Chapter 8 introduces a novel network-centric Cloud architecture that provides enhanced end-to-end connectivity services. The framework facilitates vertical and horizontal communication integration of Cloud applications and the authors demonstrate its usefulness in decoupling connectivity from the underlying network implementations.

Chapter 9 presents a new workflow-based framework called YPL-PC that sup- ports the development of (private) scientific Clouds. The authors base their work on the YML workflow programming paradigm and show how their framework can effectively integrate dedicated and volunteer computing resources to support largescale scientific applications.

Chapter 10 discusses the benefits of mixing Clouds with more traditional computing platforms. It focuses on the design of a new high-level framework that sup- ports the smooth transition of an application from a cluster or Grid to a Cloud.

Chapter 11 describes a novel mechanism for extending a Grid computing envi- ronment to use on-demand Cloud resources in order to achieve better performance.

The authors achieve this by modifying the Grid resource management architecture, and through experimentation demonstrate the performance gains of their framework in workflows with large data sets.

Chapter 12 presents a new peer-to-peer Cloud architecture called Cloud Peer. The system creates and manages an overlay network of virtual machines and the authors demonstrate how it supports load balancing and scalable resource discovery.

Chapter 13 discusses the applicability of Cloud computing for high-throughput scientific applications. It shows that the Nimrod/G toolkit can handle both volun- teer resources and commercial services. Through a case study, the authors conclude that an appropriate mixture of Grid and Cloud computing provides an ideal plat- form for high-performance scientific computations.

Part 3: Cloud Breaks

This section covers a range of challenging issues associated to Cloud computing that, if not addressed properly, may limit adoption. It includes chapters that discuss legal issues, security and limitations. Specifically, the questions here relate to how data is protected in such environments to account for privacy, confidentiality, and so on, and what legislative and regulatory challenges are faced.

Chapter 14 provides an overview of a wide spectrum of legislation and regulations applicable to Cloud computing. The authors present a detailed analysis of the considerations that potential Cloud users should make in order to protect their processes and data.

Chapter 15 discusses interoperability issues and open development frameworks for Cloud computing. It presents current standardisation efforts and identifies future key challenges in data confidentiality in particular.

Chapter 16 discusses security and risk issues related to Cloud computing, including privacy, trust and data control. The authors use this analysis to propose a

new information asset classification model to assist Cloud users when choosing amongst Cloud delivery and deployment models.

Chapter 17 focuses on the security controls that need to be deployed in order to increase the adoption of Cloud computing. This discussion leads to a set of recommendations on how various security layers can be incorporated in typical private or public Cloud provisions.

Part 4: Cloud Feedback

This section aims to argue a business case for Cloud computing by debating the impact of Clouds. Can Clouds be the basis for deploying successful digital economies? Are there any lessons learned from specific case studies involving the use of Clouds for business applications?

Chapter 18 assesses frameworks for the distribution and enforcement of policies in Cloud architectures. The authors explore the use of the Service-Oriented Architecture (SOA) Policy Enforcement Point (PEP) as a policy portal and show that this can be an effective security model for Cloud-based services.

Chapter 19 describes in detail the PeRvasive Infrastructure of Services for Media (PRISM) project that provides a Cloud-based media infrastructure to support network access to BBC content. The deployment of this system is discussed, and it is shown that the system is capable of handling petabytes of data for on-demand viewing.

Chapter 20 discusses the economic forces and business drivers affecting the adoption of Cloud computing. It provides a detailed analysis of the costs and benefits of using Clouds as well as the overall quality of experience of Cloud end-users and its link to Service-Level Agreements (SLAs).

Chapter 21 discusses the challenges that would be entailed in constructing a price comparison service for Cloud resources. Service-Level Agreements (SLAs) would be a key component in such a service and experiments are presented for costing applications on a local Grid and a public (Amazon EC2) and private

(Eucalyptus) Cloud.

Acknowledgements  The editors are grateful to the peer-review panel for supporting this book including, in no particular order, Anand Govindarajan, Bhaskar Prasad Rimal, Bin Li, Blair Bethwaite, Brian Amedro, Cyril Onwubiko, David Abramson, Hai Jin, James P. Durbano, Fabrice Huet, Francesco Palmieri, Ian Lumb, Jinlei Jiang, Kevin Mcdonald, Lakshmanan G, Rajiv Ranjan, Scott Morrison, and Terence Harmer. The editors are deeply apologetic to anyone whom they have forgotten.

  The editors also wish to thank the Springer’s editorial team for their strong and continuous support throughout the development of this book.