hadoop-common-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Harsh J <ha...@cloudera.com>
Subject Re: Question regarding network data transfer
Date Sun, 29 May 2011 02:48:25 GMT

On Sun, May 29, 2011 at 6:49 AM, Aishwarya Venkataraman
<avenkata@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

View raw message