final Optional<SortedSet<String>> participatingShardNames) {
 151         Future<Object> sent = null;
 152         if (ready || batchedModifications != null && !batchedModifications.getModifications().isEmpty()) {
 153             if (batchedModifications == null) {
 154                 batchedModifications = newBatchedModifications();
 155             }
 156
 157             LOG.debug("Tx {} sending {} batched modifications, ready: {}", getIdentifier(),
 158                     batchedModifications.getModifications().size(), ready);
 159
 160             batchedModifications.setDoCommitOnReady(doCommitOnReady);
 161             batchedModifications.setTotalMessagesSent(++totalBatchedModificationsSent);
 162
 163             final BatchedModifications toSend = batchedModifications;
 164             final int permitsToRelease = batchPermits;
 165             batchPermits = 0;
 166
 167             if (ready) {
 168                 batchedModifications.setReady(participatingShardNames);
 169                 batchedModifications.setDoCommitOnReady(doCommitOnReady);
 170                 batchedModifications = null;
 171             } else {
 172                 batchedModifications = newBatchedModifications();
 173
 174                 final Throwable failure = failedModification;
 175                 if (failure != null) {
 176                     // We have observed a modification failure, it does not make sense to send this batch. This speeds
 177                     // up the time when the application could be blocked due to messages timing out and operation
 178                     // limiter kicking in.
 179                     LOG.debug("Tx {} modifications previously failed, not sending a non-ready batch", getIdentifier());
 180                     limiter.release(permitsToRelease);
 181                     return Futures.failed(failure);
 182                 }
 183             }
 184
 185             sent = actorUtils.executeOperationAsync(getActor(), toSend.toSerializable(),
 186                 actorUtils.getTransactionCommitOperationTimeout());
 187             sent.onComplete(new OnComplete<>() {
 188                 @Override
 189                 public void onComplete(final Throwable failure, final Object success) {
 190                     if (failure != null) {
 191                         LOG.debug("Tx {} modifications failed", getIdentifier(), failure);
 192                         failedModification = failure;
 193                     } else {
 194                         LOG.debug("Tx {} modifications completed with {}", getIdentifier(), success);
 195                     }
 196                     limiter.release(permitsToRelease);
 197                 }
 198             }, actorUtils.getClientDispatcher());
 199         }
 200
 201         return sent;
 202     }
 203
 204     @Override
 205     public void executeDelete(final YangInstanceIdentifier path, final Boolean havePermit) {
 206         LOG.debug("Tx {} executeDelete called path = {}", getIdentifier(), path);
 207         executeModification(new DeleteModification(path), havePermit);
 208     }
 209
 210     @Override
 211     public void executeMerge(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data,
 212             final Boolean havePermit) {
 213         LOG.debug("Tx {} executeMerge called path = {}", getIdentifier(), path);
 214         executeModification(new MergeModification(path, data), havePermit);
 215     }
 216
 217     @Override
 218     public void executeWrite(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data,
 219             final Boolean havePermit) {
 220         LOG.debug("Tx {} executeWrite called path = {}", getIdentifier(), path);
 221         executeModification(new WriteModification(path, data), havePermit);
 222     }
 223
 224     private void executeModification(final AbstractModification modification, final Boolean havePermit) {
 225         final boolean permitToRelease;
 226         if (havePermit == null) {
 227             permitToRelease = failedModification == null && acquireOperation();
 228         } else {
 229             permitToRelease = havePermit.booleanValue();
 230         }
 231
 232         batchModification(modification, permitToRelease);
 233     }
 234
 235     @Override
 236     public <T> void executeRead(final AbstractRead<T> readCmd, final SettableFuture<T> returnFuture,
 237             final Boolean havePermit) {
 238         LOG.debug("Tx {} executeRead {} called path = {}", getIdentifier(), readCmd.getClass().getSimpleName(),
 239                 readCmd.getPath());
 240
 241         final Throwable failure = failedModification;
 242         if (failure != null) {
 243             // If we know there was a previous modification failure, we must not send a read request, as it risks
 244             // returning incorrect data. We check this before acquiring an operation simply because we want the app
 245             // to complete this transaction as soon as possible.
 246             returnFuture.setException(new ReadFailedException("Previous modification failed, cannot "
 247                     + readCmd.getClass().getSimpleName() + " for path " + readCmd.getPath(), failure));
 248             return;
 249         }
 250
 251         // Send any batched modifications. This is necessary to honor the read uncommitted semantics of the
 252         // public API contract.
 253
 254         final boolean permitToRelease = havePermit == null ? acquireOperation() : havePermit.booleanValue();
 255         sendBatchedModifications();
 256
 257         OnComplete<Object> onComplete = new OnComplete<>() {
 258             @Override
 259             public void onComplete(final Throwable failure, final Object response) {
 260                 // We have previously acquired an operation, now release it, no matter what happened
 261                 if (permitToRelease) {
 262                     limiter.release();
 263                 }
 264
 265                 if (failure != null) {
 266                     LOG.debug("Tx {} {} operation failed", getIdentifier(), readCmd.getClass().getSimpleName(),
 267                         failure);
 268
 269                     returnFuture.setException(new ReadFailedException("Error checking "
 270                         + readCmd.getClass().getSimpleName() + " for path " + readCmd.getPath(), failure));
 271                 } else {
 272                     LOG.debug("Tx {} {} operation succeeded", getIdentifier(), readCmd.getClass().getSimpleName());
 273                     readCmd.processResponse(response, returnFuture);
 274                 }
 275             }
 276         };
 277
 278         final Future<Object> future = actorUtils.executeOperationAsync(getActor(),
 279             readCmd.asVersion(getTransactionVersion()).toSerializable(), actorUtils.getOperationTimeout());
 280         future.onComplete(onComplete, actorUtils.getClientDispatcher());
 281     }
 282
 283     /**
 284      * Acquire operation from the limiter if the hand-off has completed. If the hand-off is still ongoing, this method
 285      * does nothing.
 286      *
 287      * @return True if a permit was successfully acquired, false otherwise
 288      */
 289     private boolean acquireOperation() {
 290         checkState(isOperationHandOffComplete(),
 291             "Attempted to acquire execute operation permit for transaction %s on actor %s during handoff",
 292             getIdentifier(), actor);
 293
 294         if (limiter.acquire()) {
 295             return true;
 296         }
 297
 298         LOG.warn("Failed to acquire execute operation permit for transaction {} on actor {}", getIdentifier(), actor);
 299         return false;
 300     }
 301
 302     @Override
 303     public boolean usesOperationLimiting() {
 304         return true;
 305     }
 306 }