To monitor Tomcat with Munin 2.0 on Debian GNU/Linux (tested on Debian Squeeze with Tomcat6 and Debian Backports), you need the following steps.
First, you need to install package tomcat6-admin which enables the Tomcat Manager app we will be using.
# apt-get install tomcat6-admin
Next, create a user with a manager role in Tomcat, editing /etc/tomcat6/tomcat-users.xml and adding the following two lines in the appropriate list.
<user username=”munin” password=”Munin” roles=”manager”/>
Restart Tomcat to reread its configuration and enable the newly-installed Tomcat Manager app.
# service tomcat6 restart
Configure the Munin tomcat_* plugins adding a file /etc/munin/plugin-conf.d/tomcat with the following content:
Enable the tomcat_* plugins:
# cd /etc/munin/plugins/; ln -s /usr/share/munin/plugins/tomcat_* .
Restart Munin node:
# service munin-node restart