We are running CoreDNS 1.9.3 (retrieved from the official releases on GitHub), and have been having difficulty with increasing performance of a single instance of coredns.

With GOMAXPROCS set to 1, we observe ~60k qps and full utilization of one core.

With GOMAXPROCS set to 2, we seem to hit a performance limit of ~90-100k qps, but it consumes almost entirely two cores.

With GOMAXPROCS set to 4, we observe that coredns will use all 4 cores - but throughput does not increase, and latency seems to be the same.

With GOMAXPROCS set to 8-64, we observe the same CPU usage and throughput.

We have the following corefile:

.:55 {
  file db.example.org example.org
  cache 100
  whoami
}

db.example.org

$ORIGIN example.org.
@       3600 IN SOA sns.dns.icann.org. noc.dns.icann.org. 2017042745 7200 3600 1209600 3600
        3600 IN NS a.iana-servers.net.
        3600 IN NS b.iana-servers.net.

www     IN A     127.0.0.1
        IN AAAA  ::1

We are using dnsperf: https://github.com/DNS-OARC/dnsperf

And the following command:

  dnsperf -d test.txt -s 127.0.0.1 -p 55 -Q 10000000 -c 1 -l 10000000 -S .1 -t 8

test.txt:

www.example.com AAAA

Is there anything we could be missing?

Thanks!