About 100% tmm cpu (50% in dual CPU) usage for BIG-IP 6400 LTM

 

The behavior you are describing is normal. 6400 and 6800 platforms running v9.x use a single TMM process that consumes one CPU to 100%. The second CPU handles all other functions (health checks, administration, etc...). CMP (Clustered Multi-Processing) is explained in SOL7751 (https://support.f5.com/kb/en-us/solutions/public/7000/700/sol7751.html). The solution Aaron referenced, sol3242, does reference this behavior on the 6400/6800 in the v9.4 - v9.4.1 section, just not very prominently. Here is relevant text from SOL3242:

 

 

"Although they are multi-processor platforms, BIG-IP 6400 and 6800 do not support CMP in these versions. They only run one TMM instance and process traffic as noted for BIG-IP versions 9.0 through 9.3.1 above."

 

 

In v10.x this behavior is changed on the 6400/6800 so that they match that of the other platforms; starting with v10.0.0 you will see two TMMs running, each of which can use a maximum of 90% of each CPU (each TMM is locked to a CPU). SOL9763 is a description of the performance changes that come with this change in behavior: (https://support.f5.com/kb/en-us/solutions/public/9000/700/sol9763.html).

 

 

 

--jesse