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6.4.2.2 Connection-Control System and Status Variables
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_threshold
Property Value Command-Line Format --connection-control-failed-connections-threshold=#
Introduced 5.7.17 System Variable connection_control_failed_connections_threshold
Scope Global Dynamic Yes Type Integer Default Value 3
Minimum Value 0
Maximum Value 2147483647
The number of consecutive failed connection attempts permitted to accounts 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 an account has reached the point where connection responses are delayed, a 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_threshold
interacts with other connection-control system and status variables, see Section 6.4.2.1, “Connection-Control Plugin Installation”.connection_control_max_connection_delay
Property Value Command-Line Format --connection-control-max-connection-delay=#
Introduced 5.7.17 System Variable connection_control_max_connection_delay
Scope Global Dynamic Yes Type Integer Default Value 2147483647
Minimum Value 1000
Maximum Value 2147483647
Unit milliseconds
The maximum delay in milliseconds for server response to failed connection attempts, if
connection_control_failed_connections_threshold
is greater than zero.For information about how
connection_control_max_connection_delay
interacts with other connection-control system and status variables, see Section 6.4.2.1, “Connection-Control Plugin Installation”.connection_control_min_connection_delay
Property Value Command-Line Format --connection-control-min-connection-delay=#
Introduced 5.7.17 System Variable connection_control_min_connection_delay
Scope Global Dynamic Yes Type Integer Default Value 1000
Minimum Value 1000
Maximum Value 2147483647
Unit milliseconds
The minimum delay in milliseconds for server response to failed connection attempts, if
connection_control_failed_connections_threshold
is greater than zero.For information about how
connection_control_min_connection_delay
interacts with other connection-control system and status variables, see Section 6.4.2.1, “Connection-Control Plugin Installation”.
If the CONNECTION_CONTROL
plugin is installed, it exposes this status variable:
Connection_control_delay_generated
The 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_threshold
system variable.This variable provides a simple counter. For more detailed connection-control monitoring information, examine the
INFORMATION_SCHEMA
CONNECTION_CONTROL_FAILED_LOGIN_ATTEMPTS
table; see Section 24.34.1, “The INFORMATION_SCHEMA CONNECTION_CONTROL_FAILED_LOGIN_ATTEMPTS Table”.Assigning a value to
connection_control_failed_connections_threshold
at runtime resetsConnection_control_delay_generated
to zero.This variable was added in MySQL 5.7.17.