[network-health] v3 onion services unusable for a few hours today

[Roger Dingledine]

Hi folks,

The overload bugs on the directory authorities are continuing, but they
also continue to be mostly manageable.

But today, we spent several consensus intervals in a row without making
a consensus -- which is supposed to be fine because Tor clients can do
fine so long as they have a consensus from within the last 24 hours,
but it exposed a bug in the v3 onion service implementation, where v3
onion clients and v3 onion services choose not to even attempt to fetch
or publish v3 onion descriptors:

Jan 10 11:32:24.364 [warn] No live consensus so we can't get the
responsible hidden service directories.

The fix imo is that we need to make v3 onion services work under the
same time assumptions as the other parts of Tor -- if you have a usable
consensus, then use it.

I've opened this ticket for the network team:
https://gitlab.torproject.org/tpo/core/tor/-/issues/40237

--Roger