org.apache.nutch.crawl

Class DeduplicationJob

java.lang.Object

org.apache.hadoop.conf.Configured

org.apache.nutch.crawl.DeduplicationJob

All Implemented Interfaces:

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

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

Generic deduplicator which groups fetched URLs with the same digest and marks all of them as duplicate except the one with the highest score (based on the score in the crawldb, which is not necessarily the same as the score indexed). If two (or more) documents have the same score, then the document with the latest timestamp is kept. If the documents have the same timestamp then the one with the shortest URL is kept. The documents marked as duplicate can then be deleted with the command CleaningJob.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	DeduplicationJob.DBFilter
static class	DeduplicationJob.DedupReducer
static class	DeduplicationJob.StatusUpdateReducer Combine multiple new entries for a url.

Field Summary

Fields

Modifier and Type	Field and Description
static org.slf4j.Logger	LOG

Constructor Summary

Constructors

Constructor and Description
DeduplicationJob()

Method Summary

Methods

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

Field Detail

LOG

public static final org.slf4j.Logger LOG

Constructor Detail

DeduplicationJob

public DeduplicationJob()

Method Detail

run

public int run(String[] args)
        throws IOException

Specified by:

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

Throws:

IOException

main

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

Throws:

Exception