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

   1 /*
   2  * Copyright (c) 2014 Brocade Communications 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 package org.opendaylight.controller.cluster.databroker;
   9
  10 import static com.google.common.base.Preconditions.checkArgument;
  11 import static java.util.Objects.requireNonNull;
  12 import static org.opendaylight.mdsal.dom.broker.TransactionCommitFailedExceptionMapper.CAN_COMMIT_ERROR_MAPPER;
  13 import static org.opendaylight.mdsal.dom.broker.TransactionCommitFailedExceptionMapper.COMMIT_ERROR_MAPPER;
  14 import static org.opendaylight.mdsal.dom.broker.TransactionCommitFailedExceptionMapper.PRE_COMMIT_MAPPER;
  15
  16 import com.google.common.annotations.Beta;
  17 import com.google.common.util.concurrent.AbstractFuture;
  18 import com.google.common.util.concurrent.FluentFuture;
  19 import com.google.common.util.concurrent.FutureCallback;
  20 import com.google.common.util.concurrent.Futures;
  21 import com.google.common.util.concurrent.ListenableFuture;
  22 import com.google.common.util.concurrent.MoreExecutors;
  23 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  24 import java.util.Collection;
  25 import java.util.Iterator;
  26 import java.util.List;
  27 import java.util.Map;
  28 import java.util.concurrent.Executor;
  29 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
  30 import org.opendaylight.controller.cluster.datastore.exceptions.ShardLeaderNotRespondingException;
  31 import org.opendaylight.mdsal.common.api.CommitInfo;
  32 import org.opendaylight.mdsal.common.api.DataStoreUnavailableException;
  33 import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
  34 import org.opendaylight.mdsal.common.api.TransactionCommitFailedException;
  35 import org.opendaylight.mdsal.dom.api.DOMDataTreeWriteTransaction;
  36 import org.opendaylight.mdsal.dom.broker.TransactionCommitFailedExceptionMapper;
  37 import org.opendaylight.mdsal.dom.spi.store.DOMStore;
  38 import org.opendaylight.mdsal.dom.spi.store.DOMStoreThreePhaseCommitCohort;
  39 import org.opendaylight.yangtools.util.DurationStatisticsTracker;
  40 import org.slf4j.Logger;
  41 import org.slf4j.LoggerFactory;
  42
  43 /**
  44  * ConcurrentDOMDataBroker commits transactions concurrently. The 3
  45  * commit phases (canCommit, preCommit, and commit) are performed serially and non-blocking
  46  * (ie async) per transaction but multiple transaction commits can run concurrent.
  47  *
  48  * @author Thomas Pantelis
  49  */
  50 @Beta
  51 public class ConcurrentDOMDataBroker extends AbstractDOMBroker {
  52     private static final Logger LOG = LoggerFactory.getLogger(ConcurrentDOMDataBroker.class);
  53     private static final String CAN_COMMIT = "CAN_COMMIT";
  54     private static final String PRE_COMMIT = "PRE_COMMIT";
  55     private static final String COMMIT = "COMMIT";
  56
  57     private final DurationStatisticsTracker commitStatsTracker;
  58
  59     /**
  60      * This executor is used to execute Future listener callback Runnables async.
  61      */
  62     private final Executor clientFutureCallbackExecutor;
  63
  64     public ConcurrentDOMDataBroker(final Map<LogicalDatastoreType, DOMStore> datastores,
  65             final Executor listenableFutureExecutor) {
  66         this(datastores, listenableFutureExecutor, DurationStatisticsTracker.createConcurrent());
  67     }
  68
  69     public ConcurrentDOMDataBroker(final Map<LogicalDatastoreType, DOMStore> datastores,
  70             final Executor listenableFutureExecutor, final DurationStatisticsTracker commitStatsTracker) {
  71         super(datastores);
  72         this.clientFutureCallbackExecutor = requireNonNull(listenableFutureExecutor);
  73         this.commitStatsTracker = requireNonNull(commitStatsTracker);
  74     }
  75
  76     public DurationStatisticsTracker getCommitStatsTracker() {
  77         return commitStatsTracker;
  78     }
  79
  80     @Override
  81     protected FluentFuture<? extends CommitInfo> commit(final DOMDataTreeWriteTransaction transaction,
  82             final Collection<DOMStoreThreePhaseCommitCohort> cohorts) {
  83
  84         checkArgument(transaction != null, "Transaction must not be null.");
  85         checkArgument(cohorts != null, "Cohorts must not be null.");
  86         LOG.debug("Tx: {} is submitted for execution.", transaction.getIdentifier());
  87
  88         if (cohorts.isEmpty()) {
  89             return CommitInfo.emptyFluentFuture();
  90         }
  91
  92         final AsyncNotifyingSettableFuture clientSubmitFuture =
  93                 new AsyncNotifyingSettableFuture(clientFutureCallbackExecutor);
  94
  95         doCanCommit(clientSubmitFuture, transaction, cohorts);
  96
  97         return FluentFuture.from(clientSubmitFuture).transform(ignored -> CommitInfo.empty(),
  98                 MoreExecutors.directExecutor());
  99     }
 100
 101     private void doCanCommit(final AsyncNotifyingSettableFuture clientSubmitFuture,
 102             final DOMDataTreeWriteTransaction transaction,
 103             final Collection<DOMStoreThreePhaseCommitCohort> cohorts) {
 104
 105         final long startTime = System.nanoTime();
 106
 107         final Iterator<DOMStoreThreePhaseCommitCohort> cohortIterator = cohorts.iterator();
 108
 109         // Not using Futures.allAsList here to avoid its internal overhead.
 110         FutureCallback<Boolean> futureCallback = new FutureCallback<Boolean>() {
 111             @Override
 112             public void onSuccess(final Boolean result) {
 113                 if (result == null || !result) {
 114                     handleException(clientSubmitFuture, transaction, cohorts, CAN_COMMIT, CAN_COMMIT_ERROR_MAPPER,
 115                             new TransactionCommitFailedException("Can Commit failed, no detailed cause available."));
 116                 } else if (!cohortIterator.hasNext()) {
 117                     // All cohorts completed successfully - we can move on to the preCommit phase
 118                     doPreCommit(startTime, clientSubmitFuture, transaction, cohorts);
 119                 } else {
 120                     Futures.addCallback(cohortIterator.next().canCommit(), this, MoreExecutors.directExecutor());
 121                 }
 122             }
 123
 124             @Override
 125             public void onFailure(final Throwable failure) {
 126                 handleException(clientSubmitFuture, transaction, cohorts, CAN_COMMIT, CAN_COMMIT_ERROR_MAPPER, failure);
 127             }
 128         };
 129
 130         ListenableFuture<Boolean> canCommitFuture = cohortIterator.next().canCommit();
 131         Futures.addCallback(canCommitFuture, futureCallback, MoreExecutors.directExecutor());
 132     }
 133
 134     private void doPreCommit(final long startTime, final AsyncNotifyingSettableFuture clientSubmitFuture,
 135             final DOMDataTreeWriteTransaction transaction,
 136             final Collection<DOMStoreThreePhaseCommitCohort> cohorts) {
 137
 138         final Iterator<DOMStoreThreePhaseCommitCohort> cohortIterator = cohorts.iterator();
 139
 140         // Not using Futures.allAsList here to avoid its internal overhead.
 141         FutureCallback<Void> futureCallback = new FutureCallback<Void>() {
 142             @Override
 143             public void onSuccess(final Void notUsed) {
 144                 if (!cohortIterator.hasNext()) {
 145                     // All cohorts completed successfully - we can move on to the commit phase
 146                     doCommit(startTime, clientSubmitFuture, transaction, cohorts);
 147                 } else {
 148                     ListenableFuture<Void> preCommitFuture = cohortIterator.next().preCommit();
 149                     Futures.addCallback(preCommitFuture, this, MoreExecutors.directExecutor());
 150                 }
 151             }
 152
 153             @Override
 154             public void onFailure(final Throwable failure) {
 155                 handleException(clientSubmitFuture, transaction, cohorts, PRE_COMMIT, PRE_COMMIT_MAPPER, failure);
 156             }
 157         };
 158
 159         ListenableFuture<Void> preCommitFuture = cohortIterator.next().preCommit();
 160         Futures.addCallback(preCommitFuture, futureCallback, MoreExecutors.directExecutor());
 161     }
 162
 163     private void doCommit(final long startTime, final AsyncNotifyingSettableFuture clientSubmitFuture,
 164             final DOMDataTreeWriteTransaction transaction,
 165             final Collection<DOMStoreThreePhaseCommitCohort> cohorts) {
 166
 167         final Iterator<DOMStoreThreePhaseCommitCohort> cohortIterator = cohorts.iterator();
 168
 169         // Not using Futures.allAsList here to avoid its internal overhead.
 170         FutureCallback<Void> futureCallback = new FutureCallback<Void>() {
 171             @Override
 172             public void onSuccess(final Void notUsed) {
 173                 if (!cohortIterator.hasNext()) {
 174                     // All cohorts completed successfully - we're done.
 175                     commitStatsTracker.addDuration(System.nanoTime() - startTime);
 176
 177                     clientSubmitFuture.set();
 178                 } else {
 179                     ListenableFuture<Void> commitFuture = cohortIterator.next().commit();
 180                     Futures.addCallback(commitFuture, this, MoreExecutors.directExecutor());
 181                 }
 182             }
 183
 184             @Override
 185             public void onFailure(final Throwable throwable) {
 186                 handleException(clientSubmitFuture, transaction, cohorts, COMMIT, COMMIT_ERROR_MAPPER, throwable);
 187             }
 188         };
 189
 190         ListenableFuture<Void> commitFuture = cohortIterator.next().commit();
 191         Futures.addCallback(commitFuture, futureCallback, MoreExecutors.directExecutor());
 192     }
 193
 194     @SuppressFBWarnings(value = "BC_UNCONFIRMED_CAST_OF_RETURN_VALUE",
 195             justification = "Pertains to the assignment of the 'clientException' var. FindBugs flags this as an "
 196                 + "uncomfirmed cast but the generic type in TransactionCommitFailedExceptionMapper is "
 197                 + "TransactionCommitFailedException and thus should be deemed as confirmed.")
 198     private static void handleException(final AsyncNotifyingSettableFuture clientSubmitFuture,
 199             final DOMDataTreeWriteTransaction transaction,
 200             final Collection<DOMStoreThreePhaseCommitCohort> cohorts,
 201             final String phase, final TransactionCommitFailedExceptionMapper exMapper,
 202             final Throwable throwable) {
 203
 204         if (clientSubmitFuture.isDone()) {
 205             // We must have had failures from multiple cohorts.
 206             return;
 207         }
 208
 209         // Use debug instead of warn level here because this exception gets propagate back to the caller via the Future
 210         LOG.debug("Tx: {} Error during phase {}, starting Abort", transaction.getIdentifier(), phase, throwable);
 211
 212         // Transaction failed - tell all cohorts to abort.
 213         @SuppressWarnings("unchecked")
 214         ListenableFuture<Void>[] canCommitFutures = new ListenableFuture[cohorts.size()];
 215         int index = 0;
 216         for (DOMStoreThreePhaseCommitCohort cohort : cohorts) {
 217             canCommitFutures[index++] = cohort.abort();
 218         }
 219
 220         // Propagate the original exception
 221         final Exception e;
 222         if (throwable instanceof NoShardLeaderException || throwable instanceof ShardLeaderNotRespondingException) {
 223             e = new DataStoreUnavailableException(throwable.getMessage(), throwable);
 224         } else if (throwable instanceof Exception) {
 225             e = (Exception)throwable;
 226         } else {
 227             e = new RuntimeException("Unexpected error occurred", throwable);
 228         }
 229         clientSubmitFuture.setException(exMapper.apply(e));
 230
 231         ListenableFuture<List<Void>> combinedFuture = Futures.allAsList(canCommitFutures);
 232         Futures.addCallback(combinedFuture, new FutureCallback<List<Void>>() {
 233             @Override
 234             public void onSuccess(final List<Void> notUsed) {
 235                 // Propagate the original exception to the client.
 236                 LOG.debug("Tx: {} aborted successfully", transaction.getIdentifier());
 237             }
 238
 239             @Override
 240             public void onFailure(final Throwable failure) {
 241                 LOG.error("Tx: {} Error during Abort.", transaction.getIdentifier(), failure);
 242             }
 243         }, MoreExecutors.directExecutor());
 244     }
 245
 246     /**
 247      * A settable future that uses an {@link Executor} to execute listener callback Runnables,
 248      * registered via {@link #addListener}, asynchronously when this future completes. This is
 249      * done to guarantee listener executions are off-loaded onto another thread to avoid blocking
 250      * the thread that completed this future, as a common use case is to pass an executor that runs
 251      * tasks in the same thread as the caller (ie MoreExecutors#sameThreadExecutor)
 252      * to {@link #addListener}.
 253      * FIXME: This class should probably be moved to yangtools common utils for re-usability and
 254      * unified with AsyncNotifyingListenableFutureTask.
 255      */
 256     private static class AsyncNotifyingSettableFuture extends AbstractFuture<Void> {
 257
 258         /**
 259          * ThreadLocal used to detect if the task completion thread is running the future listener Runnables.
 260          */
 261         private static final ThreadLocal<Boolean> ON_TASK_COMPLETION_THREAD_TL = new ThreadLocal<>();
 262
 263         private final Executor listenerExecutor;
 264
 265         AsyncNotifyingSettableFuture(final Executor listenerExecutor) {
 266             this.listenerExecutor = requireNonNull(listenerExecutor);
 267         }
 268
 269         @Override
 270         public void addListener(final Runnable listener, final Executor executor) {
 271             // Wrap the listener Runnable in a DelegatingRunnable. If the specified executor is one
 272             // that runs tasks in the same thread as the caller submitting the task
 273             // (e.g. {@link com.google.common.util.concurrent.MoreExecutors#sameThreadExecutor}) and
 274             // the listener is executed from the #set methods, then the DelegatingRunnable will detect
 275             // this via the ThreadLocal and submit the listener Runnable to the listenerExecutor.
 276             //
 277             // On the other hand, if this task is already complete, the call to ExecutionList#add in
 278             // superclass will execute the listener Runnable immediately and, since the ThreadLocal
 279             // won't be set, the DelegatingRunnable will run the listener Runnable inline.
 280             super.addListener(new DelegatingRunnable(listener, listenerExecutor), executor);
 281         }
 282
 283         boolean set() {
 284             ON_TASK_COMPLETION_THREAD_TL.set(Boolean.TRUE);
 285             try {
 286                 return super.set(null);
 287             } finally {
 288                 ON_TASK_COMPLETION_THREAD_TL.set(null);
 289             }
 290         }
 291
 292         @Override
 293         protected boolean setException(final Throwable throwable) {
 294             ON_TASK_COMPLETION_THREAD_TL.set(Boolean.TRUE);
 295             try {
 296                 return super.setException(throwable);
 297             } finally {
 298                 ON_TASK_COMPLETION_THREAD_TL.set(null);
 299             }
 300         }
 301
 302         private static final class DelegatingRunnable implements Runnable {
 303             private final Runnable delegate;
 304             private final Executor executor;
 305
 306             DelegatingRunnable(final Runnable delegate, final Executor executor) {
 307                 this.delegate = requireNonNull(delegate);
 308                 this.executor = requireNonNull(executor);
 309             }
 310
 311             @Override
 312             public void run() {
 313                 if (ON_TASK_COMPLETION_THREAD_TL.get() != null) {
 314                     // We're running on the task completion thread so off-load to the executor.
 315                     LOG.trace("Submitting ListenenableFuture Runnable from thread {} to executor {}",
 316                             Thread.currentThread().getName(), executor);
 317                     executor.execute(delegate);
 318                 } else {
 319                     // We're not running on the task completion thread so run the delegate inline.
 320                     LOG.trace("Executing ListenenableFuture Runnable on this thread: {}",
 321                             Thread.currentThread().getName());
 322                     delegate.run();
 323                 }
 324             }
 325         }
 326     }
 327
 328     @Override
 329     public String toString() {
 330         return "Clustered ConcurrentDOMDataBroker";
 331     }
 332 }