MySQL 8 introduce a SQL restart command
https://dev.mysql.com/doc/refman/8.0/en/restart.html

With the trend of containers it would be nice to get a RESTART command that keep the mysqld process alive, stop start controlled within the server with SHUTDOWN SOFT and RESTART SOFT

Such restart would

• block new connections
• Flush all file descriptors
• unload SE

• reload config
• reload SE
• reopen connections

Reseeding MariaDB backup can be done such way without HARD shutdown
Docker shutdown the container if the mysqld process id 1 , it's not clear for me how Galera manage reseeding without shutdown but looks like exposing some SST magic to SQL command!