[EXTERNAL] Re: Tuning suggestions for high-core-count Linux servers

Browne, Stuart Stuart.Browne at neustar.biz
Sun Jun 4 23:43:51 UTC 2017

Ugh, let me try that again (apologies if you got the half-composed version).

<lots of snip>

> The lab uses Dell R430s running Fedora Core 23 with Intel X710 10GB NICs
> and each populated with a single Xeon E5-2680 v3 2.5 GHz 12-core CPU.

R630 chassis I believe, same NIC's, smaller processor (E5-2650v4 at 2.2Ghz).


> The only major setting I've found which both helps performance and
> improves consistency is to ensure that each NIC rx/tx queue IRQ is
> assigned to a specific CPU core, with irqbalance disabled.

I've been stopping irqbalance, and have confirmed that the rx/tx queue IRQ's aren't jumping around.

> This is with a _single_ dnsperf client, too.  The settings I use are
> -c24 -q82 -T6 -x2048.   However I do use a tweaked version of dnsperf
> which assigns each thread pair (it uses separate threads for rx and tx)
> to its own core.

I didn't think of using -T. *tries that* ..

> You may find the presentation I made at the recent DNS-OARC workshop of
> interest:
> https://indico.dns-oarc.net/event/26/session/3/contribution/18

Reading it now. Many thanks.
> You didn't mention precisely which 9.10 series version you're running.
> Note that versions prior to 9.10.4 defaulted to a -U value of ncores/2,
> but investigation showed that on modern systems this was sub-optimal so
> it was changed to ncores-1.  This makes a *very* big difference.

BIND 9.10.4-P8.

> kind regards,
> Ray Bellis
> ISC Research Fellow


More information about the bind-users mailing list