### 6.4.2 The Connection-Control Plugins

[6.4.2.1 Connection-Control Plugin Installation](connection-control-installation.html)
[6.4.2.2 Connection-Control System and Status Variables](connection-control-variables.html)

 MySQL Server includes a plugin library that enables administrators to introduce an increasing delay in server response to connection attempts after a configurable number of consecutive failed attempts. This capability provides a deterrent that slows down brute force attacks against MySQL user accounts. The plugin library contains two plugins:

* `CONNECTION_CONTROL` checks incoming connection attempts and adds a delay to server responses as necessary. This plugin also exposes system variables that enable its operation to be configured and a status variable that provides rudimentary monitoring information.

   The `CONNECTION_CONTROL` plugin uses the audit plugin interface (see [Writing Audit Plugins](https://dev.mysql.com/doc/extending-mysql/8.0/en/writing-audit-plugins.html)). To collect information, it subscribes to the `MYSQL_AUDIT_CONNECTION_CLASSMASK` event class, and processes `MYSQL_AUDIT_CONNECTION_CONNECT` and `MYSQL_AUDIT_CONNECTION_CHANGE_USER` subevents to check whether the server should introduce a delay before responding to connection attempts.

* `CONNECTION_CONTROL_FAILED_LOGIN_ATTEMPTS` implements an `INFORMATION_SCHEMA` table that exposes more detailed monitoring information for failed connection attempts.

 The following sections provide information about connection-control plugin installation and configuration. For information about the [`CONNECTION_CONTROL_FAILED_LOGIN_ATTEMPTS`](information-schema-connection-control-failed-login-attempts-table.html) table, see [Section 26.6.2, “The INFORMATION\_SCHEMA CONNECTION\_CONTROL\_FAILED\_LOGIN\_ATTEMPTS Table”](information-schema-connection-control-failed-login-attempts-table.html).

