background refresh of dns cache

[Michael Voight]

mark david mcCreary wrote:
> 
> I have a large mailing list that goes out at approximately the same time
> each day.
> 
> A substaintial portion of the processing time is spent doing DNS lookups,
> and I would like to reduce that time.
> 
> I am thinking that a background program that would continuously review the
> existing DNS cache, and refresh each entry as the TTL gets close to
> expiring it.
> 
> That is, when the next day's message comes in, the local DNS cache is
> current for all domain names that were sent email the previous day.
> 
> Is there a program to accomplish this, or would this be considered a "bad"
> idea.
> 

You could create a script that does all the queries shortly before your
program executes. This would be more efficient that checking the TTL of
all of the names and it would give you the most up to date information.

Michael