I have a rather large WP 2.0.3/Apache2 install (15,000+ posts), and I'm trying to wring better performance out of it. I've enabled MySQL query caching with the Post-Query Accelerator plugin and WP-Cache2, but my machine is still bogging down under fairly light traffic.
In a past Zope install, I solved this problem by putting a Squid server in front of the Zope machine and caching the requests.
This doesn't seem to work with WordPress. I'm able to funnel requests through the Squid machine, but nothing ever gets cached (the Squid logs show every request as a TCP_MISS).
Does anyone have experience with running WP behind Squid? Is it possible to get this working correctly, or does WP not send the proper cache headers?