EDNS module Performance

[Alexandre Wicquart]

Hi Wouter,

I'm running unbound on 8 threads server and in my unbound configuration,
i already have this :

###
server:
  num-threads: 8
  so-reuseport: yes
  so-rcvbuf: 8m
  so-sndbuf: 8m
###

At this point, i have no UDP errors @280k req/sec. It's the max i can
handle with my server.

Now if i add subnetcache :

###
module-config: "subnetcache validator iterator"
###

I can go to ~50k req/sec.
Over 50k, i have the UDP errors and only with EDNS.

For example, i try to send 100k req/sec, i will 100k packets IN on my
network interface, 50k packets OUT, and 50K in UDP errors. It's really
strange.


Best Regards,
--
Alex.

* Wouter Wijngaards via Unbound-users <unbound-users at unbound.net> [2018:08:02 12:54 +0200]:
> Hi Alexandre,
>
> On 08/02/2018 12:07 PM, Alexandre Wicquart via Unbound-users wrote:
> > Hello,
> >
> >
> > I'm currently benchmarking EDNS client module for unbound and i can
> > handle about 75/80% less than before.
> >
> >
> > The tests are made on a Debian Stretch 9.5 with unbound 1.7.3 (I have
> > the same results with 1.6.7).
> >
> > My server can handle about 280k req/sec without UDP errors and a minimal
> > configuration.
> >
> > Once i add 'subnetcache' to module-config in my configuration my rate go
> > down to 55k req/sec.
> >
> > Over this limit, i have a lot of UDP errors.
>
> If what you are suffering from is UDP errors, and not really performance
> of edns-client-subnet.  Then there are a couple of options in
> unbound.conf that you can tune.  so-reuseport: yes increases performance
> and may remove UDP errors, this may happen by spreading the queries over
> threads more equally so they do not get lost.  so-rcvbuf: 4m and
> so-sndbuf: 4m may remove UDP errors, caused by the UDP buffers that can
> only have a number of queries waiting and unbound momentarily occupied
> by processing elsewhere.
>
> num-threads should also increase performance; if you haven't set it, it
> is at 1 and could go up to your number of cores.
>
> Best regards, Wouter
>
> >
> >
> > I have tried to tune some options related to EDNS in unbound.conf, but
> > it doesn't change anything.
> >
> > Is there a know issue on unbound performance when enabling this feature ? 
> >
> >
> > Best Regards
> >
> > --
> >
> > Alex
> >