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From "Julien Nioche (JIRA)" <j...@apache.org>
Subject [jira] [Resolved] (NUTCH-1416) IndexerMapReduce can index older version of a document instead of latest one
Date Sun, 20 Apr 2014 16:02:15 GMT

     [ https://issues.apache.org/jira/browse/NUTCH-1416?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Julien Nioche resolved NUTCH-1416.
----------------------------------

    Resolution: Won't Fix

There is no way to know which segment a NutchWritable (e.g. ParseText) comes from. One way
around this issue is to index the segments one by one instead of using the whole segments
dir.
Note that this should not be an issue in Nutch 2.x as the WebTable contains only the latest
version of a document

> IndexerMapReduce can index older version of a document instead of latest one
> ----------------------------------------------------------------------------
>
>                 Key: NUTCH-1416
>                 URL: https://issues.apache.org/jira/browse/NUTCH-1416
>             Project: Nutch
>          Issue Type: Bug
>          Components: indexer
>            Reporter: Jianyun He
>            Priority: Critical
>
> When we update the index,can not guarantee that the contents which be indexed is the
latest.In the class IndexerMapReduce and method reduce(), it has the following code:
> public void reduce(Text key, Iterator<NutchWritable> values,
>                      OutputCollector<Text, NutchDocument> output, Reporter reporter)
throws IOException {
>    ……
>    } else if (value instanceof ParseData) {  
>       parseData = (ParseData)value;
>    } else if (value instanceof ParseText) { 
>       parseText = (ParseText)value;
>    }
>    ……
> }
> For example,30 days ago,I fetched the web page A,now I fetch it again. Then the key A
will correspond to two ParseData objects(located in different segments).But in this code,it
does not compare the fetch time and simply overwrites the previous value.So the final value
maybe the old one.



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