Quality Evaluation of PaaS Cloud Application Design Using Generated Prototypes

With the increasing popularity of Platform as a Service (PaaS) cloud, software architects need to face new challenges of software architecture design, efficiently integrating the benefits of PaaS services. In this respect, early quality evaluation of the designed PaaS cloud application is crucial to mitigate the risk of later architectural changes due to violation of quality requirements (such as throughput, response time and scalability). Despite the emergence of architectural tactics and patterns usable for the design of PaaS cloud applications, it is challenging for the software architects to navigate in a rich set of offered services, variability of the PaaS cloud environment and quality conflicts in existing tactics, which makes it almost impossible to predicts the overall application quality without time-consuming implementation of application prototypes. In this paper, we take advantage of the cloud elasticity and introduce a design-time quality evaluation technique for PaaS applications based on automatically generated application prototypes, which are deployed to the cloud and repeatedly evaluated in the context of multiple quality attributes and environment configurations. As part of this work, we present an abstract application model designed to carefully select the details with high performance impact, and present the implementation of our tool generating the prototypes of PaaS cloud applications.