[Pdns-users] powerdns auth and recursor hardware specs

Brendan Oakley gentux2 at gmail.com
Wed Apr 30 19:32:24 UTC 2008


I can't really speak to the specifics of your setup, but some
generalities based on ours.

On Tue, Apr 29, 2008 at 10:39 PM, Eugene Pefti <eugenep at w3media.net> wrote:
> I think I miss something here. Can somebody give an example of hardware
>  specs for the authoritative server with recursor running? I run it on CentOS
>  5 with 2.6 GHz P4 and 1 GB of RAM. There's MySQL backend and about 700
>  domains hosted. Still the server experiences periods of slowness. I have
>  already presented a link to rrd graphs for the server. Do I have to run a
>  separate box with the recursor?

I have found that when running the authoritative server with the
recursor, it is necessary to set a limit on max-cache-entries. By
default, it has no limit, and that can potentially cause too much
memory usage depending on load. Also, increasing the
recursive-cache-ttl in pdns.conf helped a lot to reduce the load on
the recursor. It took some experimenting with these and other settings
to get it all fully optimized for our network.

I was surprised that allow-recursion-override=yes needed to be set,
it's no by default, so that some authoritative queries go to the
recursor. I don't get that.

I hope that's helpful.

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