Original Publication Date: 09/13/2011
Updated Date: 01/07/2013
The global CPU usage ratio is always reported as 1 regardless of the CPU utilization.
The global CPU usage ratio is an aggregated percentage of CPU utilization for the entire system calculated based on the CPU usage statistics, such as user, niced, idle, over the last 10-second interval. You can observe the global CPU usage ratio using the following methods:
The BIG-IP system reports incorrect CPU utilization.
As a result of this issue, you may encounter the following symptoms:
Note: The following output is truncated for brevity purpose.
CPU (clock ticks) Last-5-second Last-1-minute Last-5-minute Total
- (Average/sec) (Average/sec) (Average/sec) -
Utilization % (last 10 sec) - - - 1
snmpwalk -v2c -c public localhost sysGlobalHostCpuUsageRatio
If you use the snmpwalk utility in the above example to query the variable on the BIG-IP system, the snmpwalk utility returns the following output:
F5-BIGIP-SYSTEM-MIB::sysGlobalHostCpuUsageRatio.0 = Counter64: 1
F5 Product Development has assigned ID 355208 to this issue, and has confirmed that this issue exists in the products listed in the Applies To box. For information about releases or hotfixes that resolve this issue, refer to the following table:
|Type of Fix
|Release||11.0.0||SOL2200: Most recent versions of F5 software|
To work around this issue, you can query for the sysGlobalHostCpuUsageRatio5s (.126.96.36.199.4.1.33188.8.131.52.184.108.40.206) SNMP variable, which is the global CPU usage ratio over 5 seconds. To do so, you can use the snmpwalk utility to query for the sysGlobalHostCpuUsageRatio5s variable by typing the following command from the command line:
Impact of workaround: The value reported is a calculated average over a 5-second interval instead of a 10-second interval.
snmpwalk -v2c -c public localhost sysGlobalHostCpuUsageRatio5s