Cyrus IMAP and MySQL mailboxes (Building load-balancing cluster)

[Igor Zhbanov]

2006/11/17, Adam Tauno Williams <adam at morrison-ind.com>:
> > Yes, I know how failover cluster works. But what if one server
> > (active) can't process such a load? Suppose, we plan to have 100 000
> > users working actively with mail. I understand that it is possible to
> > use one monstrous server to take all of the load, but I am interested
> > in load-balancing solution on relatively inexpensive servers.
>
> (a) SANs are not that expensive.
> (b) SANs are *WAY* *WAY* more reliable than *ANY* storage solution you
> can build yourself for the same amount of money.  If you really don't
> believe that you need to lay of smoking the good stuff.  And (b.1) - if
> you have that many users but can't afford a SAN...
> (c) Then there is Cyrus replication and there is GFS.  There was long
> thread on Cyrus IMAP, HA, & GFS just back in October.
>
>
> > And what
> > about slow anti-viruses for 100 000 users' mail? Or to use
> > load-balanced front-ends connected to single SAN and connected to
> > anti-virus load-balanced cluster? :-)
>
> It doesn't require a cluster to load balance SMTP,  traditional and well
> established technologies will do that for you.  Setup multiple SMTP
> servers and publish multiple MX records.

Yes, I can use DNS-based load-balancing to spread load to several
frontends. But what about backends? :-) How to balance load for them?