We face a strange experience. There is the MySQL we are running on GCP.
The metrics (current connection count, CPU, memory, IO, and disk) aren't abnormally high. After 06:25:01, all our connections respond with "Error 9001: Max connect timeout".
I get "too many connections" even when I use the root account. (This is the first time I've seen this happen.) Until we restarted MySQL, everything was fine.
The only thing I'm suspect about is log rotation. We have the audit installed (https://github.com/mcafee-enterprise/mysql-audit). The log rotation was supposed to happen at 06:25:00 every day, but it kept writing until we manually changed it.