Nowadays, web services have to accommodate a significant and ever-increasing number of requests due to high interactivity of current applications. Although the built-in elasticity offered by a cloud can mitigate this challenge, it is highly desirable that applications can be built in a scalable fashion. State-of-the-art Web Application Frameworks (WAFs) focus on the creation of application logic and do not offer integrated cloud scaling concepts. As the creation of such scaling systems is very complex, we proposed in our recent work the concept of Web Scaling Frameworks (WSFs) in order to offload scaling to another layer of abstraction. In this work, a detailed design for WSFs including necessary modules, interfaces and components is presented. A mathematical model used for performance rating is evaluated and enhanced on a computing cluster of 42 machines. Traffic traces from over 25 million real-world applications are analysed and evaluated on the cluster to compare the WSF performance with a traditional scaling approach. The results show that the application of WSFs can substantially reduce the number of total machines needed for three representative real-world applications — a social network, a trip planner and the FIFA World Cup 98 website — by 32%, 63% and 92%, respectively.