On Mon, Nov 15, 2010 at 10:00:42PM +0100, lst_ho...@kwsoft.de wrote:
>> Conditionally compiling-in support for such a library is a bit painful,
>> though opendkim seems to have taken that approach. They have a DNS lookup
>> driver layer, and the driver reports whether it can support overlapping
>> queries... You can then choose to use an async DNS library if you have
>> one.
>
> Thanks for explaining the details. I don't really have the traffic to care
> about this "limitation", it was more of to learn about implications on
> deploying IPv6 in a network with different services running and to get
> knowledge where problems might arise.
Note that async libraries will rarely help with MX host resolution.
In almost all problem situations, one of the record types will dominate
the lookup time and Postfix will have to wait for both to complete, and
parallelizing does not speed up the slow path.
--
Viktor.
