Elastic component-based applications in PaaS clouds

Elasticity is the capability of an application to adapt its resource usage to the current workload of the system. Existing platform-as-a-service (PaaS) solutions concentrate on web applications and do not support elasticity for other kinds of applications. To change this, in this paper, the vision and partial implementation for a component-based PaaS cloud is proposed consisting of a programming model and an autonomic manager for safeguarding non-functional application requirements. To illustrate this vision, the paper focuses on two key features of a PaaS infrastructure, the scale-out of services and the on-demand deployment of application resources. The former allows for increasing the performance by distributing service calls among several service providers working in parallel, and the latter refers to the automatic packaging and transfer of needed deployment units. It will be shown how these aspects have been solved within the Jadex PaaS cloud infrastructure. Both concepts have been validated using an application scenario, which highlights the advantages of automatic service scaling and deployment for developers and users. Copyright (c) 2015 John Wiley & Sons, Ltd.