Determine if apache process pid is running

One of my small VPS was often running out it’s memory. When this occur, some processes terminating. The easiest way to find out if a daemon is running is run ps aux command and grep process name. If you got output along with process name/pid, your process is running.

The pidof command combines the ps aux and the grep command. Here is a sample script what can keeping alive your apache webserver:

#!/bin/bash
RESTART="/etc/init.d/apache2 restart"
PGREP="/usr/bin/pgrep"
HTTPD="apache2"

# find httpd pid
$PGREP ${HTTPD}

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

You can define a cron job per minute to run your script:

*/1 * * * * /home/zoner/keepalive.sh >/dev/null 2>&1