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 com.google.common.base.Preconditions.checkArgument;
  11 import static java.util.Objects.requireNonNull;
  12 import static org.opendaylight.mdsal.dom.spi.TransactionCommitFailedExceptionMapper.CAN_COMMIT_ERROR_MAPPER;
  13 import static org.opendaylight.mdsal.dom.spi.TransactionCommitFailedExceptionMapper.COMMIT_ERROR_MAPPER;
  14 import static org.opendaylight.mdsal.dom.spi.TransactionCommitFailedExceptionMapper.PRE_COMMIT_MAPPER;
  15
  16 import com.google.common.annotations.Beta;
  17 import com.google.common.util.concurrent.AbstractFuture;
  18 import com.google.common.util.concurrent.FluentFuture;
  19 import com.google.common.util.concurrent.FutureCallback;
  20 import com.google.common.util.concurrent.Futures;
  21 import com.google.common.util.concurrent.MoreExecutors;
  22 import java.util.Map;
  23 import java.util.concurrent.Executor;
  24 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
  25 import org.opendaylight.controller.cluster.datastore.exceptions.ShardLeaderNotRespondingException;
  26 import org.opendaylight.mdsal.common.api.CommitInfo;
  27 import org.opendaylight.mdsal.common.api.DataStoreUnavailableException;
  28 import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
  29 import org.opendaylight.mdsal.common.api.TransactionCommitFailedException;
  30 import org.opendaylight.mdsal.dom.api.DOMDataTreeWriteTransaction;
  31 import org.opendaylight.mdsal.dom.spi.AbstractDOMDataBroker;
  32 import org.opendaylight.mdsal.dom.spi.TransactionCommitFailedExceptionMapper;
  33 import org.opendaylight.mdsal.dom.spi.store.DOMStore;
  34 import org.opendaylight.mdsal.dom.spi.store.DOMStoreThreePhaseCommitCohort;
  35 import org.opendaylight.yangtools.util.DurationStatisticsTracker;
  36 import org.opendaylight.yangtools.yang.common.Empty;
  37 import org.slf4j.Logger;
  38 import org.slf4j.LoggerFactory;
  39
  40 /**
  41  * ConcurrentDOMDataBroker commits transactions concurrently. The 3
  42  * commit phases (canCommit, preCommit, and commit) are performed serially and non-blocking
  43  * (ie async) per transaction but multiple transaction commits can run concurrent.
  44  *
  45  * @author Thomas Pantelis
  46  */
  47 @Beta
  48 public class ConcurrentDOMDataBroker extends AbstractDOMDataBroker {
  49     private static final Logger LOG = LoggerFactory.getLogger(ConcurrentDOMDataBroker.class);
  50     private static final String CAN_COMMIT = "CAN_COMMIT";
  51     private static final String PRE_COMMIT = "PRE_COMMIT";
  52     private static final String COMMIT = "COMMIT";
  53
  54     private final DurationStatisticsTracker commitStatsTracker;
  55
  56     /**
  57      * This executor is used to execute Future listener callback Runnables async.
  58      */
  59     private final Executor clientFutureCallbackExecutor;
  60
  61     public ConcurrentDOMDataBroker(final Map<LogicalDatastoreType, DOMStore> datastores,
  62             final Executor listenableFutureExecutor) {
  63         this(datastores, listenableFutureExecutor, DurationStatisticsTracker.createConcurrent());
  64     }
  65
  66     public ConcurrentDOMDataBroker(final Map<LogicalDatastoreType, DOMStore> datastores,
  67             final Executor listenableFutureExecutor, final DurationStatisticsTracker commitStatsTracker) {
  68         super(datastores);
  69         clientFutureCallbackExecutor = requireNonNull(listenableFutureExecutor);
  70         this.commitStatsTracker = requireNonNull(commitStatsTracker);
  71     }
  72
  73     public DurationStatisticsTracker getCommitStatsTracker() {
  74         return commitStatsTracker;
  75     }
  76
  77     @Override
  78     protected FluentFuture<? extends CommitInfo> commit(final DOMDataTreeWriteTransaction transaction,
  79             final DOMStoreThreePhaseCommitCohort cohort) {
  80
  81         checkArgument(transaction != null, "Transaction must not be null.");
  82         checkArgument(cohort != null, "Cohorts must not be null.");
  83         LOG.debug("Tx: {} is submitted for execution.", transaction.getIdentifier());
  84
  85         final AsyncNotifyingSettableFuture clientSubmitFuture =
  86                 new AsyncNotifyingSettableFuture(clientFutureCallbackExecutor);
  87
  88         doCanCommit(clientSubmitFuture, transaction, cohort);
  89         return FluentFuture.from(clientSubmitFuture);
  90     }
  91
  92     private void doCanCommit(final AsyncNotifyingSettableFuture clientSubmitFuture,
  93             final DOMDataTreeWriteTransaction transaction,
  94             final DOMStoreThreePhaseCommitCohort cohort) {
  95         final long startTime = System.nanoTime();
  96
  97         Futures.addCallback(cohort.canCommit(), new FutureCallback<>() {
  98             @Override
  99             public void onSuccess(final Boolean result) {
 100                 if (result == null || !result) {
 101                     onFailure(new TransactionCommitFailedException("Can Commit failed, no detailed cause available."));
 102                 } else {
 103                     doPreCommit(startTime, clientSubmitFuture, transaction, cohort);
 104                 }
 105             }
 106
 107             @Override
 108             public void onFailure(final Throwable failure) {
 109                 handleException(clientSubmitFuture, transaction, cohort, CAN_COMMIT, CAN_COMMIT_ERROR_MAPPER, failure);
 110             }
 111         }, MoreExecutors.directExecutor());
 112     }
 113
 114     private void doPreCommit(final long startTime, final AsyncNotifyingSettableFuture clientSubmitFuture,
 115             final DOMDataTreeWriteTransaction transaction, final DOMStoreThreePhaseCommitCohort cohort) {
 116         Futures.addCallback(cohort.preCommit(), new FutureCallback<>() {
 117             @Override
 118             public void onSuccess(final Empty result) {
 119                 doCommit(startTime, clientSubmitFuture, transaction, cohort);
 120             }
 121
 122             @Override
 123             public void onFailure(final Throwable failure) {
 124                 handleException(clientSubmitFuture, transaction, cohort, PRE_COMMIT, PRE_COMMIT_MAPPER, failure);
 125             }
 126         }, MoreExecutors.directExecutor());
 127     }
 128
 129     private void doCommit(final long startTime, final AsyncNotifyingSettableFuture clientSubmitFuture,
 130             final DOMDataTreeWriteTransaction transaction, final DOMStoreThreePhaseCommitCohort cohort) {
 131         Futures.addCallback(cohort.commit(), new FutureCallback<CommitInfo>() {
 132             @Override
 133             public void onSuccess(final CommitInfo result) {
 134                 commitStatsTracker.addDuration(System.nanoTime() - startTime);
 135                 clientSubmitFuture.set();
 136             }
 137
 138             @Override
 139             public void onFailure(final Throwable throwable) {
 140                 handleException(clientSubmitFuture, transaction, cohort, COMMIT, COMMIT_ERROR_MAPPER, throwable);
 141             }
 142         }, MoreExecutors.directExecutor());
 143     }
 144
 145     private static void handleException(final AsyncNotifyingSettableFuture clientSubmitFuture,
 146             final DOMDataTreeWriteTransaction transaction, final DOMStoreThreePhaseCommitCohort cohort,
 147             final String phase, final TransactionCommitFailedExceptionMapper exMapper, final Throwable throwable) {
 148         if (clientSubmitFuture.isDone()) {
 149             // We must have had failures from multiple cohorts.
 150             return;
 151         }
 152
 153         // Use debug instead of warn level here because this exception gets propagate back to the caller via the Future
 154         LOG.debug("Tx: {} Error during phase {}, starting Abort", transaction.getIdentifier(), phase, throwable);
 155
 156         // Propagate the original exception
 157         final Exception e;
 158         if (throwable instanceof NoShardLeaderException || throwable instanceof ShardLeaderNotRespondingException) {
 159             e = new DataStoreUnavailableException(throwable.getMessage(), throwable);
 160         } else if (throwable instanceof Exception) {
 161             e = (Exception) throwable;
 162         } else {
 163             e = new RuntimeException("Unexpected error occurred", throwable);
 164         }
 165         clientSubmitFuture.setException(exMapper.apply(e));
 166
 167         // abort
 168         Futures.addCallback(cohort.abort(), new FutureCallback<Empty>() {
 169             @Override
 170             public void onSuccess(final Empty result) {
 171                 // Propagate the original exception to the client.
 172                 LOG.debug("Tx: {} aborted successfully", transaction.getIdentifier());
 173             }
 174
 175             @Override
 176             public void onFailure(final Throwable failure) {
 177                 LOG.error("Tx: {} Error during Abort.", transaction.getIdentifier(), failure);
 178             }
 179         }, MoreExecutors.directExecutor());
 180     }
 181
 182     /**
 183      * A settable future that uses an {@link Executor} to execute listener callback Runnables,
 184      * registered via {@link #addListener}, asynchronously when this future completes. This is
 185      * done to guarantee listener executions are off-loaded onto another thread to avoid blocking
 186      * the thread that completed this future, as a common use case is to pass an executor that runs
 187      * tasks in the same thread as the caller (ie MoreExecutors#sameThreadExecutor)
 188      * to {@link #addListener}.
 189      * FIXME: This class should probably be moved to yangtools common utils for re-usability and
 190      * unified with AsyncNotifyingListenableFutureTask.
 191      */
 192     private static class AsyncNotifyingSettableFuture extends AbstractFuture<CommitInfo> {
 193         /**
 194          * ThreadLocal used to detect if the task completion thread is running the future listener Runnables.
 195          */
 196         private static final ThreadLocal<Boolean> ON_TASK_COMPLETION_THREAD_TL = new ThreadLocal<>();
 197
 198         private final Executor listenerExecutor;
 199
 200         AsyncNotifyingSettableFuture(final Executor listenerExecutor) {
 201             this.listenerExecutor = requireNonNull(listenerExecutor);
 202         }
 203
 204         @Override
 205         public void addListener(final Runnable listener, final Executor executor) {
 206             // Wrap the listener Runnable in a DelegatingRunnable. If the specified executor is one
 207             // that runs tasks in the same thread as the caller submitting the task
 208             // (e.g. {@link com.google.common.util.concurrent.MoreExecutors#sameThreadExecutor}) and
 209             // the listener is executed from the #set methods, then the DelegatingRunnable will detect
 210             // this via the ThreadLocal and submit the listener Runnable to the listenerExecutor.
 211             //
 212             // On the other hand, if this task is already complete, the call to ExecutionList#add in
 213             // superclass will execute the listener Runnable immediately and, since the ThreadLocal
 214             // won't be set, the DelegatingRunnable will run the listener Runnable inline.
 215             super.addListener(new DelegatingRunnable(listener, listenerExecutor), executor);
 216         }
 217
 218         boolean set() {
 219             ON_TASK_COMPLETION_THREAD_TL.set(Boolean.TRUE);
 220             try {
 221                 return super.set(CommitInfo.empty());
 222             } finally {
 223                 ON_TASK_COMPLETION_THREAD_TL.set(null);
 224             }
 225         }
 226
 227         @Override
 228         protected boolean setException(final Throwable throwable) {
 229             ON_TASK_COMPLETION_THREAD_TL.set(Boolean.TRUE);
 230             try {
 231                 return super.setException(throwable);
 232             } finally {
 233                 ON_TASK_COMPLETION_THREAD_TL.set(null);
 234             }
 235         }
 236
 237         private static final class DelegatingRunnable implements Runnable {
 238             private final Runnable delegate;
 239             private final Executor executor;
 240
 241             DelegatingRunnable(final Runnable delegate, final Executor executor) {
 242                 this.delegate = requireNonNull(delegate);
 243                 this.executor = requireNonNull(executor);
 244             }
 245
 246             @Override
 247             public void run() {
 248                 if (ON_TASK_COMPLETION_THREAD_TL.get() != null) {
 249                     // We're running on the task completion thread so off-load to the executor.
 250                     LOG.trace("Submitting ListenenableFuture Runnable from thread {} to executor {}",
 251                             Thread.currentThread().getName(), executor);
 252                     executor.execute(delegate);
 253                 } else {
 254                     // We're not running on the task completion thread so run the delegate inline.
 255                     LOG.trace("Executing ListenenableFuture Runnable on this thread: {}",
 256                             Thread.currentThread().getName());
 257                     delegate.run();
 258                 }
 259             }
 260         }
 261     }
 262
 263     @Override
 264     public String toString() {
 265         return "Clustered ConcurrentDOMDataBroker";
 266     }
 267 }