Bug ID 956645: Per-request policy execution may timeout.

Last Modified: Feb 07, 2024

Affected Product(s):
BIG-IP APM, SSLO, SWG(all modules)

Known Affected Versions:
15.1.2,, 15.1.3,, 15.1.4,, 15.1.5,, 15.1.6,, 15.1.7, 15.1.8,,, 16.1.3,,,,,

Fixed In:
17.0.0, 16.1.4, 15.1.9,

Opened: Oct 16, 2020

Severity: 3-Major


When attempting to access a resource that requires subsession validation, the client may receive an HTTP 503 "Service Unavailable" response, and the logs indicate that per-request policy execution time has expired.


Some clients will fail to connect to their destination.


Multiple connections are accessing the same subsession, triggering subsession lock contention.


Add criteria to the gating criteria to enable more fine-grained subroutines to reduce subsession contention. For example, add category, or application name, to the gating criteria. In the case of API protection, consider concatenating credentials with the resource hostname (plus port). Increase the per-request policy execution timeout value, controlled by the variable tmm.access.prp_global_timeout, to a higher value.

Fix Information

Subesssion lock contention wait time is reduced. Clients will not fail to connect due to subsession lock contention.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips