[squid-users] How to override expires, maxage, s-maxage on reverse proxy?

I've got a reverse proxy configuration in front of a content
management system (Plone CMS if it matters). Since the CMS can be
configured to automatically purge content from the proxy whenever
most content items are edited, I would like to force the proxy to
retain the cache for a very long time without refreshing or
revalidation. In other words, I want my proxy cache to trust that it
always has the latest version. But I'm not sure I should do this via
s-maxage in the response as this setting might also apply to other
proxies upstream of me.

I looked at refresh_pattern and it's override-expire and ignore-no-
cache options but I'm not sure I can leverage this. First, because
it isn't clear whether these options will override max-age and s-
maxage if they're present in the response. And second, because I
need this behavior to be selectively applied (probably via a response
header set by the CMS) since not *all* items on the CMS will
automatically generate purge requests and there isn't a good way to
filter these by path.

I guess what I'm looking for is something like an s-maxage that will
be applied *only* to the reverse proxy and not to anything else
upstream.

Any suggestions?

Ric
Received on Sat Jul 28 2007 - 15:50:45 MDT