Exploiting Cloud and Workflow Patterns for the Analysis of Composite Cloud Services

The rapid increase in heterogeneity, scale and diversity of cloud resources and services leads to a growing-up complexity in their management and control. The development of new mechanisms to select, deploy and manage resources to achieve required quality of services is nowadays an hot research field usually addressed as {\em Resource Orchestration}(RO). It mainly applies to IaaS layer while few studies report results at SaaS. Anyway the increasing complexity of Cloud Services caused the introduction of new programming and deployment paradigms. {\em Big Vendors} promote Pattern-Based development in order to build value added services. This development methodology has the goal of providing complex services and resources by interaction of simpler ones. In this work we show how Pattern-Based description of composite Cloud Services can be used to define proper Orchestrations action, along all the "`aaS"' layers of Cloud Architecture. The methodology exploits Model Transformation techniques in order to build formal models for the analysis of properties of the whole orchestrated service.