Bug ID 448402: High CPU usage upon learning cookies for each request

Last Modified: Jul 12, 2023

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

Known Affected Versions:
11.4.1, 11.5.0

Fixed In:
11.6.0, 11.5.1, 11.5.0 HF1, 11.4.1 HF4

Opened: Feb 10, 2014

Severity: 3-Major

Symptoms

-- CPU usage is higher than normal. -- Top command shows learning_manager.pl used more than 50% CPU from time to time.

Impact

The setting might have a significant effect on application performance.

Conditions

Configure selective cookie 'Explicit Entities Learning'.

Workaround

You can lower CPI usage by changing 'Explicit Entities Learning' cookies from 'Selective' to 'Never'.

Fix Information

This release reduces the learning manager's resource usage when it processes traffic with cookies and headers, in case there are no learning suggestions for cookies or headers.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips