Under the Load Balance Members section of the Load Balance tab, select Roles from the Assignment Type drop-down list.
You can assign specific roles by clicking Add and selecting the check boxes next to the roles you want to add as members. Click OK. If you want to only view the roles that are currently configured as members, select the Show only included items check box. You can also use the Find field to enter the name of a role you want to find.
Note:
If a new user is created and added to a role, load balanced queues are not updated until after the Application Pool has been recycled.