Distributed Computing in the 21st Century: Some Aspects of Cloud Computing

The Cloud Computing paradigm has gained considerable attention owing to the notable commercial success of many Cloud service providers. Typically, a Cloud Computing service provides its customers with resources as a utility, using a pay-as-you-go model. Thus, Cloud Computing customers can reduce costs related to the acquisition and management of complex IT infrastructures, and Cloud service providers can make efficient use of large resource pools by consolidating multiple variable workloads. From the providers point of view a Cloud is a very large distributed system which poses many challenges, including monitoring, management, efficient resource sharing, fault-tolerance and so on. The amount of knowledge and experience acquired in the development of distributed systems can be used to address some of these issues, while other problems pose new challenges that need new solutions. In this paper we introduce our approach to Cloud Computing and summarize recent results we have obtained by applying this approach to the solution of some critical problems in the Cloud Computing field. 1. Dipartimento di Scienze dell’Informazione, Università di Bologna, Mura Anteo Zamboni 7, I-40127 Bologna, Italy