Current File : //lib/systemd/system/mariadb-extra@.socket
[Unit]

Description=MariaDB 10.6.20 database server (socket activation extra port multi-instance %I)
Documentation=man:mariadbd(8)
Documentation=https://mariadb.com/kb/en/library/systemd/

[Socket]

Service=mariadb@%i.service

# An "extra" as a descriptor name that means treat these ListenStreams as
# the same as an extra_port.
# Ref: https://mariadb.com/kb/en/thread-pool-system-status-variables/#extra_port

FileDescriptorName=extra

ListenStream=@mariadb-extra-%I
ListenStream=/var/lib/mysql/mysql.sock-extra-%I