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 static org.opendaylight.controller.md.sal.dom.broker.impl.TransactionCommitFailedExceptionMapper.CAN_COMMIT_ERROR_MAPPER;
  11 import static org.opendaylight.controller.md.sal.dom.broker.impl.TransactionCommitFailedExceptionMapper.COMMIT_ERROR_MAPPER;
  12 import static org.opendaylight.controller.md.sal.dom.broker.impl.TransactionCommitFailedExceptionMapper.PRE_COMMIT_MAPPER;
  13
  14 import com.google.common.annotations.Beta;
  15 import com.google.common.base.Preconditions;
  16 import com.google.common.util.concurrent.AbstractFuture;
  17 import com.google.common.util.concurrent.CheckedFuture;
  18 import com.google.common.util.concurrent.FutureCallback;
  19 import com.google.common.util.concurrent.Futures;
  20 import com.google.common.util.concurrent.ListenableFuture;
  21 import com.google.common.util.concurrent.MoreExecutors;
  22 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  23 import java.util.Collection;
  24 import java.util.Iterator;
  25 import java.util.List;
  26 import java.util.Map;
  27 import java.util.concurrent.Executor;
  28 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
  29 import org.opendaylight.controller.cluster.datastore.exceptions.ShardLeaderNotRespondingException;
  30 import org.opendaylight.controller.md.sal.common.api.data.DataStoreUnavailableException;
  31 import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
  32 import org.opendaylight.controller.md.sal.common.api.data.TransactionCommitFailedException;
  33 import org.opendaylight.controller.md.sal.dom.api.DOMDataWriteTransaction;
  34 import org.opendaylight.controller.md.sal.dom.broker.impl.TransactionCommitFailedExceptionMapper;
  35 import org.opendaylight.controller.sal.core.spi.data.DOMStore;
  36 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  37 import org.opendaylight.mdsal.common.api.MappingCheckedFuture;
  38 import org.opendaylight.yangtools.util.DurationStatisticsTracker;
  39 import org.slf4j.Logger;
  40 import org.slf4j.LoggerFactory;
  41
  42 /**
  43  * ConcurrentDOMDataBroker commits transactions concurrently. The 3
  44  * commit phases (canCommit, preCommit, and commit) are performed serially and non-blocking
  45  * (ie async) per transaction but multiple transaction commits can run concurrent.
  46  *
  47  * @author Thomas Pantelis
  48  */
  49 @Beta
  50 public class ConcurrentDOMDataBroker extends AbstractDOMBroker {
  51     private static final Logger LOG = LoggerFactory.getLogger(ConcurrentDOMDataBroker.class);
  52     private static final String CAN_COMMIT = "CAN_COMMIT";
  53     private static final String PRE_COMMIT = "PRE_COMMIT";
  54     private static final String COMMIT = "COMMIT";
  55
  56     private final DurationStatisticsTracker commitStatsTracker;
  57
  58     /**
  59      * This executor is used to execute Future listener callback Runnables async.
  60      */
  61     private final Executor clientFutureCallbackExecutor;
  62
  63     public ConcurrentDOMDataBroker(final Map<LogicalDatastoreType, DOMStore> datastores,
  64             final Executor listenableFutureExecutor) {
  65         this(datastores, listenableFutureExecutor, DurationStatisticsTracker.createConcurrent());
  66     }
  67
  68     public ConcurrentDOMDataBroker(final Map<LogicalDatastoreType, DOMStore> datastores,
  69             final Executor listenableFutureExecutor, final DurationStatisticsTracker commitStatsTracker) {
  70         super(datastores);
  71         this.clientFutureCallbackExecutor = Preconditions.checkNotNull(listenableFutureExecutor);
  72         this.commitStatsTracker = Preconditions.checkNotNull(commitStatsTracker);
  73     }
  74
  75     public DurationStatisticsTracker getCommitStatsTracker() {
  76         return commitStatsTracker;
  77     }
  78
  79     @Override
  80     protected CheckedFuture<Void, TransactionCommitFailedException> submit(final DOMDataWriteTransaction transaction,
  81             final Collection<DOMStoreThreePhaseCommitCohort> cohorts) {
  82
  83         Preconditions.checkArgument(transaction != null, "Transaction must not be null.");
  84         Preconditions.checkArgument(cohorts != null, "Cohorts must not be null.");
  85         LOG.debug("Tx: {} is submitted for execution.", transaction.getIdentifier());
  86
  87         if (cohorts.isEmpty()) {
  88             return Futures.immediateCheckedFuture(null);
  89         }
  90
  91         final AsyncNotifyingSettableFuture clientSubmitFuture =
  92                 new AsyncNotifyingSettableFuture(clientFutureCallbackExecutor);
  93
  94         doCanCommit(clientSubmitFuture, transaction, cohorts);
  95
  96         return MappingCheckedFuture.create(clientSubmitFuture, COMMIT_ERROR_MAPPER);
  97     }
  98
  99     private void doCanCommit(final AsyncNotifyingSettableFuture clientSubmitFuture,
 100             final DOMDataWriteTransaction transaction,
 101             final Collection<DOMStoreThreePhaseCommitCohort> cohorts) {
 102
 103         final long startTime = System.nanoTime();
 104
 105         final Iterator<DOMStoreThreePhaseCommitCohort> cohortIterator = cohorts.iterator();
 106
 107         // Not using Futures.allAsList here to avoid its internal overhead.
 108         FutureCallback<Boolean> futureCallback = new FutureCallback<Boolean>() {
 109             @Override
 110             public void onSuccess(final Boolean result) {
 111                 if (result == null || !result) {
 112                     handleException(clientSubmitFuture, transaction, cohorts, CAN_COMMIT, CAN_COMMIT_ERROR_MAPPER,
 113                             new TransactionCommitFailedException("Can Commit failed, no detailed cause available."));
 114                 } else if (!cohortIterator.hasNext()) {
 115                     // All cohorts completed successfully - we can move on to the preCommit phase
 116                     doPreCommit(startTime, clientSubmitFuture, transaction, cohorts);
 117                 } else {
 118                     Futures.addCallback(cohortIterator.next().canCommit(), this, MoreExecutors.directExecutor());
 119                 }
 120             }
 121
 122             @Override
 123             public void onFailure(final Throwable failure) {
 124                 handleException(clientSubmitFuture, transaction, cohorts, CAN_COMMIT, CAN_COMMIT_ERROR_MAPPER, failure);
 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(final 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(final Throwable failure) {
 153                 handleException(clientSubmitFuture, transaction, cohorts, PRE_COMMIT, PRE_COMMIT_MAPPER, failure);
 154             }
 155         };
 156
 157         ListenableFuture<Void> preCommitFuture = cohortIterator.next().preCommit();
 158         Futures.addCallback(preCommitFuture, futureCallback, MoreExecutors.directExecutor());
 159     }
 160
 161     private void doCommit(final long startTime, final AsyncNotifyingSettableFuture clientSubmitFuture,
 162             final DOMDataWriteTransaction transaction,
 163             final Collection<DOMStoreThreePhaseCommitCohort> cohorts) {
 164
 165         final Iterator<DOMStoreThreePhaseCommitCohort> cohortIterator = cohorts.iterator();
 166
 167         // Not using Futures.allAsList here to avoid its internal overhead.
 168         FutureCallback<Void> futureCallback = new FutureCallback<Void>() {
 169             @Override
 170             public void onSuccess(final Void notUsed) {
 171                 if (!cohortIterator.hasNext()) {
 172                     // All cohorts completed successfully - we're done.
 173                     commitStatsTracker.addDuration(System.nanoTime() - startTime);
 174
 175                     clientSubmitFuture.set();
 176                 } else {
 177                     ListenableFuture<Void> commitFuture = cohortIterator.next().commit();
 178                     Futures.addCallback(commitFuture, this, MoreExecutors.directExecutor());
 179                 }
 180             }
 181
 182             @Override
 183             public void onFailure(final Throwable throwable) {
 184                 handleException(clientSubmitFuture, transaction, cohorts, COMMIT, COMMIT_ERROR_MAPPER, throwable);
 185             }
 186         };
 187
 188         ListenableFuture<Void> commitFuture = cohortIterator.next().commit();
 189         Futures.addCallback(commitFuture, futureCallback, MoreExecutors.directExecutor());
 190     }
 191
 192     @SuppressFBWarnings(value = "BC_UNCONFIRMED_CAST_OF_RETURN_VALUE",
 193             justification = "Pertains to the assignment of the 'clientException' var. FindBugs flags this as an "
 194                 + "uncomfirmed cast but the generic type in TransactionCommitFailedExceptionMapper is "
 195                 + "TransactionCommitFailedException and thus should be deemed as confirmed.")
 196     private static void handleException(final AsyncNotifyingSettableFuture clientSubmitFuture,
 197             final DOMDataWriteTransaction transaction,
 198             final Collection<DOMStoreThreePhaseCommitCohort> cohorts,
 199             final String phase, final TransactionCommitFailedExceptionMapper exMapper,
 200             final Throwable throwable) {
 201
 202         if (clientSubmitFuture.isDone()) {
 203             // We must have had failures from multiple cohorts.
 204             return;
 205         }
 206
 207         LOG.warn("Tx: {} Error during phase {}, starting Abort", transaction.getIdentifier(), phase, throwable);
 208
 209         // Transaction failed - tell all cohorts to abort.
 210         @SuppressWarnings("unchecked")
 211         ListenableFuture<Void>[] canCommitFutures = new ListenableFuture[cohorts.size()];
 212         int index = 0;
 213         for (DOMStoreThreePhaseCommitCohort cohort : cohorts) {
 214             canCommitFutures[index++] = cohort.abort();
 215         }
 216
 217         // Propagate the original exception
 218         final Exception e;
 219         if (throwable instanceof NoShardLeaderException || throwable instanceof ShardLeaderNotRespondingException) {
 220             e = new DataStoreUnavailableException(throwable.getMessage(), throwable);
 221         } else if (throwable instanceof Exception) {
 222             e = (Exception)throwable;
 223         } else {
 224             e = new RuntimeException("Unexpected error occurred", throwable);
 225         }
 226         clientSubmitFuture.setException(exMapper.apply(e));
 227
 228         ListenableFuture<List<Void>> combinedFuture = Futures.allAsList(canCommitFutures);
 229         Futures.addCallback(combinedFuture, new FutureCallback<List<Void>>() {
 230             @Override
 231             public void onSuccess(final List<Void> notUsed) {
 232                 // Propagate the original exception to the client.
 233                 LOG.debug("Tx: {} aborted successfully", transaction.getIdentifier());
 234             }
 235
 236             @Override
 237             public void onFailure(final Throwable failure) {
 238                 LOG.error("Tx: {} Error during Abort.", transaction.getIdentifier(), failure);
 239             }
 240         }, MoreExecutors.directExecutor());
 241     }
 242
 243     /**
 244      * A settable future that uses an {@link Executor} to execute listener callback Runnables,
 245      * registered via {@link #addListener}, asynchronously when this future completes. This is
 246      * done to guarantee listener executions are off-loaded onto another thread to avoid blocking
 247      * the thread that completed this future, as a common use case is to pass an executor that runs
 248      * tasks in the same thread as the caller (ie MoreExecutors#sameThreadExecutor)
 249      * to {@link #addListener}.
 250      * FIXME: This class should probably be moved to yangtools common utils for re-usability and
 251      * unified with AsyncNotifyingListenableFutureTask.
 252      */
 253     private static class AsyncNotifyingSettableFuture extends AbstractFuture<Void> {
 254
 255         /**
 256          * ThreadLocal used to detect if the task completion thread is running the future listener Runnables.
 257          */
 258         private static final ThreadLocal<Boolean> ON_TASK_COMPLETION_THREAD_TL = new ThreadLocal<>();
 259
 260         private final Executor listenerExecutor;
 261
 262         AsyncNotifyingSettableFuture(final Executor listenerExecutor) {
 263             this.listenerExecutor = Preconditions.checkNotNull(listenerExecutor);
 264         }
 265
 266         @Override
 267         public void addListener(final Runnable listener, final Executor executor) {
 268             // Wrap the listener Runnable in a DelegatingRunnable. If the specified executor is one
 269             // that runs tasks in the same thread as the caller submitting the task
 270             // (e.g. {@link com.google.common.util.concurrent.MoreExecutors#sameThreadExecutor}) and
 271             // the listener is executed from the #set methods, then the DelegatingRunnable will detect
 272             // this via the ThreadLocal and submit the listener Runnable to the listenerExecutor.
 273             //
 274             // On the other hand, if this task is already complete, the call to ExecutionList#add in
 275             // superclass will execute the listener Runnable immediately and, since the ThreadLocal
 276             // won't be set, the DelegatingRunnable will run the listener Runnable inline.
 277             super.addListener(new DelegatingRunnable(listener, listenerExecutor), executor);
 278         }
 279
 280         boolean set() {
 281             ON_TASK_COMPLETION_THREAD_TL.set(Boolean.TRUE);
 282             try {
 283                 return super.set(null);
 284             } finally {
 285                 ON_TASK_COMPLETION_THREAD_TL.set(null);
 286             }
 287         }
 288
 289         @Override
 290         protected boolean setException(final Throwable throwable) {
 291             ON_TASK_COMPLETION_THREAD_TL.set(Boolean.TRUE);
 292             try {
 293                 return super.setException(throwable);
 294             } finally {
 295                 ON_TASK_COMPLETION_THREAD_TL.set(null);
 296             }
 297         }
 298
 299         private static final class DelegatingRunnable implements Runnable {
 300             private final Runnable delegate;
 301             private final Executor executor;
 302
 303             DelegatingRunnable(final Runnable delegate, final Executor executor) {
 304                 this.delegate = Preconditions.checkNotNull(delegate);
 305                 this.executor = Preconditions.checkNotNull(executor);
 306             }
 307
 308             @Override
 309             public void run() {
 310                 if (ON_TASK_COMPLETION_THREAD_TL.get() != null) {
 311                     // We're running on the task completion thread so off-load to the executor.
 312                     LOG.trace("Submitting ListenenableFuture Runnable from thread {} to executor {}",
 313                             Thread.currentThread().getName(), executor);
 314                     executor.execute(delegate);
 315                 } else {
 316                     // We're not running on the task completion thread so run the delegate inline.
 317                     LOG.trace("Executing ListenenableFuture Runnable on this thread: {}",
 318                             Thread.currentThread().getName());
 319                     delegate.run();
 320                 }
 321             }
 322         }
 323     }
 324
 325     @Override
 326     public String toString() {
 327         return "Clustered ConcurrentDOMDataBroker";
 328     }
 329 }