[dnsdist] frontend responses for resolver timeouts

[David Bader]

thank you for your help!

Remi Gacogne via dnsdist:
> I'm afraid dnsdist doesn't a ServFail when the backend resolver does not 
> respond within the UDP timeout, no, it just records that the query was 
> not answered in time and increases the 'downstream-timeouts' counter. 
> Not sending a ServFail should lead the client to retry, giving the 
> backend a second chance now that the answer might be (partially?) in cache.

Ok, so in case of a timeout, dnsdist does not send anything to the 
client and the client will also timeout (and retry).

Does that mean, it would make sense to increase the dnsdist 
configuration to use the same timeout as the client uses?
If we are in the rare position to know the client's timeout.
(dnsdist is not under heavy load)

thanks,
David