[dns-operations] co-operative cacheing

[Tony Finch]

On Wed, 7 May 2008, James R. Cutler wrote:
>
> Third:  Do a statistical analysis of your server query-response performance.

Exactly why I was hoping that someone else had already done this :-)
There are lots of good numbers in the literature on the effectiveness or
otherwise of web cache clusters (distributed or not) but I couldn't find
anything similar about the DNS other than single recursive resolver
studies.

> Considering that most user queries tend to bunch around common DNS targets,
> you will most likely not find a business case your management will accept.

MTA DNS behaviour is rather different from workstation behaviour. The
lookups that I think might be worth optimising are for reverse DNS, HELO
domain, etc. from millions of zombies all over the world, often with
distant and/or broken authoritative DNS servers. It might also be useful
for reducing DNSBL load, though my MTAs and blacklist servers are mostly
within 5ms of each other across JANET so the lookaside would have to be
very efficient to win.

Tony.
-- 
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