Aishwarya, On Sun, May 29, 2011 at 6:49 AM, Aishwarya Venkataraman <avenk...@cs.ucsd.edu> wrote: > So how does reducer obtain the mapper's output ? Does it make a network call > and read data from mappers local storage or does the mapper send the data ?
The mappers store the files at a location that is accessibly by the TaskTracker's HTTP servlet. The reducer fetches all successful map attempt outputs from the TaskTrackers when they initialize. -- Harsh J
