Unbound on FreeBSD 11, uses just one of 8 threads?

Unbound
1

I have 8 threads configured, anyone know why unbound would
do all the work in just one thread?

Build info:

  # /usr/local/sbin/unbound -h
  [...]
  Version 1.7.1
  linked libs: libevent 2.1.8-stable (it uses kqueue), OpenSSL 1.0.2o 27 Mar 2018
  linked modules: dns64 respip validator iterator
  [...]

Configuration below my signature, stats below (the machine is
running the DANE adoption survey, so yes, ~3.5 billion queries with
a low cache hit rate is right):

# /usr/local/sbin/unbound-control stats_noreset | egrep -v '=0$'
thread0.recursion.time.avg=0.000000
thread1.recursion.time.avg=0.000000
thread2.recursion.time.avg=0.000000
thread3.recursion.time.avg=0.000000
thread4.recursion.time.avg=0.000000
thread5.recursion.time.avg=0.000000
thread6.recursion.time.avg=0.000000
thread7.num.queries=3478975092
thread7.num.cachehits=1422530
thread7.num.cachemiss=3477552562
thread7.num.recursivereplies=3477552317
thread7.requestlist.avg=257.029
thread7.requestlist.max=1266
thread7.requestlist.current.all=245
thread7.requestlist.current.user=245
thread7.recursion.time.avg=0.220082
thread7.recursion.time.median=0.0963222
total.num.queries=3478975092
total.num.cachehits=1422530
total.num.cachemiss=3477552562
total.num.recursivereplies=3477552317
total.requestlist.avg=257.029
total.requestlist.max=1266
total.requestlist.current.all=245
total.requestlist.current.user=245
total.recursion.time.avg=0.220082
total.recursion.time.median=0.0120403

2

Hi Viktor,

I have 8 threads configured, anyone know why unbound would
do all the work in just one thread?

Previously people that asked this, had a usage that one thread could
satisfy. Perhaps the other cpu cores are running some other process.
It it the systems scheduler for delivering packets to the listening
network socket that determines which thread gets the content.
so-reuseport: yes reportedly improves distribution between threads on Linux.

Best regards, Wouter

3

> I have 8 threads configured, anyone know why unbound would
> do all the work in just one thread?

Previously people that asked this, had a usage that one thread could
satisfy. Perhaps the other cpu cores are running some other process.

Or it seems that on FreeBSD (and perhaps other BSDs) SO_REUSEPORT
does not dispatch to multiple threads. One thread gets all the
traffic.

It it the systems scheduler for delivering packets to the listening
network socket that determines which thread gets the content.
so-reuseport: yes reportedly improves distribution between threads on Linux.

On FreeBSD it seems to cause all the traffic to go one thread. I
turned it off, restarted unbound, and now all the threads are busy.
The throughput has not however changed significantly. Perhaps as
you say one thread is enough...