MySQL 5.6 Reference Manual Including MySQL NDB Cluster 7.3-7.4 Reference Guide
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
Command-Line Format | --connection-control-failed-connections-threshold=# |
---|---|
Introduced | 5.6.35 |
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 attempt
N
+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
Command-Line Format | --connection-control-max-connection-delay=# |
---|---|
Introduced | 5.6.35 |
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
Command-Line Format | --connection-control-min-connection-delay=# |
---|---|
Introduced | 5.6.35 |
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 21.33.1, “The INFORMATION_SCHEMA CONNECTION_CONTROL_FAILED_LOGIN_ATTEMPTS Table”.
Assigning a value to
connection_control_failed_connections_threshold
at runtime resets
Connection_control_delay_generated
to zero.
This variable was added in MySQL 5.6.35.