Re: difference in dnscache installs

richard lucassen wrote:

>> Didn't you say these two caches were busy?  There's a fixed upper
>> limit on the number of outstanding queries (200?), and dnscache drops
>> the oldest query if that limit is reached.

> This sounds very logical. But OTOH DJB would have build this in as a
> variable, wouldn't he?

Documented here - <http://cr.yp.to/djbdns/dnscache.html>  - "In versions
1.03 and above, if a new UDP query arrives when dnscache is already
handling 200 simultaneous UDP queries, dnscache drops the oldest query."

I'm fairly certain that limit is hardwired.

> To give you an impression: writing 1MB of non-filtered logs through
> multilog takes less than a second.

It's not really anything to do with your setup, but more an issue with
the amount of time it takes to resolve that name using dnscache's
heuristics, combined with the, shall we say, less than stellar setup
of the domain in question that is being resolved.

> But where can I find this upper limit?

dnscache.c: #define MAXUDP 200

I don't know what negative effect increasing this limit would be (apart
from increasing the scan time of what appears to be a linearly searched
table).


-- 
Regards,
  Daryl Tester

"Every time a marketeer uses the phrase 'light-year' as a unit of time,
 God kills an astrophysicist."