[dns-operations] DNS server benchmarking sanity check

[Florian Weimer]

* Anand Buddhdev:

> On my hardware (10 cpus, visible as 20 to the OS), running nsd with 20
> worker processes and SO_REUSEPORT, it is able to answer 100% of the
> queries at 1.2 million q/s, and 97% of the queries at 1.6 million q/s.
> By this point, all 20 cpus are at 100% utilisation, so there's no way I
> can get anything better, and performance drops with increasing query
> rates. The only thing to do is to get faster cpus.

You could make sure that most time is spent in user space, and if not
look at perf output (on Linux), check to make sure that packets are
received on the CPU which later handles them, and so on.

I can ask around, but I assume it is possible to saturate 10G on such
hardware.