Do u have enough data to start more than one mapper? If entire data is less than a block size then only 1 mapper will run.
Best Regards, Anil On Feb 1, 2012, at 4:21 PM, Mark Kerzner <[email protected]> wrote: > Hi, > > I have a simple MR job, and I want each Mapper to get one line from my > input file (which contains further instructions for lengthy processing). > Each line is 100 characters long, and I tell Hadoop to read only 100 bytes, > > job.getConfiguration().setInt("mapreduce.input.linerecordreader.line.maxlength", > 100); > > I see that this part works - it reads only one line at a time, and if I > change this parameter, it listens. > > However, on a cluster only one node receives all the map tasks. Only one > map tasks is started. The others never get anything, they just wait. I've > added 100 seconds wait to the mapper - no change! > > Any advice? > > Thank you. Sincerely, > Mark
