When configuring debugging for a business process in a clustered environment, you need to configure each instance in the cluster for debugging and you need to set the breakpoints and attach the port number using a separate NetBeans IDE instance for each cluster instance.
Launch the GlassFish Admin Console.
In the navigation bar on the left, expand JBI, expand Components, and then select sun-bpel-engine.
In the View/Update Instance field, select an instance you want to monitor.
Set the Debug Enabled property to true.
Set the Debug Port property to a unique valid port number.
Click Save.
Repeat the above steps for each instance you want to monitor.
If you set breakpoints in the business process and attach a port number, you need to launch a new NetBeans IDE instance, set a break point, and then attach the port numbers for each instance in the cluster.