[Dnsmasq-discuss] Google's DNS servers

[Tom Metro]

I read an article about how Google is providing DNS servers that they 
believe will respond to queries faster than the typical ISP's servers. 
They say they're offering them as a service to the net, and claim that 
they're frequently purging the logs and not correlating the data with 
other Google services.

The article said that they weren't releasing the code, but instead were 
documenting the concepts (there's probably a white paper somewhere that 
goes into details) and hoped that existing software would adopt the 
concepts.

The main concept mentioned in the article was doing a statistical 
analysis of the queried domains, and then pre-seeding the cache with 
those domains. It also sounded like for those popular domains, when 
their TTL expires, they fetch an update immediately, rather than waiting 
for the next request for it to arrive. (The article also mentioned some 
security enhancements, such as adding junk data to outbound queries as a 
sort of security token to thwart forged replies.)

Anyone thought about building something like this around Dnsmasq? 
Probably make sense for the initial implementation to be built external 
to Dnsmasq. Say a program that analyzes the query log daily (obviously 
query logging would have to be turned on), and updates a database. 
Another that fetches the domains in the database, which would be called 
from the Dnsmasq startup script. I'm not sure what the best way would be 
to trigger a query on TTL expiration, unless TTLs were stored in the 
database, and a daemon process fired queries at the appropriate time. 
But that's starting to feel a bit redundant. Might be simpler to just 
re-seed the cache daily.

What I wonder is whether all this added complexity would really be worth 
while for a small scale installation. With tens of queries per minute, 
instead of millions, could you even spot much difference in the 
benchmarks? Would the difference be perceptible to end-users?

  -Tom

-- 
Tom Metro
Venture Logic, Newton, MA, USA
"Enterprise solutions through open source."
Professional Profile: http://tmetro.venturelogic.com/