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 java.util.concurrent.ExecutionException;
  12 import org.opendaylight.controller.cluster.datastore.identifiers.ShardTransactionIdentifier;
  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.controller.md.sal.dom.store.impl.InMemoryDOMDataStore;
  17 import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
  18 import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
  19 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  20 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  21 import org.slf4j.Logger;
  22
  23 /**
  24  * Participates in raft snapshotting on behalf of a Shard actor.
  25  *
  26  * @author Thomas Pantelis
  27  */
  28 class ShardSnapshotCohort implements RaftActorSnapshotCohort {
  29
  30     private static final YangInstanceIdentifier DATASTORE_ROOT = YangInstanceIdentifier.builder().build();
  31
  32     private int createSnapshotTransactionCounter;
  33     private final ShardTransactionActorFactory transactionActorFactory;
  34     private final InMemoryDOMDataStore store;
  35     private final Logger log;
  36     private final String logId;
  37
  38     ShardSnapshotCohort(ShardTransactionActorFactory transactionActorFactory, InMemoryDOMDataStore store,
  39             Logger log, String logId) {
  40         this.transactionActorFactory = transactionActorFactory;
  41         this.store = store;
  42         this.log = log;
  43         this.logId = logId;
  44     }
  45
  46     @Override
  47     public void createSnapshot(ActorRef actorRef) {
  48         // Create a transaction actor. We are really going to treat the transaction as a worker
  49         // so that this actor does not get block building the snapshot. THe transaction actor will
  50         // after processing the CreateSnapshot message.
  51
  52         ShardTransactionIdentifier transactionID = new ShardTransactionIdentifier(
  53                 "createSnapshot" + ++createSnapshotTransactionCounter);
  54
  55         ActorRef createSnapshotTransaction = transactionActorFactory.newShardTransaction(
  56                 TransactionProxy.TransactionType.READ_ONLY, transactionID, "", DataStoreVersions.CURRENT_VERSION);
  57
  58         createSnapshotTransaction.tell(CreateSnapshot.INSTANCE, actorRef);
  59     }
  60
  61     @Override
  62     public void applySnapshot(byte[] snapshotBytes) {
  63         // Since this will be done only on Recovery or when this actor is a Follower
  64         // we can safely commit everything in here. We not need to worry about event notifications
  65         // as they would have already been disabled on the follower
  66
  67         log.info("{}: Applying snapshot", logId);
  68
  69         try {
  70             DOMStoreWriteTransaction transaction = store.newWriteOnlyTransaction();
  71
  72             NormalizedNode<?, ?> node = SerializationUtils.deserializeNormalizedNode(snapshotBytes);
  73
  74             // delete everything first
  75             transaction.delete(DATASTORE_ROOT);
  76
  77             // Add everything from the remote node back
  78             transaction.write(DATASTORE_ROOT, node);
  79             syncCommitTransaction(transaction);
  80         } catch (InterruptedException | ExecutionException e) {
  81             log.error("{}: An exception occurred when applying snapshot", logId, e);
  82         } finally {
  83             log.info("{}: Done applying snapshot", logId);
  84         }
  85
  86     }
  87
  88     void syncCommitTransaction(final DOMStoreWriteTransaction transaction)
  89             throws ExecutionException, InterruptedException {
  90         DOMStoreThreePhaseCommitCohort commitCohort = transaction.ready();
  91         commitCohort.preCommit().get();
  92         commitCohort.commit().get();
  93     }
  94 }