Bug ID 700385: Behavioral Clarification For Tcl After Command

Last Modified: Apr 27, 2023

Affected Product(s):
BIG-IP LTM(all modules)

Known Affected Versions:
12.1.0, 12.1.0 HF1, 12.1.0 HF2, 12.1.1, 12.1.1 HF1, 12.1.1 HF2, 12.1.2, 12.1.2 HF1, 12.1.2 HF2, 12.1.3,,,,,,,, 12.1.4,, 12.1.5,,,, 12.1.6, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0,,,,,,,,, 13.1.1,,,,, 13.1.3,,,,,,, 13.1.4,, 13.1.5,

Fixed In:

Opened: Jan 02, 2018

Severity: 2-Critical


Flows with after commands accrue in the TMM due to not-yet-executed after scripts, causing memory pressure.


Potential memory pressure, leading to out of memory and TMM failover. Traffic disrupted while tmm restarts.


After command used in a Tcl script with a timeout beyond the connection lifetime.


If the after command does not need to execute after the flow has been expired, use one of the *_CLOSED events to cancel the after command.

Fix Information

After commands on a closed or aborted flow will now be removed as soon as possible, rather than waiting for their timer to fire and detect they cannot be run, thereby significantly decreasing memory pressure.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips