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

   1 /*
   2  * Copyright (c) 2017 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.sharding;
   9
  10 import static akka.actor.ActorRef.noSender;
  11 import static com.google.common.base.Preconditions.checkArgument;
  12 import static com.google.common.base.Preconditions.checkState;
  13 import static java.util.Objects.requireNonNull;
  14
  15 import akka.actor.ActorRef;
  16 import akka.actor.PoisonPill;
  17 import akka.dispatch.Futures;
  18 import akka.dispatch.Mapper;
  19 import akka.dispatch.OnComplete;
  20 import akka.util.Timeout;
  21 import java.util.Collection;
  22 import java.util.Optional;
  23 import java.util.concurrent.CompletionStage;
  24 import java.util.concurrent.ConcurrentHashMap;
  25 import org.opendaylight.controller.cluster.datastore.exceptions.LocalShardNotFoundException;
  26 import org.opendaylight.controller.cluster.datastore.messages.MakeLeaderLocal;
  27 import org.opendaylight.controller.cluster.datastore.utils.ActorUtils;
  28 import org.opendaylight.controller.cluster.datastore.utils.ClusterUtils;
  29 import org.opendaylight.controller.cluster.dom.api.CDSShardAccess;
  30 import org.opendaylight.controller.cluster.dom.api.LeaderLocation;
  31 import org.opendaylight.controller.cluster.dom.api.LeaderLocationListener;
  32 import org.opendaylight.controller.cluster.dom.api.LeaderLocationListenerRegistration;
  33 import org.opendaylight.controller.cluster.raft.LeadershipTransferFailedException;
  34 import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
  35 import org.slf4j.Logger;
  36 import org.slf4j.LoggerFactory;
  37 import scala.compat.java8.FutureConverters;
  38 import scala.concurrent.Future;
  39
  40 /**
  41  * Default {@link CDSShardAccess} implementation. Listens on leader location
  42  * change events and distributes them to registered listeners. Also updates
  43  * current information about leader location accordingly.
  44  *
  45  * <p>
  46  * Sends {@link MakeLeaderLocal} message to local shards and translates its result
  47  * on behalf users {@link #makeLeaderLocal()} calls.
  48  *
  49  * <p>
  50  * {@link org.opendaylight.controller.cluster.dom.api.CDSDataTreeProducer} that
  51  * creates instances of this class has to call {@link #close()} once it is no
  52  * longer valid.
  53  */
  54 @Deprecated(forRemoval = true)
  55 final class CDSShardAccessImpl implements CDSShardAccess, LeaderLocationListener, AutoCloseable {
  56     private static final Logger LOG = LoggerFactory.getLogger(CDSShardAccessImpl.class);
  57
  58     private final Collection<LeaderLocationListener> listeners = ConcurrentHashMap.newKeySet();
  59     private final DOMDataTreeIdentifier prefix;
  60     private final ActorUtils actorUtils;
  61     private final Timeout makeLeaderLocalTimeout;
  62
  63     private ActorRef roleChangeListenerActor;
  64
  65     private volatile LeaderLocation currentLeader = LeaderLocation.UNKNOWN;
  66     private volatile boolean closed = false;
  67
  68     CDSShardAccessImpl(final DOMDataTreeIdentifier prefix, final ActorUtils actorUtils) {
  69         this.prefix = requireNonNull(prefix);
  70         this.actorUtils = requireNonNull(actorUtils);
  71         this.makeLeaderLocalTimeout =
  72                 new Timeout(actorUtils.getDatastoreContext().getShardLeaderElectionTimeout().duration().$times(2));
  73
  74         // register RoleChangeListenerActor
  75         // TODO Maybe we should do this in async
  76         final Optional<ActorRef> localShardReply =
  77                 actorUtils.findLocalShard(ClusterUtils.getCleanShardName(prefix.getRootIdentifier()));
  78         checkState(localShardReply.isPresent(),
  79                 "Local shard for {} not present. Cannot register RoleChangeListenerActor", prefix);
  80         roleChangeListenerActor =
  81                 actorUtils.getActorSystem().actorOf(RoleChangeListenerActor.props(localShardReply.get(), this));
  82     }
  83
  84     private void checkNotClosed() {
  85         checkState(!closed, "CDSDataTreeProducer, that this CDSShardAccess is associated with, is no longer valid");
  86     }
  87
  88     @Override
  89     public DOMDataTreeIdentifier getShardIdentifier() {
  90         checkNotClosed();
  91         return prefix;
  92     }
  93
  94     @Override
  95     public LeaderLocation getLeaderLocation() {
  96         checkNotClosed();
  97         // TODO before getting first notification from roleChangeListenerActor
  98         // we will always return UNKNOWN
  99         return currentLeader;
 100     }
 101
 102     @Override
 103     public CompletionStage<Void> makeLeaderLocal() {
 104         // TODO when we have running make leader local operation
 105         // we should just return the same completion stage
 106         checkNotClosed();
 107
 108         // TODO can we cache local shard actorRef?
 109         final Future<ActorRef> localShardReply =
 110                 actorUtils.findLocalShardAsync(ClusterUtils.getCleanShardName(prefix.getRootIdentifier()));
 111
 112         // we have to tell local shard to make leader local
 113         final scala.concurrent.Promise<Object> makeLeaderLocalAsk = Futures.promise();
 114         localShardReply.onComplete(new OnComplete<ActorRef>() {
 115             @Override
 116             public void onComplete(final Throwable failure, final ActorRef actorRef) {
 117                 if (failure instanceof LocalShardNotFoundException) {
 118                     LOG.debug("No local shard found for {} - Cannot request leadership transfer to local shard.",
 119                             getShardIdentifier(), failure);
 120                     makeLeaderLocalAsk.failure(failure);
 121                 } else if (failure != null) {
 122                     // TODO should this be WARN?
 123                     LOG.debug("Failed to find local shard for {} - Cannot request leadership transfer to local shard.",
 124                             getShardIdentifier(), failure);
 125                     makeLeaderLocalAsk.failure(failure);
 126                 } else {
 127                     makeLeaderLocalAsk
 128                             .completeWith(actorUtils
 129                                     .executeOperationAsync(actorRef, MakeLeaderLocal.INSTANCE, makeLeaderLocalTimeout));
 130                 }
 131             }
 132         }, actorUtils.getClientDispatcher());
 133
 134         // we have to transform make leader local request result
 135         Future<Void> makeLeaderLocalFuture = makeLeaderLocalAsk.future()
 136                 .transform(new Mapper<Object, Void>() {
 137                     @Override
 138                     public Void apply(final Object parameter) {
 139                         return null;
 140                     }
 141                 }, new Mapper<Throwable, Throwable>() {
 142                     @Override
 143                     public Throwable apply(final Throwable parameter) {
 144                         if (parameter instanceof LeadershipTransferFailedException) {
 145                             // do nothing with exception and just pass it as it is
 146                             return parameter;
 147                         }
 148                         // wrap exception in LeadershipTransferFailedEx
 149                         return new LeadershipTransferFailedException("Leadership transfer failed", parameter);
 150                     }
 151                 }, actorUtils.getClientDispatcher());
 152
 153         return FutureConverters.toJava(makeLeaderLocalFuture);
 154     }
 155
 156     @Override
 157     public <L extends LeaderLocationListener> LeaderLocationListenerRegistration<L>
 158             registerLeaderLocationListener(final L listener) {
 159         checkNotClosed();
 160         requireNonNull(listener);
 161         checkArgument(!listeners.contains(listener), "Listener %s is already registered with ShardAccess %s", listener,
 162             this);
 163
 164         LOG.debug("Registering LeaderLocationListener {}", listener);
 165
 166         listeners.add(listener);
 167
 168         return new LeaderLocationListenerRegistration<>() {
 169             @Override
 170             public L getInstance() {
 171                 return listener;
 172             }
 173
 174             @Override
 175             public void close() {
 176                 listeners.remove(listener);
 177             }
 178         };
 179     }
 180
 181     @Override
 182     @SuppressWarnings("checkstyle:IllegalCatch")
 183     public void onLeaderLocationChanged(final LeaderLocation location) {
 184         if (closed) {
 185             // we are closed already. Do not dispatch any new leader location
 186             // change events.
 187             return;
 188         }
 189
 190         LOG.debug("Received leader location change notification. New leader location: {}", location);
 191         currentLeader = location;
 192         listeners.forEach(listener -> {
 193             try {
 194                 listener.onLeaderLocationChanged(location);
 195             } catch (Exception e) {
 196                 LOG.warn("Ignoring uncaught exception thrown be LeaderLocationListener {} "
 197                         + "during processing leader location change {}", listener, location, e);
 198             }
 199         });
 200     }
 201
 202     @Override
 203     public void close() {
 204         // TODO should we also remove all listeners?
 205         LOG.debug("Closing {} ShardAccess", prefix);
 206         closed = true;
 207
 208         if (roleChangeListenerActor != null) {
 209             // stop RoleChangeListenerActor
 210             roleChangeListenerActor.tell(PoisonPill.getInstance(), noSender());
 211             roleChangeListenerActor = null;
 212         }
 213     }
 214 }