9.2.5 db causes high cpu? was: Re: BIND 9.2.5rc1 is now available.

[sthaug at nethelp.no]

> Dear List, what are you using for/on your recursive Nameservers?

8.4.6.

We would certainly prefer to use BIND 9 - but our experience is that
BIND 9 only works moderately well as a recursive name server (it works
just fine as an authoritative name server).

Our problems with BIND 9 as a recursive name server:

- Higher CPU usage than BIND 8 (around 50% higher in our measurements).

- Most important: We have had repeated cases of BIND 9 failing when the
cache reaches a size of around 250 Mbps (which is still well below any
datasize limit for the named process). "Failing" means that some queries
are simply never answered. Starting the named process again makes the
problem disappear (until the cache grows big again).

We have had the Nominum Caching Name Server (CNS) on trial, and would
*really* prefer to use this, if the price was better. It works just
great, and for us it was an order of magnitude more efficient than BIND
9. However, the price was high enough that we concluded BIND 8 plus
throwing more hardware at the problem was a better solution.

(If you can afford CNS, it's a wonderful product and I recommend it
highly.)

Steinar Haug, Nethelp consulting, sthaug at nethelp.no