I'm still working on my HTTP proxy server. I have now reached the point, where the server cache should be implemented for maximum performance, but I don't know how. It's not the details of how the web documents will be stored. I think I can figure that out myself... The problem is for the server to determine, when the files in cache should be updated. Some items (e.g. ASP/PHP/CGI) will sometimes chance every time a proxy user requests it, but it's harder with HTML documents and pictures. You never know whether they are updated every day or once a month.

How good is a server cache, if it out-of-date and giving the users old news etc??? On the other hand : How good is a server cache if it has to connect to the webservers every time, to ensure that it has not been updated???

Therefore my question to you fellow VB programmers is, how do I fix this dilemma? I have been giving it a lot of thought, but no solution has occured to me!!

Does anyone know, how the big professional proxy servers handles this problem?