On Tue, Jan 20, 2015 at 11:44:46AM +0100, Network Operations Center wrote:
Thank you!
https://atlas.torproject.org/#details/3D7E274A87D9A89AF064C13D1EE4CA1F184F26...
The votes from the directory authorities for the last consensus period are here: http://freehaven.net/~arma/moria1-v3-status-votes
In this case it looks like schokomilch has these votes for the w line:
w Bandwidth=2525 Measured=1600 [moria1] w Bandwidth=2525 [dizum] w Bandwidth=2525 [Faravahar] w Bandwidth=2525 [gabelmoo] w Bandwidth=2525 [dannenberg] w Bandwidth=2525 [urras] w Bandwidth=2525 [longclaw] w Bandwidth=2525 Measured=674 [tor26] w Bandwidth=2525 [maatuska]
So since only two directory authorities vote a Measured value for it, and the design calls for three opinions, it ends up unmeasured, and thus with a consensus weight of 20.
You can read about the reasoning for requiring Measured votes here: https://trac.torproject.org/projects/tor/ticket/2286
In theory gabelmoo and longclaw are supposed to have opinions about your relay too: https://consensus-health.torproject.org/consensus-health.html#bwauthstatus
But they don't, so here we are.
The problem is likely that the bwauth (bandwidth authority) scripts are old and buggy and unmaintained. See https://trac.torproject.org/projects/tor/query?status=!closed&component=... especially the tickets towards the bottom.
We've already known about this in the context of "the bandwidth authority scripts are very poorly tuned for the changes that have happened in the Tor network since the scripts were written, so they vote wildly varying numbers for relays". But I don't think that we'd realized the "some relays don't get three votes at all, so they basically get zeroed out" issue. Hm.
(Ultimately I am hoping for the bwauth scripts to get phased out, in favor of one of the secure bandwidth measurement schemes that various research groups have been working on lately. Those other designs also will have the advantage that it's harder to game the system by lying about your bandwidth. But it will be some months at least until we have one of those designs to evaluate.)
--Roger