opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/ThreePhaseCommitCohortProxy.java

   1 /*
   2  * Copyright (c) 2014 Cisco 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
   9 package org.opendaylight.controller.cluster.datastore;
  10
  11 import akka.actor.ActorPath;
  12 import akka.actor.ActorSelection;
  13 import akka.dispatch.Futures;
  14 import akka.dispatch.OnComplete;
  15
  16 import com.google.common.collect.Lists;
  17 import com.google.common.util.concurrent.ListenableFuture;
  18 import com.google.common.util.concurrent.SettableFuture;
  19
  20 import org.opendaylight.controller.cluster.datastore.messages.AbortTransaction;
  21 import org.opendaylight.controller.cluster.datastore.messages.AbortTransactionReply;
  22 import org.opendaylight.controller.cluster.datastore.messages.CanCommitTransaction;
  23 import org.opendaylight.controller.cluster.datastore.messages.CanCommitTransactionReply;
  24 import org.opendaylight.controller.cluster.datastore.messages.CommitTransaction;
  25 import org.opendaylight.controller.cluster.datastore.messages.CommitTransactionReply;
  26 import org.opendaylight.controller.cluster.datastore.messages.PreCommitTransaction;
  27 import org.opendaylight.controller.cluster.datastore.messages.PreCommitTransactionReply;
  28 import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
  29 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  30 import org.slf4j.Logger;
  31 import org.slf4j.LoggerFactory;
  32
  33 import scala.concurrent.Future;
  34
  35 import java.util.Collections;
  36 import java.util.List;
  37
  38 /**
  39  * ThreePhaseCommitCohortProxy represents a set of remote cohort proxies
  40  */
  41 public class ThreePhaseCommitCohortProxy implements DOMStoreThreePhaseCommitCohort{
  42
  43     private static final Logger LOG = LoggerFactory.getLogger(DistributedDataStore.class);
  44
  45     private final ActorContext actorContext;
  46     private final List<ActorPath> cohortPaths;
  47     private final String transactionId;
  48
  49     public ThreePhaseCommitCohortProxy(ActorContext actorContext, List<ActorPath> cohortPaths,
  50             String transactionId) {
  51         this.actorContext = actorContext;
  52         this.cohortPaths = cohortPaths;
  53         this.transactionId = transactionId;
  54     }
  55
  56     @Override
  57     public ListenableFuture<Boolean> canCommit() {
  58         LOG.debug("txn {} canCommit", transactionId);
  59
  60         Future<Iterable<Object>> combinedFuture =
  61                 invokeCohorts(new CanCommitTransaction().toSerializable());
  62
  63         final SettableFuture<Boolean> returnFuture = SettableFuture.create();
  64
  65         combinedFuture.onComplete(new OnComplete<Iterable<Object>>() {
  66             @Override
  67             public void onComplete(Throwable failure, Iterable<Object> responses) throws Throwable {
  68                 if(failure != null) {
  69                     returnFuture.setException(failure);
  70                     return;
  71                 }
  72
  73                 boolean result = true;
  74                 for(Object response: responses) {
  75                     if (response.getClass().equals(CanCommitTransactionReply.SERIALIZABLE_CLASS)) {
  76                         CanCommitTransactionReply reply =
  77                                 CanCommitTransactionReply.fromSerializable(response);
  78                         if (!reply.getCanCommit()) {
  79                             result = false;
  80                             break;
  81                         }
  82                     } else {
  83                         LOG.error("Unexpected response type {}", response.getClass());
  84                         returnFuture.setException(new IllegalArgumentException(
  85                                 String.format("Unexpected response type {}", response.getClass())));
  86                         return;
  87                     }
  88                 }
  89
  90                 returnFuture.set(Boolean.valueOf(result));
  91             }
  92         }, actorContext.getActorSystem().dispatcher());
  93
  94         return returnFuture;
  95     }
  96
  97     private Future<Iterable<Object>> invokeCohorts(Object message) {
  98         List<Future<Object>> futureList = Lists.newArrayListWithCapacity(cohortPaths.size());
  99         for(ActorPath actorPath : cohortPaths) {
 100
 101             LOG.debug("txn {} Sending {} to {}", transactionId, message, actorPath);
 102
 103             ActorSelection cohort = actorContext.actorSelection(actorPath);
 104
 105             futureList.add(actorContext.executeRemoteOperationAsync(cohort, message,
 106                     ActorContext.ASK_DURATION));
 107         }
 108
 109         return Futures.sequence(futureList, actorContext.getActorSystem().dispatcher());
 110     }
 111
 112     @Override
 113     public ListenableFuture<Void> preCommit() {
 114         LOG.debug("txn {} preCommit", transactionId);
 115         return voidOperation(new PreCommitTransaction().toSerializable(),
 116                 PreCommitTransactionReply.SERIALIZABLE_CLASS, true);
 117     }
 118
 119     @Override
 120     public ListenableFuture<Void> abort() {
 121         LOG.debug("txn {} abort", transactionId);
 122
 123         // Note - we pass false for propagateException. In the front-end data broker, this method
 124         // is called when one of the 3 phases fails with an exception. We'd rather have that
 125         // original exception propagated to the client. If our abort fails and we propagate the
 126         // exception then that exception will supersede and suppress the original exception. But
 127         // it's the original exception that is the root cause and of more interest to the client.
 128
 129         return voidOperation(new AbortTransaction().toSerializable(),
 130                 AbortTransactionReply.SERIALIZABLE_CLASS, false);
 131     }
 132
 133     @Override
 134     public ListenableFuture<Void> commit() {
 135         LOG.debug("txn {} commit", transactionId);
 136         return voidOperation(new CommitTransaction().toSerializable(),
 137                 CommitTransactionReply.SERIALIZABLE_CLASS, true);
 138     }
 139
 140     private ListenableFuture<Void> voidOperation(final Object message,
 141             final Class<?> expectedResponseClass, final boolean propagateException) {
 142
 143         Future<Iterable<Object>> combinedFuture = invokeCohorts(message);
 144
 145         final SettableFuture<Void> returnFuture = SettableFuture.create();
 146
 147         combinedFuture.onComplete(new OnComplete<Iterable<Object>>() {
 148             @Override
 149             public void onComplete(Throwable failure, Iterable<Object> responses) throws Throwable {
 150
 151                 Throwable exceptionToPropagate = failure;
 152                 if(exceptionToPropagate == null) {
 153                     for(Object response: responses) {
 154                         if(!response.getClass().equals(expectedResponseClass)) {
 155                             exceptionToPropagate = new IllegalArgumentException(
 156                                     String.format("Unexpected response type {}",
 157                                             response.getClass()));
 158                             break;
 159                         }
 160                     }
 161                 }
 162
 163                 if(exceptionToPropagate != null) {
 164                     if(propagateException) {
 165                         // We don't log the exception here to avoid redundant logging since we're
 166                         // propagating to the caller in MD-SAL core who will log it.
 167                         returnFuture.setException(exceptionToPropagate);
 168                     } else {
 169                         // Since the caller doesn't want us to propagate the exception we'll also
 170                         // not log it normally. But it's usually not good to totally silence
 171                         // exceptions so we'll log it to debug level.
 172                         LOG.debug(String.format("%s failed",  message.getClass().getSimpleName()),
 173                                 exceptionToPropagate);
 174                         returnFuture.set(null);
 175                     }
 176                 } else {
 177                     returnFuture.set(null);
 178                 }
 179             }
 180         }, actorContext.getActorSystem().dispatcher());
 181
 182         return returnFuture;
 183     }
 184
 185     public List<ActorPath> getCohortPaths() {
 186         return Collections.unmodifiableList(this.cohortPaths);
 187     }
 188 }