Let me ask following additional question.
It is understandable that idle (or hot) standby is not supported for Tomcat.

So here, let me ask about cold standby.
There is some explanation about cold standby in the following link.
http://pic.dhe.ibm.com/infocenter/clmhelp/v4r0/index.jsp?topic=%2Fcom.ibm.jazz.install.doc%2Ftopics%2Ft_planning_idle_standby_deployment.html

The explanation is based on WAS.
Considering the configuration, if databases and indices(and some other files, if necessary)
are properly shared between primary server and backup server, cold standby configuration should work
even though the application server is Tomcat.

So if we use cold standby configuration with Tomcat, is it supported?