[Dovecot] Dovecot Failover

[Nikolaos Milas]

Hello,

Assuming we have two (low traffic) servers (on different data centers) 
replicated using dsync, what is the best way to automatically direct 
users to the main server when it is up and to the redundant one when the 
main server is down?

Using DNS? I've seen that DNS-based failover has generally issues (for 
example: 
http://serverfault.com/questions/60553/why-is-dns-failover-not-recommended, 
which is informative although it refers to web servers).

What is the suggested approach? HAProxy? Heartbeat/Pacemaker?

Any advice will be appreciated.

Thanks and regards,
Nick