Re: mod_perl output filter and mod_proxy, mod_cache

Hi.

I have to apologise.
I misunderstood your first post, and I wanted to verify on the Tomcat list, so I quoted 
the following passage of your first post in my message there :

"Sadly, the tomcat dev's forgot to set any caching headers in the HTTP response (either 
Expires, Last-Modified or Cache-control) so the sites are largely uncacheable by browsers 
and the various tomcats are becoming overloaded."

Unfortunately, the Tomcat Dev's there took it rather seriously, and as a consequence now 
you name is shit on the Tomcat list.


.. just kidding, I did not quote your name.

Anyway, apart from a few huffed responses to my misquote (since then rectified), someone 
provided a suggestion that may not be the simplest, but might be helpful anyway in some 
cases :

Have a look at : http://www.tuckey.org/urlrewrite/

This is a "Java Servlet Filter", which can be added transparently "around" any Tomcat web 
application (by adding the required section in the web.xml config file of that web 
application).
Java Servlet Filters are such that the Tomcat web application is not even aware that it is 
there, and continues to work as before.  Much like Apache input and output filters in 
fact, except that a Java Servlet Filter is both at the same time (it "wraps" the webapp on 
both sides).

Anyway, this filter can do such things as conditionally or not adding response headers to 
anything the webapp produces.  And it can do much more, as with time it has evolved into 
some kind of mish-mash of mod_rewrite, mod_headers and mod_proxy.

It is more one-by-one work than doing something at the Apache front-end level or via a 
proxy, but it also provides better fine-tuning possibilities.
So, if you can for instance easily identify the worst offenders, it might be an option.

And it is certainly a good tool to have in one's toolcase.