[warn] Received http status code 404 ("Consensus not signed by sufficient number of requested authorities")
Tor relay operators and clients report seeing a series of these scary-sounding log messages this evening. An example:
Dec 01 15:56:27.720 [warn] Received http status code 404 ("Consensus not signed by sufficient number of requested authorities") from server 126.96.36.199:443 while fetching consensus directory.
I believe these messages are harmless so long as they are only transient.
What's happening I believe is that some relays still believe in Faravahar as a directory authority, so if they get a consensus with five signatures including one from Faravahar they accept it and serve it; whereas modern Tor clients no longer believe Faravahar is one of the directory authorities, so from their perspective that consensus only has four acceptable signatures on it, so they decline to download it and later they try again somewhere else.
So, as long as the situation is transient, i.e. most of the time most relays are serving a consensus with six or more sigs on it, then everything should be fine.
I'm opening this ticket as a placeholder in case people come to report the bug, or in case the support team gets questions about it.
We should be able to close this ticket
on Tuesday when we finish doing the synchronized switch-over at the other directory authorities, after which we should stop generating consensus documents that include signatures from Faravahar. once the new Tor version is out with moria1's new keys and it is in a Tor Browser too. [edit: Sebastian correctly points out that while we're seeing this issue with Faravahar's key currently, we could see it after Tuesday with moria1's new key as well.]