Dear Raghava,
I also faced this problem. It mostly happens if the computation for the data
that reduce received is taking more time
and is not able to finish within the default time-out 600s. You can also
increase the time-out to ensure that all reduces
complete by setting the property "mapred.task.timeout".
On Thu, Apr 8, 2010 at 11:57 PM, Eric Arenas <eare...@rocketmail.com> wrote:
> Yes Raghava,
>
> I have experience that issue before, and the solution that you mentioned
> also solved my issue (adding a context.progress or setcontext to tell the JT
> that my jobs are still running)
>
> regards
> Eric Arenas
>
>
>
>
> ________________________________
> From: Raghava Mutharaju <m.vijayaragh...@gmail.com>
> To: common-user@hadoop.apache.org; mapreduce-u...@hadoop.apache.org
> Sent: Thu, April 8, 2010 10:30:49 AM
> Subject: Reduce gets struck at 99%
>
> Hello all,
>
> I got the time out error as mentioned below -- after 600 seconds,
> that attempt was killed and the attempt would be deemed a failure. I
> searched around about this error, and one of the suggestions to include
> "progress" statements in the reducer -- it might be taking longer than 600
> seconds and so is timing out. I added calls to context.progress() and
> context.setStatus(str) in the reducer. Now, it works fine -- there are no
> timeout errors.
>
> But, for a few jobs, it takes awfully long time to move from "Map
> 100%, Reduce 99%" to Reduce 100%. For some jobs its 15mins and for some it
> was more than an hour. The reduce code is not complex -- 2 level loop and
> couple of if-else blocks. The input size is also not huge, for the job that
> gets struck for an hour at reduce 99%, it would take in 130. Some of them
> are 1-3 MB in size and couple of them are 16MB in size.
>
> Has anyone encountered this problem before? Any pointers? I use
> Hadoop 0.20.2 on a linux cluster of 16 nodes.
>
> Thank you.
>
> Regards,
> Raghava.
>
>
> On Thu, Apr 1, 2010 at 2:24 AM, Raghava Mutharaju <
> m.vijayaragh...@gmail.com> wrote:
>
> Hi all,
> >
> > I am running a series of jobs one after another. While executing
> the 4th job, the job fails. It fails in the reducer --- the progress
> percentage would be map 100%, reduce 99%. It gives out the following message
> >
> >10/04/01 01:04:15 INFO mapred.JobClient: Task Id :
> attempt_201003240138_0110_r_000018_1, Status : FAILED
> >Task attempt_201003240138_0110_r_000018_1 failed to report status for 602
> seconds. Killing!
> >
> >It makes several attempts again to execute it but fails with similar
> message. I couldn't get anything from this error message and wanted to look
> at logs (located in the default dir of ${HADOOP_HOME/logs}). But I don't
> find any files which match the timestamp of the job. Also I did not find
> history and userlogs in the logs folder. Should I look at some other place
> for the logs? What could be the possible causes for the above error?
> >
> > I am using Hadoop 0.20.2 and I am running it on a cluster with 16
> nodes.
> >
> >Thank you.
> >
> >Regards,
> >Raghava.
> >
>
--
Thanks and Regards,
Prashant Ullegaddi,
Search and Information Extraction Lab,
IIIT-Hyderabad, India.
