[Pdns-users] CPU consumption of pdns_recursor

[Remi Gacogne]

Hi,

On 4/6/21 8:35 AM, Otto Moerbeek via Pdns-users wrote:
> On Mon, Apr 05, 2021 at 05:30:11PM +0000, Nejedlo, Mark via Pdns-users wrote:
> 
> Some thoughts:
> 
> 2 distributior thread feels a bit overkill, 1 distributor thread
> should be able to feed 8 workers. Did you do measurements to come to
> this value?
> 
> Your maintenance function looks like it could run for a while if
> timeouts happen. I don't know how bad that would be from the top of
> my head, but it could have an impact.
> 
> Your packet cache hit ratio is extremenly low. Are you running dnsdist
> with a packetcache in front of this recursor? Or can you explain it
> from the type of queries you are getting?

I see that XPF is enabled between dnsdist and the recursor, which likely 
kills the recursor's packet cache. That might explain the bad 
performance results.
Would you mind sharing your dnsdist configuration as well?

> If you are setting up a lab env, I certainly would try to use 4.4 or
> 4.5 (which is in beta) they both contain performance improvememnts.

And then using the proxy protocol instead of XPF could be a huge 
improvement.

Best regards,
-- 
Remi Gacogne
PowerDNS.COM BV - https://www.powerdns.com/