The key provided by the default FileInputFormat is not Text, but an integer offset into the split(which is not very usful IMHO). Try changing your mapper back to <WritableComparable, Text>. If you are expecting the file name to be the key, you will (I think) need to write your own InputFormat.
Jeff -----Original Message----- From: Prasan Ary [mailto:[EMAIL PROTECTED] Sent: Friday, March 07, 2008 3:50 PM To: hadoop Subject: Map/Reduce Type Mismatch error Hi All, I am running a Map/Reduce on a textfile. Map takes <Text,Text> as (key,value) input pair , and outputs <Text,IntWritable> as (key,value) output pair. Reduce takes <Text,IntWritable> as (key,value) input pair, and outputs <Text,Text> as (key,value) output pair. I am getting a type mismatch error. Any suggestion? JobConf job = new JobConf(.............. job.setOutputKeyClass(Text.class); job.setOutputValueClass(Text.class); ----------------------------- public static class Map extends MapReduceBase implements Mapper<Text, Text, Text, IntWritable> { ...... public void map(Text key, Text value, OutputCollector<Text, IntWritable> output, Reporter reporter) throws IOException { ...... output.collect(key,new IntWritable(1)); ---------------------------- public static class Reduce extends MapReduceBase implements Reducer<Text, IntWritable, Text, Text> { public void reduce(Text key, Iterator<IntWritable> values, OutputCollector<Text,Text> output, Reporter reporter) throws IOException { .............. output.collect(key, new Text("SomeText"); --------------------------------- Never miss a thing. Make Yahoo your homepage.
