MySQL 8.0 Release Notes
MySQL 8.0 Source Code Documentation
Pre-General Availability Draft: 2017-07-17
This section describes the system and status variables that the
CONNECTION_CONTROL plugin provides to enable
its operation to be configured and monitored.
If the CONNECTION_CONTROL plugin is
installed, it exposes these system variables:
connection_control_failed_connections_thresholdIntroduced 8.0.1 Command-Line Format --connection-control-failed-connections-threshold=#System Variable Name connection_control_failed_connections_thresholdVariable Scope Global Dynamic Variable Yes Permitted Values Type integer Default 3Min Value 0Max Value 2147483647The number of consecutive failed connection attempts permitted to clients before the server adds a delay for subsequent connection attempts:
If the variable has a nonzero value
N, the server adds a delay beginning with consecutive failed attemptN+1. If a client has reached the point where connection responses are delayed, the delay also occurs for the next subsequent successful connection.Setting this variable to zero disables failed-connection counting. In this case, the server never adds delays.
For information about how
connection_control_failed_connections_thresholdinteracts with other connection-control system and status variables, see Section 6.5.2.1, “Connection-Control Plugin Installation”.connection_control_max_connection_delayIntroduced 8.0.1 Command-Line Format --connection-control-max-connection-delay=#System Variable Name connection_control_max_connection_delayVariable Scope Global Dynamic Variable Yes Permitted Values Type integer Default 2147483647Min Value 1000Max Value 2147483647The maximum delay in milliseconds for server response to failed connection attempts, if
connection_control_failed_connections_thresholdis greater than zero.For information about how
connection_control_max_connection_delayinteracts with other connection-control system and status variables, see Section 6.5.2.1, “Connection-Control Plugin Installation”.connection_control_min_connection_delayIntroduced 8.0.1 Command-Line Format --connection-control-min-connection-delay=#System Variable Name connection_control_min_connection_delayVariable Scope Global Dynamic Variable Yes Permitted Values Type integer Default 1000Min Value 1000Max Value 2147483647The minimum delay in milliseconds for server response to failed connection attempts, if
connection_control_failed_connections_thresholdis greater than zero. This is also the amount by which the server increases the delay for additional successive failures once it begins delaying.For information about how
connection_control_min_connection_delayinteracts with other connection-control system and status variables, see Section 6.5.2.1, “Connection-Control Plugin Installation”.
If the CONNECTION_CONTROL plugin is
installed, it exposes this status variable:
Connection_control_delay_generatedThe number of times the server added a delay to its response to a failed connection attempt. This does not count attempts that occur before reaching the threshold defined by the
connection_control_failed_connections_thresholdsystem variable.This variable provides a simple counter. For more detailed connection-control monitoring information, examine the
INFORMATION_SCHEMACONNECTION_CONTROL_FAILED_LOGIN_ATTEMPTStable; see Section 24.32.1, “The INFORMATION_SCHEMA CONNECTION_CONTROL_FAILED_LOGIN_ATTEMPTS Table”.Assigning a value to
connection_control_failed_connections_thresholdat runtime resetsConnection_control_delay_generatedto zero.