because, without the CONNECTION_CONTROL  plugin to provide the data that populates the CONNECTION_CONTROL_FAILED_LOGIN_ATTEMPTS  table, the table is always empty. 

## Connection Delay Configuration 

•Connection Delay Configuration 

•Connection Failure Assessment 

•Connection Failure Monitoring 

To enable configuring its operation, the CONNECTION_CONTROL  plugin exposes these system variables: 

• connection_control_failed_connections_threshold : The number of consecutive failed connection attempts permitted to accounts before the server adds a delay for subsequent connection attempts. To disable failed-connection counting, set connection_control_failed_connections_threshold  to zero. 

• connection_control_min_connection_delay : The minimum delay in milliseconds for connection failures above the threshold. 

• connection_control_max_connection_delay : The maximum delay in milliseconds for connection failures above the threshold. 

If connection_control_failed_connections_threshold  is nonzero, failed-connection counting is enabled and has these properties: 

•The delay is zero up through connection_control_failed_connections_threshold consecutive failed connection attempts. 

•Thereafter, the server adds an increasing delay for subsequent consecutive attempts, until a successful connection occurs. The initial unadjusted delays begin at 1000 milliseconds (1 second) and increase by 1000 milliseconds per attempt. That is, once delay has been activated for an account, the unadjusted delays for subsequent failed attempts are 1000 milliseconds, 2000 milliseconds, 3000 milliseconds, and so forth. 

•The actual delay experienced by a client is the unadjusted delay, adjusted to lie within the values of the connection_control_min_connection_delay  and connection_control_max_connection_delay  system variables, inclusive. 

•Once delay has been activated for an account, the first successful connection thereafter by the account also experiences a delay, but failure counting is reset for subsequent connections. 

For example, with the default connection_control_failed_connections_threshold value of 3, there is no delay for the first three consecutive failed connection attempts by an account. The actual adjusted delays experienced by the account for the fourth and subsequent failed connections depend on the connection_control_min_connection_delay  and connection_control_max_connection_delay  values: 

•If connection_control_min_connection_delay  and connection_control_max_connection_delay  are 1000 and 20000, the adjusted delays are the same as the unadjusted delays, up to a maximum of 20000 milliseconds. The fourth and subsequent failed connections are delayed by 1000 milliseconds, 2000 milliseconds, 3000 milliseconds, and so forth. 

•If connection_control_min_connection_delay  and connection_control_max_connection_delay  are 1500 and 20000, the adjusted delays for the fourth and subsequent failed connections are 1500 milliseconds, 2000 milliseconds, 3000 milliseconds, and so forth, up to a maximum of 20000 milliseconds. 

