Viktor Dukhovni:
> On Mon, Jan 27, 2014 at 03:53:19PM -0500, Wietse Venema wrote:
>
> > > Before inventing new lookup mechanisms, have you considered the
> > > possibility of making the existing mechanisms available for LMTP?
> > >
> > > - Using multiple A records per name? If all hosts are equivalent
> > > that would be the way to go.
> >
> > This can also be used to implement unequal preferences, by listing
> > an IP address multiple times. Postfix will by default randomly
> > shuffle the address list.
>
> Perhaps, but see below:
>
> > > - Using MX lookups, and multiple MX records per name? This would
> > > make sense if some hosts are more preferred than others.
> >
> > This requires some SMTP client code duplication. because MX lookups
> > are not part of the LMTP protocol spec.
>
> Indeed, MX records are out scope for LMTP. To load-balance LMTP
> in a manner similar to MX records would require SRV record support.
> Which would (hypothetically) also take care of any desire for
> weighting. I am not eager to add SRV support, but it is doable
> in principle.
I agree that we hold off on new mechanisms until a need exists.
Equal-preference A records should solve 90% of the problem. By not
solving the remaining 10% at great effort, we can spend the limited
development cycles more wisely.
Wietse
