After Yii install MariaDB inaccessible

I installed Yii last night and ran the basic application that is working as expected: ie, I can navigate and do the demo/admin logins.

My problem is that I immediately lost connection to my MariaDB server running on the same machine. Ubuntu 19.10.x asks if another database is using the same mysql.sock. I don’t know and can’t tell from looking at the running services.

Does Yii start a db server and if so, how do I stop it?