[imp] load balancing

[Eric Rostetter]

Quoting Brian Clark <bclark@protocolusa.com>:

> We use BigIP from F5 to load balance our mail (smtp, pop, imap, ldap)
> traffic amongst three servers. We've got two of them that work in a
> fail-over configuration. If the primary fails, the secondary takes over
> for it.
> http://www.f5.com/f5products/bigip/

Good choice!
 
> However, I haven't figured out the best way load balance an IMP
> installation. I use LDAP to store all of my user information, and all of
> my user mailboxes are stored on an NFS server. How do I store _all_ of
> the user-specific configuration information for IMP in an LDAP
> directory?

You would need to be more specific.  Basically everything should be easy
to setup with ldap except sessions.  If you can get the sessions in ldap
also, then you would be home free.

> Also, for true redundancy, would I need to install a
> database on each of my Horde/IMP servers? I use PostgreSQL for the one
> server that I have running IMP right now.

I'd use ldap instead of the database, and set up ldap replication between
the servers.  (One would be the master, the other the read-only replication
of the master.  If the master fails, then you would need a script to detect
that and bring up the read-only replica as the master).

Of course, I've never actually done any of this, but I am thinking about 
moving everything to ldap in the (nearish) future.  Just started working
on an ldap setup yesterday in fact...
 
> Brian!

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

Why get even? Get odd!