topic Re: Killing processes automatically. in Operating System - HP-UX

Killing processes automatically.

santosh jha — Mon, 19 Sep 2005 08:52:59 GMT

I want to kill weblogic process through a script.

i use the command

"kill -9 `ps -e |grep weblogic.server |cut -c 3-6`"

But there is chance that the number of digits in the pid may increase and than the script will not work.

Please help

Santosh jha

Re: Killing processes automatically.

Doug O'Leary — Mon, 19 Sep 2005 08:58:40 GMT

Hey;

Automatically killing processes is generally a bad idea. If, for some reason, your script identifies process 1, for instance, your system is history.

That being said:

ps -ef | grep [w]eblogic_serve | awk '{print $2}' | xargs -i kill {}

is the syntax I'd use if I wanted to do something as dangerous...

Doug

Re: Killing processes automatically.

Pete Randall — Mon, 19 Sep 2005 08:59:36 GMT

Use awk rather than cut:

"kill -9 `ps -e |grep weblogic.server | awk '{ print $2 }'`"

Pete

Re: Killing processes automatically.

santosh jha — Mon, 19 Sep 2005 09:02:04 GMT

Thnaks a lot guys .

Re: Killing processes automatically.

Hakan Aribas — Mon, 19 Sep 2005 09:04:36 GMT

You can use the following script to kill processes.

Usage:
killall

Example:
killall weblogic
---------------------

#!/usr/bin/sh

PS=/usr/bin/ps
AWK=/usr/bin/awk
GREP=/usr/bin/grep
KILL=/usr/bin/kill

if [ $# -ne 1 ]
then
echo Kullanim : ./killall proses_adi
exit
fi

for pid in `$PS -e | $GREP $1 | $GREP -v grep | $AWK ' { print $1 }'`
do
$KILL -9 $pid
echo $pid $1 killed
done
-------------

Re: Killing processes automatically.

Geoff Wild — Mon, 19 Sep 2005 09:05:51 GMT

Don't use -9 as you can windup leaving zombies and/or shared memory not cleared, etc....

kill -18 is better or just the default (15)...

What I used to do for example - on zombies:

logfile=/tmp/killzombies.log
if [ -f $logfile ];
then
rm $logfile
touch $logfile
else
touch $logfile
fi

Rgds...Geoff

for i in `ps -el|grep -v SZ|grep Z|awk '{print $5}'`
do
ps -ef|grep -v grep|grep ${i} >>$logfile 2>&1
mailx -s "Check Zombie(s)" me@mydomain.com <$logfile

Re: Killing processes automatically.

Bill Hassell — Mon, 19 Sep 2005 09:36:35 GMT

Not a good design at all. kill -9 is the first problem. NEVER use kill -9 until you have tried kill -15 and perhaps kill -1. The reason is that kill -9 prevents the program code from cleaning up open files and logs and releasing shared memory, semaphores and memory mapped files. I would suggest that your script try each kill signal and then issue a warning when resorting to kill -9.

The secon d is ps and grep--a deadly combination. grep doesn't care what it finds on the ps line. The string "weblogic.server" will appear is the ps listing as part of the grep string or it may appear as a parameter given to some program. A worse case is where you grep for weblogic and there are users with that username, there are programs like weblogic.control, etc, all will be found and blindly killed by such a script.

Now true, you are using ps -e rather than -ef which drops the command line arguments, but it is always recommeded to use ps to locate your process by name, not grep. To show you how bad this can be, try these two commands:

ps -ef | grep sh
UNIX95= ps -C sh

The first will find critical system processes like unhashdaemon (don't kill that one!) while the second only find sh (and not ksh or csh, etc)

Here is a general method where the program name is assigned to a variable, and it exactly located with ps -C (note that -c -H and -o are enhanced ps commands and need the UNIX95 variable temporarily set to activate these options)

#!/usr/bin/sh
set -u
export PATH=/usr/bin
PROGNAME=sleep
PROGLIST=$(UNIX95= ps -C $PROGNAME -o pid=)

if [ "$PROGLIST" = "" ]
then
echo "\n$PROGNAME not running\n"
exit 1
fi

for PIDNUM in $PROGLIST
do
echo "\nKilling PID $PIDNUM:"
ps -fp $PIDNUM
kill -15 $PIDNUM
sleep 1
ps -fp $PIDNUM > /dev/null
if [ $? -eq 0 ]
then
kill -1 $PIDNUM
sleep 1
ps -fp $PIDNUM > /dev/null
if [ $? -eq 0 ]
then
kill -9 $PIDNUM
sleep 1
echo "(kill -9 $PIDNUM required)
ps -fp $PIDNUM > /dev/null
if [ $? -eq 0 ]
then
echo "\nWARNING: $PIDNUM cannot be killed\n"
fi
fi
fi
done

Now in this example, I've set PROGNAME to "sleep" so you can test it. It will handle zero or more copies of the same program name, first trying to terminate with SIGTERM (-15), then SIGHUP (-1) and finally SIGKILL (-9) with a warning. And if the process is still not dead, it is hung on I/O and can never be killed.

Re: Killing processes automatically.

Bill Hassell — Mon, 19 Sep 2005 09:41:56 GMT

Ops, one typo:

echo "(kill -9 $PIDNUM required)

is missing " at the end, should look like this:

echo "(kill -9 $PIDNUM required)"

Re: Killing processes automatically.

santosh jha — Tue, 20 Sep 2005 03:44:14 GMT

Thanks a lot Bill.I will sure follow your instructions.

Santosh Jha

Re: Killing processes automatically.

Rory R Hammond — Tue, 20 Sep 2005 12:49:22 GMT

Instead of relying on ps,

Try

fuser -k programname

If Weblogic as startup script use the traditional shutdown and startup
/sbin/init.d/weblogic restart

or

/sbin/init.d/weblogic stop
/sbin/init.d/weblogic start

Rory