1. A method of processing a request to at least one server, comprising the steps of: a processor receiving the request; and the processor determining when to submit the request to the at least one server based on: (i) a quality-of-service (QoS) class assigned to a client from which the request originated; (ii) a response target associated with the QoS class; and (iii) an estimated response time associated with the at least one server.