The Challenge of Service Level Scalability for the Cloud

This paper presents a brief overview of the available literature on distributed systems scalability that serves as a justification for presenting some of the most prominent challenges that current Cloud systems need to face in order to deliver their pledged easy-to-use scalability. Through illustrative comparisons and examples, this paper aims to make the reader's acquaintance with this long needed problem in distributed systems: user-oriented service-level scalability. Scalability issues are analyzed from the Infrastructure as a Service (IaaS) and the Platform as a Service (PaaS) point of view, as they deal with different functions and abstraction levels.