Webmethods IS Load in Cluster environment

Dear Experts,

Currently we are using Webmethods 9.5 which has 2 IS server in cluster under Windows 2012.

And we found out during monitoring the CPU utilization, the loads looks like only running in 1 server and the other is idle.
Even during idle state, looks like if 1 IS server being utilized, the other is keep low.

Attached is the graph of CPU monitoring of our IS server. See the yellow (prd-wm-its02) and the orange (prd-wm-its01) colors.

We are expecting that both servers are utilized fully, but looks like currently we are running only in half capacity.

Wondering whether is it something to do with setting, or this is normal behaviour?

Appreciate any input & comment.

Thank you,
Fanny T

Found the answer in the documentation : Webmethods Integration Server Clustering Guide page no 11.

Load Balancing in a Cluster
Load balancing is an optimizing feature you use with clustered webMethods Integration
Servers. Load balancing controls how requests are distributed to the servers in the cluster.
You must use a third-party load balancer to perform load balancing. A third-party load
balancer can be useful if you need load balancing for multiple types of servers, for
example, web servers and application servers, in addition to webMethods Integration
Servers. Third-party load balancers also offer virtual IP support, but they are not “out of
the box.” Most third-party load balancers perform load balancing in a round-robin
manner or based on network level metrics such as TCP connections and network
response time.

So basically need to use third party software/hardware to perform the load balancing before it goes to webmethods cluster servers.

Hello Fanny,

May I know your CPU Monitoring Tool?