The simplest method to see that a Service Catalog node is serving pages to the users is to look in the tomcat log. This can be found at
This log shows the pages being served by Tomcat, under the default logging level. For instance, here is an example of my user being successfully sent the Dashboard page after logging in:
"GET /usm/wpf?Node=icguinode.portalgetdashboard HTTP/1.1" 200 4905
Using this method, you can see if each node is actively used, rather than the load balancer only sending users to one.