Re: [DNSOP] Fw: New Version Notification for draft-yao-dnsop-root-cache-00.txt

[Shane Kerr <[e-mail]>]

Jiankang Yao,

I think a simpler approach that works in general is the "HAMMER"
approach proposed by Warren Kumari, Roy Arends, and Suzanne Woolf a
couple of years ago:

https://tools.ietf.org/html/draft-wkumari-dnsop-hammer

Basically the idea is that if a query is made for a RRSET that is near
expiration from the cache, then the resolver will answer normally but
will also try to refresh the TTL by performing another query.

Note that Unbound already implements something like this today, with
the "prefetch" option:

https://unbound.net/documentation/unbound.conf.html

BIND 9 does as well, with "prefetch":

https://deepthought.isc.org/article/AA-01122/0/Early-refresh-of-cache

The "HAMMER" approach works for all domains, not just the root zone,
and doesn't require any separate cache, or indeed any additional state
at all.

The approach you propose will have some small advantage if someone
queries for an entry in the root zone that is not in cache. However
given the long TTL of root zone entries, such a query will be rare so
the benefit is quite small.

Cheers,

--
Shane

On Tue, 29 Sep 2015 12:28:06 +0800
"Jiankang Yao" <[e-mail]> wrote:

> 
> Dear all,
> 
>       I submit a draft about Decreasing Fetch time of DNS  Root Data.
> 
>    Many DNS recursive resolvers have long round trip times to the DNS
>    root server.  It has been an obstacle to increse the performance of
>    DNS query.  In order to decrease fetch time of DNS root data, this
>    document proposes a new mechanism by improving the mechanism of root
>    data cacheing.
> 
>        Pls kindly help to review it and give the comments.
> 
>       I would also like to apply 10 minutes slot to introduce this idea in the  next IETF meeting
> 
> thanks a lot.
> 
> 
> 
> 
> Jiankang Yao
> 
> From: internet-drafts
> Date: 2015-09-29 12:20
> To: XiaoDong Lee; Jiankang Yao; Xiaodong Li; Jiankang Yao; Ning Kong; Ning Kong
> Subject: New Version Notification for draft-yao-dnsop-root-cache-00.txt
> 
> A new version of I-D, draft-yao-dnsop-root-cache-00.txt
> has been successfully submitted by Jiankang Yao and posted to the
> IETF repository.
> 
> Name: draft-yao-dnsop-root-cache
> Revision: 00
> Title: Decreasing Fetch time of Root Data by Improving the Mechanism of Root Data Cacheing
> Document date: 2015-09-28
> Group: Individual Submission
> Pages: 10
> URL:            https://www.ietf.org/internet-drafts/draft-yao-dnsop-root-cache-00.txt
> Status:         https://datatracker.ietf.org/doc/draft-yao-dnsop-root-cache/
> Htmlized:       https://tools.ietf.org/html/draft-yao-dnsop-root-cache-00
> 
> 
> Abstract:
>    Many DNS recursive resolvers have long round trip times to the DNS
>    root server.  It has been an obstacle to increse the performance of
>    DNS query.  In order to decrease fetch time of DNS root data, this
>    document proposes a new mechanism by improving the mechanism of root
>    data cacheing.
> 
>                                                                                   
> 
> 
> Please note that it may take a couple of minutes from the time of submission
> until the htmlized version and diff are available at tools.ietf.org.
> 
> The IETF Secretariat