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