If using Ubuntu 11 or lower, the mod jk install has a flaw where jk.conf is not automatically created.
Create jk.conf
The approach I take here is to make the mod_jk available at the global level to all Apache Virtual hosts. If we wanted things to be more granular you could instead put the contents of jk.conf in a specific virtual host.
mod_jk may be installed but it still needs to be configured. Create the file /etc/apache2/mods-available/jk.conf using sudo with the following contents,
<IfModule mod_jk.c> JkWorkersFile "/etc/libapache2-mod-jk/workers.properties" JkLogFile "/var/log/apache2/mod_jk.log" # Use debug mode if you have trouble # JkLogLevel debug JkLogLevel info </IfModule>
There are much more configuration options. But this should be enough to get you started for a small to medium scale website.