How to chain mapper/reducer in Hadoop 1.0.4?
I was also searching for the same. I did get the answer and even though its late I thought sharing this may help someone.
From Hadoop 2.0 onwards you can find ChainMapper and ChainReducer in the package org.apache.hadoop.mapreduce.lib.chain
ChainMapper usage pattern:...Job job = new Job(conf, "MyJob");Configuration map1Conf = new Configuration(false); ... ChainMapper.addMapper(job, AMap.class, LongWritable.class, Text.class, Text.class, Text.class, true, map1Conf);Configuration map2Conf = new Configuration(false); ... ChainMapper.addMapper(job, BMap.class, Text.class, Text.class, LongWritable.class, Text.class, false, map2Conf);Configuration map3Conf = new Configuration(false); ... ChainReducer.setReducer(job, CReducer.class, Text.class, Text.class, LongWritable.class, Text.class, false, map3Conf);...job.waitForComplettion(true);...