CPU Monitoring Script
June 27th, 2009
Have you ever had a rogue process chew up all the CPU on your Linux server for a days and nobody notice?
This happens to me quite a lot so I decided to write a bash script that looks for these processes and send an alert email.
#!/bin/bash
#
# cpumon - monitors CPU usage and sends an alert email if limit is exceeded
#
# 2009 - martin@teamburns.com
#
host=`hostname`
file="/tmp/cpumon.txt"
rm $file > /dev/null 2>&1
function sendEmail() {
subject="High CPU on $host"
/usr/bin/mail -s "$subject" user@domain.com < $file
}
while read a b c
do
pid="$a"
cmd="$b"
cpu_percentage="$c"
if [[ -z "$cpu_percentage" ]]
then
echo "process $pid $cmd is using less than zero percent of the cpu!"
continue
else
cpu_percentage_integer=$(echo "$cpu_percentage"|sed 's/^\([^\.]*\)\..*$/\1/')
fi
if [[ $cpu_percentage_integer -gt 10 ]]
then
echo "$pid $cmd is using $cpu_percentage_integer percent of our CPU" >> $file
fi
done <<< "`ps --no-heading -eo pid,comm,pcpu`"
if [[ -f $file ]]
then
sendEmail
fi
This script can be scheduled to run periodically by placing an entry in the crontab file. Make sure use replace username with a valid name:
*/30 * * * * username /home/username/cpumon >/dev/null 2>&1
