Hello Jan! I've implemented systemd in Debian in https://anonscm.debian.org/git/pkg-mysql/mariadb-10.1.git/commit/?id=9ff0a57dcbce86031d654dd85edd5bfe8c795dfa based on the scripts shipped by upstream.
It also contains a mariadb@.service intended for the multi mysqld use case. Read more at: https://mariadb.com/kb/en/mariadb/systemd/ Could you review it? And help test is works as expected? Test binaries available via repo # Debian unstable deb http://labs.seravo.fi/~otto/mariadb-repo/ mariadb-10.1-sid-amd64/