On Wed, 2008-03-26 at 14:37 -0700, Jeroen van Aart wrote:
> Or is there a way to access a server directly, automatically, when a
> load balancer fails? Maybe I am missing some obvious things.
You are :)
If you're using Linux boxes, and you have only two - forgetting for a
moment the obvious issue of a shared mailstore - then they can act
simultaneously as:
= load balancers
= high availability servers
= MTA, MSA
= IMAP / POP / Web servers
Using LVS -
http://www.linuxvirtualserver.org/ - which is built in to
the Linux kernel.
Heartbeat gives you the HA part
Heartbeat can trigger ldirectord, the linux-ha project's load balancing
manager
Exim does the MTA, MSA part
You choose what to do the rest with :)
The difficulty with a two box solution is the last part - how to achieve
a shared mailbox store. Oh, hang on, it's not *that* hard if you use
something like DRBD -
http://www.drbd.org/ - which Heartbeat can also
manage...
So, with a pair of boxes and a reasonably recent version of Linux (I
choose RHEL based distros from personal preference and familiarity, but
that's a religious fight I'd rather see raised here!) you've got it all.
No need for a third box, no SPOF in sight.
Be ready, however, for a learning curve...
Graeme
