Bug ID 428706: False positive messages warning of 100% CPU utilization

Last Modified: Oct 06, 2020

Bug Tracker

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

Known Affected Versions:
10.2.3, 11.2.1, 11.3.0, 11.4.0, 11.4.1

Fixed In:
11.5.0, 11.4.1 HF2, 11.4.0 HF4, 11.3.0 HF9, 11.2.1 HF10

Opened: Aug 23, 2013
Severity: 3-Major
Related AskF5 Article:
K14939

Symptoms

False positive messages warning of 100% CPU use such as the following will appear every 5 minutes in the ltm log: Sep 30 11:08:41 B11000-R36-S13 notice chmand[7257]: 012a0005:5: Cpu utilization over 300 seconds is 100%, exceeded log level 80%

Impact

The issue is benign with no affect on system performance.

Conditions

The device has recorded more than 248.5 days of idle time in total across all CPU cores and the DB variable cpu.logthreshold > 0. The duration is different on each platform. It is inversely related to the number of CPU cores and proportional to the time spent idle. cpu.logthreshold is default to 80 on throttled platforms. View current setting with: tmsh list sys db cpu.logthreshold

Workaround

Turn off the CPU utilisation warning with: tmsh modify sys db cpu.logthreshold value 0

Fix Information

False positive messages warning of 100% CPU use have been corrected.

Behavior Change