Feature request - disable internal recursion cache

[JINMEI Tatuya / 神明達哉]

At Mon, 02 Nov 2009 18:24:54 +0300,
Dmitry Rybin <kirgudu at corbina.net> wrote:
> 
> Kevin Darcy wrote:
> >> Daemon as unbound, pdns-recursor - much faster in recursion queries, 
> >> that bind. :(
> >> _______________________________________________
> > So, you don't cache locally, you forward to another daemon that (in the 
> > best case) answers from *its* cache.
> > 
> > How have you improved performance by changing nothing else and adding a 
> > network hop?
> 
> recursion possibilities of bind is very pity in compare with 
> powerdns-recursor, unbound & so on. It allocate a lot of memory and make 
> high CPU usage.

I don't deny in some cases BIND9 caching server may require a lot of
memory and may run slowly, but if you are still using a massive number
of views as you've previously reported:

https://lists.isc.org/pipermail/bind-users/2008-December/074173.html

the excessive number of views can be a main reason for the performance
problems, in which case comparison with other implementations that
don't support views doesn't make much sense.

Anyway, if you want to forward incoming queries to a different server
without caching the results, I believe setting max-cache-ttl (and
perhaps max-ncache-ttl also) to 0 does pretty much of
it. (max-cache-ttl = 0 has a bad effect, as noted in recent ARM, but
if you only care about results from an external forwarder, it should
be okay)

---
JINMEI, Tatuya
Internet Systems Consortium, Inc.