Quality of Service (QoS) provides security and reliability to a service. It supports highly available deployments, horizontal scaling via clustering with stateless server architecture, dynamic discovery of services using WS-Discovery, lazy loading via ghost deployers and Apache Zookeeper based coordination support.
Applying a QOS to services is vital since it creates high quality services in terms of non functional attributes like security and reliability.
If you have a configured policy file, you can apply QoS for a proxy service by setting the Security Enabled property to true, pointing to the policy key under Service Policies in the proxy properties, and specifying the
allowRoles parameter (and any additional parameters) under the Service Parameters property to specify which users can access the proxy service. For example, if you want to make this proxy service available to users who have the Admin or Dev role, you would specify the
allowRoles parameter as follows: