Elasticity and Scalability Centric Quality Model for the Cloud

Cloud computing seems to be the most logical shift in terms of Information Technology after Internet, Social Networking... Despite the potential benefits that cloud computing offers, the model brings new issues, challenges, and needs in term of SLA formalization, Quality of Service (QoS) evaluation due to the heterogeneous resources and to the special features it implies, such as Elasticity and Scalability. In the scope of this paper we focus on the Elasticity and Scalability attributes to assess their impact on the QoS. The paper provides a multi-lenses overview that can help both cloud consumers and potential business application's owners to understand, analyze, and evaluate important aspects related to Scalability and Elasticity capabilities. We determine and analyze the key features of these characteristics and derive metrics that evaluate the cloud elasticity-centric capabilities. We present a specific quality model for those two characteristics derived from their sub-attributes.