de.hpi.fgis.voidgen.hadoop
Class Start

java.lang.Object
  extended by de.hpi.fgis.voidgen.hadoop.Driver
      extended by de.hpi.fgis.voidgen.hadoop.Start
All Implemented Interfaces:
org.apache.hadoop.conf.Configurable, org.apache.hadoop.util.Tool

public class Start
extends Driver

This class is the user client (provides the interface to the user) for running the generation of VoID descriptions on a Hadoop MapReduce cluster.

The following environments for running are supported:

Running on MapReduce cluster

Export this package and sub-packages in a jar file and deploy it on the cluster. Or put the delivered voidgen.jar file on your cluster. Use 'hadoop jar <your jar path> de.hpi.fgis.voidgen.hadoop.Start +' to run.
e.g. hadoop jar bin/voidgen.jar de.hpi.fgis.voidgen.hadoop.Start -conf conf/void_config.xml

Running via Amazon Management Console

Export to jar as mentioned above. Copy the jar to your S3 bucket. Run the jar via the amazon management console. When specifying the parameters use 'de.hpi.fgis.voidgen.hadoop.Start' as first parameter indicating that this class contains the main method. Append all necessary properties using generic options.
Remark: using '-conf' for specifying an XML configuration file will not work if using the management console.

Configuration

This class only evaluates command line arguments given as generic options. Other command line arguments are ignored.
First the generic options are parsed and a configuration containing all set properties is generated.
Second all tasks specified in the configuration will be executed sequentially in the order they appear in the list of tasks.
Every task obtains a copy of the parsed configuration. Using this driver does not support running the same task with different configuration within the same instance of this driver. Running multiple unique tasks is supported.
For running this driver an example configuration file is provided.

The following table lists the properties necessary to set.

property name description example value
de.hpi.fgis.voidgen.hadoop.Start.tasks The comma-separated list of Driver classes to run. de.hpi.fgis.voidgen.hadoop.tasks.InputStatistics
de.hpi.fgis.voidgen.hadoop.Start.stop_if_task_failed Optional. Default true. Declares whether the execution of further tasks shall be canceled if the execution of a preceding task failed.

Tasks

Tasks delivered with the first version of the voidGen project can be found in package de.hpi.fgis.voidgen.hadoop.tasks.

Author:
Johannes Gosda, Hasso Plattner Institute at University of Potsdam, Germany

Constructor Summary
Start()
           
 
Method Summary
static void main(java.lang.String[] args)
          The starting point for all tasks.
 int run(java.lang.String[] args)
           
 
Methods inherited from class de.hpi.fgis.voidgen.hadoop.Driver
getConf, getPath, getPaths, setConf
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

Start

public Start()
Method Detail

main

public static void main(java.lang.String[] args)
The starting point for all tasks.

Parameters:
args - Hadoop generic options

run

public int run(java.lang.String[] args)
        throws java.lang.Exception
Throws:
java.lang.Exception