Maintained by: NLnet Labs

[Unbound-users] Configuration suggestions?

Sven Ulland
Mon Apr 15 10:35:46 CEST 2013


On 04/13/2013 11:43 AM, Anders Lindborg wrote:
> We have used PowerDNS a while ago and it was quite speedy

Same here, and while it performs nicely, two things kept cropping up:

* In rare cases, cache entries never expired and were kept around
   forever, meaning that it kept responding with the old data way after
   TTL expiry. It was pretty much impossible to debug, and ended up
   being a dealbreaker, unfortunately.

* Upon start/restart, the load of new requests to a clean cache would
   cause it to somehow fail a lot of queries (queue full?) and return
   SERVFAIL. This response would be cached for quite a while (60s?),
   and cause it to serve SERVFAIL to even the most popular queries like
   facebook, google and youtube. It can be resolved with a slowstart
   mechanism in the loadbalancer, though.

As for performance itself, have you observed any significant and/or
reproducible differences between PowerDNS and Unbound?

sven