Try with number of reducers = 1 .

-Amareshwari

On 8/16/10 12:25 PM, "rajgopalv" <[email protected]> wrote:



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Hi. I'm a newbie in Hadoop. I'm trying out the Wordcount program.

Now to try out multiple output files, i use MultipleOutputFormat. this link
helped me in doing it.
http://hadoop.apache.org/common/docs/r0.19.0/api/org/apache/hadoop/mapred/lib/MultipleOutputs.html

in my driver class i had

    MultipleOutputs.addNamedOutput(conf, "even",
            org.apache.hadoop.mapred.TextOutputFormat.class, Text.class,
            IntWritable.class);

    MultipleOutputs.addNamedOutput(conf, "odd",
            org.apache.hadoop.mapred.TextOutputFormat.class, Text.class,
            IntWritable.class);`

and my reduce class became this

public static class Reduce extends MapReduceBase implements
        Reducer<Text, IntWritable, Text, IntWritable> {
    MultipleOutputs mos = null;

    public void configure(JobConf job) {
        mos = new MultipleOutputs(job);
    }

    public void reduce(Text key, Iterator<IntWritable> values,
            OutputCollector<Text, IntWritable> output, Reporter reporter)
            throws IOException {
        int sum = 0;
        while (values.hasNext()) {
            sum += values.next().get();
        }
        if (sum % 2 == 0) {
            mos.getCollector("even", reporter).collect(key, new
IntWritable(sum));
        }else {
            mos.getCollector("odd", reporter).collect(key, new
IntWritable(sum));
        }
        //output.collect(key, new IntWritable(sum));
    }
    @Override
    public void close() throws IOException {
        // TODO Auto-generated method stub
    mos.close();
    }
}

Things worked , but i get LOT of files, (one odd and one even for every
map-reduce)

Question is : How can i have just 2 output files (odd & even) so that every
odd output of every reduce gets written into that odd file, and same for
even.

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