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 com.google.common.base.Preconditions;
  11 import akka.actor.ActorRef;
  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.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  18 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  19 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  20 import org.slf4j.Logger;
  21
  22 /**
  23  * Participates in raft snapshotting on behalf of a Shard actor.
  24  *
  25  * @author Thomas Pantelis
  26  */
  27 class ShardSnapshotCohort implements RaftActorSnapshotCohort {
  28
  29     private static final YangInstanceIdentifier DATASTORE_ROOT = YangInstanceIdentifier.builder().build();
  30
  31     private int createSnapshotTransactionCounter;
  32     private final ShardTransactionActorFactory transactionActorFactory;
  33     private final ShardDataTree store;
  34     private final Logger log;
  35     private final String logId;
  36
  37     ShardSnapshotCohort(ShardTransactionActorFactory transactionActorFactory, ShardDataTree store,
  38             Logger log, String logId) {
  39         this.transactionActorFactory = transactionActorFactory;
  40         this.store = Preconditions.checkNotNull(store);
  41         this.log = log;
  42         this.logId = logId;
  43     }
  44
  45     @Override
  46     public void createSnapshot(ActorRef actorRef) {
  47         // Create a transaction actor. We are really going to treat the transaction as a worker
  48         // so that this actor does not get block building the snapshot. THe transaction actor will
  49         // after processing the CreateSnapshot message.
  50
  51         ShardTransactionIdentifier transactionID = new ShardTransactionIdentifier(
  52                 "createSnapshot" + ++createSnapshotTransactionCounter);
  53
  54         ActorRef createSnapshotTransaction = transactionActorFactory.newShardTransaction(
  55                 TransactionProxy.TransactionType.READ_ONLY, transactionID, "", DataStoreVersions.CURRENT_VERSION);
  56
  57         createSnapshotTransaction.tell(CreateSnapshot.INSTANCE, actorRef);
  58     }
  59
  60     @Override
  61     public void applySnapshot(byte[] snapshotBytes) {
  62         // Since this will be done only on Recovery or when this actor is a Follower
  63         // we can safely commit everything in here. We not need to worry about event notifications
  64         // as they would have already been disabled on the follower
  65
  66         log.info("{}: Applying snapshot", logId);
  67
  68         try {
  69             ReadWriteShardDataTreeTransaction transaction = store.newReadWriteTransaction("snapshot-" + logId, null);
  70
  71             NormalizedNode<?, ?> node = SerializationUtils.deserializeNormalizedNode(snapshotBytes);
  72
  73             // delete everything first
  74             transaction.getSnapshot().delete(DATASTORE_ROOT);
  75
  76             // Add everything from the remote node back
  77             transaction.getSnapshot().write(DATASTORE_ROOT, node);
  78             syncCommitTransaction(transaction);
  79         } catch (InterruptedException | ExecutionException e) {
  80             log.error("{}: An exception occurred when applying snapshot", logId, e);
  81         } finally {
  82             log.info("{}: Done applying snapshot", logId);
  83         }
  84
  85     }
  86
  87     void syncCommitTransaction(final ReadWriteShardDataTreeTransaction transaction)
  88             throws ExecutionException, InterruptedException {
  89         DOMStoreThreePhaseCommitCohort commitCohort = store.finishTransaction(transaction);
  90         commitCohort.preCommit().get();
  91         commitCohort.commit().get();
  92     }
  93 }