[Dovecot] Dovecot Failover

[list at airstreamcomm.net]

On 4/19/13 2:49 AM, Timo Sirainen wrote:
> On 19.4.2013, at 10.43, Timo Sirainen <tss at iki.fi> wrote:
>
>> On 19.4.2013, at 9.59, Nikolaos Milas <nmilas at noa.gr> wrote:
>>
>>> 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).
> BTW. I'm kind of hoping that if dsync replication becomes more commonly used with people commonly setting up two A records for the IMAP server, the IMAP clients would evolve to support this by trying out all the listed IPs. Web browsers already do this nowadays (and that's why I think your URL is a bit out of date).
>
>

If DNS were the preferred method for load balancing IMAP/POP3 (or 
others) I would recommend the clients begin supporting SRV records as 
they were specifically designed to handle this kind of scenario.