Limit A Process Cron Execution Time

JustinK101 · 11-06-2007, 09:09 PM

So I have a naughty perl script which runs via cron every 10 minutes. After a few days of uptime on server, for some reason the process doesnt seem to die and the perl process eats all my CPU and doesnt close.

I am wondering if there is a parm you can pass to the perl program which limits execution to say 30 seconds and then automatically kills the process? If not through perl, how about through cron tab, again limit to 30 seconds and after that time automatically kill the perl process.

Thanks for the help.

checkmate3001 · 11-06-2007, 11:40 PM

You could create another script and tell it to run every 10 mins (like your perl script) and then have it wait 30 secs - check to see if the perl script is running (vi ps or something) and then kill it if it is still running.

Just an idea.

JustinK101 · 11-08-2007, 06:55 PM

checkmate3001,

So how would this script look? Currently perl is being naughty and has stuck open. How do I check if the process is running? Do I just check for perl? How do I know I am not killing other perl processes that are running, but are not the naughty processes?

I suppose I could run it under a custom username (perlCron) in cron, then I check for perl running under user (perlCron), if it is running then kill PID.

Could you write a script which does what I explained above? I not good at scripting.

Thanks.

checkmate3001 · 11-17-2007, 02:05 AM

Sorry JustinK101 - I've been away for awhile.

It would take me too long to write. I'm not that good at scripts either.

unSpawn · 11-17-2007, 03:01 AM

Say your cronjob spawns a process with the commandline "/usr/sbin/larch.pl /etc/trees.conf", then you could add a cronjob like this:

Code:

#!/bin/sh
# Sleep for 30 seconds.
sleep 30s
# Find process by commandline and -KILL it.
pkill -9 -f "/usr/sbin/larch.pl /etc/trees.conf"
# Exit the shellscript the right way.
exit 0

It should be scheduled to run at the same interval as your other cronjob.

JustinK101 · 11-19-2007, 11:44 AM

UnSpawn,

Thank you very much, I tweaked your scipt a little bit since when I first tried it, it did not kill the processes. Basically I run the perl process under its own username in the crontab, perlCron. So the script now looks like:

Code:

#!/bin/sh
sleep 60s
pkill -9 -u perlCron perl
exit 0

unSpawn · 11-19-2007, 12:13 PM

OK, thanks for posting the feedback.

chrism01 · 11-20-2007, 01:23 AM

try
man ulimit
also, you might want to try posting the problem script (or a simplified ver) to the prog forum