On Wed, Aug 12, 2009 at 1:15 PM, Mayuran Yogarajah < [email protected]> wrote:
> I had 3 jobs running and I saw something a bit odd. Two of the tasks > are reducing, one of them is using all the reducers so the other is > waiting, this is OK. However the 3rd job is still in the mapping phase > and even though the web interface shows map capacity at 96 I only > see about 7-12 mappers actually running. I'm wondering if theres > some setting I need to change, perhaps I've hit some system limit. Can > someone point me in the right direction please? > Are there any pending mappers remaining? Are you using any scheduler? > > The other thing was that with the two jobs that are in the reducing phase, > the reducer for one job wouldn't actually start until all the mappers of > the > _other_ job completed which seems kind of odd. Is this expected ? > Reducers dont really start the "reduce" phase till the mappers are completed. However, the process gets spawned off and the copying of the intermediate keys from the mapper starts off. > thanks, > M >
