[squid-users] icq.com + connect-timeout weirdness...

I'm seeing an interesting phenomenon on the www.icq.com website. When
loading the complete page (i.e. forcing a refresh, or visiting it for
the first time) two or three images do not load for 120 seconds, and a
third or fourth image remains loading for 240 seconds. The images that
do not load are always among the tiny little "letter" images at the top
of the page (L for User Lists, W for Whitepages, etc.) but it's not
always the same ones that do not load.

The delay in loading these images is tied directly to the
connect-timeout that is defined, and for the first two/three images that
'hang' the delay exactly matches the connect-timeout in squid.conf,
while the last image to load takes precisely twice the connect-timeout.

So halving the connect-timeout results in delays of 30 and 60 seconds.
Turning off client and/or server side persistent connections and half
closed clients has no impact. Both of the Squid versions I use
(2.2STABLE5+hno and 2.4 daily from 07302001) are affected in the same
way (and are effected whether operating as an interception proxy or as a
traditional proxy).

I suspected something to do with multiple origin servers (they do load
balancing via round robin DNS...and I think it is backed up to an L7
switch balanced web server cluster), but siteselect_timeout has no
impact on the behavior.

DNS is also definitely not the culprit...it's happening at all of our
sites with several different DNS servers (from BIND 4.9.x to BIND 8 to
the Win 2000 DNS server--all of which are answering quickly on lookups
of the icq addresses).

I'm seeing this on Linux 2.2 and 2.4 (quite recent versions of each).
And I tested with Netscape 4.77 and Mozilla 0.9.3 clients, which do not
display the problem when going direct.

Anyone have thoughts on what's going on here, and possibly how to
fix/debug the problem? This one has had me stumped for several days
now. I'd also be interested to know if anyone using other OS' are
seeing this problem.

Thanks!
                                   --
                      Joe Cooper <joe@swelltech.com>
                  Affordable Web Caching Proxy Appliances
                         http://www.swelltech.com
Received on Wed Aug 08 2001 - 10:47:11 MDT