Strictly speaking reduce can only start once all map is done. However copy is part of the reported reduce metrics. So that's maybe why you are asking the question. A simple answer is because you don't have much data so there is only one mapper which means the copy will have to start after all (only one) map finish.
Could you provide more information about your case? Like the metrics? Regards Bertrand On Thu, Sep 27, 2012 at 7:40 PM, Abhishek <abhishek.dod...@gmail.com> wrote: > Hi all, > > In some of my hive scripts, reduce phase is not starting until map > finishes 100%.What would be the reason for this. > > Regards > Abhi > > > Sent from my iPhone -- Bertrand Dechoux
