Nagios tool is very helpful for monitoring server process, load, free space and etc. On this post how to configure at specific process like rsyslogd, cpanel, csf and other process.

For example do you want to monitor rsyslogd on nagios server?

# ps aux | grep rsyslogd

root     12541  0.1  0.5 152411   5656 ?        SNl  03:37   0:47 /sbin/rsyslogd -i /var/run/
root     20658  0.0  0.0 175215   864 pts/2    S+   12:35   0:00 grep rsyslogd

Download a process monitoring script from nagios and save to under  /usr/local/nagios/libexec/  directory,

Give execute permission and user permission,
#  cd /usr/local/nagios/libexec

#  chown nagios:nagios

#  chmod +x

Execute the below command,
# /usr/local/nagios/libexec/ -p rsyslogd -w 10 -c 20 -t cpu

OK - Process: rsyslogd, User: root, CPU: 1.0%, RAM: 0.6%, Start: 17:10, CPU Time: 74 min | 'cpu'=1.0 'memory'=0.6 'cputime'=74 ]

-w specified to Warning Status
-c  specified to Critical Status

If you may get the below error like, bc: command not found. Need to be install bc package in your system.
# /usr/local/nagios/libexec/  -p rsyslogd -w 10 -c 20 -t cpu

/usr/local/nagios/libexec/check_ps: line 152: bc: command not found
OK - Process: rsyslogd, User: root, CPU: 0.1%, RAM: 0.5%, Start: 03:37, CPU Time:  min | 'cpu'=0.1 'memory'=0.5 'cputime'= ]