Re: caching - which machine should we use?

>  we used since may the cern httpd 3.0 for caching (with about 20 
>  accesses at the same time). in this month we want to expand our
>  service to 300-400 accesses.
>  does someone know how many performance one process of the cern httdp needs?
>  has anyone expirience which machine we should use (buy) or should
>  we use 2-4 server?
>                     R. Waldhofer 

We experience >330,000 hits a day, with up to 20 requests per second
and at the moment we have about 680 concurrent users. This runs on a
dual processor SGI Challenge DM with the disks set up to provide a
sustained 20Mb/s.  However, the big difference between us and you is
that we are running the Netscape Proxy Server. I don't know if Netscape
have measured, (cue Ari...), but I would guess that the process model
means that the Netscape Proxy is at least twice as (CPU) efficient as
the CERN server. However, having said that our two CPUs do seem to
spend a lot of their time idle so such a machine might suit your

We shall soon be deploying 5 more machines to improve the national
caching service in the UK. At that point we should have plenty more
opportunity for experimentation and analysis of performance.

I suggest that you invest some of the money you have to provide servers
in software licences.

Neil G. Smith
The University of Kent