I like to have the Tomcat manager webapp installed on each instance, so I can play with the webapps, and see how many active sessions there are. To do this, make a file called manager.xml file in the webapps directory of your Tomcat instance. One I like to use is this:
<Context path="/manager"
docBase="/usr/local/tomcat/server/webapps/manager"
debug="0"
privileged="true">
<ResourceLink name="users"
global="UserDatabase"
type="org.apache.catalina.UserDatabase"/>
<Valve className="org.apache.catalina.valves.RemoteAddrValve"
allow="127.0.0.1,192.168.100.100"/>
</Context>
The key bit is the docBase attribute, which needs to point to the webapp in the Tomcat installation directory. I add a RemoteAddrValve to keep evil people from trying to break into the manager.
You'll also need to add a user account with permission to use the manager. Put a file called tomcat-users.xml into the conf directory of the Tomcat instance, which should have something like the following:
<tomcat-users> <role rolename="manager"/> <user username="admin" password="hard2Guess" roles="manager"/> </tomcat-users>
Finally, your server.xml file needs to have a UserDatabase configured. This is in the example configuration files from the Tomcat installation.