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.access.concepts.ClientIdentifier;
  14 import org.opendaylight.controller.cluster.access.concepts.FrontendIdentifier;
  15 import org.opendaylight.controller.cluster.access.concepts.FrontendType;
  16 import org.opendaylight.controller.cluster.access.concepts.LocalHistoryIdentifier;
  17 import org.opendaylight.controller.cluster.access.concepts.MemberName;
  18 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  19 import org.opendaylight.controller.cluster.datastore.messages.CreateSnapshot;
  20 import org.opendaylight.controller.cluster.datastore.utils.SerializationUtils;
  21 import org.opendaylight.controller.cluster.raft.RaftActorSnapshotCohort;
  22 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  23 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  24 import org.slf4j.Logger;
  25
  26 /**
  27  * Participates in raft snapshotting on behalf of a Shard actor.
  28  *
  29  * @author Thomas Pantelis
  30  */
  31 class ShardSnapshotCohort implements RaftActorSnapshotCohort {
  32     private static final FrontendType SNAPSHOT_APPLY = FrontendType.forName("snapshot-apply");
  33     private static final FrontendType SNAPSHOT_READ = FrontendType.forName("snapshot-read");
  34
  35     private final ShardTransactionActorFactory transactionActorFactory;
  36     private final LocalHistoryIdentifier applyHistoryId;
  37     private final LocalHistoryIdentifier readHistoryId;
  38     private final ShardDataTree store;
  39     private final String logId;
  40     private final Logger log;
  41
  42     private long applyCounter;
  43     private long readCounter;
  44
  45     ShardSnapshotCohort(MemberName memberName, ShardTransactionActorFactory transactionActorFactory, ShardDataTree store,
  46             Logger log, String logId) {
  47         this.transactionActorFactory = Preconditions.checkNotNull(transactionActorFactory);
  48         this.store = Preconditions.checkNotNull(store);
  49         this.log = log;
  50         this.logId = logId;
  51
  52         this.applyHistoryId = new LocalHistoryIdentifier(ClientIdentifier.create(
  53             FrontendIdentifier.create(memberName, SNAPSHOT_APPLY), 0), 0);
  54         this.readHistoryId = new LocalHistoryIdentifier(ClientIdentifier.create(
  55             FrontendIdentifier.create(memberName, SNAPSHOT_READ), 0), 0);
  56     }
  57
  58     @Override
  59     public void createSnapshot(ActorRef actorRef) {
  60         // Create a transaction actor. We are really going to treat the transaction as a worker
  61         // so that this actor does not get block building the snapshot. THe transaction actor will
  62         // after processing the CreateSnapshot message.
  63
  64         ActorRef createSnapshotTransaction = transactionActorFactory.newShardTransaction(
  65                 TransactionType.READ_ONLY, new TransactionIdentifier(readHistoryId, readCounter++));
  66
  67         createSnapshotTransaction.tell(CreateSnapshot.INSTANCE, actorRef);
  68     }
  69
  70     @Override
  71     public void applySnapshot(byte[] snapshotBytes) {
  72         // Since this will be done only on Recovery or when this actor is a Follower
  73         // we can safely commit everything in here. We not need to worry about event notifications
  74         // as they would have already been disabled on the follower
  75
  76         log.info("{}: Applying snapshot", logId);
  77
  78         try {
  79             ReadWriteShardDataTreeTransaction transaction = store.newReadWriteTransaction(
  80                 new TransactionIdentifier(applyHistoryId, applyCounter++));
  81
  82             NormalizedNode<?, ?> node = SerializationUtils.deserializeNormalizedNode(snapshotBytes);
  83
  84             // delete everything first
  85             transaction.getSnapshot().delete(YangInstanceIdentifier.EMPTY);
  86
  87             // Add everything from the remote node back
  88             transaction.getSnapshot().write(YangInstanceIdentifier.EMPTY, node);
  89             syncCommitTransaction(transaction);
  90         } catch (InterruptedException | ExecutionException e) {
  91             log.error("{}: An exception occurred when applying snapshot", logId, e);
  92         } finally {
  93             log.info("{}: Done applying snapshot", logId);
  94         }
  95
  96     }
  97
  98     void syncCommitTransaction(final ReadWriteShardDataTreeTransaction transaction)
  99             throws ExecutionException, InterruptedException {
 100         ShardDataTreeCohort commitCohort = store.finishTransaction(transaction);
 101         commitCohort.preCommit().get();
 102         commitCohort.commit().get();
 103     }
 104 }