COSCA: an easy-to-use component-based PaaS cloud system for common applications

The emergence of cloud computing marks a significant change in the way computers are used in both enterprise and personal environments. Yet, as a young technology, cloud computing is far from being mature. Platform-as-a-service (PaaS) clouds promise to reduce maintenance and administration costs, but current frameworks lack crucial features for supporting a broad range of applications. Especially rigid constraints of the current PaaS programming models limit broader usage. Based on this observation we compiled eleven requirements of typical business applications such as programming model, placement, scalability, routing, isolation, load balancing, accounting, adaptability and modularity. We further observe that none of current platforms support a majority of these requested features. As a result, we present our own PaaS system, called COSCA that meets all of these requirements. COSCA's component-based design especially supports adaptability and modularity. We believe that our requirements and architecture may serve as a valuable guide for PaaS designers, implementers, and providers.