Service specification in cloud environments based on extensions to open standards

Cloud computing technologies are changing the way in which services are deployed and operated nowadays, introducing advantages such as a great degree of flexibility (e.g. pay-peruse models, automatic scalability, etc.). However, existing offerings (Amazon EC2, GoGrid, etc.) are based on proprietary service definition mechanisms, thus introducing vendor lock-in to the customers who deploy their services on those clouds. On the other hand, there are open standards that address the problem of packaging and distributing virtual appliances (i.e. complete software stacks deployed in one or more virtual machines), but they have not been designed specifically for clouds. This paper proposes a service specification language for cloud computing platforms, based on the DMTF's Open Virtualization Format standard, extending it to address the specific requirements of these environments. In order to assess the feasibility of our proposal, we have implemented a prototype system able to deploy and scale service specifications using the proposed extensions. Additionally, practical results are presented based on an industrial case study that demonstrates using the software prototype how to automatically deploy and flexibly scale the Sun Grid Engine application.