Bug: "conenct to DB" feature can block upgrades

[ankush]

1. Connect to DB and read something. Now you have a shared lock on table metadata. Leave this connection open and go for a smoke chaas break.
2. Your colleague is now trying to update, but that table will get stuck on the metadata lock.

Fix: Check if any timeouts can help reduce the dangers of this. performance_schema.metadata_locks allows checking the current lock but that might be too complex.

[ankush]

https://mariadb.com/kb/en/server-system-variables/#lock_wait_timeout

Drop this from 1 day to 5 minutes maybe

[ankush]

Or possibly timeout the DB connections via proxysql. They are used for reads 99% of the time, so it doesn't matter.