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 java.util.concurrent.ExecutionException;
  16 import org.opendaylight.controller.cluster.access.concepts.ClientIdentifier;
  17 import org.opendaylight.controller.cluster.access.concepts.FrontendIdentifier;
  18 import org.opendaylight.controller.cluster.access.concepts.FrontendType;
  19 import org.opendaylight.controller.cluster.access.concepts.LocalHistoryIdentifier;
  20 import org.opendaylight.controller.cluster.access.concepts.MemberName;
  21 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  22 import org.opendaylight.controller.cluster.datastore.actors.ShardSnapshotActor;
  23 import org.opendaylight.controller.cluster.datastore.persisted.ShardDataTreeSnapshot;
  24 import org.opendaylight.controller.cluster.raft.RaftActorSnapshotCohort;
  25 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  26 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  27 import org.slf4j.Logger;
  28
  29 /**
  30  * Participates in raft snapshotting on behalf of a Shard actor.
  31  *
  32  * @author Thomas Pantelis
  33  */
  34 class ShardSnapshotCohort implements RaftActorSnapshotCohort {
  35     private static final FrontendType SNAPSHOT_APPLY = FrontendType.forName("snapshot-apply");
  36
  37     private final LocalHistoryIdentifier applyHistoryId;
  38     private final ActorRef snapshotActor;
  39     private final ShardDataTree store;
  40     private final String logId;
  41     private final Logger log;
  42
  43     private long applyCounter;
  44
  45     private ShardSnapshotCohort(final LocalHistoryIdentifier applyHistoryId, final ActorRef snapshotActor,
  46             final ShardDataTree store, final Logger log, final String logId) {
  47         this.applyHistoryId = Preconditions.checkNotNull(applyHistoryId);
  48         this.snapshotActor = Preconditions.checkNotNull(snapshotActor);
  49         this.store = Preconditions.checkNotNull(store);
  50         this.log = log;
  51         this.logId = logId;
  52     }
  53
  54     static ShardSnapshotCohort create(final ActorContext actorContext, final MemberName memberName,
  55             final ShardDataTree store, final Logger log, final String logId) {
  56         final LocalHistoryIdentifier applyHistoryId = new LocalHistoryIdentifier(ClientIdentifier.create(
  57             FrontendIdentifier.create(memberName, SNAPSHOT_APPLY), 0), 0);
  58         final String snapshotActorName = "shard-" + memberName.getName() + ':' + "snapshot-read";
  59
  60         // Create a snapshot actor. This actor will act as a worker to offload snapshot serialization for all
  61         // requests.
  62         final ActorRef snapshotActor = actorContext.actorOf(ShardSnapshotActor.props(), snapshotActorName);
  63
  64         return new ShardSnapshotCohort(applyHistoryId, snapshotActor, store, log, logId);
  65     }
  66
  67     @Override
  68     public void createSnapshot(final ActorRef actorRef) {
  69         // Forward the request to the snapshot actor
  70         ShardSnapshotActor.requestSnapshot(snapshotActor, store.takeRecoverySnapshot(), actorRef);
  71     }
  72
  73     private void deserializeAndApplySnapshot(final byte[] snapshotBytes) {
  74         final ShardDataTreeSnapshot snapshot;
  75         try {
  76             snapshot = ShardDataTreeSnapshot.deserialize(snapshotBytes);
  77         } catch (IOException e) {
  78             log.error("{}: Failed to deserialize snapshot", logId, e);
  79             return;
  80         }
  81
  82         try {
  83             final ReadWriteShardDataTreeTransaction transaction = store.newReadWriteTransaction(
  84                 new TransactionIdentifier(applyHistoryId, applyCounter++));
  85
  86             // delete everything first
  87             transaction.getSnapshot().delete(YangInstanceIdentifier.EMPTY);
  88
  89             final Optional<NormalizedNode<?, ?>> maybeNode = snapshot.getRootNode();
  90             if (maybeNode.isPresent()) {
  91                 // Add everything from the remote node back
  92                 transaction.getSnapshot().write(YangInstanceIdentifier.EMPTY, maybeNode.get());
  93             }
  94
  95             store.applyRecoveryTransaction(transaction);
  96         } catch (Exception e) {
  97             log.error("{}: An exception occurred when applying snapshot", logId, e);
  98         }
  99
 100     }
 101
 102     void syncCommitTransaction(final ReadWriteShardDataTreeTransaction transaction)
 103             throws ExecutionException, InterruptedException {
 104         ShardDataTreeCohort commitCohort = store.finishTransaction(transaction);
 105         commitCohort.preCommit().get();
 106         commitCohort.commit().get();
 107     }
 108
 109     @Override
 110     public void applySnapshot(final byte[] snapshotBytes) {
 111         // Since this will be done only on Recovery or when this actor is a Follower
 112         // we can safely commit everything in here. We not need to worry about event notifications
 113         // as they would have already been disabled on the follower
 114
 115         log.info("{}: Applying snapshot", logId);
 116         deserializeAndApplySnapshot(snapshotBytes);
 117         log.info("{}: Done applying snapshot", logId);
 118     }
 119 }