Package org.apache.hadoop.hdfs.server.protocol

Class BlockStorageMovementCommand

java.lang.Object

org.apache.hadoop.hdfs.server.protocol.ServerCommand

org.apache.hadoop.hdfs.server.protocol.DatanodeCommand

org.apache.hadoop.hdfs.server.protocol.BlockStorageMovementCommand

public class BlockStorageMovementCommand
extends DatanodeCommand

A BlockStorageMovementCommand is an instruction to a DataNode to move the given set of blocks to specified target DataNodes to fulfill the block storage policy. Upon receiving this command, this DataNode pass the array of block movement details to ExternalSPSBlockMoveTaskHandler service. Later, ExternalSPSBlockMoveTaskHandler will schedule block movement tasks for these blocks and monitors the completion of each task. After the block movement attempt is finished(with success or failure) this DataNode will send response back to NameNode about the block movement attempt finished details.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	BlockStorageMovementCommand.BlockMovingInfo	Stores block to storage info that can be used for block movement.

Constructor Summary

Constructors

Constructor	Description
BlockStorageMovementCommand(int action, String blockPoolId, Collection<BlockStorageMovementCommand.BlockMovingInfo> blockMovingInfos)	Block storage movement command constructor.

Method Summary

Modifier and Type	Method	Description
Collection<BlockStorageMovementCommand.BlockMovingInfo>	getBlockMovingTasks()	Returns the list of blocks to be moved.
String	getBlockPoolId()	Returns block pool ID.

Methods inherited from class org.apache.hadoop.hdfs.server.protocol.ServerCommand

getAction, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Details

BlockStorageMovementCommand

public BlockStorageMovementCommand(int action,
 String blockPoolId,
 Collection<BlockStorageMovementCommand.BlockMovingInfo> blockMovingInfos)

Block storage movement command constructor.

Parameters:

action - protocol specific action

blockMovingInfos - block to storage info that will be used for movement

Method Details

getBlockPoolId

public String getBlockPoolId()

Returns block pool ID.

getBlockMovingTasks

public Collection<BlockStorageMovementCommand.BlockMovingInfo> getBlockMovingTasks()

Returns the list of blocks to be moved.