[Pdns-users] Performance drop after upgrade from auth 3.4.11 to 4.0.4

[Klaus Darilion]

Hi!

Setup: PowerDNS with gqgsql backend, several 100.000 zones (type=NATIVE)
on a 4 CPU VM with 8GB Ram
cache-ttl=120
negquery-cache-ttl=120
query-cache-ttl=240
distributor-threads=8
receiver-threads=1


I am running 2 tests with dnsperf:
1. query the SOA of every authoritative zone: every zone will be queried
once
2. query the A for www.<zone> of every authoritative zone: every zone
will be queried once

dnsperf 2.1 is used with default setting.

Here are the results (average values)


     Version |  3.4.11         4.0.4
Test         |
-------------+---------------------------------
SOA          |  3800q/s        4800q/s
A            |  2200q/s        1400q/s

Hence, SOA queries became faster while A queries became much slower.


Playing with threads (eg 4/2 receiver/distributor) does not change the
values.


Any ideas where there is a drop in q/s when doing A queries? Where can I
debug to find the issue? Any changed default settings in 4.0.4? I know
Master should be faster then 4.0.4, but I would like to use a stable
version.

Thanks
Klaus