How to capture Status 503

[Thomas Strauß <t....@srs-management.de>]

Hi,

I would like to setup a "maintenance in progress" page.

I want to cover the following situations:
1 - Removing an application 	-> tomcat throws 404
2 - Stopping an application	-> tomcat throws 503
3 - Restarting Tomcat		-> tomcat does not answer 

(1) is already solved using an error page in the ROOT Context.
(2) is open to be solved, as tomcat does know the context is stopped
    and I cannot convince him to use an error page from another context
(3) is not to be solved with tomcat. I think about an apache server that 
    normally just forwards everything. If I want to reboot apache, I switch 
    on forwarding to an apache Maintenance Page instead of tomcat. I have no 
    idea yet how to do it, but this should work.

My question now is: How do you solve problem (2) and (3)? Is there a best practice for that? I searched for status redirection, but did not find anything.

Best regards, 
   Thomas