The MODAClouds Model-Driven Development

The Cloud computing market encompasses an ever-growing number of providers offering a multitude of infrastructure-as-a-service (IaaS) and platform-as-a-service (PaaS) solutions. In order to exploit the peculiarities of each Cloud solution as well as to optimize performances, availability, and cost, an emergent need is to run and manage multi-Cloud applications [1] (i.e., applications that can execute on multiple Cloud infrastructures and platforms). However, current stacks, libraries and frameworks lack in software engineering methodologies and tools to design, deploy and maintain multi-Cloud systems as stated in the CORDIS reports on Cloud computing [2, 3], “whilst a distributed data environment (IaaS) cannot be easily moved to any platform provider (PaaS) [...], it is also almost impossible to move a service/image/environment between providers on the same level.” Model-Driven Development (MDD) [4] techniques are particularly useful to address these challenges. They allow shifting the paradigm from code-centric to model-centric. Models are thus the main artefacts of the development process and enable developers to work at a high level of abstraction, focusing on Cloud concerns rather than implementation details. Model transformations help automating the work of going from abstract concepts to implementation. This approach, which is commonly summarized as “model once, generate anywhere”, is thus particularly relevant when it comes to design and management of applications across multiple Clouds,