(dws)Re: CGI Caching question

[dws]

Just so this gets said...

If you use a "force content expiration" scheme that relies only on using a unique ID in the URL, you run a risk: If there is a caching proxy between the web server and some browser, that proxy's cache is going to hang on to otherwise expired content (i.e., prior unique IDs and their responses), and will spill valid content sooner, thus reducing the effectiveness of the cache.

To be friendly to caching proxy servers, use "Cache-control: no-cache" as part of your scheme.

By the way, caching proxy servers are starting to crop up all over. I'm seeing a lot of them near corporate firewalls, as a means for the corporation to better utilize bandwidth.