Network Solution for Windows – Windows system, Linux system, Ubuntu server configuration tip

Here is a simple shell script tested on CentOS / RHEL / Fedora / Debian / Ubuntu Linux. Should work under any other UNIX liker operating system. It will check for httpd pid using pgrep command

Pgrep command

pgrep looks through the currently running processes and lists the process IDs which matches the selection criteria to screen. If no process found it will simply return exit status 0 (zero).

Download the script and set cronjob as follows:

*/5 * * * * /path/to/script.sh >/dev/null 2>&1

Sample script:

#!/bin/bash
# Apache Process Monitor
# Restart Apache Web Server When It Goes Down
# --------------------------------
# Copyright (c) 2003 nixCraft project <http://cyberciti.biz/fb/>
# This script is licensed under GNU GPL version 2.0 or above
# --------------------------------
# This script is part of nixCraft shell script collection (NSSC)
# Visit http://bash.cyberciti.biz/ for more information.
# --------------------------------
# RHEL / CentOS / Fedora Linux restart command
RESTART="/sbin/service httpd restart"# uncomment if you are using Debian / Ubuntu Linux
#RESTART="/etc/init.d/apache2 restart"

#path to pgrep command
PGREP="/usr/bin/pgrep"

# Httpd daemon name,
# Under RHEL/CentOS/Fedora it is httpd
# Under Debian 4.x it is apache2
HTTPD="httpd"

# find httpd pid
$PGREP ${HTTPD}

if [ $? -ne 0 ] # if apache not running
then
# restart apache
$RESTART
fi

A better and more reliable solution is monit monitoring software for restarting services such as mysql, apache and sendmail under UNIX / Linux operating systems.