opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/actors/ShardSnapshotActor.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.actors;
   9
  10 import akka.actor.ActorRef;
  11 import akka.actor.Props;
  12 import com.google.common.base.Preconditions;
  13 import java.io.IOException;
  14 import java.io.ObjectOutputStream;
  15 import java.io.OutputStream;
  16 import java.util.Optional;
  17 import org.opendaylight.controller.cluster.common.actor.AbstractUntypedActorWithMetering;
  18 import org.opendaylight.controller.cluster.datastore.persisted.ShardDataTreeSnapshot;
  19 import org.opendaylight.controller.cluster.datastore.persisted.ShardSnapshotState;
  20 import org.opendaylight.controller.cluster.raft.base.messages.CaptureSnapshotReply;
  21
  22 /**
  23  * This is an offload actor, which is given an isolated snapshot of the data tree. It performs the potentially
  24  * time-consuming operation of serializing the snapshot.
  25  *
  26  * @author Robert Varga
  27  */
  28 public final class ShardSnapshotActor extends AbstractUntypedActorWithMetering {
  29     // Internal message
  30     private static final class SerializeSnapshot {
  31         private final ShardDataTreeSnapshot snapshot;
  32         private final Optional<OutputStream> installSnapshotStream;
  33         private final ActorRef replyTo;
  34
  35         SerializeSnapshot(final ShardDataTreeSnapshot snapshot, final Optional<OutputStream> installSnapshotStream,
  36                 final ActorRef replyTo) {
  37             this.snapshot = Preconditions.checkNotNull(snapshot);
  38             this.installSnapshotStream = Preconditions.checkNotNull(installSnapshotStream);
  39             this.replyTo = Preconditions.checkNotNull(replyTo);
  40         }
  41
  42         ShardDataTreeSnapshot getSnapshot() {
  43             return snapshot;
  44         }
  45
  46         Optional<OutputStream> getInstallSnapshotStream() {
  47             return installSnapshotStream;
  48         }
  49
  50         ActorRef getReplyTo() {
  51             return replyTo;
  52         }
  53     }
  54
  55     //actor name override used for metering. This does not change the "real" actor name
  56     private static final String ACTOR_NAME_FOR_METERING = "shard-snapshot";
  57
  58     private ShardSnapshotActor() {
  59         super(ACTOR_NAME_FOR_METERING);
  60     }
  61
  62     @Override
  63     protected void handleReceive(final Object message) throws Exception {
  64         if (message instanceof SerializeSnapshot) {
  65             onSerializeSnapshot((SerializeSnapshot) message);
  66         } else {
  67             unknownMessage(message);
  68         }
  69     }
  70
  71     private void onSerializeSnapshot(final SerializeSnapshot request) {
  72         Optional<OutputStream> installSnapshotStream = request.getInstallSnapshotStream();
  73         if (installSnapshotStream.isPresent()) {
  74             try (ObjectOutputStream out = new ObjectOutputStream(installSnapshotStream.get())) {
  75                 request.getSnapshot().serialize(out);
  76             } catch (IOException e) {
  77                 // TODO - we should communicate the failure in the CaptureSnapshotReply.
  78                 LOG.error("Error serializing snapshot", e);
  79             }
  80         }
  81
  82         request.getReplyTo().tell(new CaptureSnapshotReply(new ShardSnapshotState(request.getSnapshot()),
  83                 installSnapshotStream), ActorRef.noSender());
  84     }
  85
  86     /**
  87      * Sends a request to a ShardSnapshotActor to process a snapshot and send a CaptureSnapshotReply.
  88      *
  89      * @param snapshotActor the ShardSnapshotActor
  90      * @param snapshot the snapshot to process
  91      * @param installSnapshotStream Optional OutputStream that is present if the snapshot is to also be installed
  92      *        on a follower.
  93      * @param replyTo the actor to which to send the CaptureSnapshotReply
  94      */
  95     public static void requestSnapshot(final ActorRef snapshotActor, final ShardDataTreeSnapshot snapshot,
  96             final Optional<OutputStream> installSnapshotStream, final ActorRef replyTo) {
  97         snapshotActor.tell(new SerializeSnapshot(snapshot, installSnapshotStream, replyTo), ActorRef.noSender());
  98     }
  99
 100     public static Props props() {
 101         return Props.create(ShardSnapshotActor.class);
 102     }
 103 }