The reason what you were trying didn't work is because those Java options are getting applied to your com.MyDriver, not the MR job.
- Robert On Tue, Apr 16, 2013 at 11:07 AM, Frank Luo <[email protected]> wrote: > Thanks for reply and I will try to use JobConf to set it. > > The way I was trying to is the following and it didn't work: > > <main-class>com.MyDriver</main-class> > <java-opts>-Dmapred.reduce.tasks=${reducer_count}</java-opts> > > -----Original Message----- > From: Robert Kanter [mailto:[email protected]] > Sent: Tuesday, April 16, 2013 12:50 PM > To: [email protected] > Subject: Re: how to use Oozie launch a M/R job using a driver and specify > number of reducers > > Hi Frank, > > If you use the Java action, you should be able to do just about anything > you want in there. So, if you wanted to write your own driver class, you > can use the Java action to have Oozie run it, and do all configuration for > your MR job from within your driver class; if I recall correctly, you can > set the number of reducers from the JobConf object (in your driver). > > - Robert > > > > On Tue, Apr 16, 2013 at 10:16 AM, Frank Luo <[email protected]> wrote: > > > If I understand correctly, in order to specify the number of reducers > > in Oozie, one must use an action of type "map-reduce" (correct me if I > > am wrong). > > > > However, with "map-reduce" type, there is no option of setting driver > > class. > > > > So my question is that what options are if one needs to use a driver > > class, such as using htable as an input, and at the same time, set the > > number of reducers. > > > > Thanks. > > > >
