[imp] Help Req. : Sizing a Horde\IMP system for 12,000 users

[Eric Rostetter]

Quoting Martin Searle <M.A.Searle@ukc.ac.uk>:

> We do have a limited budget and we would like to continue to use Sun
> hardware. So does anyone have any thoughts or have first hand
> experience with setting up a system to handle more than 10,000
> concurrent users ? My gut reaction is too look at clustering and use
> spare space on existing servers.

Three options:

1) Cluster the Sun machines.  No experience with this for Horde/IMP use,
   but should help a lot.

2) Use a load balancer to balance over multiple servers.  UT Austin does
   this to serve webmail to its 52K students and 17K staff.  (Bunch of
   Sun servers behind some Cisco LocalDirector boxes).

3) Split functions across machines.  One machine for SMTP, one for webmail
   web server, one for IMAP/POP3, one for SQL/LDAP, etc.

Any of these should work and should provide you with better throughput.
Personally I'd say the first two will get you better performance than the
last one.

-- 
Eric Rostetter
The Department of Physics
The University of Texas at Austin

Why get even? Get odd!