You need to explictly set number of reducers to 0 to disable reducers; otherwise, the default value is applied (which is non-zero).
On Fri, Mar 11, 2011 at 11:23 AM, Sagar Kohli <[email protected]> wrote: > Hi , > > > > I am trying to run a job which does not require reducer, I commented out the > reducer configuration from the job, but now its throwing following error > > > > java.lang.ClassCastException: class java.nio.ByteBuffer > > at java.lang.Class.asSubclass(Unknown Source) > > at > org.apache.hadoop.mapred.JobConf.getOutputKeyComparator(JobConf.java:599) > > at > org.apache.hadoop.mapred.MapTask$MapOutputBuffer.<init>(MapTask.java:791) > > at > org.apache.hadoop.mapred.MapTask$NewOutputCollector.<init>(MapTask.java:524) > > at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:613) > > at org.apache.hadoop.mapred.MapTask.run(MapTask.java:305) > > at > org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:177) > > 11/03/11 11:19:12 INFO mapred.JobClient: map 0% reduce 0% > > > > > > Is it possible to run a job only with mapper?? > > > > > > Regards > > Sagar > > ________________________________ > Are you exploring a Big Data Strategy ? Listen to this recorded webinar on > Planning your Hadoop/ NoSQL projects for 2011 at > www.impetus.com/featured_webinar?eventid=37 > > Follow us on www.twitter.com/impetuscalling or visit www.impetus.com to know > more. > > > NOTE: This message may contain information that is confidential, > proprietary, privileged or otherwise protected by law. The message is > intended solely for the named addressee. If received in error, please > destroy and notify the sender. Any use of this email is prohibited when > received in error. Impetus does not represent, warrant and/or guarantee, > that the integrity of this communication has been maintained nor that the > communication is free of errors, virus, interception or interference. > -- Harsh J www.harshj.com
