[imp] load balancing

[Liam Hoekenga]

Hey guys -

We've got nine machines dedicated to webmail (Horde/IMP/Turba) in our
server farm.  We're currently distributing the load between them using
sort of "round robin" technique - we're not actually using round robin
DNS, rather redirects from a central "gateway" (mail.umich.edu) to one of
the nine hosts.  This worked ok when our service was starting up, but our
audience has grown considerably (we had 38,000 unique users last month and
51,000 since we moved our webmail to IMP 3.x in January), and we're
considering alternatives.

We're looking for something to more efficiently distribute the load
amongst the servers.  We do have busy times of day, but all of the
machines get hugely loaded at the same time.  We may have a load of > 20
on 3 machines, but have a load of < 1 on the other 6.

What are people using for load balancers?

Liam