I would like to configure Squid to always revalidate a cached object
(identified by its URL). Revalidation must happen even if HTTP rules say
that the cached object is still fresh.
There are, of course, ways to do the opposite (i.e., prohibit
revalidation of a stale object), but I cannot find a way that is
_guaranteed_ to trigger (unnecessary from HTTP p.o.v.) revalidation. For
example, I can set
refresh_pattern ... max-stale=0
but max-stale configuration is ignored for many fresh responses.
I do not control the client or the origin server. I could add a
Cache-Control:no-cache directive to a request or response using
adaptation, but I am looking for a solution that does not involve
Am I missing a trick that triggers revalidation of fresh objects?