[tor-relays] publish current AuthDirMaxServersPerAddr limit?

[Roger Dingledine]

On Sun, Feb 12, 2023 at 01:08:56PM +0100, Sebastian Hahn wrote:
> > On 12. Feb 2023, at 11:46, nusenu <nusenu-lists at riseup.net> wrote:
> > would it be possible to publish
> > the currently enforced value of AuthDirMaxServersPerAddr
> > on some tpo website? Maybe consensus-health.tpo?
> 
> that's a bit hard to do automatically, as the value is currently not
> exported by the dirauths. We'd need a feature to include the value in
> the votes, then it could be displayed. Not sure if the network team
> would work on such a feature, I'd be in favor.

Good idea. I've implemented it in my ```ticket40753``` branch,
described here:
https://gitlab.torproject.org/tpo/core/tor/-/issues/40753

moria1 is including its AuthDirMaxServersPerAddr value in the
consensus params section of its vote, which makes its way to this
webpage:
https://consensus-health.torproject.org/#consensusparams

I'm not sure if this is the best possible design (we're sort of
blurring the line between what is a ConsensusParam and what isn't),
but it should be an easy and safe change at least. :)

nusenu: note that once enough dir auths vote this param, they will
compute a 'consensus' value for it in put that value in the consensus,
but nothing actually looks at or uses that consensus value.

--Roger