I still have yet to get a stack trace but I think I track the problem
down to a tread library issue with RHat. It is similar to some problems
that Tomcat has had on RHat 9+. I have set the LD_ASSUME_KERNEL=2.2.5
this forces it to use the old thread libraries for the JVM. This seems
to be working but it has only been in affect for about 2.5 hours. Here
is a basic description of the program.
The program is setting two timers using java.util.Timer. both send
emails if they are not canceled. The process then makes an HTTP call to
my webservers and reads the output. if this returns before the Timers
go off it cancels them if not it sends an email. It then runs a
external grep on PS to determine the number of java processes and apache
process and write the date, time it took to make the http call, number
of java processes and number of apache process to a log file.
Creighton
On Wed, 2004-04-14 at 10:35, Jason Kretzer/STAR BASE Consulting Inc.
wrote:
> So which are you using to make it fire every 5 minutes? The timer or
> the cron?
>
> I do not mean to insult your intelligence but even the best of us make
> this type of mistake so I must ask this. Did you remember to use
> System.exit() when if finishes?
>
> I know I have done this more than once. Sorry if it is too simplistic.
>
> -Jason
>
>
>
>
> Creighton Kirkendall
> <ckirkendall@xxxxxxxxxxxxxx>
>
> 04/14/2004 09:01 AM
> To
> users@xxxxxxxxxx
> cc
>
> Subject
> [cinjug-users]
> Java process
> hangs
>
>
>
>
> I have a problem. I have a simple java process that runs as a cron
> every 5 minutes. About once every 2 hours give or take the process
> hangs and appears to be in deadlock. I cannot figure out why. I have
> tried to access a stack dump by doing a "kill -3 <pid>" but all I get
> to
> stderr is:
>
> JVMDG217: Dump Handler is Processing a Signal - Please Wait.
>
> But no dump ever appears. The process is simple but it does use the
> java.util.Timer. Why can't I get a stack trace? I have looked at the
> state using "ps aux" and it suggests it is still fine. Since I can
> not get a stack trace from the JVM. I tried an strace -p <pid> and it
> looks like it is waiting.
>
> Here is the dump from strace.
> futex(0xb4226780, FUTEX_WAIT, 126, NULL
>
> Here is the stats on the machine.
> IBMJDK 1.4.1-02
> LINUX RHAT ENTERPRISE
>
> Any help would be very appreciated.
>
> Creighton Kirkendall
>
>
>
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