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