How can I get parameters form mappers ?

[kauu <my...@yahoo.com.cn>]

How can I get parameters form mappers ?


I can't do it with jobconf, I've try it
.


 


-----邮件原件-----


发件人: redpony@gmail.com
[mailto:redpony@gmail.com] 代表 Chris Dyer


发送时间: 2007年11月7日 6:04


收件人: hadoop-user@lucene.apache.org;
stuhood@webmail.us


主题: Re: configuration for mappers?


 


Hi Stu- Thanks for the tip!


Chris


 


On 11/3/07, Stu Hood
<st...@webmail.us> wrote:


> 


> Hi Chris,


> 


> A very comfortable way to pass
configuration parameters to mappers is in


> your JobConf. By using
JobConf.set(String,String), you can set arbitrary


> parameters that will be distributed
to all mappers.


> 


> In order to fetch these parameters
in your Mapper, you will need to


> override the
MapReduceBase.configure(JobConf) method. The default


> implementation of this method in
MapReduceBase does nothing with the


> configuration, but you can
implement it to change the configuration of the


> mapper by .get(String)'ing the
parameters you stored and setting private


> variables, etc.


> 


> Good luck!


> 


> Thanks,


> Stu


> 


> 


> -----Original Message-----


> From: Chris Dyer
<re...@umd.edu>


> Sent: Saturday, November 3, 2007
5:42pm


> To: hadoop-user@lucene.apache.org


> Subject: configuration for mappers?


> 


> Hi hadoopers,


> 


> What is the recommended way to send
configuration type information


> from the job client down to the
individual map and reduce processes


> that are running?  I'd like to be able to specify a few options
that


> control the behavior of these
processes, but I haven't been able to


> find any documentation on how to do
this.


> 


> Thanks for any help!


> 


> Chris


> 


> 


> 






      ___________________________________________________________ 
雅虎邮箱传递新年祝福，个性贺卡送亲朋！ 
http://cn.mail.yahoo.com/gc/index.html?entry=5&souce=mail_mailletter_tagline