[dnsdist] dnsdist 1.4 and Debian Buster

Chris lists+pdns at gbe0.com
Wed Aug 7 15:01:19 UTC 2019

Hi Remi,

On 7/08/2019 10:07 pm, Remi Gacogne wrote:
> Are you sure about that? In the strace I see some of the metrics in HTTP
> exchanges (you might want to change your HTTP password, by the way,
> sorry about that), and it looks like the counters of received UDP
> queries in the frontend do increase a bit?
I double checked, it definitely doesn't increase the counters from UDP 
queries from the console using dumpStats. I do see some counters 
increasing (related to FD's, CPU usage, memory usage) but not query 
related counters. For the password it is temporary until this works (it 
is firewalled for outside), thanks for the reminder.

> I also see some healthchecks failing in the strace, sometimes with a
> timeout and sometimes even with a connection refused. Several backends
> in the metrics appear to be down. Is that expected?

Yeah, some backends I have taken offline as they are getting OS upgrades

> I have a couple ideas to know a bit more about what's happening:
> - running dnsdist in verbose mode, it will log a lot but if you can
> reproduce the issue in less than a minute it might be bearable ;

I will give this a try in the morning.

> - having a look at the network traffic with tcpdump, for example, to see
> if the queries are forwarded to the backends and whether these respond.

With a tcpdump I can see the queries coming in to dnsdist but they do 
not get forwarded to the backends at all. The only queries going out to 
the backends that I can see are for the health checks.

> I wouldn't mind having a look at your configuration either, since I can
> see in the metrics that you have some rules.

I will also supply this tomorrow.


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