Christopher Baines <mail@cbaines.net> writes:

> This has been on my mind for a while, as I wonder what effect it has on
> users fetching substitues.
>
> The narinfo caching as I understand it works as follows:
>
>  Default success TTL => 36 hours
>  Negative TTL        => 1 hour
>  Transient error TTL => 10 minutes
>
> I'm ignoring the success TTL, I'm just interested in the negative and
> transient error values. Negative means that when a server says it
> doesn't have an output, that response will be cached for an
> hour. Transient errors are for other HTTP response codes, like 504.
>
> I had a look through the Git history, caching negative lookups has been
> a thing for a while. Caching transient errors was added, but I couldn't
> see why.
>
> Personally I don't see a reason to keep either behaviours?

I've now sent a patch to remove this behaviour:

  https://issues.guix.gnu.org/47897