mythfilldatabase runs for hours until mysql restarted

[white-haired-uncle]

So far I've just seen this on Ubuntu24 and things based on it. I'm pretty sure it's really related to MySQL8.x. After mythtv is installed from package (ppa:mythbuntu/35), mythfilldatabase will take hours (I gave up around 12 hours in). Low CPU utilization, high I/O wait. Granted, I'm running on light VM on an ancient host, but the difference between normal (decent CPU use, almost no wait, 15-20min to complete) and this is pretty remarkable. A "reboot" fixes this (I'm pretty sure it's actually just restarting mysql).

I also noticed this when building from source, but in that case it wouldn't ever improve until I figured out it was binary logging enabled that was causing the problem. My theory is that either the package install puts that mythconverg.cnf file in place after mysql starts, or perhaps the setting doesn't take effect on the first start because mythconverg doesn't exist yet. Either way, I can repeatedly break/fix the issue by removing/installing mythconverg.cnf and restarting mysql.