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;
  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         this(datastores, listenableFutureExecutor, DurationStatisticsTracker.createConcurrent());
  59     }
  60
  61     public ConcurrentDOMDataBroker(final Map<LogicalDatastoreType, DOMStore> datastores, Executor listenableFutureExecutor,
  62             DurationStatisticsTracker commitStatsTracker) {
  63         super(datastores);
  64         this.clientFutureCallbackExecutor = Preconditions.checkNotNull(listenableFutureExecutor);
  65         this.commitStatsTracker = Preconditions.checkNotNull(commitStatsTracker);
  66     }
  67
  68     public DurationStatisticsTracker getCommitStatsTracker() {
  69         return commitStatsTracker;
  70     }
  71
  72     @Override
  73     protected CheckedFuture<Void, TransactionCommitFailedException> submit(DOMDataWriteTransaction transaction,
  74             Collection<DOMStoreThreePhaseCommitCohort> cohorts) {
  75
  76         Preconditions.checkArgument(transaction != null, "Transaction must not be null.");
  77         Preconditions.checkArgument(cohorts != null, "Cohorts must not be null.");
  78         LOG.debug("Tx: {} is submitted for execution.", transaction.getIdentifier());
  79
  80         if(cohorts.isEmpty()){
  81             return Futures.immediateCheckedFuture(null);
  82         }
  83
  84         final AsyncNotifyingSettableFuture clientSubmitFuture =
  85                 new AsyncNotifyingSettableFuture(clientFutureCallbackExecutor);
  86
  87         doCanCommit(clientSubmitFuture, transaction, cohorts);
  88
  89         return MappingCheckedFuture.create(clientSubmitFuture,
  90                 TransactionCommitFailedExceptionMapper.COMMIT_ERROR_MAPPER);
  91     }
  92
  93     private void doCanCommit(final AsyncNotifyingSettableFuture clientSubmitFuture,
  94             final DOMDataWriteTransaction transaction,
  95             final Collection<DOMStoreThreePhaseCommitCohort> cohorts) {
  96
  97         final long startTime = System.nanoTime();
  98
  99         final Iterator<DOMStoreThreePhaseCommitCohort> cohortIterator = cohorts.iterator();
 100
 101         // Not using Futures.allAsList here to avoid its internal overhead.
 102         FutureCallback<Boolean> futureCallback = new FutureCallback<Boolean>() {
 103             @Override
 104             public void onSuccess(Boolean result) {
 105                 if (result == null || !result) {
 106                     handleException(clientSubmitFuture, transaction, cohorts,
 107                             CAN_COMMIT, TransactionCommitFailedExceptionMapper.CAN_COMMIT_ERROR_MAPPER,
 108                             new TransactionCommitFailedException(
 109                                             "Can Commit failed, no detailed cause available."));
 110                 } else {
 111                     if(!cohortIterator.hasNext()) {
 112                         // All cohorts completed successfully - we can move on to the preCommit phase
 113                         doPreCommit(startTime, clientSubmitFuture, transaction, cohorts);
 114                     } else {
 115                         ListenableFuture<Boolean> canCommitFuture = cohortIterator.next().canCommit();
 116                         Futures.addCallback(canCommitFuture, this, MoreExecutors.directExecutor());
 117                     }
 118                 }
 119             }
 120
 121             @Override
 122             public void onFailure(Throwable t) {
 123                 handleException(clientSubmitFuture, transaction, cohorts, CAN_COMMIT,
 124                         TransactionCommitFailedExceptionMapper.CAN_COMMIT_ERROR_MAPPER, t);
 125             }
 126         };
 127
 128         ListenableFuture<Boolean> canCommitFuture = cohortIterator.next().canCommit();
 129         Futures.addCallback(canCommitFuture, futureCallback, MoreExecutors.directExecutor());
 130     }
 131
 132     private void doPreCommit(final long startTime, final AsyncNotifyingSettableFuture clientSubmitFuture,
 133             final DOMDataWriteTransaction transaction,
 134             final Collection<DOMStoreThreePhaseCommitCohort> cohorts) {
 135
 136         final Iterator<DOMStoreThreePhaseCommitCohort> cohortIterator = cohorts.iterator();
 137
 138         // Not using Futures.allAsList here to avoid its internal overhead.
 139         FutureCallback<Void> futureCallback = new FutureCallback<Void>() {
 140             @Override
 141             public void onSuccess(Void notUsed) {
 142                 if(!cohortIterator.hasNext()) {
 143                     // All cohorts completed successfully - we can move on to the commit phase
 144                     doCommit(startTime, clientSubmitFuture, transaction, cohorts);
 145                 } else {
 146                     ListenableFuture<Void> preCommitFuture = cohortIterator.next().preCommit();
 147                     Futures.addCallback(preCommitFuture, this, MoreExecutors.directExecutor());
 148                 }
 149             }
 150
 151             @Override
 152             public void onFailure(Throwable t) {
 153                 handleException(clientSubmitFuture, transaction, cohorts, PRE_COMMIT,
 154                         TransactionCommitFailedExceptionMapper.PRE_COMMIT_MAPPER, t);
 155             }
 156         };
 157
 158         ListenableFuture<Void> preCommitFuture = cohortIterator.next().preCommit();
 159         Futures.addCallback(preCommitFuture, futureCallback, MoreExecutors.directExecutor());
 160     }
 161
 162     private void doCommit(final long startTime, final AsyncNotifyingSettableFuture clientSubmitFuture,
 163             final DOMDataWriteTransaction transaction,
 164             final Collection<DOMStoreThreePhaseCommitCohort> cohorts) {
 165
 166         final Iterator<DOMStoreThreePhaseCommitCohort> cohortIterator = cohorts.iterator();
 167
 168         // Not using Futures.allAsList here to avoid its internal overhead.
 169         FutureCallback<Void> futureCallback = new FutureCallback<Void>() {
 170             @Override
 171             public void onSuccess(Void notUsed) {
 172                 if(!cohortIterator.hasNext()) {
 173                     // All cohorts completed successfully - we're done.
 174                     commitStatsTracker.addDuration(System.nanoTime() - startTime);
 175
 176                     clientSubmitFuture.set();
 177                 } else {
 178                     ListenableFuture<Void> commitFuture = cohortIterator.next().commit();
 179                     Futures.addCallback(commitFuture, this, MoreExecutors.directExecutor());
 180                 }
 181             }
 182
 183             @Override
 184             public void onFailure(Throwable t) {
 185                 handleException(clientSubmitFuture, transaction, cohorts, COMMIT,
 186                         TransactionCommitFailedExceptionMapper.COMMIT_ERROR_MAPPER, t);
 187             }
 188         };
 189
 190         ListenableFuture<Void> commitFuture = cohortIterator.next().commit();
 191         Futures.addCallback(commitFuture, futureCallback, MoreExecutors.directExecutor());
 192     }
 193
 194     private static void handleException(final AsyncNotifyingSettableFuture clientSubmitFuture,
 195             final DOMDataWriteTransaction transaction,
 196             final Collection<DOMStoreThreePhaseCommitCohort> cohorts,
 197             final String phase, final TransactionCommitFailedExceptionMapper exMapper,
 198             final Throwable t) {
 199
 200         if (clientSubmitFuture.isDone()) {
 201             // We must have had failures from multiple cohorts.
 202             return;
 203         }
 204
 205         LOG.warn("Tx: {} Error during phase {}, starting Abort", transaction.getIdentifier(), phase, t);
 206         final Exception e;
 207         if(t instanceof NoShardLeaderException || t instanceof ShardLeaderNotRespondingException) {
 208             e = new DataStoreUnavailableException(t.getMessage(), t);
 209         } else if (t instanceof Exception) {
 210             e = (Exception)t;
 211         } else {
 212             e = new RuntimeException("Unexpected error occurred", t);
 213         }
 214
 215         final TransactionCommitFailedException clientException = exMapper.apply(e);
 216
 217         // Transaction failed - tell all cohorts to abort.
 218
 219         @SuppressWarnings("unchecked")
 220         ListenableFuture<Void>[] canCommitFutures = new ListenableFuture[cohorts.size()];
 221         int i = 0;
 222         for (DOMStoreThreePhaseCommitCohort cohort : cohorts) {
 223             canCommitFutures[i++] = cohort.abort();
 224         }
 225
 226         ListenableFuture<List<Void>> combinedFuture = Futures.allAsList(canCommitFutures);
 227         Futures.addCallback(combinedFuture, new FutureCallback<List<Void>>() {
 228             @Override
 229             public void onSuccess(List<Void> notUsed) {
 230                 // Propagate the original exception to the client.
 231                 clientSubmitFuture.setException(clientException);
 232             }
 233
 234             @Override
 235             public void onFailure(Throwable t) {
 236                 LOG.error("Tx: {} Error during Abort.", transaction.getIdentifier(), t);
 237
 238                 // Propagate the original exception as that is what caused the Tx to fail and is
 239                 // what's interesting to the client.
 240                 clientSubmitFuture.setException(clientException);
 241             }
 242         }, MoreExecutors.directExecutor());
 243     }
 244
 245     /**
 246      * A settable future that uses an {@link Executor} to execute listener callback Runnables,
 247      * registered via {@link #addListener}, asynchronously when this future completes. This is
 248      * done to guarantee listener executions are off-loaded onto another thread to avoid blocking
 249      * the thread that completed this future, as a common use case is to pass an executor that runs
 250      * tasks in the same thread as the caller (ie MoreExecutors#sameThreadExecutor)
 251      * to {@link #addListener}.
 252      *
 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<Boolean>();
 262
 263         private final Executor listenerExecutor;
 264
 265         AsyncNotifyingSettableFuture(Executor listenerExecutor) {
 266             this.listenerExecutor = Preconditions.checkNotNull(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(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 = Preconditions.checkNotNull(delegate);
 308                 this.executor = Preconditions.checkNotNull(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 }