50-mariadb_safe.cnf was only ever intended to be a reference file. With mariadbd-safe falling into disuse in Debian since systemd became a service it was assumed this files wasn't used.

It is however read by galera-sst scripts. This forks off the logger process to write the output to /dev/log, which on a systemd service the journalctl is reading anyway.

It would be much more direct just to go straight to stdout/error like what would happen without this configuration.

In a1211a4eda9c7348295ce4a6fdfa8e94860e5e14 the debian 50-mariadb_safe.cnf changed its name so the sst script like mariabackup still reads only mysqld_safe.

This is a problem however in container based Galera, which doesn't have a journald or syslog listening on /dev/log.

Since MariaDB operator now has support for Galera, its important to disable this.