[tor-talk] Tor users from Finland jumped from 25 000 to 200 000

[David Fifield]

On Thu, Jan 13, 2022 at 06:09:24PM +0200, Markus Ottela via tor-talk wrote:
> I've been experiencing weird behavior with Tor + Stem + Flask Onion Services
> dying randomly once every 1..5 days. I wrote a script that's making
> connections to a test an Onion Service to see when exactly the servers
> disappear -- and creating logs based on that. The system spins up new
> requests client instance for each connection, so those might be what's
> appearing on the graph. I'm just puzzled why they'd appear as different
> users, given that the public IP has remained static. (Also the script
> automatically spins up new Onion Service once it's been down for an hour, so
> that could explain the spikes.)
> 
> Again I'm not sure that's what this is about, but both the start time, and
> the most recent major downtime spikes match. I've killed testing, let's see
> if it returns to normal; I think there's enough data to open a ticket about
> my issue anyway.

That's an interesting hypothesis. The user count estimate does not use
IP addresses; rather it counts directory requests. See:
https://gitweb.torproject.org/metrics-web.git/tree/src/main/resources/doc/users-q-and-a.txt?id=6c2679ec1797976e171a68bbd3d7442a34f0a5d1

> Q: How is it even possible to count users in an anonymity network?
> A: We actually don't count users, but we count requests to the
> directories that clients make periodically to update their list of
> relays and estimate user numbers indirectly from there.

> Q: What if a user runs tor on a laptop and changes their IP address a
> few times per day?  Don't you overcount that user?
> A: No, because that user updates their list of relays as often as a
> user that doesn't change IP address over the day.

In your experiments, were you starting tor with an empty DataDirectory
and a cold directory cache each time (e.g., in a freshly initialized
container), or were you reusing the same DataDirectory? The former I
would expect to have an effect on estimated users; the latter not.