[Pdns-users] Re: PowerDNS performance compared to other nameservers

bert hubert ahu at ds9a.nl
Tue Dec 2 16:48:58 UTC 2003

On Tue, Dec 02, 2003 at 05:34:35PM +0100, Stephane Bortzmeyer wrote:
> > I've just came accross a small page comparing PowerDNS with a few other 
> > nameservers:
> > 	http://www.nic-generique.prd.fr/sheets/practical/nameserver-en.html
> And the author is on the list, to make flaming easier :-)


Have you tried running your test a second time? PowerDNS can be considered a
'lazy loader' of zones. The first time you run PowerDNS, the cache is cold
and all queries need database access.

Secondly, PowerDNS sometimes is very slow on SMP systems. This is a glibc issue.
Symptoms are massive 'cs' counts in vmstat 1 output caused by spinlocks that

We tested with .org and saw 50.000 q/s on a tuned setup, so I find 13
queries/second highly disappointing and three orders of magnitude below what
I would expect.

I'd love to see what is causing the abysmal performance. There are some
hints in the documentation:


http://www.PowerDNS.com      Open source, database driven DNS Software 
http://lartc.org           Linux Advanced Routing & Traffic Control HOWTO

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