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