Squid load balances ZEO clients using a round-robin approach. Squid does a name lookup using DNS or /etc/hosts, and caches those values, so when you run Squid as an accelerator, it will round-robin between all IPs it has in its IP cache for a given domain name. Virtual hosting is handled using a VHM in Zope, and a redirector in Squid (fills same role as mod_rewrite in Apache). With a redirector, you do not need to specify virtual in the httpd_accel_host option, as it is ignored for rewritten URLs... pyredir is a very easy to modify redirector written in Python... With Squid in front of Zope, you can use accelerated HTTP cache managers to explicity tell Squid cache info, along with any RAM cache managers you need... Sean -----Original Message----- From: bak [mailto:kedai@kedai.com.my] Sent: Tuesday, November 20, 2001 5:27 PM To: Chris McDonough Cc: zope@zope.org Subject: Re: [Zope] Urgent help needed: Zope falls over under moderate load On Wednesday 21 November 2001 05:38 am, you wrote:

The big "bang for buck" solution provider is caching. Assuming that you had no problems *before* the slashdotting, that will solve your problem because it will cause Zope to need to serve far fewer requests, closer to the number of requests you normally get. And this is (I assume) the outcome that you actually want. I highly recommend setting up a caching proxy in front of Zope if this sort of load will be recurring. It's way faster and cheaper than trying to understand the problem deeply. ;-) Most commercial sites are developed using this principle, AFAICT.

butting in with questions :) with 2.3.x, RAM Cache Manager has no refresh/expire/max_age feature. you get that with 2.4.x and above only. so that might give users stale pages. i know, i've encountered it. i *really* think that there should be a RAM Cache Manager howto/best approach. i'd like to write it, but i need inormation. i'm currently caching my pages, but i'm not sure i'm doing it right. properties such as REQUEST variables (there's two forms available. 1- at the method's page, 2-at the cachemanager page), statistics (seems that the url does have some effect on the cache hit rates), etc. confirmation from product author/zc would really help. i guess that i should really look at the source ..., and i will. today. now, for putting squid in front of zope. how do others do this, when you have more than one server (using zeo). there's the virtual parameter in squid, but i don't get it. any body done this? my solution for now is putting in caching manager, and if *really* necessary adding in another zeo client. thanks _______________________________________________ Zope maillist - Zope@zope.org http://lists.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope-dev )