Re: Infinite loop?

["Frances Stewart" <francess@xxxxxxxxxx>]

Ito might be that the garbage collector has kicked in for some reason (such
as alot of stuff to collect) and is trying to cleanup. I have seen sone
case where the job appeared like it would not end, but in actuality it took
to 14 hours, because the collector was returning heap to the system (that
is the simplified form of what was happening).

A process dump of all the threads (or the single thread) when the job is
consuming the CPU would show whether it was the garbage collector or not,
and also would show the stack for the thread in question.  Have done a
WRKSYSSTS to see if storage is being returned (i.e. percent used is going
down) or if there is an inordinate amount of paging etc. going on in the
storage pool in which WAS runs?

What I would recommend ideally is that you talk to IBM Support about the
problem and get things setup so that when the problem occurs (hopefully
during normal working hours), IBM Support can get on the system and debug
the problem.

Frances Stewart
WebSphere Application Server for iSeries 400
IBM Rochester




                      Dieter.Bender@t-o
                      nline.de (Dieter         To:       java400-l@midrange.com
                      Bender)                  cc:
                      Sent by:                 Subject:  Infinite loop?
                      java400-l-admin@m
                      idrange.com


                      12/22/2002 04:39
                      AM
                      Please respond to
                      java400-l





Hi,

we use WebSphere 3.5.6 running on as400 V5R1;
from time to time CPU usage reaches near 100% all used by one thread of the
application server. Nobody is working with the application and only
PWRDWNSYS
*immed brings down WebSphere. It's impossible to end the server from the
WepSphere console, or to stop it in another way. Neither endjob, normal or
abnormal, nor endsbs kills WebsFear.
It looks like an infinite loop, maybe in the JIT compile. CRTJVAPGM to
clearify this is a little bit complicated, beacause we use JSPs and it is
running hours to days.
The problem doesn't occur running WebSphere on another box (NT).

any ideas?
--
mfG

Dieter Bender
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