http acceleration and Date headers (fwd)

Apologies for any duplicates - we'd had a network outage
and I hadn't seen this turn up on the Squid list...
---------- Forwarded message ----------
Date: Sun, 8 Mar 1998 13:44:31 -0800 (PST)
From: Andrew Daviel <andrew@andrew.triumf.ca>
To: squid-users@nlanr.net, http-wg@cuckoo.hpl.hp.com
Subject: http acceleration and Date headers

I have been doing a survey of clock accuracy
(http://vancouver-webpages.com/time/) and have found that, while the
majority of Web server clocks (as derived from the http Date header)
are very accurate, a few are way off.

I then wondered what the effect was of running an http accelerator (Squid
in httpd_accel mode, for instance) and tried it. It seems that the
Server header is unmodified, but that the Date header remains set at
whatever the origin server said until someone does an unconditional GET
(shift-reload in Netscape) (or presumeably until the original page is
modified...).

I can't easily tell if this is actually the reason for
the clock errors I've seen.

I wondered if this was the way that httpd accelerators were intended to
work.

Andrew Daviel
Vancouver Webpages & TRIUMF
Received on Tue Mar 10 1998 - 09:21:10 MST