Setting up Apache monitoring with Munin

07 October 2009 | Matt Perdeaux | Backend,  Sysadmin

After a few solid days of Linux server wrangling, I found getting Munin to monitor our Apache server more hassle than I thought it would be.

Salient system details:

• Ubuntu Hardy
• Nginx web server (port 80) proxy
• Apache web server (port 8080)

So, if only for my own future reference, here's how I managed it:

1. Make sure the WWW Protocol library for Perl is installed:
   sudo apt-get install libwww-perl
2. Apache needs to be running mod_status (which serves of the stats that Munin draws charts for). Add the following somewhere in /etc/apache2/apache2.conf:
   
ExtendedStatus On
<Location /server-status>
    SetHandler server-status
    Order deny,allow
    Deny from all
    Allow from 127.0.0.1
</Location>

3. Restart Apache:
   sudo /etc/init.d/apache2 restart
   
4. The Munin plugins actually live in /usr/share/munin/plugins, and are symlinked to in /etc/munin/plugins:
   
   
   
sudo ln -s /usr/share/munin/plugins/apache_accesses /etc/munin/plugins/apache_accesses
sudo ln -s /usr/share/munin/plugins/apache_activity /etc/munin/plugins/apache_activity
sudo ln -s /usr/share/munin/plugins/apache_processes /etc/munin/plugins/apache_processes
sudo ln -s /usr/share/munin/plugins/apache_volume /etc/munin/plugins/apache_volume

   
   
   NB - If you have uploaded any additional plugins, ensure root has execute permission:
   sudo chmod 755 apache_activity
   
5. Make sure the Munin plugins are monitoring port 8080 - in this setup I've got Nginx on the default port. Add the following to /etc/munin/plugin-conf.d/munin-node:
   
[apache_*]
env.ports 8080

   
6. Restart the Munin node:
   sudo /etc/init.d/munin-node restart