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.identifiers.ShardTransactionIdentifier;
  14 import org.opendaylight.controller.cluster.datastore.messages.CreateSnapshot;
  15 import org.opendaylight.controller.cluster.datastore.utils.SerializationUtils;
  16 import org.opendaylight.controller.cluster.raft.RaftActorSnapshotCohort;
  17 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  18 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  19 import org.slf4j.Logger;
  20
  21 /**
  22  * Participates in raft snapshotting on behalf of a Shard actor.
  23  *
  24  * @author Thomas Pantelis
  25  */
  26 class ShardSnapshotCohort implements RaftActorSnapshotCohort {
  27     private final ShardTransactionActorFactory transactionActorFactory;
  28     private final ShardDataTree store;
  29     private final String logId;
  30     private final Logger log;
  31
  32     private int createSnapshotTransactionCounter;
  33
  34     ShardSnapshotCohort(ShardTransactionActorFactory transactionActorFactory, ShardDataTree store,
  35             Logger log, String logId) {
  36         this.transactionActorFactory = transactionActorFactory;
  37         this.store = Preconditions.checkNotNull(store);
  38         this.log = log;
  39         this.logId = logId;
  40     }
  41
  42     @Override
  43     public void createSnapshot(ActorRef actorRef) {
  44         // Create a transaction actor. We are really going to treat the transaction as a worker
  45         // so that this actor does not get block building the snapshot. THe transaction actor will
  46         // after processing the CreateSnapshot message.
  47
  48         ShardTransactionIdentifier transactionID = new ShardTransactionIdentifier(
  49                 "createSnapshot" + ++createSnapshotTransactionCounter);
  50
  51         ActorRef createSnapshotTransaction = transactionActorFactory.newShardTransaction(
  52                 TransactionType.READ_ONLY, transactionID, "");
  53
  54         createSnapshotTransaction.tell(CreateSnapshot.INSTANCE, actorRef);
  55     }
  56
  57     @Override
  58     public void applySnapshot(byte[] snapshotBytes) {
  59         // Since this will be done only on Recovery or when this actor is a Follower
  60         // we can safely commit everything in here. We not need to worry about event notifications
  61         // as they would have already been disabled on the follower
  62
  63         log.info("{}: Applying snapshot", logId);
  64
  65         try {
  66             ReadWriteShardDataTreeTransaction transaction = store.newReadWriteTransaction("snapshot-" + logId, null);
  67
  68             NormalizedNode<?, ?> node = SerializationUtils.deserializeNormalizedNode(snapshotBytes);
  69
  70             // delete everything first
  71             transaction.getSnapshot().delete(YangInstanceIdentifier.EMPTY);
  72
  73             // Add everything from the remote node back
  74             transaction.getSnapshot().write(YangInstanceIdentifier.EMPTY, node);
  75             syncCommitTransaction(transaction);
  76         } catch (InterruptedException | ExecutionException e) {
  77             log.error("{}: An exception occurred when applying snapshot", logId, e);
  78         } finally {
  79             log.info("{}: Done applying snapshot", logId);
  80         }
  81
  82     }
  83
  84     void syncCommitTransaction(final ReadWriteShardDataTreeTransaction transaction)
  85             throws ExecutionException, InterruptedException {
  86         ShardDataTreeCohort commitCohort = store.finishTransaction(transaction);
  87         commitCohort.preCommit().get();
  88         commitCohort.commit().get();
  89     }
  90 }