Modern E-commerce services are offered in a flexible but complex setup involving multiple websites, for example, business web portals or price comparison websites, which are used in drawing the prices of a variety of online products from related websites and presenting them to millions of customers. Though this modern style of service provisioning is very attractive it significantly increases load on the web servers implementing the E-commerce services. The concern is that overloaded servers will become unresponsive and will drop requests which are beyond their capacity. This paper presents a new approach to the synthesis of performance management mechanisms, which we contend, provides more effective way for managing the performance of modern E-commerce services. The proposed approach is formally specified and is implemented as a Java-based prototype system. A number of experiments are conducted in order to test the performance management of the proposed approach.