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