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 com.google.common.annotations.Beta;
  11 import com.google.common.base.Preconditions;
  12 import com.google.common.util.concurrent.AbstractFuture;
  13 import com.google.common.util.concurrent.CheckedFuture;
  14 import com.google.common.util.concurrent.FutureCallback;
  15 import com.google.common.util.concurrent.Futures;
  16 import com.google.common.util.concurrent.ListenableFuture;
  17 import com.google.common.util.concurrent.MoreExecutors;
  18 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  19 import java.util.Collection;
  20 import java.util.Iterator;
  21 import java.util.List;
  22 import java.util.Map;
  23 import java.util.concurrent.Executor;
  24 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
  25 import org.opendaylight.controller.cluster.datastore.exceptions.ShardLeaderNotRespondingException;
  26 import org.opendaylight.controller.md.sal.common.api.data.DataStoreUnavailableException;
  27 import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
  28 import org.opendaylight.controller.md.sal.common.api.data.TransactionCommitFailedException;
  29 import org.opendaylight.controller.md.sal.dom.api.DOMDataWriteTransaction;
  30 import org.opendaylight.controller.md.sal.dom.broker.impl.TransactionCommitFailedExceptionMapper;
  31 import org.opendaylight.controller.sal.core.spi.data.DOMStore;
  32 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  33 import org.opendaylight.yangtools.util.DurationStatisticsTracker;
  34 import org.opendaylight.yangtools.util.concurrent.MappingCheckedFuture;
  35 import org.slf4j.Logger;
  36 import org.slf4j.LoggerFactory;
  37
  38 /**
  39  * ConcurrentDOMDataBroker commits transactions concurrently. The 3
  40  * commit phases (canCommit, preCommit, and commit) are performed serially and non-blocking
  41  * (ie async) per transaction but multiple transaction commits can run concurrent.
  42  *
  43  * @author Thomas Pantelis
  44  */
  45 @Beta
  46 public class ConcurrentDOMDataBroker extends AbstractDOMBroker {
  47     private static final Logger LOG = LoggerFactory.getLogger(ConcurrentDOMDataBroker.class);
  48     private static final String CAN_COMMIT = "CAN_COMMIT";
  49     private static final String PRE_COMMIT = "PRE_COMMIT";
  50     private static final String COMMIT = "COMMIT";
  51
  52     private final DurationStatisticsTracker commitStatsTracker;
  53
  54     /**
  55      * This executor is used to execute Future listener callback Runnables async.
  56      */
  57     private final Executor clientFutureCallbackExecutor;
  58
  59     public ConcurrentDOMDataBroker(final Map<LogicalDatastoreType, DOMStore> datastores,
  60             Executor listenableFutureExecutor) {
  61         this(datastores, listenableFutureExecutor, DurationStatisticsTracker.createConcurrent());
  62     }
  63
  64     public ConcurrentDOMDataBroker(final Map<LogicalDatastoreType, DOMStore> datastores,
  65             Executor listenableFutureExecutor, DurationStatisticsTracker commitStatsTracker) {
  66         super(datastores);
  67         this.clientFutureCallbackExecutor = Preconditions.checkNotNull(listenableFutureExecutor);
  68         this.commitStatsTracker = Preconditions.checkNotNull(commitStatsTracker);
  69     }
  70
  71     public DurationStatisticsTracker getCommitStatsTracker() {
  72         return commitStatsTracker;
  73     }
  74
  75     @Override
  76     protected CheckedFuture<Void, TransactionCommitFailedException> submit(DOMDataWriteTransaction transaction,
  77             Collection<DOMStoreThreePhaseCommitCohort> cohorts) {
  78
  79         Preconditions.checkArgument(transaction != null, "Transaction must not be null.");
  80         Preconditions.checkArgument(cohorts != null, "Cohorts must not be null.");
  81         LOG.debug("Tx: {} is submitted for execution.", transaction.getIdentifier());
  82
  83         if (cohorts.isEmpty()) {
  84             return Futures.immediateCheckedFuture(null);
  85         }
  86
  87         final AsyncNotifyingSettableFuture clientSubmitFuture =
  88                 new AsyncNotifyingSettableFuture(clientFutureCallbackExecutor);
  89
  90         doCanCommit(clientSubmitFuture, transaction, cohorts);
  91
  92         return MappingCheckedFuture.create(clientSubmitFuture,
  93                 TransactionCommitFailedExceptionMapper.COMMIT_ERROR_MAPPER);
  94     }
  95
  96     private void doCanCommit(final AsyncNotifyingSettableFuture clientSubmitFuture,
  97             final DOMDataWriteTransaction transaction,
  98             final Collection<DOMStoreThreePhaseCommitCohort> cohorts) {
  99
 100         final long startTime = System.nanoTime();
 101
 102         final Iterator<DOMStoreThreePhaseCommitCohort> cohortIterator = cohorts.iterator();
 103
 104         // Not using Futures.allAsList here to avoid its internal overhead.
 105         FutureCallback<Boolean> futureCallback = new FutureCallback<Boolean>() {
 106             @Override
 107             public void onSuccess(Boolean result) {
 108                 if (result == null || !result) {
 109                     handleException(clientSubmitFuture, transaction, cohorts,
 110                             CAN_COMMIT, TransactionCommitFailedExceptionMapper.CAN_COMMIT_ERROR_MAPPER,
 111                             new TransactionCommitFailedException(
 112                                             "Can Commit failed, no detailed cause available."));
 113                 } else {
 114                     if (!cohortIterator.hasNext()) {
 115                         // All cohorts completed successfully - we can move on to the preCommit phase
 116                         doPreCommit(startTime, clientSubmitFuture, transaction, cohorts);
 117                     } else {
 118                         ListenableFuture<Boolean> canCommitFuture = cohortIterator.next().canCommit();
 119                         Futures.addCallback(canCommitFuture, this, MoreExecutors.directExecutor());
 120                     }
 121                 }
 122             }
 123
 124             @Override
 125             public void onFailure(Throwable failure) {
 126                 handleException(clientSubmitFuture, transaction, cohorts, CAN_COMMIT,
 127                         TransactionCommitFailedExceptionMapper.CAN_COMMIT_ERROR_MAPPER, failure);
 128             }
 129         };
 130
 131         ListenableFuture<Boolean> canCommitFuture = cohortIterator.next().canCommit();
 132         Futures.addCallback(canCommitFuture, futureCallback, MoreExecutors.directExecutor());
 133     }
 134
 135     private void doPreCommit(final long startTime, final AsyncNotifyingSettableFuture clientSubmitFuture,
 136             final DOMDataWriteTransaction transaction,
 137             final Collection<DOMStoreThreePhaseCommitCohort> cohorts) {
 138
 139         final Iterator<DOMStoreThreePhaseCommitCohort> cohortIterator = cohorts.iterator();
 140
 141         // Not using Futures.allAsList here to avoid its internal overhead.
 142         FutureCallback<Void> futureCallback = new FutureCallback<Void>() {
 143             @Override
 144             public void onSuccess(Void notUsed) {
 145                 if (!cohortIterator.hasNext()) {
 146                     // All cohorts completed successfully - we can move on to the commit phase
 147                     doCommit(startTime, clientSubmitFuture, transaction, cohorts);
 148                 } else {
 149                     ListenableFuture<Void> preCommitFuture = cohortIterator.next().preCommit();
 150                     Futures.addCallback(preCommitFuture, this, MoreExecutors.directExecutor());
 151                 }
 152             }
 153
 154             @Override
 155             public void onFailure(Throwable failure) {
 156                 handleException(clientSubmitFuture, transaction, cohorts, PRE_COMMIT,
 157                         TransactionCommitFailedExceptionMapper.PRE_COMMIT_MAPPER, failure);
 158             }
 159         };
 160
 161         ListenableFuture<Void> preCommitFuture = cohortIterator.next().preCommit();
 162         Futures.addCallback(preCommitFuture, futureCallback, MoreExecutors.directExecutor());
 163     }
 164
 165     private void doCommit(final long startTime, final AsyncNotifyingSettableFuture clientSubmitFuture,
 166             final DOMDataWriteTransaction transaction,
 167             final Collection<DOMStoreThreePhaseCommitCohort> cohorts) {
 168
 169         final Iterator<DOMStoreThreePhaseCommitCohort> cohortIterator = cohorts.iterator();
 170
 171         // Not using Futures.allAsList here to avoid its internal overhead.
 172         FutureCallback<Void> futureCallback = new FutureCallback<Void>() {
 173             @Override
 174             public void onSuccess(Void notUsed) {
 175                 if (!cohortIterator.hasNext()) {
 176                     // All cohorts completed successfully - we're done.
 177                     commitStatsTracker.addDuration(System.nanoTime() - startTime);
 178
 179                     clientSubmitFuture.set();
 180                 } else {
 181                     ListenableFuture<Void> commitFuture = cohortIterator.next().commit();
 182                     Futures.addCallback(commitFuture, this, MoreExecutors.directExecutor());
 183                 }
 184             }
 185
 186             @Override
 187             public void onFailure(Throwable throwable) {
 188                 handleException(clientSubmitFuture, transaction, cohorts, COMMIT,
 189                         TransactionCommitFailedExceptionMapper.COMMIT_ERROR_MAPPER, throwable);
 190             }
 191         };
 192
 193         ListenableFuture<Void> commitFuture = cohortIterator.next().commit();
 194         Futures.addCallback(commitFuture, futureCallback, MoreExecutors.directExecutor());
 195     }
 196
 197     @SuppressFBWarnings(value = "BC_UNCONFIRMED_CAST_OF_RETURN_VALUE",
 198             justification = "Pertains to the assignment of the 'clientException' var. FindBugs flags this as an "
 199                 + "uncomfirmed cast but the generic type in TransactionCommitFailedExceptionMapper is "
 200                 + "TransactionCommitFailedException and thus should be deemed as confirmed.")
 201     private static void handleException(final AsyncNotifyingSettableFuture clientSubmitFuture,
 202             final DOMDataWriteTransaction transaction,
 203             final Collection<DOMStoreThreePhaseCommitCohort> cohorts,
 204             final String phase, final TransactionCommitFailedExceptionMapper exMapper,
 205             final Throwable throwable) {
 206
 207         if (clientSubmitFuture.isDone()) {
 208             // We must have had failures from multiple cohorts.
 209             return;
 210         }
 211
 212         // Use debug instead of warn level here because this exception gets propagate back to the caller via the Future
 213         LOG.debug("Tx: {} Error during phase {}, starting Abort", transaction.getIdentifier(), phase, throwable);
 214
 215         // Transaction failed - tell all cohorts to abort.
 216         @SuppressWarnings("unchecked")
 217         ListenableFuture<Void>[] canCommitFutures = new ListenableFuture[cohorts.size()];
 218         int index = 0;
 219         for (DOMStoreThreePhaseCommitCohort cohort : cohorts) {
 220             canCommitFutures[index++] = cohort.abort();
 221         }
 222
 223         // Propagate the original exception
 224         final Exception e;
 225         if (throwable instanceof NoShardLeaderException || throwable instanceof ShardLeaderNotRespondingException) {
 226             e = new DataStoreUnavailableException(throwable.getMessage(), throwable);
 227         } else if (throwable instanceof Exception) {
 228             e = (Exception)throwable;
 229         } else {
 230             e = new RuntimeException("Unexpected error occurred", throwable);
 231         }
 232         clientSubmitFuture.setException(exMapper.apply(e));
 233
 234         ListenableFuture<List<Void>> combinedFuture = Futures.allAsList(canCommitFutures);
 235         Futures.addCallback(combinedFuture, new FutureCallback<List<Void>>() {
 236             @Override
 237             public void onSuccess(List<Void> notUsed) {
 238                 // Propagate the original exception to the client.
 239                 LOG.debug("Tx: {} aborted successfully", transaction.getIdentifier());
 240             }
 241
 242             @Override
 243             public void onFailure(Throwable failure) {
 244                 LOG.error("Tx: {} Error during Abort.", transaction.getIdentifier(), failure);
 245             }
 246         }, MoreExecutors.directExecutor());
 247     }
 248
 249     /**
 250      * A settable future that uses an {@link Executor} to execute listener callback Runnables,
 251      * registered via {@link #addListener}, asynchronously when this future completes. This is
 252      * done to guarantee listener executions are off-loaded onto another thread to avoid blocking
 253      * the thread that completed this future, as a common use case is to pass an executor that runs
 254      * tasks in the same thread as the caller (ie MoreExecutors#sameThreadExecutor)
 255      * to {@link #addListener}.
 256      * FIXME: This class should probably be moved to yangtools common utils for re-usability and
 257      * unified with AsyncNotifyingListenableFutureTask.
 258      */
 259     private static class AsyncNotifyingSettableFuture extends AbstractFuture<Void> {
 260
 261         /**
 262          * ThreadLocal used to detect if the task completion thread is running the future listener Runnables.
 263          */
 264         private static final ThreadLocal<Boolean> ON_TASK_COMPLETION_THREAD_TL = new ThreadLocal<>();
 265
 266         private final Executor listenerExecutor;
 267
 268         AsyncNotifyingSettableFuture(Executor listenerExecutor) {
 269             this.listenerExecutor = Preconditions.checkNotNull(listenerExecutor);
 270         }
 271
 272         @Override
 273         public void addListener(final Runnable listener, final Executor executor) {
 274             // Wrap the listener Runnable in a DelegatingRunnable. If the specified executor is one
 275             // that runs tasks in the same thread as the caller submitting the task
 276             // (e.g. {@link com.google.common.util.concurrent.MoreExecutors#sameThreadExecutor}) and
 277             // the listener is executed from the #set methods, then the DelegatingRunnable will detect
 278             // this via the ThreadLocal and submit the listener Runnable to the listenerExecutor.
 279             //
 280             // On the other hand, if this task is already complete, the call to ExecutionList#add in
 281             // superclass will execute the listener Runnable immediately and, since the ThreadLocal
 282             // won't be set, the DelegatingRunnable will run the listener Runnable inline.
 283             super.addListener(new DelegatingRunnable(listener, listenerExecutor), executor);
 284         }
 285
 286         boolean set() {
 287             ON_TASK_COMPLETION_THREAD_TL.set(Boolean.TRUE);
 288             try {
 289                 return super.set(null);
 290             } finally {
 291                 ON_TASK_COMPLETION_THREAD_TL.set(null);
 292             }
 293         }
 294
 295         @Override
 296         protected boolean setException(Throwable throwable) {
 297             ON_TASK_COMPLETION_THREAD_TL.set(Boolean.TRUE);
 298             try {
 299                 return super.setException(throwable);
 300             } finally {
 301                 ON_TASK_COMPLETION_THREAD_TL.set(null);
 302             }
 303         }
 304
 305         private static final class DelegatingRunnable implements Runnable {
 306             private final Runnable delegate;
 307             private final Executor executor;
 308
 309             DelegatingRunnable(final Runnable delegate, final Executor executor) {
 310                 this.delegate = Preconditions.checkNotNull(delegate);
 311                 this.executor = Preconditions.checkNotNull(executor);
 312             }
 313
 314             @Override
 315             public void run() {
 316                 if (ON_TASK_COMPLETION_THREAD_TL.get() != null) {
 317                     // We're running on the task completion thread so off-load to the executor.
 318                     LOG.trace("Submitting ListenenableFuture Runnable from thread {} to executor {}",
 319                             Thread.currentThread().getName(), executor);
 320                     executor.execute(delegate);
 321                 } else {
 322                     // We're not running on the task completion thread so run the delegate inline.
 323                     LOG.trace("Executing ListenenableFuture Runnable on this thread: {}",
 324                             Thread.currentThread().getName());
 325                     delegate.run();
 326                 }
 327             }
 328         }
 329     }
 330
 331     @Override
 332     public String toString() {
 333         return "Clustered ConcurrentDOMDataBroker";
 334     }
 335 }