Bug ID 956189: BIG-IP APM variable increases over time

Last Modified: Nov 22, 2021

Bug Tracker

Affected Product:  See more info
BIG-IP APM(all modules)

Opened: Oct 15, 2020
Severity: 2-Critical

Symptoms

Variables in BIG-IP APM access policies, such as policies implemented to process VPE actions, may report an increased number of values it stores over time. For example, given the following Variable Assign TCL expression: session.custom.tcl.variable = lappend my_groups "foo";return "$my_groups"; The number of value "foo" stored in variable my_groups will increase over time as the Access Policy is implemented in processes sessions, i.e. as the number of Access Policy sessions processed increases so does the number of stored values. The ratio of Access Policy sessions to a value increase found in testing is 40:1.

Impact

Value size in variables increase over time.

Conditions

Implement Access Policy TCL code that appends a value to a variable.

Workaround

To reset affected variables you can either reboot or restart apmd: bigstart restart apmd Note: this action will not affect Active Access Policy sessions. To stop variables from increasing, terminate or reset them. Examples: 1) set my_groups ""; lappend my_groups "foo";return "$my_groups"; 2) proc getMyGroups {} {lappend my_groups "foo";return "$my_groups";} getMyGroups;

Fix Information

None

Behavior Change