[dns-operations] DNS server benchmarking sanity check
x2t at foxtrot.emu.st
Sun Aug 14 21:19:13 UTC 2016
On 14Aug16, Anand Buddhdev allegedly wrote:
> NSD can spawn multiple processes, and each process binds to a socket.
> However, the kernel doesn't distribute queries evenly amongst the
> processes. This can lead to some processes being overworked while others
> are lightly loaded.
> SO_REUSEPORT solves this by letting the kernel divide the queries much
> more evenly amongst all the processes, so that they can deliver the
> maximum number of responses each.
In either case, about a year or two ago, I found that the mainstream
kernels still do a lot of serialization in the UDP stack such that
it's not possible to utilize all available cores on a modern machine.
It's possible that has changed recently, but it generally seems that
UDP hasn't had the love that TCP gets.
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