MariaDB supports SSL connections to gain a better security level. Also, authentication plugins are mainly supported to use external authentication sources instead of MariaDB authentication. We tried the unix_socket plugin as an example in order to show how to use the system authentication. PAM authentication is also supported. It is also possible to limit the actions that a user can execute in an hour, preventing them from using too many resources.

It is possible for a user to connect via SSL or use an authentication plugin. This requirement can always be valid or may only apply when the user connects from certain hosts. This is possible because MariaDB permissions are based on accounts, a combination of username and hostname. The LIKE operator's wildcards can be used to match a few permissions to multiple usernames or hostnames.

MariaDB supports two thread handling methods: one thread per connection is the one that was historically used in MySQL, and pool of threads is a new method, which collects threads into groups, to improve the connections management with some workloads (typically, OLTP). MariaDB uses two different pool of threads implementations on Unix and Windows systems, which must be configured in different ways.

The SHOW PROCESSLIST statement, the information_schema.PROCESS table, and the performance_schema.threads table allow monitoring the active connections and their activities. If necessary, the KILL command (which has a rich syntax in MariaDB) can be used to terminate connections.

The next chapter discusses the caches used by MariaDB and various storage engines.