+1, jstack is crucial to solve these kinds of issues. Also, which scheduler are you using?
Thanks -Todd On Thu, Jun 17, 2010 at 2:38 PM, Ted Yu <yuzhih...@gmail.com> wrote: > Is upgrading to hadoop-0.20.2+228 possible ? > > Use jstack to get stack trace of job tracker process when this happens > again. > Use jmap to get shared object memory maps or heap memory details. > > On Thu, Jun 17, 2010 at 2:00 PM, Li, Tan <t...@shopping.com> wrote: > > > Folks, > > > > I need some help on job tracker. > > I am running a two hadoop clusters (with 30+ nodes) on Ubuntu. One is > with > > version 0.19.1 (apache) and the other one is with version 0.20. 1+169.68 > > (Cloudera). > > > > I have the same problem with both the clusters: the job tracker hangs > > almost once a day. > > Symptom: The job tracker web page can not be loaded, the command "hadoop > > job -list" hangs and jobtracker.log file stops being updated. > > No useful information can I find in the job tracker log file. > > The symptom is gone after I restart the job tracker and the cluster runs > > fine for another 20+ hour period. And then the symptom comes back. > > > > I do not have serious problem with HDFS. > > > > Any ideas about the causes? Any configuration parameter that I can change > > to reduce the chances of the problem? > > Any tips for diagnosing and troubleshooting? > > > > Thanks! > > > > Tan > > > > > > > > > -- Todd Lipcon Software Engineer, Cloudera
