Duane On Sun, Jul 23, 2023 at 9:20 PM Wessels, Duane <dwess...@verisign.com> wrote:
> Tim, > > You said you received some operational feedback. I wonder if it would be > appropriate to add this operational (or implementation?) feedback to the > (currently empty) Implementation Status section that Peter van Dijk > suggested we add, in his DNS directorate review? > This seems very reasonable. I'll work with them on this. > I’m not necessarily opposed to reducing the minimum caching time from 5 to > 1, especially if we can document valid reasons for doing so. However, I do > think it is going a bit to far to weaken both the minimum caching time and > the requirement level for exponential backoff. So I would really argue to > keep the SHOULD in the second paragraph. > > Alternatively, we might consider something like 5 seconds without an > exponential backoff implementation OR an initial 1 second cache time with > an exponential backoff. > My first opinion is to keep the SHOULD, and let folks speak up if they feel this is wrong. I liked the way you worded the timeout range in section 3.1. I do think/feel the value should be configurable by the operator. thanks tim > DW > > > > > On Jul 23, 2023, at 9:00 PM, Tim Wicinski <tjw.i...@gmail.com> wrote: > > > > > > > > All, > > > > We had a discussion this morning during the hackathon about a value with > > the document caching-resolution-failures. The current text in 3.2 says: > > > > Resolvers MUST cache resolution failures for at least 5 seconds. The > > value of 5 seconds is chosen as a reasonable amount of time that an > > end user could be expected to wait. > > > > Resolvers SHOULD employ an exponential backoff algorithm to increase > > the amount of time for subsequent resolution failures. For example, > > the initial time for negatively caching a resolution failure is set > > to 5 seconds. The time is doubled after each retry that results in > > another resolution failure. Consistent with [RFC2308], resolution > > failures MUST NOT be cached for longer than 5 minutes. > > > > > > There was some operational feedback that suggests 1 second is also > > a very reasonable value here. With some discussion, here is some > > suggested text: > > > > Resolvers MUST cache resolution failures for at least 1 second. > > The initial duration SHOULD be configurable by the operator. A > > longer cache duration for resolution failures will reduce the > > processing burden from repeated queries, but will also lengthen > > the recovery period from transitory issues. > > > > Resolvers MAY* employ an exponential backoff algorithm to increase > > the cache duration when resolution failures are persistent. For > > example, the initial time for negatively caching a resolution > > failure could be set to 5 seconds, and doubled after each retry > > that results in another resolution failure, up to a configurable > > maximum. > > > > Consistent with [RFC2308], resolution failures MUST NOT be cached > > for longer than 5 minutes. > > --- > > > > * Note that the original text has this as SHOULD. I've heard reasons for > both SHOULD and MAY. > > > > We'd like to hear from the working group on this value, and what the > working group thinks of this change > > > > thanks > > tim > > > > _______________________________________________ > > DNSOP mailing list > > DNSOP@ietf.org > > > https://secure-web.cisco.com/1EOBeLhMBEWg1uxqfTYxtUCMTcEb3F3FEA2EO7c3JOioTtVNfCLJH16XnnbuotVr49ldBsx_KxI4Vx5CjDqNuYdQ17vtalwP-jShq2peErxec4rVO5LJ33FG2rYySJ-hZugq-0SR7DVGxYLZEl-uJBfoRv8Zktrm5CSMGpC4jjfksy9itIXwMXbnVKRQ8qOV2E-xDb5PqUtQMLBambGxjnlXoTHtQl2dqFRx1kA7Tyg6-9vnpU5kAoRVbl_5ghCwqXM4Go0HV4s-Z-P0vPvWnuXP40ATm_rhOsymJUvwkppy58V9UrsCxC81vA7ic1gIe/https%3A%2F%2Fwww.ietf.org%2Fmailman%2Flistinfo%2Fdnsop > >
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