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

Class BlockECReconstructionCommand

java.lang.Object

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

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

org.apache.hadoop.hdfs.server.protocol.BlockECReconstructionCommand

@Private
@Evolving
public class BlockECReconstructionCommand
extends DatanodeCommand

A BlockECReconstructionCommand is an instruction to a DataNode to reconstruct a striped block group with missing blocks. Upon receiving this command, the DataNode pulls data from other DataNodes hosting blocks in this group and reconstructs the lost blocks through codec calculation. After the reconstruction, the DataNode pushes the reconstructed blocks to their final destinations if necessary (e.g., the destination is different from the reconstruction node, or multiple blocks in a group are to be reconstructed).

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	BlockECReconstructionCommand.BlockECReconstructionInfo	Block and targets pair

Constructor Summary

Constructors

Constructor	Description
BlockECReconstructionCommand(int action, java.util.Collection<BlockECReconstructionCommand.BlockECReconstructionInfo> blockECReconstructionInfoList)	Create BlockECReconstructionCommand from a collection of BlockECReconstructionCommand.BlockECReconstructionInfo, each representing a reconstruction task

Method Summary

Modifier and Type	Method	Description
java.util.Collection<BlockECReconstructionCommand.BlockECReconstructionInfo>	getECTasks()
java.lang.String	toString()

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

getAction

Methods inherited from class java.lang.Object

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

Constructor Detail

BlockECReconstructionCommand

public BlockECReconstructionCommand(int action,
                                    java.util.Collection<BlockECReconstructionCommand.BlockECReconstructionInfo> blockECReconstructionInfoList)

Create BlockECReconstructionCommand from a collection of BlockECReconstructionCommand.BlockECReconstructionInfo, each representing a reconstruction task

Method Detail

toString

public java.lang.String toString()

Overrides:

toString in class ServerCommand

getECTasks

public java.util.Collection<BlockECReconstructionCommand.BlockECReconstructionInfo> getECTasks()