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

   1 /*
   2  * Copyright (c) 2016 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 package org.opendaylight.controller.cluster.datastore;
   9
  10 import static com.google.common.base.Preconditions.checkState;
  11 import static java.util.Objects.requireNonNull;
  12
  13 import akka.actor.ActorRef;
  14 import akka.actor.Status;
  15 import akka.actor.Status.Failure;
  16 import akka.dispatch.ExecutionContexts;
  17 import akka.dispatch.Futures;
  18 import akka.dispatch.OnComplete;
  19 import akka.dispatch.Recover;
  20 import akka.pattern.Patterns;
  21 import akka.util.Timeout;
  22 import com.google.common.collect.Lists;
  23 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  24 import java.util.AbstractMap.SimpleImmutableEntry;
  25 import java.util.ArrayList;
  26 import java.util.Collection;
  27 import java.util.Iterator;
  28 import java.util.List;
  29 import java.util.Map.Entry;
  30 import java.util.Optional;
  31 import java.util.concurrent.CompletableFuture;
  32 import java.util.concurrent.CompletionStage;
  33 import java.util.concurrent.Executor;
  34 import org.eclipse.jdt.annotation.NonNull;
  35 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  36 import org.opendaylight.controller.cluster.datastore.DataTreeCohortActor.CanCommit;
  37 import org.opendaylight.controller.cluster.datastore.DataTreeCohortActor.Success;
  38 import org.opendaylight.yangtools.yang.data.tree.api.DataTreeCandidate;
  39 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  40 import org.slf4j.Logger;
  41 import org.slf4j.LoggerFactory;
  42 import scala.compat.java8.FutureConverters;
  43 import scala.concurrent.Future;
  44
  45 /**
  46  * Composite cohort, which coordinates multiple user-provided cohorts as if it was only one cohort.
  47  * <p/>
  48  * It tracks current operation and list of cohorts which successfuly finished previous phase in
  49  * case, if abort is necessary to invoke it only on cohort steps which are still active.
  50  */
  51 class CompositeDataTreeCohort {
  52     private static final Logger LOG = LoggerFactory.getLogger(CompositeDataTreeCohort.class);
  53
  54     private enum State {
  55         /**
  56          * Cohorts are idle, no messages were sent.
  57          */
  58         IDLE,
  59         /**
  60          * CanCommit message was sent to all participating cohorts.
  61          */
  62         CAN_COMMIT_SENT,
  63         /**
  64          * Successful canCommit responses were received from every participating cohort.
  65          */
  66         CAN_COMMIT_SUCCESSFUL,
  67         /**
  68          * PreCommit message was sent to all participating cohorts.
  69          */
  70         PRE_COMMIT_SENT,
  71         /**
  72          * Successful preCommit responses were received from every participating cohort.
  73          */
  74         PRE_COMMIT_SUCCESSFUL,
  75         /**
  76          * Commit message was send to all participating cohorts.
  77          */
  78         COMMIT_SENT,
  79         /**
  80          * Successful commit responses were received from all participating cohorts.
  81          */
  82         COMMITED,
  83         /**
  84          * Some of cohorts responded back with unsuccessful message.
  85          */
  86         FAILED,
  87         /**
  88          * Abort message was send to all cohorts which responded with success previously.
  89          */
  90         ABORTED
  91     }
  92
  93     static final Recover<Object> EXCEPTION_TO_MESSAGE = new Recover<>() {
  94         @Override
  95         public Failure recover(final Throwable error) {
  96             return new Failure(error);
  97         }
  98     };
  99
 100     private final DataTreeCohortActorRegistry registry;
 101     private final TransactionIdentifier txId;
 102     private final SchemaContext schema;
 103     private final Executor callbackExecutor;
 104     private final Timeout timeout;
 105
 106     private @NonNull List<Success> successfulFromPrevious = List.of();
 107     private State state = State.IDLE;
 108
 109     CompositeDataTreeCohort(final DataTreeCohortActorRegistry registry, final TransactionIdentifier transactionID,
 110         final SchemaContext schema, final Executor callbackExecutor, final Timeout timeout) {
 111         this.registry = requireNonNull(registry);
 112         txId = requireNonNull(transactionID);
 113         this.schema = requireNonNull(schema);
 114         this.callbackExecutor = requireNonNull(callbackExecutor);
 115         this.timeout = requireNonNull(timeout);
 116     }
 117
 118     void reset() {
 119         switch (state) {
 120             case CAN_COMMIT_SENT:
 121             case CAN_COMMIT_SUCCESSFUL:
 122             case PRE_COMMIT_SENT:
 123             case PRE_COMMIT_SUCCESSFUL:
 124             case COMMIT_SENT:
 125                 abort();
 126                 break;
 127             case ABORTED:
 128             case COMMITED:
 129             case FAILED:
 130             case IDLE:
 131                 break;
 132             default:
 133                 throw new IllegalStateException("Unhandled state " + state);
 134         }
 135
 136         successfulFromPrevious = List.of();
 137         state = State.IDLE;
 138     }
 139
 140     Optional<CompletionStage<Void>> canCommit(final DataTreeCandidate tip) {
 141         if (LOG.isTraceEnabled()) {
 142             LOG.trace("{}: canCommit - candidate: {}", txId, tip);
 143         } else {
 144             LOG.debug("{}: canCommit - candidate rootPath: {}", txId, tip.getRootPath());
 145         }
 146
 147         final List<CanCommit> messages = registry.createCanCommitMessages(txId, tip, schema);
 148         LOG.debug("{}: canCommit - messages: {}", txId, messages);
 149         if (messages.isEmpty()) {
 150             successfulFromPrevious = List.of();
 151             changeStateFrom(State.IDLE, State.CAN_COMMIT_SUCCESSFUL);
 152             return Optional.empty();
 153         }
 154
 155         final List<Entry<ActorRef, Future<Object>>> futures = new ArrayList<>(messages.size());
 156         for (CanCommit message : messages) {
 157             final ActorRef actor = message.getCohort();
 158             final Future<Object> future = Patterns.ask(actor, message, timeout).recover(EXCEPTION_TO_MESSAGE,
 159                 ExecutionContexts.global());
 160             LOG.trace("{}: requesting canCommit from {}", txId, actor);
 161             futures.add(new SimpleImmutableEntry<>(actor, future));
 162         }
 163
 164         changeStateFrom(State.IDLE, State.CAN_COMMIT_SENT);
 165         return Optional.of(processResponses(futures, State.CAN_COMMIT_SENT, State.CAN_COMMIT_SUCCESSFUL));
 166     }
 167
 168     Optional<CompletionStage<Void>> preCommit() {
 169         LOG.debug("{}: preCommit - successfulFromPrevious: {}", txId, successfulFromPrevious);
 170
 171         if (successfulFromPrevious.isEmpty()) {
 172             changeStateFrom(State.CAN_COMMIT_SUCCESSFUL, State.PRE_COMMIT_SUCCESSFUL);
 173             return Optional.empty();
 174         }
 175
 176         final List<Entry<ActorRef, Future<Object>>> futures = sendMessageToSuccessful(
 177             new DataTreeCohortActor.PreCommit(txId));
 178         changeStateFrom(State.CAN_COMMIT_SUCCESSFUL, State.PRE_COMMIT_SENT);
 179         return Optional.of(processResponses(futures, State.PRE_COMMIT_SENT, State.PRE_COMMIT_SUCCESSFUL));
 180     }
 181
 182     Optional<CompletionStage<Void>> commit() {
 183         LOG.debug("{}: commit - successfulFromPrevious: {}", txId, successfulFromPrevious);
 184         if (successfulFromPrevious.isEmpty()) {
 185             changeStateFrom(State.PRE_COMMIT_SUCCESSFUL, State.COMMITED);
 186             return Optional.empty();
 187         }
 188
 189         final List<Entry<ActorRef, Future<Object>>> futures = sendMessageToSuccessful(
 190             new DataTreeCohortActor.Commit(txId));
 191         changeStateFrom(State.PRE_COMMIT_SUCCESSFUL, State.COMMIT_SENT);
 192         return Optional.of(processResponses(futures, State.COMMIT_SENT, State.COMMITED));
 193     }
 194
 195     Optional<CompletionStage<?>> abort() {
 196         LOG.debug("{}: abort - successfulFromPrevious: {}", txId, successfulFromPrevious);
 197
 198         state = State.ABORTED;
 199         if (successfulFromPrevious.isEmpty()) {
 200             return Optional.empty();
 201         }
 202
 203         final DataTreeCohortActor.Abort message = new DataTreeCohortActor.Abort(txId);
 204         final List<Future<Object>> futures = new ArrayList<>(successfulFromPrevious.size());
 205         for (Success s : successfulFromPrevious) {
 206             futures.add(Patterns.ask(s.getCohort(), message, timeout));
 207         }
 208
 209         return Optional.of(FutureConverters.toJava(Futures.sequence(futures, ExecutionContexts.global())));
 210     }
 211
 212     private List<Entry<ActorRef, Future<Object>>> sendMessageToSuccessful(final Object message) {
 213         LOG.debug("{}: sendMesageToSuccessful: {}", txId, message);
 214
 215         final List<Entry<ActorRef, Future<Object>>> ret = new ArrayList<>(successfulFromPrevious.size());
 216         for (Success s : successfulFromPrevious) {
 217             final ActorRef actor = s.getCohort();
 218             ret.add(new SimpleImmutableEntry<>(actor, Patterns.ask(actor, message, timeout)));
 219         }
 220         return ret;
 221     }
 222
 223     private @NonNull CompletionStage<Void> processResponses(final List<Entry<ActorRef, Future<Object>>> futures,
 224             final State currentState, final State afterState) {
 225         LOG.debug("{}: processResponses - currentState: {}, afterState: {}", txId, currentState, afterState);
 226         final CompletableFuture<Void> returnFuture = new CompletableFuture<>();
 227         Future<Iterable<Object>> aggregateFuture = Futures.sequence(Lists.transform(futures, Entry::getValue),
 228                 ExecutionContexts.global());
 229
 230         aggregateFuture.onComplete(new OnComplete<Iterable<Object>>() {
 231             @Override
 232             public void onComplete(final Throwable failure, final Iterable<Object> results) {
 233                 callbackExecutor.execute(
 234                     () -> processResponses(failure, results, currentState, afterState, returnFuture));
 235             }
 236         }, ExecutionContexts.global());
 237
 238         return returnFuture;
 239     }
 240
 241     // FB issues violation for passing null to CompletableFuture#complete but it is valid and necessary when the
 242     // generic type is Void.
 243     @SuppressFBWarnings(value = "NP_NONNULL_PARAM_VIOLATION")
 244     private void processResponses(final Throwable failure, final Iterable<Object> results,
 245             final State currentState, final State afterState, final CompletableFuture<Void> resultFuture) {
 246         if (failure != null) {
 247             successfulFromPrevious = List.of();
 248             resultFuture.completeExceptionally(failure);
 249             return;
 250         }
 251
 252         final Collection<Failure> failed = new ArrayList<>(1);
 253         final List<Success> successful = new ArrayList<>();
 254         for (Object result : results) {
 255             if (result instanceof DataTreeCohortActor.Success) {
 256                 successful.add((Success) result);
 257             } else if (result instanceof Status.Failure) {
 258                 failed.add((Failure) result);
 259             } else {
 260                 LOG.warn("{}: unrecognized response {}, ignoring it", txId, result);
 261             }
 262         }
 263
 264         LOG.debug("{}: processResponses - successful: {}, failed: {}", txId, successful, failed);
 265
 266         if (!failed.isEmpty()) {
 267             changeStateFrom(currentState, State.FAILED);
 268             final Iterator<Failure> it = failed.iterator();
 269             final Throwable firstEx = it.next().cause();
 270             while (it.hasNext()) {
 271                 firstEx.addSuppressed(it.next().cause());
 272             }
 273
 274             successfulFromPrevious = List.of();
 275             resultFuture.completeExceptionally(firstEx);
 276         } else {
 277             successfulFromPrevious = successful;
 278             changeStateFrom(currentState, afterState);
 279             resultFuture.complete(null);
 280         }
 281     }
 282
 283     void changeStateFrom(final State expected, final State followup) {
 284         checkState(state == expected);
 285         state = followup;
 286     }
 287 }