Implementing Elastic Capacity in a Service-Oriented PaaSAdvances in Service-Oriented and Cloud Computing

In their quest for elastic capacity that balances resource lease at the infrastructure level with quality of service at the top, SaaS providers have a hard time at mapping application requirements onto infrastructure performance indicators. The role of a pure service-oriented platform layer to that regard has not been completely investigated and still less exploited. In this paper we illustrate a case study in which we enabled elastic scalability within an existing SOA cloud platform prototype: PaaSSOA. The latter integration and its subsequent tests allowed us to demonstrate the potential benefits arising from exploiting SOA and PaaS capabilities together, especially to release SaaS providers from the burden of reserving infrastructure capacity to met SLAs and of managing web application