DNS Server That Constantly Refreshes Cache?

[Will]

"Barry Margolin" <barmar at alum.mit.edu> wrote in message 
news:fpljo5$2ceb$1 at sf1.isc.org...
> In article <fpktfi$13nj$1 at sf1.isc.org>, Kevin Darcy <kcd at chrysler.com>
> wrote:
>
>> Matus UHLAR - fantomas wrote:
>> > On 18.02.08 17:52, Will wrote:
>> >
>> >> I'm looking for a DNS server that will proactively go out after a 
>> >> cache
>> >> record expires and refresh its cache on its own.   The result would be 
>> >> a
>> >> server with an enormous memory cache of prefetched records, which 
>> >> should
>> >> always have up to date records in its cache, even when the domain has 
>> >> not
>> >> been used internally for weeks or months.   Note, I'm NOT referring to 
>> >> a
>> >> standard DNS server with a large cache setting.    I'm looking for a
>> >> proactive server behavior to prefetch records whose DNS cache is 
>> >> reaching
>> >> expiration.
>> >>
>> >> Does such a product exist for Windows or Unix?
>> >>
>> >
>> > this way you will end up having all dns records on the net in the cache 
>> > and
>> > still refresing them even if you don't need them.
>> >
>> What an anti-social thing to do.
>>
>> If I set the TTL of one of my RRsets to 60 seconds, it doesn't mean I
>> expect you (and everyone like you) to query it *every* 60 seconds
>> *forever*. The 60-second TTL is only for peak usage times, where
>> load-balancing/sharing is necessary. I expect the query traffic to fall
>> off during non-peak times, in parallel with the dropoff of actual
>> production volume.
>
> If this were done adaptively it could work well.
>
> The caching server could keep track of which records it's received
> frequent requests for.  If a record has been accessed numerous times
> since it was last cached, it would be a good idea to prefetch it.  But
> if lookups have dropped off, it shouldn't bother.
>
> The idea is similar to disk prefetching in filesystem and virtual memory
> systems.

That's precisely what I was looking for.   Thank you for saying it more 
precisely.

-- 
Will