How to check CPU Utilization on LTM

From GUI Statistics/Dashboard ?

Please bare in mind there are 2 kind of CPU in BIGIP. The TMM and the CPU (used by linux).

TMM is the most important. You can find TMM usage in TMSH with "show sys tmm-info" command.

You can use a watch command in the linux to automate the display : watch -n 2 "tmsh show sys tmm-info | grep Seconds"

Global TMM Process Id 15333 Running TMM Id 0 TMM Count 1 CPU Id 0

Memory (bytes) Total 3.4G Used 254.0M

CPU Usage Ratio (%) Last 5 Seconds 1 Last 1 Minute 2 Last 5 Minutes 1

Global TMM Process Id 15333 Running TMM Id 1 TMM Count 1 CPU Id 1

Memory (bytes) Total 0 Used 0

CPU Usage Ratio (%) Last 5 Seconds 1 Last 1 Minute 1 Last 5 Minutes 1

You can use 'top' command which provides a real-time view of a running system https://support.f5.com/kb/en-us/solutions/public/16000/700/sol16739.html

It's complexe and it depends the TMOS release.

With 11.5, we introduced HTSplit. That means some TMM works for Dataplane et some others for Controlplane. But not with the same Performance factor and TMM Dataplane can "eat" TMM ressource dedicated for management.

• Dataplane : traffic
• Controlplane : management

Before 11.5, 10% of TMM was used for Controlplane (very roughly). From 11.5, with HyperThread per core:

• Even HT : TMM process (traffic)
• Odd HT : management with 20% max usage and Even TMM can "eat" Odd TMM ressources.

Make sense :) ?