6.4.2 The Connection-Control Plugins

6.4.2.1 Connection-Control Plugin Installation

6.4.2.2 Connection-Control System and Status Variables

As of MySQL 5.7.17, 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). 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 table, see Section 24.6.2, “The INFORMATION_SCHEMA CONNECTION_CONTROL_FAILED_LOGIN_ATTEMPTS Table”.