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From Apache Wiki <wikidi...@apache.org>
Subject [Lucene-hadoop Wiki] Update of "WordCount" by HairongKuang
Date Wed, 28 Jun 2006 00:32:40 GMT
Dear Wiki user,

You have subscribed to a wiki page or wiki category on "Lucene-hadoop Wiki" for change notification.

The following page has been changed by HairongKuang:

New page:
= WordCount Example =

'''WordCount''' example reads text files and counts how often words occur.  The input is text
files and the output is text files, each line of which contains a word and the count of how
often it occured, separated by a tab.

Each mapper takes a line as input and breaks it into words. It then emits word and 1 pair.
Each reducer sums the frequencies of a word.

The output of maps are locally summed by setting the comibiner class to be the same as the
Reducer class.

To run the example, the command syntax is[[BR]]
bin/hadoop org.apache.hadoop.examples.WordCount [-m <#maps>] [-r <#reducers>]
<in-dir> <out-dir>

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