Applying Architectural Templates for Design-Time Scalability and Elasticity Analyses of SaaS Applications

Software architects plan, model, and analyze architectures of large software like Software-as-a-Service (SaaS) applications. The scalability and elasticity of these applications is crucially impacted by architects' early decision for an architectural style. However, whether this decision fostered scalability and elasticity can currently only be tested with the final application deployed in the target cloud computing environment. This process leads to the high risk of unsatisfying scalability/elasticity and expensive re-implementations. To tackle this problem, we propose scalability/elasticity analyses using the architectural template (AT) language, a constraint language to specify templates (based on architectural styles) of component models for early quality analyses. This work-in-progress paper provides a first formalization of the AT language and investigates its applicability to analyze the scalability and elasticity of SaaS applications at early design-time by using a 3-tier example scenario. Our results indicate the language is applicable to such 3-tier scenarios.