As harsh suggested, you might want to check the task logs on slaves (you can do it though web UI by clicking on map/reduce task links) and see if there are any exceptions .
On Wed, Nov 21, 2012 at 8:06 PM, jamal sasha <jamalsha...@gmail.com> wrote: > Hi > Thanks for the insights. > I noticed that these restarts of mappers were because in the shebang i had > Usr/env/bin instead of usr/env/bin python > Any clue of what was going on with reducers not starting but mappers being > executed again and again. > Probably a very naive question but i am newbie you see :) > > > > On Wednesday, November 21, 2012, Jean-Marc Spaggiari < > jean-m...@spaggiari.org> wrote: > > Just FYI, you don't need to stop the job, update the host, and retry. > > > > Just update the host while the job is running and it should retry and > restart. > > > > I had a similar issue with one of my node where the hosts file were > > not updated. After the updated it has automatically resume the work... > > > > JM > > > > 2012/11/21, praveenesh kumar <praveen...@gmail.com>: > >> Sometimes its network issue, reducers are not able to find hostnames or > IPs > >> of the other machines. Make sure your /etc/hosts entries and hostnames > are > >> correct. > >> > >> Regards, > >> Praveenesh > >> > >> On Tue, Nov 20, 2012 at 10:46 PM, Harsh J <ha...@cloudera.com> wrote: > >> > >>> Your mappers are failing (possibly a user-side error or an > >>> environmental one) and are being reattempted by the framework (default > >>> behavior, attempts 4 times to avoid transient failure scenario). > >>> > >>> Visit your job's logs in the JobTracker web UI, to find more > >>> information on why your tasks fail. > >>> > >>> On Tue, Nov 20, 2012 at 10:22 PM, jamal sasha <jamalsha...@gmail.com> > >>> wrote: > >>> > > >>> > > >>> > > >>> > I am not sure whats happening, but I wrote a simple mapper and > reducer > >>> > script. > >>> > > >>> > > >>> > > >>> > And I am testing it against a small dataset (like few lines long). > >>> > > >>> > > >>> > > >>> > For some reason reducer is just not starting.. and mapper is > executing > >>> again > >>> > and again? > >>> > > >>> > > >>> > > >>> > 12/11/20 09:21:18 INFO streaming.StreamJob: map 0% reduce 0% > >>> > > >>> > 12/11/20 09:22:05 INFO streaming.StreamJob: map 50% reduce 0% > >>> > > >>> > 12/11/20 09:22:10 INFO streaming.StreamJob: map 100% reduce 0% > >>> > > >>> > 12/11/20 09:32:05 INFO streaming.StreamJob: map 50% reduce 0% > >>> > > >>> > 12/11/20 09:32:11 INFO streaming.StreamJob: map 0% reduce 0% > >>> > > >>> > 12/11/20 09:32:20 INFO streaming.StreamJob: map 50% reduce 0% > >>> > > >>> > 12/11/20 09:32:31 INFO streaming.StreamJob: map 100% reduce 0% > >>> > > >>> > 12/11/20 09:42:20 INFO streaming.StreamJob: map 50% reduce 0% > >>> > > >>> > 12/11/20 09:42:31 INFO streaming.StreamJob: map 0% reduce 0% > >>> > > >>> > 12/11/20 09:42:32 INFO streaming.StreamJob: map 50% reduce 0% > >>> > > >>> > 12/11/20 09:42:50 INFO streaming.StreamJob: map 100% reduce 0% > >>> > > >>> > > >>> > > >>> > > >>> > > >>> > Let me know if you want the code also. > >>> > > >>> > Any clues of where I am going wrong? > >>> > > >>> > Thanks > >>> > > >>> > > >>> > > >>> > > >>> > > >>> > > >>> > >>> > >>> > >>> -- > >>> Harsh J > >>> > >> > > > -- Regards, Bharath .V w:http://researchweb.iiit.ac.in/~bharath.v
