I had JT OOME in hadoop version 1.2.1 and applied the patch based on the
fix given by Apache contributors for jira issue mapreduce-5508.
After applying that fix the heap size gradually increases but after one
week jobtracker completely hangs and slowdown but didn't get JT OOME. No
error in JT logs.
Without this fix weekly once JT heap size increases and got OOME.
Please help its our production environment.