Cloud Computing Applications

Cloud computing focuses on elasticity, i.e., providing constant quality of service independent of workload. For achieving elasticity, cloud computing applications utilize virtualized infrastructures, distributed platforms, and other software-as-a-service offerings. The surge of cloud computing applications responds to the ability of cloud computing environments to only pay for utilized resources while saving upfront costs (e.g., buying and setting up infrastructure) and allowing for dynamic allocation of resources even in public-private hybrid scenarios.This chapter investigates the shift from classical three-tier web applications to such elastic cloud computing applications. After characterizing web applications, we describe cloud computing characteristics and derive how web applications can exploit these characteristics.Our results motivate novel requirements that have to be engineered and modeled, as further described in this chapter.