High avaliabilty for IMAP/PROXY

[Vincent Fox]

On 9/18/2014 11:58 AM, Fabio S. Schmidt wrote:
> Hi,
>
> - Sorry if it seems to be a little off-topic -
>
> We have deployed Cyrus Aggregator and currently we provide load
> balancing and high availability for the Cyrus Front Ends through DNS.
> With this scenario, if a Frontend is unavailable it will receive
> connections unless we remove it from the DNS record for the IMAP
> service.
>
> Does anyone have any better ideas to improve the high availability? I
> was wondering about using HAPROXY vs NGINX but I do not know their
> behaviours in cases like I mentioned above.
>
We have for about 8 years used Perdition for POP/IMAP proxy.

3 simple Linux boxes in a load balanced pool.

Friends don't let friends do Round Robin DNS.  You can't count
on removing DNS entries, since propagation can be very slow and
some clients don't even respect TTL.