Paul, Thanks for the question, I'm sorry for the delayed response, I was traveling home across the country yesterday. It really depends on the application itself, I've worked with customers that had issues with smart caching implementations that pre-date serve stale where the stale data was returned before performing the fetch and they had to disable the feature because their applications couldn't tolerate it. In that case it was in the resolver versus the client, but the behavior was similar, using stale data before fetching. I don't know their underlying applications enough to tell you why, but I've seen it more than once.
>From a normal GSLB perspective, in some cases it could run in to issues if persistence was tracked very closely to the same timeframe as the TTL, assuming that persistence is critically important, which it is in some cases. I've also come across issues in the past where clients not behaving as normal stub resolvers (usually because they were running dnsmasq or a local BIND instance) experienced unique application issues. So making clients behave in unexpected ways can certainly lead to unintended consequences. That is why I called it out as a potential issue, because that is definitely not expected client behavior today, and thus, it could lead to some negative unintended consequences. Thanks, Ross On Fri, Jun 5, 2026 at 12:04 PM Paul Hoffman <[email protected]> wrote: > On Jun 5, 2026, at 08:19, Ross Gibson <[email protected]> wrote: > > > > The concept of shifting that behavior to the client versus having the > DNS infrastructure handle it could have a wide array of undesirable > consequences. Given the prevalence of the use of global server load > balancing (GSLB) technology, which often relies on low TTLs to be able to > control traffic flow, this kind of behavior could possibly break all kinds > of application infrastructures both internally and externally. > > Please say more about what kind of breakage you are imagining. Maybe I'm > being unimaginative, but I can't see why a record with a 30 second TTL that > was last fetched in the last 60 seconds should have a negative effect if it > is prefetched. > > --Paul Hoffman > > _______________________________________________ > DNSOP mailing list -- [email protected] > To unsubscribe send an email to [email protected] >
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