Abstract — The Topology and Orchestration Specification for

Cloud Applications (TOSCA) is an emerging framework aiming at enhancing the portability of cloud applications by standardizing their life cycle management in a vendor-neutral way. TOSCA captures the description of cloud application and infrastructure services, the relationships between parts of the services, and the operational behavior of these services (e.g., deploy, patch, shutdown). However, it lacks support for the equally important aspect of managing elasticity, i.e., managing the dynamic scaling of cloud applications at run-time. In this work we present the Elastic-TOSCA framework, which extends TOSCA to address this issue. We then describe how Elastic-TOSCA can be used to support a variety of analytical model-based approaches for elasticity management in complex cloud applications. We further provide a detailed example describing how Elastic TOSCA can be used to support easily a dynamic scaling approach based on a queueing system model. Using a case study for managing the elasticity of a multi-tier e-commerce service, we demonstrate the effectiveness of both the Elastic-TOSCA framework and the scaling approach used. Keywords-TOSCA; cloud; elasticity; scaling approaches; queueing system I