Increasing Flexibility of Hybrid Clouds by Application Portability

Many demands in engineering software, including legal, privacy, cost and technical issues influence the deployment of the software. With cloud computing, applications can be deployed in a provider cloud as an alternative to on-premises infrastructure. Thus, software should be ready for local or provider cloud deployment or a hybrid (mixed) setup. For the user of the application, the location of application parts should remain transparent. The goal is to provide flexibility to this regard while maintaining the basic advantages of cloud computing. This paper introduces and discusses some of the key issues when designing an application for a hybrid setup, in terms of software architecture, communication and security between modules. We give recent trends and recommendations on how to solve these issues so as to achieve application portability.