[anti-censorship-team] Spike in client polls from Snowflake broker metrics

I was alerted by trinity-1686a on irc that Snowflake standalone proxy operators were reporting on #tor-relays about increased OOM errors from increased load as of 2023-08-28.

After looking at the Snowfake broker metrics[0], there's a huge jump in client polls (seen by summing the client-denied-count and client-snowflake-match-count).

I've attached a graph of the collected prometheus metrics that shows this spike happening at exactly 17:40 UTC on 2023-08-27. It looks like way too sharp an increase to me to be a censorship event, perhaps it is a DoS?

It's still too early to see the bridge metrics from the metrics page, but we should start to see the effects there tomorrow.

[0] https://metrics.torproject.org/collector.html#snowflake-stats