HELP!! Tomcat/Apache, Clustering and Static Classes...

I have a clustered application setup using Tomcat 5.5, Apache 2.3 with mod_proxy_balancer. Everything is working great.

However, I have come across an issue with static classes. I am using a static class to cache a whole bunch of strings. When certain events occur in the application I invalidate some or all of the strings cache.

The problem is that The cache is only invalidated on the current tomcat instance's JVM. Thus meaning that the cache of the other cluster members is not invalidated.

Is there some kind of mechanism for replicating static classes across clusters, or does anyone have suggestions on how I can go about creating a better caching mechanism. I really want to avoid file/database access for this caching since these string may be read thousands and thousands of times every time a page is hit. The cache needs to be shared among all users so using the session to cache the string is not an option.

Thanks,

Matt