Suppose I had various servers for different types of content sitting behing an Apache server. Firstly, am I right in thinking I can configure Apache to connect to the relevant computer when everything's static? Secondly, what if things moved dynamicaly, for example if I maintained a dynamic cache, either on the same or a different machine to the one running Apache. Where Apache should look for a given resource would be specified by an external program. Can I do this? I'd need to be able to pass the external program not just the http request but also and session variables.

Cheers