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

   1 /*
   2  * Copyright (c) 2015 Brocade Communications 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 akka.actor.ActorContext;
  11 import akka.actor.ActorRef;
  12 import com.google.common.base.Preconditions;
  13 import java.io.IOException;
  14 import java.util.Optional;
  15 import org.opendaylight.controller.cluster.access.concepts.ClientIdentifier;
  16 import org.opendaylight.controller.cluster.access.concepts.FrontendIdentifier;
  17 import org.opendaylight.controller.cluster.access.concepts.FrontendType;
  18 import org.opendaylight.controller.cluster.access.concepts.LocalHistoryIdentifier;
  19 import org.opendaylight.controller.cluster.access.concepts.MemberName;
  20 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  21 import org.opendaylight.controller.cluster.datastore.actors.ShardSnapshotActor;
  22 import org.opendaylight.controller.cluster.datastore.persisted.ShardDataTreeSnapshot;
  23 import org.opendaylight.controller.cluster.raft.RaftActorSnapshotCohort;
  24 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  25 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  26 import org.slf4j.Logger;
  27
  28 /**
  29  * Participates in raft snapshotting on behalf of a Shard actor.
  30  *
  31  * @author Thomas Pantelis
  32  */
  33 class ShardSnapshotCohort implements RaftActorSnapshotCohort {
  34     private static final FrontendType SNAPSHOT_APPLY = FrontendType.forName("snapshot-apply");
  35
  36     private final LocalHistoryIdentifier applyHistoryId;
  37     private final ActorRef snapshotActor;
  38     private final ShardDataTree store;
  39     private final String logId;
  40     private final Logger log;
  41
  42     private long applyCounter;
  43
  44     private ShardSnapshotCohort(final LocalHistoryIdentifier applyHistoryId, final ActorRef snapshotActor,
  45             final ShardDataTree store, final Logger log, final String logId) {
  46         this.applyHistoryId = Preconditions.checkNotNull(applyHistoryId);
  47         this.snapshotActor = Preconditions.checkNotNull(snapshotActor);
  48         this.store = Preconditions.checkNotNull(store);
  49         this.log = log;
  50         this.logId = logId;
  51     }
  52
  53     static ShardSnapshotCohort create(final ActorContext actorContext, final MemberName memberName,
  54             final ShardDataTree store, final Logger log, final String logId) {
  55         final LocalHistoryIdentifier applyHistoryId = new LocalHistoryIdentifier(ClientIdentifier.create(
  56             FrontendIdentifier.create(memberName, SNAPSHOT_APPLY), 0), 0);
  57         final String snapshotActorName = "shard-" + memberName.getName() + ':' + "snapshot-read";
  58
  59         // Create a snapshot actor. This actor will act as a worker to offload snapshot serialization for all
  60         // requests.
  61         final ActorRef snapshotActor = actorContext.actorOf(ShardSnapshotActor.props(), snapshotActorName);
  62
  63         return new ShardSnapshotCohort(applyHistoryId, snapshotActor, store, log, logId);
  64     }
  65
  66     @Override
  67     public void createSnapshot(final ActorRef actorRef) {
  68         // Forward the request to the snapshot actor
  69         ShardSnapshotActor.requestSnapshot(snapshotActor, store.takeRecoverySnapshot(), actorRef);
  70     }
  71
  72     private void deserializeAndApplySnapshot(final byte[] snapshotBytes) {
  73         final ShardDataTreeSnapshot snapshot;
  74         try {
  75             snapshot = ShardDataTreeSnapshot.deserialize(snapshotBytes);
  76         } catch (IOException e) {
  77             log.error("{}: Failed to deserialize snapshot", logId, e);
  78             return;
  79         }
  80
  81         try {
  82             final ReadWriteShardDataTreeTransaction transaction = store.newReadWriteTransaction(
  83                 new TransactionIdentifier(applyHistoryId, applyCounter++));
  84
  85             // delete everything first
  86             transaction.getSnapshot().delete(YangInstanceIdentifier.EMPTY);
  87
  88             final Optional<NormalizedNode<?, ?>> maybeNode = snapshot.getRootNode();
  89             if (maybeNode.isPresent()) {
  90                 // Add everything from the remote node back
  91                 transaction.getSnapshot().write(YangInstanceIdentifier.EMPTY, maybeNode.get());
  92             }
  93
  94             store.applyRecoveryTransaction(transaction);
  95         } catch (Exception e) {
  96             log.error("{}: An exception occurred when applying snapshot", logId, e);
  97         }
  98
  99     }
 100
 101     @Override
 102     public void applySnapshot(final byte[] snapshotBytes) {
 103         // Since this will be done only on Recovery or when this actor is a Follower
 104         // we can safely commit everything in here. We not need to worry about event notifications
 105         // as they would have already been disabled on the follower
 106
 107         log.info("{}: Applying snapshot", logId);
 108         deserializeAndApplySnapshot(snapshotBytes);
 109         log.info("{}: Done applying snapshot", logId);
 110     }
 111 }