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

Reply via email to