Re: dnscache memory requirements for large number of server files

Lloyd Standish wrote:

> Please help me estimate memory requirements to run dnscache
> with about 769,000 files in the "servers" directory
> (/etc/service/dncache/root/servers).

Wow.  Even if you could get away with loading this much data, I don't
think you'd want to as the code doesn't appear to be optimised for
such an extreme case.  From a quick look at the relevant code (roots.c)
it would appear to be roughly the length of the domain name (in wire
format) + 64 bytes per domain name.  And the resultant "array" (it's
actually a string) is linearly searched, which could be a killer.

If your C is up to it, I'd look at modifying dnscache to perform a CDB
lookup on the domain+querytype, and if you get a hit return your
fictitious answer, otherwise proceed with the query normally.


-- 
Regards,
  Daryl Tester

"It's bad enough to have two heads, but it's worse when one's unoccupied."
  -- Scatterbrain, "I'm with Stupid."