[MAPREDUCE-2410] document multiple keys per reducer oddity in hadoop streaming FAQ

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 0.20.2
• Fix Version/s: 0.22.0
• Component/s: contrib/streaming, documentation
• Labels: newbie
• Hadoop Flags: Reviewed
• Release Note: Add an FAQ entry regarding the differences between Java API and Streaming development of MR programs.
• Tags: streaming
• Assignee: Harsh J
• Reporter: Dieter Plaetinck
• Created: 30/Mar/11 07:53
• Updated: 16/May/11 20:07
• Resolved: 12/May/11 07:16

Description

Hi,
for a newcomer to hadoop streaming, it comes as a surprise that the reducer receives arbitrary keys, unlike the "real" hadoop where a reducer works on a single key.
An explanation for this is @ http://mail-archives.apache.org/mod_mbox/hadoop-common-user/201103.mbox/browser

I suggest to add this to the FAQ of hadoop streaming