dovecot director and keepalived

[Aki Tuomi]

> On 15/03/2021 20:54 Paterakis E. Ioannis <jpat at uoc.gr> wrote:
> 
>  
> On 15/3/2021 6:09 μ.μ., Steven Varco wrote:
> > Hi John
> >
> > Thanks for you input.
> >
> > So you basically state that („physically“) separating the director servers from keepalive/haproxy servers is the only option?
> > I would like to avoid setting up two additional machines for that whenever possible, as any node more in the chain potentially is another point of failure… ;)
> 
> Nope, it's not the only option. You can always have all three daemons 
> (keepalived/haproxy/director) on each machine. Keepalived will handle 
> the floating ip job, haproxies will have no problems with the floating 
> ip, the directors will always be binded to the static ips of the 
> machines and have their setup in the haproxies. That's all.
> 
> But, if you plan to make a Highly available environment, u have to 
> consider splitting your services to different VMs, and them to different 
> hypervisors in order to be as Highly available as you can....
> 
> John

The point of dovecot director is that it acts as a proxy that always routes users to same backend. You can use keepalived, if it supports external commands, to maybe tell director which backends are up / down.

You should have separate server for director(s) and each backend.

Aki