Hi, I have a similar experience, where prefetch seems to poison the cache with negative responses.
This is a good read; https://unbound.docs.nlnetlabs.nl/en/latest/topics/core/serve-stale.html Can any one clarify a parameter combination which allows immediate cache responses, and which tells prefetch to always ignore negative responses? I wonder if taking the advice of the above article (and being mindful of this https://github.com/NLnetLabs/unbound/issues/533 it is possible to get this working). Just can’t figure out how to force prefetch to ignore negative responses. Please share your results :) Andy. > On 31 Jul 2024, at 20:33, sir izake via Unbound-users > <unbound-users@lists.nlnetlabs.nl> wrote: > > > Hi > I have installed unbound version: 1.20.0 on a FreeBSD 14 server. This was > working fine until the server lost internet connectivity to the upstream > internet provider. Prior to this the average cache hit rate on the server was > 99.0% with only 1% recursive replies. > Part of my unbound.conf file is shown below > > server: > prefetch: yes > serve-expired: yes > # serve-expired-ttl: 0 > # serve-expired-ttl-reset: no > After loss of internet average cache hit rate has reduced to 14% whiles > recursive queries is showing 86% (still internet is not restored) > My expectation is > Caching server should continue to serve expired and keep the cache hit rate > high because the serve-expired-ttl is default > (meaning it should continue serving cached content until upstream is > restored). > My observation is the opposite. Is there anything I am missing? How can i > ensure that the caching server will continue serving cache data several days > after upstream > internet is lost > Regards > Isaac > > >
