For the MariaDB database you need the org.mariadb.jdbc:mariadb-java-client driver. It is available at https://mvnrepository.com/artifact/org.mariadb.jdbc/mariadb-java-client, and it is preconfigured in the database-drivers pom.xml.

You should delete all other dependencies in database-drivers. They do not harm, but you do not need them, and libraries always bear the risk of introducing security vulnerabilities.

Afterwards, you can configure the database as follows:

sql.store.driver=org.mariadb.jdbc.Driver
sql.store.url=jdbc:mariadb://localhost:3306/<user>
sql.store.user=<user>
sql.store.password=<password>

Replace <user> and <password> as appropriate. Lower case is recommended. You create a separate database and a separate user for each server as follows:

CREATE DATABASE <user> CHARACTER SET utf8mb4 COLLATE utf8mb4_bin;
CREATE USER '<user>'@'localhost' IDENTIFIED BY '<password>';
CREATE USER '<user>'@'%' IDENTIFIED BY '<password>';
GRANT ALL PRIVILEGES ON <user>.* TO '<user>'@'%', '<user>'@'localhost';

Again, replace <user> and <password>.

Password Check Plugins

MariaDB Enterprise Server by default ships with the Simple Password Check Plugin enabled. Ensure, to align the chosen passwords with the configured policy.

It is expected, that you have configured your MariaDB instance to default to the InnoDB storage engine. By default, the caches for this storage engine are configured very small. Consider increasing the MariaDB startup option innodb_buffer_pool_size. Also, increasing innodb_log_file_size will improve write performance, because log files are rotated less often.