org.apache.hadoop.tools.dynamometer

Class SimulatedDataNodes

java.lang.Object

org.apache.hadoop.conf.Configured

org.apache.hadoop.tools.dynamometer.SimulatedDataNodes

All Implemented Interfaces:

org.apache.hadoop.conf.Configurable, org.apache.hadoop.util.Tool

public class SimulatedDataNodes
extends org.apache.hadoop.conf.Configured
implements org.apache.hadoop.util.Tool

Starts up a number of DataNodes within the same JVM. These DataNodes all use SimulatedFSDataset, so they do not store any actual data, and do not persist anything to disk; they maintain all metadata in memory. This is useful for testing and simulation purposes.

The DataNodes will attempt to connect to a NameNode defined by the default FileSystem. There will be one DataNode started for each block list file passed as an argument. Each of these files should contain a list of blocks that the corresponding DataNode should contain, as specified by a triplet of block ID, block size, and generation stamp. Each line of the file is one block, in the format:

blockID,blockGenStamp,blockSize

This class is loosely based off of DataNodeCluster.

Constructor Summary

Constructors

Constructor and Description
SimulatedDataNodes()

Method Summary

Modifier and Type	Method and Description
static void	main(String[] args)
int	run(String[] args)

Methods inherited from class org.apache.hadoop.conf.Configured

getConf, setConf

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.hadoop.conf.Configurable

getConf, setConf

Constructor Detail

SimulatedDataNodes

public SimulatedDataNodes()

Method Detail

main

public static void main(String[] args)
                 throws Exception

Throws:

Exception

run

public int run(String[] args)
        throws Exception

Specified by:

run in interface org.apache.hadoop.util.Tool

Throws:

Exception