1 - So what's the reason to exist 2 group of phases? 2 - A JobTracker and a TaskTracker also has phases?
On Thu, Mar 24, 2011 at 6:42 PM, Arun C Murthy <a...@yahoo-inc.com> wrote: > > On Mar 24, 2011, at 11:37 AM, Pedro Costa wrote: > >> Hi, >> >> 1 - A Task is composed by several phases: >> STARTING, MAP/REDUCE, SHUFFLE, SORT, CLEANUP. >> > > Right. These are 'phases' for a map and/or reduce task after it starts > running. > >> A JobTracker and a TaskTracker also has phases? >> >> 2 - It exists also the following phases >> RUNNING, >> SUCCEEDED, >> FAILED, >> UNASSIGNED, >> KILLED, >> COMMIT_PENDING, >> FAILED_UNCLEAN, >> KILLED_UNCLEAN, >> >> These phases also belong to the Map or Reduce tasks. So, it exists two >> group of phases. Why is that? >> > > These are 'states' for either map or reduce tasks, starting from their > creation. > > Hope that helps. > > Arun > -- Pedro
