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Posted to common-dev@hadoop.apache.org by hyoung jun kim <ha...@gmail.com> on 2008/09/02 11:23:09 UTC

map reduce permission

Hi,
To get supergroup's file access mode is possible in map&reduce class.
I wrote a code like this

class MyMap implements Mapper {
  public void map(...) {
     Configuration conf = new Configuration();
     FileSystem fs = FileSystem.get(conf);
     fs.open(new Path("/user/supergroup_user/file_name");
  }
}

If no "hadoop.job.ugi" property in configuration, UserGroupInformation class
uses linux user(run shell command "whoami").

Re: map reduce permission

Posted by "Edward J. Yoon" <ed...@apache.org>.

Are you mean that It is possible to collect super group files in
mapred? I think this is a good tip.

BTW, Is there no access control matrix on HDFS?

-Ed

On Tue, Sep 2, 2008 at 6:23 PM, hyoung jun kim <ha...@gmail.com> wrote:
> Hi,
> To get supergroup's file access mode is possible in map&reduce class.
> I wrote a code like this
>
> class MyMap implements Mapper {
>  public void map(...) {
>     Configuration conf = new Configuration();
>     FileSystem fs = FileSystem.get(conf);
>     fs.open(new Path("/user/supergroup_user/file_name");
>  }
> }
>
> If no "hadoop.job.ugi" property in configuration, UserGroupInformation class
> uses linux user(run shell command "whoami").
>



-- 
Best regards, Edward J. Yoon
edwardyoon@apache.org
http://blog.udanax.org