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