monit is an open source software that monitor services on your server. It can restart if any of the service go down.

Download latest version of file from

http://mmonit.com/monit/download/

cd /usr/local/src
wget http://mmonit.com/monit/dist/monit-5.0.3.tar.gz
tar -zxvf monit-5.0.3.tar.gz
cd monit-5.0.3
./configure
make
make install

Copy control file to /etc

cp monitrc /etc/

Edit /etc/monitrc

vi /etc/monitrc

At the end of the file add or uncomment

include /etc/monit.d/*

Now to monitor Apache, create a file /etc/monit.d/apache

vi /etc/monit.d/apache

Add following content

check process httpd with pidfile /var/run/httpd.pid
group apache
start program = "/etc/init.d/httpd start"
stop program = "/etc/init.d/httpd stop"
if failed host 127.0.0.1 port 80 protocol http
   and request "/phpinfo.php"
   then restart
if 5 restarts within 5 cycles then timeout

You can change

and request "/phpinfo.php"

To any file on your web server. I do have a phpinfo file on my server, so i used it.

Some says phpinfo.php is a security risk, to me it is only a security risk if you run vlunerable application on your web server. If you use update software on your server, some one seeing your phpinfo is not a security issue.

To run monit, edit /etc/rc.local

vi /etc/rc.local

Add

/usr/local/bin/monit -d 60 -v -c /etc/monitrc  -p /var/run/monit.pid -l /var/log/monit.log