hadoop-mapreduce-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "GOEKE, MATTHEW (AG/1000)" <matthew.go...@monsanto.com>
Subject RE: How to pull data in the Map/Reduce functions?
Date Mon, 26 Sep 2011 02:51:02 GMT
A quick google search for "mapreduce new api" came up with a link for http://wisdombase.net/wiki/index.php?title=Upgrading_to_the_new_2.0_mapreduce_API.
After quickly reviewing it I would say this is a decent reference that you can follow. There
are definitely some better ones out there but this is just to help you get started.


From: Praveen Sripati [mailto:praveensripati@gmail.com]
Sent: Saturday, September 24, 2011 11:57 AM
To: mapreduce-user@hadoop.apache.org
Subject: Re: How to pull data in the Map/Reduce functions?


Neither of the books have much information about the new MR API. I was reading the 'Hadoop
- The Definitive Guide' and came across a single pager on new API. I wanted to try the new
MR, but could not find much information neither in the book nor on the internet.

On Sat, Sep 24, 2011 at 8:20 PM, GOEKE, MATTHEW (AG/1000) <matthew.goeke@monsanto.com<mailto:matthew.goeke@monsanto.com>>

Functionality wise you don't gain much from using the new API and most would actually recommend
that you stay with the old API as it will not be "officially" deprecated until 0.22 / 0.23
(I can't remember which one). If you want to take a look at the classes dig into the packages
for org.apache.hadoop.mapred.* (old) and org.apache.hadoop.mapreduce.* (new). Also, I thought
that Definitive Guide second edition and Hadoop In Action covered the new api.


From: Praveen Sripati [mailto:praveensripati@gmail.com<mailto:praveensripati@gmail.com>]
Sent: Saturday, September 24, 2011 8:43 AM
To: mapreduce-user@hadoop.apache.org<mailto:mapreduce-user@hadoop.apache.org>
Subject: How to pull data in the Map/Reduce functions?


Normally the Hadoop framework calls the map()/reduce() for each record in the input split.
I read in the 'Hadoop : The Definitive Guide' that that data can be pulled using the new MR

What is the new API for pulling the data in the map()/reduce() or is there a sample code?

This e-mail message may contain privileged and/or confidential information, and is intended
to be received only by persons entitled
to receive such information. If you have received this e-mail in error, please notify the
sender immediately. Please delete it and
all attachments from any servers, hard drives or any other media. Other use of this e-mail
by you is strictly prohibited.

All e-mails and attachments sent and received are subject to monitoring, reading and archival
by Monsanto, including its
subsidiaries. The recipient of this e-mail is solely responsible for checking for the presence
of "Viruses" or other "Malware".
Monsanto, along with its subsidiaries, accepts no liability for any damage caused by any such
code transmitted by or accompanying
this e-mail or any attachment.

The information contained in this email may be subject to the export control laws and regulations
of the United States, potentially
including but not limited to the Export Administration Regulations (EAR) and sanctions regulations
issued by the U.S. Department of
Treasury, Office of Foreign Asset Controls (OFAC).  As a recipient of this information you
are obligated to comply with all
applicable U.S. export laws and regulations.

View raw message