Semantic Representation of Cloud Services: A Case Study for Microsoft Windows Azure

Starting with the provision of ready-to-use infrastructures, such as storage and compute resources, cloud computing quickly became a flexible, cost-effective and complete environment for a wide range of IT services offered over the Internet. A growing number of cloud providers started to expose their own services to the market, to answer consumer´s need, engaging a competition in the attempt to offer the easiest access to resources and the wider catalogue of services. Being integrated with proprietary services and infrastructures, these offerings makes difficult to switch between different underlying technologies, so that the customer is tied to the service provider´s strategy. This lack in standards interfaces, service requirements and technologies brings into the cloud the vendor lock-in problem. Due to this complex scenery, a categorization of services to support the choice of the right solution, as well as a semantic and computable description of services that enables the comparison and the mapping between different providers´ services, proves to be extremely appealing. In an attempt to take a first important step in this context we propose the semantic description of some cloud services, exposing them in terms of functionalities, parameters exchanged, and collaboration between services. In particular in this paper we present the semantic representation of Microsoft Windows Azure APIs, describing functional and non-functional properties of the services.