[squid-users] Overriding longer Expires: headers on an accelerator proxy

We're running some internal squids as reverse-proxy accelerators, to
"flatten" pseudo-dynamic content and hold it for a few minutes, thus
relieving load on the origin server (the accelerators pull from a different
port on localhost).

All the documentation I can find about configuring squid to override
Expires: headers seem to be attempting to make squid hold data longer than
what the origin server specifies, (to thwart bad clocks out there, or people
who set their servers to demand they never cache)...

What we want is to go the other way, and configure squid to never cache
content longer than, say, five minutes. This saves us having to scramble to
manually expire content in the cache that we normally tell "outside" caches
to hold for 30 minutes, but would like the option of fixing typos in and
such in closer to real-time.

With refresh_pattern, we can do this pretty reliably, but for any of our
content that sets an Expires: header, refresh_pattern seems to obey the
Expires: header. We want to say "look, squid, consider ANY file in your
cache that's older than five minutes to be stale, and go fetch it again."

we can't change the Expires at the origin server, as that would undo the
reason we set it in the first place, which is to get our
content-distribution-network's caches to hold our stuff for the prescribed
amount of time. Those guys have a manual "expire this wildcard" mechanism
we can use.

I'd think that telling squid to never hold anything longer than N minutes
should be easy, but I can't find it in the faq/manual. Any help?

Ryan Nelson
Lead Unix Systems Engineer
Major League Baseball Advanced Media
ryan.nelson@mlb.com - www.mlb.com
--- see www.ryan.net for my PGP public key ---

==============================================================================
"MLB Mail Domain" made the following
 annotations on 03/28/03 15:38:59
------------------------------------------------------------------------------------------------------------------------------------------------------------
[INFO] -- Virus Manager:
No Viruses were detected in this message.

==============================================================================
Received on Fri Mar 28 2003 - 13:33:36 MST