Server can go down if "Check users for spam" left blank and over 100+ listed about phpbb3.1-3.2-antispam

[alexandergull]

Hello. Thank you. We will inspect this in a few days.

[mdrejhon]

Thanks.

I suspect it is probably hard to reproduce unless you let your subscription lapse sufficiently long enough on a very busy discussion forum.

[ArtemAnoshin]

Thank you for your comment. This task will not be solved quickly, the approximate time is one month.

[mdrejhon]

Thanks.

I'm now resubscribed (for many years) and the backlog is gone, so it's not likely a sufficiently-risky backlog will happen to me again in the near future --

That being said.... it will likely impact other users who decide to re-subscribe after a long gap between subscriptions (the precise time you want to maintain a good impression).

BTW, normally the database queries self-throttle, but it felt like a possible race condition -- where 100+ simultaneous table locks were waiting for each other and created some kind of infinite loop or deadlock. (Keep in mind I had a full dedicated server, and also only 25% of RAM was used up). If this was a concurrent multithreaded forking of SQL queries that also had network calls (and thus slowed down query completion), maybe throttle it based on network calls (e.g. calls to cleantalk API), to prevent the table from being locked for longer than necessary while waiting for result from cleantalk servers. Just running off theories why I witnessed so many concurrent table locks waiting on each other. Hopefully these observation clues helps you find a quick fix, which will help other people in the future.