ABSTRACT
In 1997, Professor Ramnath Chellappa of Emory University de ned cloud computing for the rst time, calling it an important new “computing paradigm where the boundaries of computing will be determined by economic rationale rather than technical limits alone.”* Even though the international IT literature and media have come forward since then with many de nitions, models, and architectures for cloud computing, autonomic and utility computing were the foundations of what the community commonly referred to as cloud computing. In the early 2000s, companies started rapidly adopting this concept upon the realization that cloud computing could bene t both the providers and the consumers of services. Businesses started delivering computing functionality via the Internet, enterprise-level applications, web-based retail services, document-sharing capabilities, and fully hosted IT platforms, to mention only a few cloud computing uses of the 2000s. e latest widespread adoption of virtualization and service-oriented architecture (SOA) has promulgated cloud computing as a fundamental and increasingly important part of any delivery and critical-mission strategy. It enables existing and new products and services to be o ered and consumed more eciently, conveniently, and securely. Not surprisingly, cloud computing became one of the hottest trends in IT, with a unique and complementary set of properties, such as elasticity, resiliency, rapid provisioning, and multitenancy.
