[dnsdist] dnsdist 1.4 and Debian Buster

[Chris]

Hi Remi,

I deployed a new copy of a PowerDNS authoritative server on Debian 
Buster and ran into a similar problem but with a slight twist. As with 
dnsdist I use multiple instances of PowerDNS which use different SQL DB's.

As with dnsdist, after a period of time I stopped being able to make UDP 
queries but TCP queries worked fine. The built in web server also works 
(I guess because its TCP). This happened to all instances on the server 
at the same time (even an instance which only gets health check queries 
from a few dnsdist servers).

I wanted to see if I could see anything different comparing a working 
instance with a not working instance on the same server so I restarted 
one of the instances. When I restart that one instance all started 
working again as expected. With that in mind it sounds like some sort of 
limit gets hit. I do raise 'LimitNOFILE' and 'TasksMax' settings in a 
systemd service.d file for each instance already.

As with dnsdist I couldn't find anything in the system logs indicating 
why. The auth servers have the same configuration and server setup as I 
was running on Debian Stretch - I deploy a minimal install with puppet 
installed and it will deploy the rest.

On 8/08/2019 9:15 pm, Remi Gacogne wrote:
> Be careful that dig (the 9.14.4 I have here at least) uses TCP by
> default for ANY queries so you might need a +notcp to actually test UDP.

Thanks, I double checked and it is using UDP for those queries.

I'll have to keep digging to see if I can find out why, as of now I 
don't understand why its happening like this.

Thanks