ojh06@... wrote:
> I've written a map task that will on occasion not compute the correct
> result. This can easily be detected, at which point I'd like the map
> task to report the error and terminate the entire map/reduce job. Does
> anyone know of a way I can do this?
You can easily kill the job from a map task. Just use the mapred.job.id
job property to get the job id, then use JobClient to kill the job.
Reporting the error could be done by setting the task's state in the
reporter, and then scanning task reports from your job client after the
job is killed for such state strings. Or you could perhaps just set a
counter on the reporter in the map task, and then checking that counter
on the RunningJob, so that you don't have to scan all the tasks. You
might need to sleep a few seconds after setting the state or counter
before killing the job, so that these reports have a chance to make it
back to the jobtracker.
Doug
