BIND memory statistics?

[Kevin Darcy]

Matus UHLAR - fantomas wrote:
> Hello,
>
> I am currently running bind 9.5.0-p1 with cache limit turned off. I would
> like to turn it on, however It would be better with knowing how is memory
> used after some time (e.g. a week).
>
> I know how much of RRs do I have in cache but what are their average TTL's,
> were their TTL's when they were received and how often are they used?
>
> This should imho help me to know how effective the caching is, so I could
> tune memory usage. As I mentioned, my limit is currently turned off, but
> this could lead to excessive memory consumption of named process.
>
> I am also planning to turn on acache, but the problem is similar - I'd like
> to have an idea how effective it is...
>
> Can anyone advise me, if/how, is possible to do this?
>   
Well, you can look at the memory consumption of the process, and you can 
use a sniffer to see how much traffic -- when you get cache misses -- is 
going between your nameserver and the authoritative nameservers it's 
querying on behalf of local clients, what else would you measure and, 
once measured, how would you optimize? max-cache-ttl? max-ncache-ttl? 
cleaning-interval? For BIND, usually the solution to memory problems is 
to buy more memory; there's only so much you can twiddle in named.conf 
to try and squeeze more performance from a memory-starved box.

- Kevin