-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Jason Haar writes:
> On Tue, Aug 17, 2004 at 08:31:41AM -0400, Jeff Koch wrote:
> > I question your statement that these DNSRBL can handle the load. Our 
> > mailservers are handling over 10K messages per hour - but to be 
> > conservative assume there are a million SA boxes checking 1.0K messages per 
> > hour. Is it reasonable to assume that each DNSRBL can handle a billion 
> > queries an hour?
> 
> We really need negative caching for DNS lookups. DNS TTLs are great for
> caching *successful* lookups - but failed lookups aren't cached. 
> 
> This is the problem with the RBL style. It has retro-fitted DNS to do a job
> it wasn't designed to do. Another example of a product with the same issues
> is the Squid proxy server. They designed negative DNS caching into Squid to
> reduce the amount of network DNS calls Squid makes.
> 
> Has anyone looked into adding a DNS cache component into SA? You could cache
> both positive and negative lookups for (say) 5-10 minutes without really
> causing any bad side effects...

We were considering it, since it'd be doable now that we prefork and keep
a spamd process running for a few hundred messages.   However, the other
devs were pretty sure that a local caching "named" process would probably
do the trick nicely enough.  (me, I'm not quite convinced ;)

So a local caching named won't cache negative lookups?  That *could*
be quite an improvement if that's the case...

- --j.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (GNU/Linux)
Comment: Exmh CVS

iD8DBQFBJAVHQTcbUG5Y7woRAvkDAKDvwmXuClTigClrGYCP04DP7cFNYwCePXnP
Ne3UUyuQxArmYJ4D+AMa+is=
=k9To
-----END PGP SIGNATURE-----

Reply via email to