Invalidation after updates or deletions

RFC2616 says that POST, PUT, DELETE and unrecognised request methods  
passing through a cache MUST invalidate one or more cache entries  
(depending on the values of the Location and Content-Location headers).

   http://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html#sec13.10

In my informal (and not yet complete) testing, I've only found one  
cache implementation -- client or intermediary -- that actually does  
this. I've tried to engage various vendors, etc. to fix it, but  
haven't seen much interest.

Why is that? Is there some non-obvious impediment to implementation?  
Lazy developers?

If it doesn't see any take-up, perhaps it should be deprecated, or  
relegated to a cache extension; e.g.,

Cache-Control: no-cache, max-age-if-you-actually-invalidate=300

Thoughts?

--
Mark Nottingham     http://www.mnot.net/

Received on Tuesday, 18 July 2006 04:36:50 UTC