How to override too-short TTL?

[Kevin Darcy]

Frankly, if the makers of BIND wanted such an option to exist, it would
have existed a long time ago. This short-TTL problem has existed as long as
DNS has, although it is being increasingly exacerbated by the popularity of
DNS-based load-balancing schemes. I'm sure you can appreciate, however,
that the idea of holding onto a cache entry after the domain owner has
claimed any validity or currency of the entry's value, understandably makes
many folks quite queasy. This is not within the spirit of the original
DNS RFCs or anything since.

Perhaps a better approach would be to come up with a cache-invalidation
scheme whereby nameservers and/or caches could inform their downstream
clients when a piece of data changes before its TTL has expired. This could
be a generalized form of NOTIFY, and I've already toyed with such an idea
in my mind and -- to a much lesser degree -- in the BIND 9 codebase.

bind-users, however, would not be an appropriate forum to discuss such a
protocol change.


- Kevin

Daemeon Reiydelle wrote:

> Perhaps you would be more appreciated if you read the email and your
> reply before you hit send.
>
> Your answer, now that you give your understanding, is "I don't know or
> wish to point out how to do so in the code, and there is no parameter to
> do so".
>
> Bind is not the RFC's. Bind is an IMPLEMENTATION of the applicable
> RFC's, together with a few workarounds (like allowing '_' and '-' in
> host names), some bits with DHCP leases, etc.
>
> Unless you are the final arbiter for all things BIND, it seems that this
> may be a topic for discussion.
>
> Is there any justification to include a minimal ttl override in
> ns_cache's storage of the data? This would override ALL TTL's, even my
> own. It seems to me that this is a good idea, since the TTL override is
> a bozo filter, even for my own bozoness (like forgetting to put a ttl
> stanza in, which I have of course NEVER done ;{)
>
> Any thoughts anyone?
>
> Joseph S D Yao wrote:
>
> > On Mon, Aug 20, 2001 at 01:58:39PM -0700, Daemeon Reiydelle wrote:
> >
> >>Duh, thanks. I can read the RFC (and have). Did you have something
> >>constructive to say or do you specialize in repeating old emails?
> >>
> >
> > If you have read "the RFC", then you have not read "the RFCs".
> >
> > I have not had time to read all BIND mail.  I answer some questions,
> > trusting that if a person already knows part of the answer of the
> > question they ask, they would have the courtesy to say so.  It is a
> > pity that the speed of the Internet sometimes makes courtesy a lost
> > art.
> >
> >
> >>The question was: is there a way to force a minimum time to live?
> >>
> >
> > Which I answered - not with BIND.
> >
> >
>
> --
> Daemeon Reiydelle Ph: 510.231.0880
> Systems Engineer, Anthropomorphics Inc.