[squid-users] Config for "multiplexing" non-caching proxy

Hi,

I've noticed that either by design or as a side-effect of squid's
caching that if I request the same object from multiple clients at the
same time, squid will effectively "multiplex" the transfer - that is,
use a single transfer from origin to feed the object to each client as
it receives the incoming http transfer. IMO this is a Good Thing.

I'm wondering if it's possible to extend this behavior to a non-
caching proxy - this would allow the utilization of squid as a non-
caching CARP proxy while protecting a parent from large numbers of
requests for a single object (which in a CARP setup would normally all
get sent to the same parent, potentially overloading it).

So the goal is to utilize this multiplexing capability in squid while
not actually caching the content. However, testing shows that when I
disable disk caching (via "cache_dir null" or by "maximum_object_size
0 KB", this behavior is no longer present.

What would one recommend as the minimum feasible caching config to
enable this behavior, while either disabling or minimizing any
"actual" object caching?

One option could be set up a small disk cache, but enforce a very
short expiry time (say, 5 minutes) on all incoming objects. However, I
don't see a refresh-pattern directive or other config option to
enforce this on objects with longer Expires: or Cache-Control: max-age
headers (override-expire enforces min-age, not max-age). Any
suggestions here?

Thanks,

-Chris
Received on Thu Apr 09 2009 - 15:04:47 MDT