[Pdns-users] low TTL, recursor and preresolve

[Alfred B. M. Cordero]

On Thu, 17 Mar 2011 10:50:00 -0700 Kenneth Marshall <ktm at rice.edu> 
wrote:
>
>You might be interested in this pre-release version that supports
>what I described:
>
>http://mailman.powerdns.com/pipermail/pdns-users/2010-
>November/007190.html

Thank you again Kenneth.  The next thing to understand is how to 
differentiate a
response that came from the cache from one that did not. Is there a 
way to do
that using lua?

For sake of discussion any TTL < 301 is changed to 86400.
If a query is for xyz.com and the data is not cached and the TTL is
300 we change the TTL to 86400 and return the query results. Now 
the data
is stored in cache. As time passes a query for xyz.com is made and 
the cached
TTL < 301 again so the TTL is returned as 86400. The better thing 
to do is to
go make a new query, check the TTL and if TTL < 301 return 86400.