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