hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/sps/IntraSPSNameNodeBlockMoveTaskHandler.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.hadoop.hdfs.server.namenode.sps;

import java.io.IOException;

import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.hdfs.server.blockmanagement.BlockManager;
import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeDescriptor;
import org.apache.hadoop.hdfs.server.namenode.Namesystem;
import org.apache.hadoop.hdfs.server.protocol.BlockStorageMovementCommand.BlockMovingInfo;

/**
 * This class handles the internal SPS block movements. This will assign block
 * movement tasks to target datanode descriptors.
 */
@InterfaceAudience.Private
public class IntraSPSNameNodeBlockMoveTaskHandler
    implements BlockMoveTaskHandler {

  private BlockManager blockManager;
  private Namesystem namesystem;

  public IntraSPSNameNodeBlockMoveTaskHandler(BlockManager blockManager,
      Namesystem namesytem) {
    this.blockManager = blockManager;
    this.namesystem = namesytem;
  }

  @Override
  public void submitMoveTask(BlockMovingInfo blkMovingInfo) throws IOException {
    namesystem.readLock();
    try {
      DatanodeDescriptor dn = blockManager.getDatanodeManager()
          .getDatanode(blkMovingInfo.getTarget().getDatanodeUuid());
      if (dn == null) {
        throw new IOException("Failed to schedule block movement task:"
            + blkMovingInfo + " as target datanode: "
            + blkMovingInfo.getTarget() + " doesn't exists");
      }
      dn.incrementBlocksScheduled(blkMovingInfo.getTargetStorageType());
      dn.addBlocksToMoveStorage(blkMovingInfo);
    } finally {
      namesystem.readUnlock();
    }
  }
}