Raj Hadoop 2013-04-17, 04:49
Ramesh R Nair 2013-04-17, 07:36
You are correct, map outputs are stored in LFS not in HDFS.
Sent from remote device, Please excuse typos
From: Ramesh R Nair <[EMAIL PROTECTED]>
Date: Wed, 17 Apr 2013 13:06:32
To: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
Subject: Re: Basic Doubt in Hadoop
Regarding the output of Map phase, does Hadoop store it in local fs or
I believe it is in the former. Correct me if I am wrong.
On Wed, Apr 17, 2013 at 10:30 AM, <[EMAIL PROTECTED]> wrote:
> The data is in HDFS in case of WordCount MR sample.
> In hdfs, you have the metadata in NameNode and actual data as blocks
> replicated across DataNodes.
> In case of reducer, If a reducer is running on a particular node then you
> have one replica of the blocks in the same node (If there is no space
> issues) and rest replicas on other nodes.
> Bejoy KS
> Sent from remote device, Please excuse typos
> *From: * Raj Hadoop <[EMAIL PROTECTED]>
> *Date: *Tue, 16 Apr 2013 21:49:34 -0700 (PDT)
> *To: *[EMAIL PROTECTED]<[EMAIL PROTECTED]>
> *ReplyTo: * [EMAIL PROTECTED]
> *Subject: *Basic Doubt in Hadoop
> I am new to Hadoop. I started reading the standard Wordcount program. I
> got this basic doubt in Hadoop.
> After the Map - Reduce is done, where is the output generated? Does the
> reducer ouput sit on individual DataNodes ? Please advise.