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
   9 package org.opendaylight.controller.cluster.datastore;
  10
  11 import akka.actor.Status;
  12 import akka.actor.Status.Failure;
  13 import akka.dispatch.ExecutionContexts;
  14 import akka.dispatch.Futures;
  15 import akka.dispatch.Recover;
  16 import akka.japi.Function;
  17 import akka.pattern.Patterns;
  18 import akka.util.Timeout;
  19 import com.google.common.base.Preconditions;
  20 import com.google.common.base.Throwables;
  21 import com.google.common.collect.Iterables;
  22 import java.util.Collection;
  23 import java.util.Iterator;
  24 import java.util.Optional;
  25 import java.util.concurrent.ExecutionException;
  26 import java.util.concurrent.TimeoutException;
  27 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  28 import org.opendaylight.controller.cluster.datastore.DataTreeCohortActor.CanCommit;
  29 import org.opendaylight.controller.cluster.datastore.DataTreeCohortActor.Success;
  30 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  31 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  32 import scala.concurrent.Await;
  33 import scala.concurrent.Future;
  34
  35 /**
  36  *
  37  * Composite cohort, which coordinates multiple user-provided cohorts as if it was only one cohort.
  38  *
  39  * It tracks current operation and list of cohorts which successfuly finished previous phase in
  40  * case, if abort is necessary to invoke it only on cohort steps which are still active.
  41  *
  42  */
  43 class CompositeDataTreeCohort {
  44
  45     private enum State {
  46         /**
  47          * Cohorts are idle, no messages were sent.
  48          */
  49         IDLE,
  50         /**
  51          * CanCommit message was sent to all participating cohorts.
  52          */
  53         CAN_COMMIT_SENT,
  54         /**
  55          * Successful canCommit responses were received from every participating cohort.
  56          */
  57         CAN_COMMIT_SUCCESSFUL,
  58         /**
  59          * PreCommit message was sent to all participating cohorts.
  60          */
  61         PRE_COMMIT_SENT,
  62         /**
  63          * Successful preCommit responses were received from every participating cohort.
  64          */
  65         PRE_COMMIT_SUCCESSFUL,
  66         /**
  67          * Commit message was send to all participating cohorts.
  68          */
  69         COMMIT_SENT,
  70         /**
  71          * Successful commit responses were received from all participating cohorts.
  72          */
  73         COMMITED,
  74         /**
  75          * Some of cohorts responsed back with unsuccessful message.
  76          *
  77          */
  78         FAILED,
  79         /**
  80          *
  81          * Abort message was send to all cohorts which responded with success previously.
  82          *
  83          */
  84         ABORTED
  85     }
  86
  87     protected static final Recover<Object> EXCEPTION_TO_MESSAGE = new Recover<Object>() {
  88         @Override
  89         public Failure recover(final Throwable error) throws Throwable {
  90             return new Failure(error);
  91         }
  92     };
  93
  94
  95     private final DataTreeCohortActorRegistry registry;
  96     private final TransactionIdentifier txId;
  97     private final SchemaContext schema;
  98     private final Timeout timeout;
  99     private Iterable<Success> successfulFromPrevious;
 100     private State state = State.IDLE;
 101
 102     CompositeDataTreeCohort(final DataTreeCohortActorRegistry registry, final TransactionIdentifier transactionID,
 103         final SchemaContext schema, final Timeout timeout) {
 104         this.registry = Preconditions.checkNotNull(registry);
 105         this.txId = Preconditions.checkNotNull(transactionID);
 106         this.schema = Preconditions.checkNotNull(schema);
 107         this.timeout = Preconditions.checkNotNull(timeout);
 108     }
 109
 110     void canCommit(final DataTreeCandidate tip) throws ExecutionException, TimeoutException {
 111         Collection<CanCommit> messages = registry.createCanCommitMessages(txId, tip, schema);
 112         // FIXME: Optimize empty collection list with pre-created futures, containing success.
 113         Future<Iterable<Object>> canCommitsFuture =
 114                 Futures.traverse(messages, new Function<CanCommit, Future<Object>>() {
 115                     @Override
 116                     public Future<Object> apply(final CanCommit input) {
 117                         return Patterns.ask(input.getCohort(), input, timeout).recover(EXCEPTION_TO_MESSAGE,
 118                                 ExecutionContexts.global());
 119                     }
 120                 }, ExecutionContexts.global());
 121         changeStateFrom(State.IDLE, State.CAN_COMMIT_SENT);
 122         processResponses(canCommitsFuture, State.CAN_COMMIT_SENT, State.CAN_COMMIT_SUCCESSFUL);
 123     }
 124
 125     void preCommit() throws ExecutionException, TimeoutException {
 126         Preconditions.checkState(successfulFromPrevious != null);
 127         Future<Iterable<Object>> preCommitFutures = sendMesageToSuccessful(new DataTreeCohortActor.PreCommit(txId));
 128         changeStateFrom(State.CAN_COMMIT_SUCCESSFUL, State.PRE_COMMIT_SENT);
 129         processResponses(preCommitFutures, State.PRE_COMMIT_SENT, State.PRE_COMMIT_SUCCESSFUL);
 130     }
 131
 132     void commit() throws ExecutionException, TimeoutException {
 133         Preconditions.checkState(successfulFromPrevious != null);
 134         Future<Iterable<Object>> commitsFuture = sendMesageToSuccessful(new DataTreeCohortActor.Commit(txId));
 135         changeStateFrom(State.PRE_COMMIT_SUCCESSFUL, State.COMMIT_SENT);
 136         processResponses(commitsFuture, State.COMMIT_SENT, State.COMMITED);
 137     }
 138
 139     Optional<Future<Iterable<Object>>> abort() {
 140         if (successfulFromPrevious != null) {
 141             return Optional.of(sendMesageToSuccessful(new DataTreeCohortActor.Abort(txId)));
 142         }
 143
 144         return Optional.empty();
 145     }
 146
 147     private Future<Iterable<Object>> sendMesageToSuccessful(final Object message) {
 148         return Futures.traverse(successfulFromPrevious, new Function<DataTreeCohortActor.Success, Future<Object>>() {
 149
 150             @Override
 151             public Future<Object> apply(final DataTreeCohortActor.Success cohortResponse) throws Exception {
 152                 return Patterns.ask(cohortResponse.getCohort(), message, timeout);
 153             }
 154
 155         }, ExecutionContexts.global());
 156     }
 157
 158     private void processResponses(final Future<Iterable<Object>> resultsFuture, final State currentState, final State afterState)
 159             throws TimeoutException, ExecutionException {
 160         final Iterable<Object> results;
 161         try {
 162             results = Await.result(resultsFuture, timeout.duration());
 163         } catch (Exception e) {
 164             successfulFromPrevious = null;
 165             Throwables.propagateIfInstanceOf(e, TimeoutException.class);
 166             throw Throwables.propagate(e);
 167         }
 168         Iterable<Failure> failed = Iterables.filter(results, Status.Failure.class);
 169         Iterable<Success> successful = Iterables.filter(results, DataTreeCohortActor.Success.class);
 170         successfulFromPrevious = successful;
 171         if (!Iterables.isEmpty(failed)) {
 172             changeStateFrom(currentState, State.FAILED);
 173             Iterator<Failure> it = failed.iterator();
 174             Throwable firstEx = it.next().cause();
 175             while (it.hasNext()) {
 176                 firstEx.addSuppressed(it.next().cause());
 177             }
 178             Throwables.propagateIfPossible(firstEx, ExecutionException.class);
 179             Throwables.propagateIfPossible(firstEx, TimeoutException.class);
 180             throw Throwables.propagate(firstEx);
 181         }
 182         changeStateFrom(currentState, afterState);
 183     }
 184
 185     void changeStateFrom(final State expected, final State followup) {
 186         Preconditions.checkState(state == expected);
 187         state = followup;
 188     }
 189 }