Cloud computing is the new consolidated trend in ICT, often considered as the panacea to all the problems of existing large-scale distributed paradigms such as Grid and hierarchical clustering. The Cloud breakthrough is the service oriented perspective of providing everything “as a service”. Different from the others large-scale distributed paradigms, it was born from commercial contexts, with the aim of selling the temporarily unexploited computing resources of huge datacenters in order to reduce the costs. Since this business model is really attractive and convenient for both providers and consumers, the Cloud paradigm is quickly growing and widely spreading, even in non commercial context. In fact, several activities on the Cloud, such as Nimbus, Eucalyptus, OpenNEbula, and Reservoir, etc., have been undertaken, aiming at specifying open Cloud infrastructure middleware.
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In this context, the idea is to implement a volunteer-Cloud, in which the infrastructure is obtained by merging heterogeneous resources that could be provided by different domains and/or providers such as other Clouds, Grid farms, clusters, and datacenters, etc, till single desktops. Such a new paradigm has to implement the characteristics of the Cloud paradigm (service oriented interface, dynamic service provisioning, and QoS guaranteed offer, etc.) as well as all the mechanisms for aggregating, enrolling, and managing the resources also considering SLA and QoS requirements. It can be considered a mix between Cloud and volunteer computing, thus it is named Cloud@Home. In order to accomplish its mission, Cloud@Home has to be supported by adequate technology, especially for concerns regarding the Internet and the directions identified by the Future Internet.
This chapter presents the Cloud@Home paradigm, providing a general overview and identifying all its aims and goals. Thus, the chapter tries to address the main issues and challenges of Cloud@Home into a specific middleware architecture composed of several modules. It therefore discusses some possible implications of Cloud@Home in the Future Internet, some possible application scenarios and finally it provides a critical overview of the paradigm against existing Cloud solutions.
Cloud Computing is emerging as a promising paradigm capable of providing a flexible, dynamic, resilient and cost effective infrastructure for both academic and business environments. It aims at raising the level of abstraction of physical resources toward a “user-centric” perspective, focused on the concept of service as the elementary unit for building any application. All the Cloud’s resources, both physical/hardware and logical/abstract (software, data, etc) are therefore considered “as a service” and so all Cloud’s design and implementation choices follow a “service oriented” philosophy.
Cloud is actually a real, operating, and effective solution in commercial and business context, offering computing resources and services for rent, accessed through the Web according to a client-server paradigm regulated by specific SLA. In fact, several commercial solutions and infrastructure providers make business on the Cloud, such as Amazon EC2 and S3, Microsoft Azure, Rackspace, and so on. Recently Cloud computing is quickly and widely spreading also in open contexts such as scientific, academic, and social communities, due to the increasing demand of computing resources required by their users. As an example, there are several research activities and projects on Cloud, such as RESERVOIR (The RESERVOIR Consortium, 2011), OpenNEbula (Universidad Complutense de Madrid, 2011), Eucalyptus (Nurmi et al., 2008), Nimrod/G (MeSsAGE Lab-Monash eScience and Grid Engineering Laboratory, 2011), OpenQRM (openQRM Developer Community, 2011), Hadoop (Apache Software Foundation, 2011), CLEVER (Tusa, Paone, Villari, & Puliafito, 2010), OpenCyrrus (HP, Intel, Yahoo!, 2011) and OpenStack (The Openstack Community, 2011), OCCI (OCCI Work Group, 2011), etc., aiming at implementing their open infrastructure providing specific middleware.
Among the reasons behind the success of Cloud, excepting the low costs, there are: the user-centric interface that acts as a unique, user friendly, point of access for users’ needs and requirements; on-demand service provision; the QoS guaranteed offer, and the autonomous system for managing hardware, software and data transparently to users (Wang et al., 2008).