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.ActorRef;
  11 import com.google.common.base.Preconditions;
  12 import java.util.concurrent.ExecutionException;
  13 import org.opendaylight.controller.cluster.datastore.messages.CreateSnapshot;
  14 import org.opendaylight.controller.cluster.datastore.utils.SerializationUtils;
  15 import org.opendaylight.controller.cluster.raft.RaftActorSnapshotCohort;
  16 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  17 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  18 import org.slf4j.Logger;
  19
  20 /**
  21  * Participates in raft snapshotting on behalf of a Shard actor.
  22  *
  23  * @author Thomas Pantelis
  24  */
  25 class ShardSnapshotCohort implements RaftActorSnapshotCohort {
  26     private final ShardTransactionActorFactory transactionActorFactory;
  27     private final ShardDataTree store;
  28     private final String logId;
  29     private final Logger log;
  30
  31     private int createSnapshotTransactionCounter;
  32
  33     ShardSnapshotCohort(ShardTransactionActorFactory transactionActorFactory, ShardDataTree store,
  34             Logger log, String logId) {
  35         this.transactionActorFactory = transactionActorFactory;
  36         this.store = Preconditions.checkNotNull(store);
  37         this.log = log;
  38         this.logId = logId;
  39     }
  40
  41     @Override
  42     public void createSnapshot(ActorRef actorRef) {
  43         // Create a transaction actor. We are really going to treat the transaction as a worker
  44         // so that this actor does not get block building the snapshot. THe transaction actor will
  45         // after processing the CreateSnapshot message.
  46
  47         ActorRef createSnapshotTransaction = transactionActorFactory.newShardTransaction(
  48                 TransactionType.READ_ONLY, "createSnapshot" + ++createSnapshotTransactionCounter, "");
  49
  50         createSnapshotTransaction.tell(CreateSnapshot.INSTANCE, actorRef);
  51     }
  52
  53     @Override
  54     public void applySnapshot(byte[] snapshotBytes) {
  55         // Since this will be done only on Recovery or when this actor is a Follower
  56         // we can safely commit everything in here. We not need to worry about event notifications
  57         // as they would have already been disabled on the follower
  58
  59         log.info("{}: Applying snapshot", logId);
  60
  61         try {
  62             ReadWriteShardDataTreeTransaction transaction = store.newReadWriteTransaction("snapshot-" + logId, null);
  63
  64             NormalizedNode<?, ?> node = SerializationUtils.deserializeNormalizedNode(snapshotBytes);
  65
  66             // delete everything first
  67             transaction.getSnapshot().delete(YangInstanceIdentifier.EMPTY);
  68
  69             // Add everything from the remote node back
  70             transaction.getSnapshot().write(YangInstanceIdentifier.EMPTY, node);
  71             syncCommitTransaction(transaction);
  72         } catch (InterruptedException | ExecutionException e) {
  73             log.error("{}: An exception occurred when applying snapshot", logId, e);
  74         } finally {
  75             log.info("{}: Done applying snapshot", logId);
  76         }
  77
  78     }
  79
  80     void syncCommitTransaction(final ReadWriteShardDataTreeTransaction transaction)
  81             throws ExecutionException, InterruptedException {
  82         ShardDataTreeCohort commitCohort = store.finishTransaction(transaction);
  83         commitCohort.preCommit().get();
  84         commitCohort.commit().get();
  85     }
  86 }