Concepts associated with cloud computing

Cloud Computing

A resource pooling architecture is based on the use of one or more resource pools in which identical IT resources are grouped and maintained by a system that automatically ensures they remain synchronized.

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Cloud Computing Concepts, Technology & Architecture

Thomas Erl, Zaigham Mahmood, and Ricardo Puttini

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Praise for this Book

“Cloud computing, more than most disciplines in IT, suffers from too much talk and not enough practice. Thomas Erl has written a timely book that condenses the theory and buttresses it with real-world examples that demystify this important technology. An important guidebook for your journey into the cloud.”

—Scott Morrison, Chief Technology Officer, Layer 7 Technologies

“An excellent, extremely well-written, lucid book that provides a comprehensive picture of cloud computing, covering multiple dimensions of the subject. The case studies presented in the book provide a real-world, practical perspective on leveraging cloud computing in an organization. The book covers a wide range of topics, from technology aspects to the business value provided by cloud computing. This is the best, most comprehensive book on the subject—a must-read for any cloud computing practitioner or anyone who wants to get an in-depth picture of cloud computing concepts and practical implementation.”

—Suzanne D’Souza, SOA/BPM Practice Lead, KBACE Technologies

“This book offers a thorough and detailed description of cloud computing concepts, architectures, and technologies. It serves as a great reference for both newcomers and experts and is a must-read for any IT professional interested in cloud computing.”

—Andre Tost, Senior Technical Staff Member, IBM Software Group

“This is a great book on the topic of cloud computing. It is impressive how the content spans from taxonomy, technology, and architectural concepts to important business considerations for cloud adoption. It really does provide a holistic view to this technology paradigm.”

—Kapil Bakshi, Architecture and Strategy, Cisco Systems Inc.

“I have read every book written by Thomas Erl and Cloud Computing is another excellent publication and demonstration of Thomas Erl’s rare ability to take the most complex topics and provide critical core concepts and technical information in a logical and understandable way.”

—Melanie A. Allison, Principal, Healthcare Technology Practice, Integrated Consulting Services

“Companies looking to migrate applications or infrastructure to the cloud are often misled by buzzwords and industry hype. This work cuts through the hype and provides a detailed look, from investigation to contract to implementation to termination, at what it takes for an organization to engage with cloud service providers. This book really lays out the benefits and struggles with getting a company to an IaaS, PaaS, or SaaS solution.”

—Kevin Davis, Ph.D., Solutions Architect

“Thomas, in his own distinct and erudite style, provides a comprehensive and a definitive book on cloud computing. Just like his previous masterpiece, Service-Oriented Architecture: Concepts, Technology, and Design, this book is sure to engage CxOs, cloud architects, and the developer community involved in delivering software assets on the cloud. Thomas and his authoring team have taken great pains in providing great clarity and detail in documenting cloud architectures, cloud delivery models, cloud governance, and economics of cloud, without forgetting to explain the core of cloud computing that revolves around Internet architecture and virtualization. As a reviewer for this outstanding book, I must admit I have learned quite a lot while reviewing the material. A ‘must have’ book that should adorn everybody’s desk!”

—Vijay Srinivasan, Chief Architect - Technology, Cognizant Technology Solutions

“This book provides comprehensive and descriptive vendor-neutral coverage of cloud computing technology, from both technical and business aspects. It provides a deep-down analysis of cloud architectures and mechanisms that capture the real-world moving parts of cloud platforms. Business aspects are elaborated on to give readers a broader perspective on choosing and defining basic cloud computing business models. Thomas Erl’s Cloud Computing: Concepts, Technology & Architecture is an excellent source of knowledge of fundamental and in- depth coverage of cloud computing.”

—Masykur Marhendra Sukmanegara, Communication Media & Technology, Consulting Workforce Accenture

“The richness and depth of the topics discussed are incredibly impressive. The depth and breadth of the subject matter are such that a reader could become an expert in a short amount of time.”

—Jamie Ryan, Solutions Architect, Layer 7 Technologies

“Demystification, rationalization, and structuring of implementation approaches have always been strong parts in each and every one of Thomas Erl’s books. This book is no exception. It provides the definitive, essential coverage of cloud computing and, most importantly, presents this content in a very comprehensive manner. Best of all, this book follows the conventions of the previous service technology series titles, making it read like a natural extension of the library. I strongly believe that this will be another bestseller from one of the top-selling IT authors of the past decade.”

—Sergey Popov, Senior Enterprise Architect SOA/Security, Liberty Global International

“A must-read for anyone involved in cloud design and decision making! This insightful book provides in-depth, objective, vendor-neutral coverage of cloud computing concepts, architecture models, and technologies. It will prove very valuable to anyone who needs to gain a solid understanding of how cloud environments work and how to design and migrate solutions to clouds.”

—Gijs in ’t Veld, Chief Architect, Motion10

“A reference book covering a wide range of aspects related to cloud providers and cloud consumers. If you would like to provide or consume a cloud service and need to know how, this is your book. The book has a clear structure to facilitate a good understanding of the various concepts of cloud.”

—Roger Stoffers, Solution Architect

“Cloud computing has been around for a few years, yet there is still a lot of confusion around the term and what it can bring to developers and deployers alike. This book is a great way of finding out what’s behind the cloud, and not in an abstract or high-level manner: It dives into all of the details that you’d need to know in order to plan for developing applications on cloud and what to look for when using applications or

services hosted on a cloud. There are very few books that manage to capture this level of detail about the evolving cloud paradigm as this one does. It’s a must for architects and developers alike.”

—Dr. Mark Little, Vice President, Red Hat

“This book provides a comprehensive exploration of the concepts and mechanics behind clouds. It’s written for anyone interested in delving into the details of how cloud environments function, how they are architected, and how they can impact business. This is the book for any organization seriously considering adopting cloud computing. It will pave the way to establishing your cloud computing roadmap.”

—Damian Maschek, SOA Architect, Deutsche Bahn

“One of the best books on cloud computing I have ever read. It is complete yet vendor technology neutral and successfully explains the major concepts in a well-structured and disciplined way. It goes through all the definitions and provides many hints for organizations or professionals who are approaching and/or assessing cloud solutions. This book gives a complete list of topics playing fundamental roles in the cloud computing discipline. It goes through a full list of definitions very clearly stated. Diagrams are simple to understand and self-contained. Readers with different skill sets, expertise, and backgrounds will be able to understand the concepts seamlessly.”

—Antonio Bruno, Infrastructure and Estate Manager, UBS AG

“Cloud Computing: Concepts, Technology & Architecture is a comprehensive book that focuses on what cloud computing is really all about.... This book will become the foundation on which many organizations will build successful cloud adoption projects. It is a must- read reference for both IT infrastructure and application architects interested in cloud computing or involved in cloud adoption projects. It contains extremely useful and comprehensive information for those who need to build cloud-based architectures or need to explain it to customers thinking about adopting cloud computing technology in their organization.”

—Johan Kumps, SOA Architect, RealDolmen

“This book defines the basic terminology and patterns for the topic—a

useful reference for the cloud practitioner. Concepts from multitenancy to hypervisor are presented in a succinct and clear manner. The underlying case studies provide wonderful real-worldness.”

—Dr. Thomas Rischbeck, Principal Architect, ipt

“The book provides a good foundation to cloud services and issues in cloud service design. Chapters highlight key issues that need to be considered in learning how to think in cloud technology terms; this is highly important in today’s business and technology environments where cloud computing plays a central role in connecting user services with virtualized resources and applications.”

—Mark Skilton, Director, Office of Strategy and Technology, Global Infrastructure Services, Capgemini

“The book is well organized and covers basic concepts, technologies, and business models about cloud computing. It defines and explains a comprehensive list of terminologies and glossaries about cloud computing so cloud computing experts can speak and communicate with the same set of standardized language. The book is easy to understand and consistent with early published books from Thomas Erl.... It is a must-read for both beginners and experienced professionals.”

—Jian “Jeff” Zhong, Chief Technology Officer (Acting) and Chief Architect for SOA and Cloud Computing, Futrend Technology Inc.

“Students of the related specialties can fulfill their educational process with very easily understood materials that are broadly illustrated and clearly described. Professors of different disciplines, from business analysis to IT implementation—even legal and financial monitoring— can use the book as an on-table lecturing manual. IT specialists of all ranks and fields of application will find the book as a practical and useful support for sketching solutions unbound to any particular vendor or brand.”

—Alexander Gromoff, Director of Science & Education, Center of Information Control Technologies, Chairman of BPM Chair in Business Informatics Department, National Research University

“Higher School of Economics”

“Cloud Computing: Concepts, Technology & Architecture is a

comprehensive compendium of all the relevant information about the transformative cloud technology. Erl’s latest title concisely and clearly illustrates the origins and positioning of the cloud paradigm as the next- generation computing model. All the chapters are carefully written and arranged in an easy-to-understand manner. This book will be immeasurably beneficial for business and IT professionals. It is set to shake up and help organize the world of cloud computing.”

—Pethuru Raj, Ph.D., Enterprise Architecture Consultant, Wipro

“A cloud computing book that will stand out and survive the test of time, even in one of the fastest evolving areas of technology. This book does a great job breaking down the high level of complexity of cloud computing into easy-to-understand pieces. It goes beyond the basic, often repeated, explanations. It examines the fundamental concepts and the components, as well as the mechanisms and architectures that make up cloud computing environments. The approach gradually builds the reader’s understanding from the ground up. “In a rapidly evolving area like cloud computing, it’s easy to focus on details and miss the big picture. The focus on concepts and architectural models instead of vendor-specific details allows readers to quickly gain essential knowledge of complex topics. The concepts come together in the last part of the book, which should be required reading for any decision maker evaluating when and how to start a transition to cloud computing. Its thorough, comprehensive coverage of fundamentals and advanced topics makes the book a valuable resource to keep on your desk or your eBook reader, regardless if you’re new to the topic or you already have cloud experience.

“I highly recommend the book to those looking to implement or evaluate cloud environments, or simply looking to educate themselves in a field that will shape IT over the next decade.”

—Christoph Schittko, Principal Technology Strategist & Cloud Solution Director, Microsoft

“Cloud Computing: Concepts, Technology & Architecture is an excellent resource for IT professionals and managers who want to learn and understand cloud computing, and who need to select or build cloud systems and solutions. It lays the foundation for cloud concepts, models,

technologies, and mechanisms. As the book is vendor-neutral, it will remain valid for many years. We will recommend this book to Oracle customers, partners, and users for their journey toward cloud computing. This book has the potential to become the basis for a cloud computing manifesto, comparable to what was accomplished with the SOA manifesto.” —Jürgen Kress, Fusion Middleware Partner Adoption, Oracle EMEA

To my family and friends —Thomas Erl

To Zoya, Hanya, and Ozair with love —Zaigham Mahmood

To Silvia, Luiza, Isadora, and Lucas —Ricardo Puttini

Contents at a Glance

Foreword

Chapter 1: Introduction

Chapter 2: Case Study Background

Part I: Fundamental Cloud Computing

Chapter 3: Understanding Cloud Computing

Chapter 4: Fundamental Concepts and Models

Chapter 5: Cloud-Enabling Technology

Chapter 6: Fundamental Cloud Security

Part II: Cloud Computing Mechanisms

Chapter 7: Cloud Infrastructure Mechanisms

Chapter 8: Specialized Cloud Mechanisms

Chapter 9: Cloud Management Mechanisms

Chapter 10: Cloud Security Mechanisms

Part III: Cloud Computing Architecture

Chapter 11: Fundamental Cloud Architectures

Chapter 12: Advanced Cloud Architectures

Chapter 13: Specialized Cloud Architectures

Part IV: Working with Clouds

Chapter 14: Cloud Delivery Model Considerations

Chapter 15: Cost Metrics and Pricing Models

Chapter 16: Service Quality Metrics and SLAs

Part V: Appendices

Appendix A: Case Study Conclusions

Appendix B: Industry Standards Organizations

Appendix C: Mapping Mechanisms to Characteristics

Appendix D: Data Center Facilities (TIA-942)

Appendix E: Emerging Technologies

Appendix F: Cloud Provisioning Contracts

Appendix G: Cloud Business Case Template

About the Authors

About the Foreword Contributor

About the Contributors

Index

Contents

Foreword

Acknowledgments

Chapter 1: Introduction 1.1 Objectives of This Book 1.2 What This Book Does Not Cover 1.3 Who This Book Is For 1.4 How This Book Is Organized

Part I: Fundamental Cloud Computing Chapter 3: Understanding Cloud Computing Chapter 4: Fundamental Concepts and Models Chapter 5: Cloud-Enabling Technology Chapter 6: Fundamental Cloud Security

Part II: Cloud Computing Mechanisms Chapter 7: Cloud Infrastructure Mechanisms Chapter 8: Specialized Cloud Mechanisms Chapter 9: Cloud Management Mechanisms Chapter 10: Cloud Security Mechanisms

Part III: Cloud Computing Architecture Chapter 11: Fundamental Cloud Architectures Chapter 12: Advanced Cloud Architectures Chapter 13: Specialized Cloud Architectures

Part IV: Working with Clouds Chapter 14: Cloud Delivery Model Considerations Chapter 15: Cost Metrics and Pricing Models Chapter 16: Service Quality Metrics and SLAs

Part V: Appendices Appendix A: Case Study Conclusions Appendix B: Industry Standards Organizations

Appendix C: Mapping Mechanisms to Characteristics Appendix D: Data Center Facilities (TIA-942) Appendix E: Emerging Technologies Appendix F: Cloud Provisioning Contracts Appendix G: Cloud Business Case Template

1.5 Conventions Symbols and Figures Summary of Key Points

1.6 Additional Information Updates, Errata, and Resources (www.servicetechbooks.com) Referenced Specifications (www.servicetechspecs.com) The Service Technology Magazine (www.servicetechmag.com) International Service Technology Symposium (www.servicetechsymposium.com) What Is Cloud? (www.whatiscloud.com) What Is REST? (www.whatisrest.com) Cloud Computing Design Patterns (www.cloudpatterns.org) Service-Orientation (www.serviceorientation.com) CloudSchool.com™ Certified Cloud (CCP) Professional (www.cloudschool.com) SOASchool.com® SOA Certified (SOACP) Professional (www.soaschool.com) Notification Service

Chapter 2: Case Study Background 2.1 Case Study #1: ATN

Technical Infrastructure and Environment Business Goals and New Strategy Roadmap and Implementation Strategy

2.2 Case Study #2: DTGOV Technical Infrastructure and Environment Business Goals and New Strategy

Roadmap and Implementation Strategy 2.3 Case Study #3: Innovartus Technologies Inc.

Technical Infrastructure and Environment Business Goals and Strategy Roadmap and Implementation Strategy

Part I: Fundamental Cloud Computing

Chapter 3: Understanding Cloud Computing 3.1 Origins and Influences

A Brief History Definitions Business Drivers Capacity Planning Cost Reduction Organizational Agility

Technology Innovations Clustering Grid Computing Virtualization Technology Innovations vs. Enabling Technologies

3.2 Basic Concepts and Terminology Cloud IT Resource On-Premise Cloud Consumers and Cloud Providers Scaling Horizontal Scaling Vertical Scaling

Cloud Service Cloud Service Consumer

3.3 Goals and Benefits

Reduced Investments and Proportional Costs Increased Scalability Increased Availability and Reliability

3.4 Risks and Challenges Increased Security Vulnerabilities Reduced Operational Governance Control Limited Portability Between Cloud Providers Multi-Regional Compliance and Legal Issues

Chapter 4: Fundamental Concepts and Models 4.1 Roles and Boundaries

Cloud Provider Cloud Consumer Cloud Service Owner Cloud Resource Administrator Additional Roles Organizational Boundary Trust Boundary

4.2 Cloud Characteristics On-Demand Usage Ubiquitous Access Multitenancy (and Resource Pooling) Elasticity Measured Usage Resiliency

4.3 Cloud Delivery Models Infrastructure-as-a-Service (IaaS) Platform-as-a-Service (PaaS) Software-as-a-Service (SaaS) Comparing Cloud Delivery Models Combining Cloud Delivery Models IaaS + PaaS

IaaS + PaaS + SaaS 4.4 Cloud Deployment Models

Public Clouds Community Clouds Private Clouds Hybrid Clouds Other Cloud Deployment Models

Chapter 5: Cloud-Enabling Technology 5.1 Broadband Networks and Internet Architecture

Internet Service Providers (ISPs) Connectionless Packet Switching (Datagram Networks) Router-Based Interconnectivity Physical Network Transport Layer Protocol Application Layer Protocol

Technical and Business Considerations Connectivity Issues Network Bandwidth and Latency Issues Cloud Carrier and Cloud Provider Selection

5.2 Data Center Technology Virtualization Standardization and Modularity Automation Remote Operation and Management High Availability Security-Aware Design, Operation, and Management Facilities Computing Hardware Storage Hardware Network Hardware Carrier and External Networks Interconnection

Web-Tier Load Balancing and Acceleration LAN Fabric SAN Fabric NAS Gateways

Other Considerations 5.3 Virtualization Technology

Hardware Independence Server Consolidation Resource Replication Operating System-Based Virtualization Hardware-Based Virtualization Virtualization Management Other Considerations

5.4 Web Technology Basic Web Technology Web Applications

5.5 Multitenant Technology 5.6 Service Technology

Web Services REST Services Service Agents Service Middleware

5.7 Case Study Example

Chapter 6: Fundamental Cloud Security 6.1 Basic Terms and Concepts

Confidentiality Integrity Authenticity Availability Threat Vulnerability

Risk Security Controls Security Mechanisms Security Policies

6.2 Threat Agents Anonymous Attacker Malicious Service Agent Trusted Attacker Malicious Insider

6.3 Cloud Security Threats Traffic Eavesdropping Malicious Intermediary Denial of Service Insufficient Authorization Virtualization Attack Overlapping Trust Boundaries

6.4 Additional Considerations Flawed Implementations Security Policy Disparity Contracts Risk Management

6.5 Case Study Example

Part II: Cloud Computing Mechanisms

Chapter 7: Cloud Infrastructure Mechanisms 7.1 Logical Network Perimeter

Case Study Example 7.2 Virtual Server

Case Study Example 7.3 Cloud Storage Device

Cloud Storage Levels

Network Storage Interfaces Object Storage Interfaces Database Storage Interfaces Relational Data Storage Non-Relational Data Storage

Case Study Example 7.4 Cloud Usage Monitor

Monitoring Agent Resource Agent Polling Agent Case Study Example

7.5 Resource Replication Case Study Example

7.6 Ready-Made Environment Case Study Example

Chapter 8: Specialized Cloud Mechanisms 8.1 Automated Scaling Listener

Case Study Example 8.2 Load Balancer

Case Study Example 8.3 SLA Monitor

Case Study Example SLA Monitor Polling Agent SLA Monitoring Agent

8.4 Pay-Per-Use Monitor Case Study Example

8.5 Audit Monitor Case Study Example

8.6 Failover System Active-Active Active-Passive

Case Study Example 8.7 Hypervisor

Case Study Example 8.8 Resource Cluster

Case Study Example 8.9 Multi-Device Broker

Case Study Example 8.10 State Management Database

Case Study Example

Chapter 9: Cloud Management Mechanisms 9.1 Remote Administration System

Case Study Example 9.2 Resource Management System

Case Study Example 9.3 SLA Management System

Case Study Example 9.4 Billing Management System

Case Study Example

Chapter 10: Cloud Security Mechanisms 10.1 Encryption

Symmetric Encryption Asymmetric Encryption Case Study Example

10.2 Hashing Case Study Example

10.3 Digital Signature Case Study Example

10.4 Public Key Infrastructure (PKI) Case Study Example

10.5 Identity and Access Management (IAM)

Case Study Example 10.6 Single Sign-On (SSO)

Case Study Example 10.7 Cloud-Based Security Groups

Case Study Example 10.8 Hardened Virtual Server Images

Case Study Example

Part III: Cloud Computing Architecture

Chapter 11: Fundamental Cloud Architectures 11.1 Workload Distribution Architecture 11.2 Resource Pooling Architecture 11.3 Dynamic Scalability Architecture 11.4 Elastic Resource Capacity Architecture 11.5 Service Load Balancing Architecture 11.6 Cloud Bursting Architecture 11.7 Elastic Disk Provisioning Architecture 11.8 Redundant Storage Architecture 11.9 Case Study Example

Chapter 12: Advanced Cloud Architectures 12.1 Hypervisor Clustering Architecture 12.2 Load Balanced Virtual Server Instances Architecture 12.3 Non-Disruptive Service Relocation Architecture 12.4 Zero Downtime Architecture 12.5 Cloud Balancing Architecture 12.6 Resource Reservation Architecture 12.7 Dynamic Failure Detection and Recovery Architecture 12.8 Bare-Metal Provisioning Architecture 12.9 Rapid Provisioning Architecture 12.10 Storage Workload Management Architecture

12.11 Case Study Example

Chapter 13: Specialized Cloud Architectures 13.1 Direct I/O Access Architecture 13.2 Direct LUN Access Architecture 13.3 Dynamic Data Normalization Architecture 13.4 Elastic Network Capacity Architecture 13.5 Cross-Storage Device Vertical Tiering Architecture 13.6 Intra-Storage Device Vertical Data Tiering Architecture 13.7 Load Balanced Virtual Switches Architecture 13.8 Multipath Resource Access Architecture 13.9 Persistent Virtual Network Configuration Architecture 13.10 Redundant Physical Connection for Virtual Servers Architecture 13.11 Storage Maintenance Window Architecture

Part IV: Working with Clouds

Chapter 14: Cloud Delivery Model Considerations 14.1 Cloud Delivery Models: The Cloud Provider Perspective

Building IaaS Environments Data Centers Scalability and Reliability Monitoring Security

Equipping PaaS Environments Scalability and Reliability Monitoring Security

Optimizing SaaS Environments Security

14.2 Cloud Delivery Models: The Cloud Consumer Perspective Working with IaaS Environments IT Resource Provisioning Considerations

Working with PaaS Environments IT Resource Provisioning Considerations

Working with SaaS Services 14.3 Case Study Example

Chapter 15: Cost Metrics and Pricing Models 15.1 Business Cost Metrics

Up-Front and On-Going Costs Additional Costs Case Study Example Product Catalog Browser On-Premise Up-Front Costs On-Premise On-Going Costs Cloud-Based Up-Front Costs Cloud-Based On-Going Costs

Client Database On-Premise Up-Front Costs On-Premise On-Going Costs Cloud-Based Up-Front Costs Cloud-Based On-Going Costs

15.2 Cloud Usage Cost Metrics Network Usage Inbound Network Usage Metric Outbound Network Usage Metric Intra-Cloud WAN Usage Metric

Server Usage On-Demand Virtual Machine Instance Allocation Metric Reserved Virtual Machine Instance Allocation Metric

Cloud Storage Device Usage On-Demand Storage Space Allocation Metric I/O Data Transferred Metric

Cloud Service Usage

Application Subscription Duration Metric Number of Nominated Users Metric Number of Transactions Users Metric

15.3 Cost Management Considerations Pricing Models Additional Considerations Case Study Example Virtual Server On-Demand Instance Allocation Virtual Server Reserved Instance Allocation Cloud Storage Device WAN Traffic

Chapter 16: Service Quality Metrics and SLAs 16.1 Service Quality Metrics

Service Availability Metrics Availability Rate Metric Outage Duration Metric

Service Reliability Metrics Mean-Time Between Failures (MTBF) Metric Reliability Rate Metric

Service Performance Metrics Network Capacity Metric Storage Device Capacity Metric Server Capacity Metric Web Application Capacity Metric Instance Starting Time Metric Response Time Metric Completion Time Metric

Service Scalability Metrics Storage Scalability (Horizontal) Metric Server Scalability (Horizontal) Metric Server Scalability (Vertical) Metric

Service Resiliency Metrics Mean-Time to Switchover (MTSO) Metric Mean-Time System Recovery (MTSR) Metric

16.2 Case Study Example 16.3 SLA Guidelines 16.4 Case Study Example

Scope and Applicability Service Quality Guarantees Definitions Usage of Financial Credits SLA Exclusions

Part V: Appendices

Appendix A: Case Study Conclusions

A.1 ATN A.2 DTGOV A.3 Innovartus

Appendix B: Industry Standards Organizations

B.1 National Institute of Standards and Technology (NIST) B.2 Cloud Security Alliance (CSA) B.3 Distributed Management Task Force (DMTF) B.4 Storage Networking Industry Association (SNIA) B.5 Organization for the Advancement of Structured Information Standards (OASIS) B.6 The Open Group B.7 Open Cloud Consortium (OCC) B.8 European Telecommunications Standards Institute (ETSI) B.9 Telecommunications Industry Association (TIA) B.10 Liberty Alliance B.11 Open Grid Forum (OGF)

Appendix C: Mapping Mechanisms to Characteristics

Appendix D: Data Center Facilities (TIA-942)

D.1 Primary Rooms Electrical Room Mechanical Room Storage and Staging Offices, Operations Center, and Support Telecommunications Entrance Computer Room

D.2 Environmental Controls External Electrical Power Provider Interconnection Power Distribution Uninterruptible Power Source (UPS) Power Engine-Generator

D.3 Infrastructure Redundancy Summary

Appendix E: Emerging Technologies

E.1 Autonomic Computing E.2 Grid Computing

Service Grids

Appendix F: Cloud Provisioning Contracts

F.1 Cloud Provisioning Contract Structure Terms of Service Service Usage Policy Security and Privacy Policy Warranties and Liabilities Rights and Responsibilities Termination and Renewal

Specifications and SLAs Pricing and Billing Other Issues

Legal and Compliance Issues Auditability and Accountability Changes in the Contract Terms and Conditions

F.2 Cloud Provider Selection Guidelines Cloud Provider Viability

Appendix G: Cloud Business Case Template

G.1 Business Case Identification G.2 Business Needs G.3 Target Cloud Environment G.4 Technical Issues G.5 Economic Factors

About the Authors Thomas Erl Zaigham Mahmood Ricardo Puttini

About the Foreword Contributor Pamela J. Wise-Martinez, MSc

About the Contributors Gustavo Azzolin, BSc, MSc Amin Naserpour Vinícius Pacheco, MSc Matthias Ziegler

Index

Foreword by Pamela J. Wise-Martinez

The idea of cloud computing isn’t new, or overly complicated from a technology resources and internetworking perspective. What’s new is the growth and maturity of cloud computing methods, and strategies that enable the goals of business agility. Looking back, the phrase “utility computing” didn’t captivate or create the stir in the information industry as the term “cloud computing” has in recent years. Nevertheless, appreciation of readily available resources has arrived and the utilitarian or servicing features are what are at the heart of outsourcing the access of information technology resources and services. In this light, cloud computing represents a flexible, cost-effective, and proven delivery platform for business and consumer information services over the Internet. Cloud computing has become an industry game changer as businesses and information technology leaders realize the potential in combining and sharing computing resources as opposed to building and maintaining them. There’s seemingly no shortage of views regarding the benefits of cloud computing nor is there a shortage of vendors willing to offer services in either open source or promising commercial solutions. Beyond the hype, there are many aspects of the cloud that have earned new consideration due to their increased service capability and potential efficiencies. The ability to demonstrate transforming results in cloud computing to resolve traditional business problems using information technology management best practices now exists. In the case of economic impacts, the principle of pay-as-you-go and computer agnostic services are concepts ready for prime time. We can measure performance as well as calculate the economic and environmental effects of cloud computing today. The architectural change from client-server to service orientation led to an evolution of composable and reusable code; though the practice had been around for many years, it is now the de facto approach used to lower cost and identify best practices and patterns for increasing business agility. This has advanced the computer software industry’s design methods, components, and engineering. Comparatively, the wide acceptance and adoption of cloud computing is revolutionizing information and technology resource management. We now have the ability to outsource hardware and software capabilities on a large-scale to fulfill end-to-end business automation requirements. Marks and Lozano understood this emergence and the need for better software design: “...we now have the ability to collect, transport, process, store, and access data nearly

anywhere in nearly arbitrary volume.” The limitations depend largely on how “cloudy” or cloud-aware the service/component is, and hence the need for better software architecture. (Eric A. Marks and Roberto Lozano [Executive Guide to Cloud Computing]). The reusable evolution through service architecture reinforces a focus on business objectives as opposed to the number of computing platforms to support. As a viable resource management alternative, cloud computing is fundamentally changing the way we think about computing solutions in retail, education, and public sectors. The use of cloud computing architecture and standards are driving unique ways in which computing solutions are delivered, as well as platform diversity to meet bottom-line business objectives. Thomas Erl’s body of work on service technology guided the technology industry through eloquent illustrations and literature over the past decade. Thomas’ brilliant efforts on principles, concepts, patterns, and expressions gave the information technology community an evolved software architecture approach that now forms a foundation for cloud computing goals to be successfully fulfilled in practice. This is a key assertion, as cloud computing is no longer a far-reaching concept of the future, but rather a dominant information technology service option and resource delivery presence. Thomas’ Cloud Computing: Concepts, Technology & Architecture takes the industry beyond the definitions of cloud computing and juxtaposes virtualization, grid, and sustainment strategies as contrasted in day to day operations. Thomas and his team of authors take the reader from beginning to end with the essential elements of cloud computing, its history, innovation, and demand. Through case studies and architectural models they articulate service requirements, infrastructure, security, and outsourcing of salient computing resources. Thomas again enlightens the industry with poignant analysis and reliable architecture-driven practices and principles. No matter the level of interest or experience, the reader will find clear value in this in-depth, vendor-neutral study of cloud computing. Pamela J. Wise-Martinez, Inventor and Chief Architect Department of Energy, National Nuclear Security Administration (Disclaimer: The views expressed are the personal views of the author and are not intended to reflect either the views of the U.S. Government, the U.S. Department of Energy, or the National Nuclear Security Administration.)

Acknowledgments

In alphabetical order by last name: • Ahmed Aamer, AlFaisaliah Group • Randy Adkins, Modus21 • Melanie Allison, Integrated Consulting Services • Gabriela Inacio Alves, University of Brasilia • Marcelo Ancelmo, IBM Rational Software Services • Kapil Bakshi, Cisco Systems • Toufic Boubez, Metafor Software • Antonio Bruno, UBS AG • Dr. Paul Buhler, Modus21 • Pethuru Raj Cheliah, Wipro • Kevin Davis, Ph.D. • Suzanne D’Souza, KBACE Technologies • Alexander Gromoff, Center of Information Control Technologies • Chris Haddad, WSO2 • Richard Hill, University of Derby • Michaela Iorga, Ph.D. • Johan Kumps, RealDolmen • Gijs in ’t Veld, Motion10 • Masykur Marhendra, Consulting Workforce Accenture • Damian Maschek, Deutshe Bahn • Claynor Mazzarolo, IBTI • Steve Millidge, C2B2 • Jorge Minguez, Thales Deutschland • Scott Morrison, Layer 7 • Amin Naserpour, HP • Vicente Navarro, European Space Agency • Laura Olson, IBM WebSphere • Tony Pallas, Intel

• Cesare Pautasso, University of Lugano • Sergey Popov, Liberty Global International • Olivier Poupeney, Dreamface Interactive • Alex Rankov, EMC • Dan Rosanova, West Monroe Partners • Jaime Ryan, Layer 7 • Filippos Santas, Credit Suisse • Christoph Schittko, Microsoft • Guido Schmutz, Trivadis • Mark Skilton, Capgemini • Gary Smith, CloudComputingArchitect.com • Vijay Srinivasan, Cognizant • Daniel Starcevich, Raytheon • Roger Stoffers, HP • Andre Toffanello, IBTI • Andre Tost, IBM Software Group • Bernd Trops, talend • Clemens Utschig, Boehringer Ingelheim Pharma • Ignaz Wanders, Archimiddle • Philip Wik, Redflex • Jorge Williams, Rackspace • Dr. Johannes Maria Zaha • Jeff Zhong, Futrend Technologies

Special thanks to the CloudSchool.com research and development team that produced the CCP course modules upon which this book is based.

http://CloudSchool.com
Chapter 1. Introduction

1.1 Objectives of This Book 1.2 What This Book Does Not Cover 1.3 Who This Book Is For 1.4 How This Book Is Organized 1.5 Conventions 1.6 Additional Information

The past couple of decades saw the business-centric concept of outsourcing services and the technology-centric notion of utility computing evolve along relatively parallel streams. When they finally met to form a technology landscape with a compelling business case and seismic impacts on the IT industry as a whole, it became evident that what resultantly was termed and branded as “cloud computing” was more than just another IT trend. It had become an opportunity to further align and advance the goals of the business with the capabilities of technology.

Those who understand this opportunity can seize it to leverage proven and mature components of cloud platforms to not only fulfill existing strategic business goals, but to even inspire businesses to set new objectives and directions based on the extent to which cloud-driven innovation can further help optimize business operations. The first step to succeeding is education. Cloud computing adoption is not trivial. The cloud computing marketplace is unregulated. And, not all products and technologies branded with “cloud” are, in fact, sufficiently mature to realize or even supportive of realizing actual cloud computing benefits. To add to the confusion, there are different definitions and interpretations of cloud-based models and frameworks floating around IT literature and the IT media space, which leads to different IT professionals acquiring different types of cloud computing expertise. And then, of course, there is the fact that cloud computing is, at its essence, a form of service provisioning. As with any type of service we intend to hire or outsource (IT-related or otherwise), it is commonly understood that we will be confronted with a marketplace comprised of service providers of varying quality and reliability. Some may offer attractive rates and terms, but may have unproven business histories or highly proprietary environments. Others may have a solid business background, but may demand higher rates and less flexible terms. Others yet, may simply be insincere or temporary business ventures that unexpectedly disappear or are acquired within a short period of time. Back to the importance of getting educated. There is no greater danger to a business than approaching cloud computing adoption with ignorance. The magnitude of a failed adoption effort not only correspondingly impacts IT departments, but can actually regress a business to a point where it finds itself steps behind from where it was prior to the adoption—and, perhaps, even more steps behind competitors that have been successful at achieving their goals in the meantime. Cloud computing has much to offer but its roadmap is riddled with pitfalls, ambiguities, and mistruths. The best way to navigate this landscape is to chart each part of the journey by making educated decisions about how and to what extent your project should proceed. The scope of an adoption is equally important to its approach, and both of these aspects need to be determined by business requirements. Not by a product vendor, not by a cloud vendor, and not by self-proclaimed cloud experts. Your organization’s business goals must be fulfilled in a concrete and measurable manner with each completed phase of the adoption. This validates your scope, your approach, and the overall direction of

the project. In other words, it keeps your project aligned. Gaining a vendor-neutral understanding of cloud computing from an industry perspective empowers you with the clarity necessary to determine what is factually cloud-related and what is not, as well as what is relevant to your business requirements and what is not. With this information you can establish criteria that will allow you to filter out the parts of the cloud computing product and service provider marketplaces to focus on what has the most potential to help you and your business to succeed. We developed this book to assist you with this goal. —Thomas Erl

1.1. Objectives of This Book This book is the result of more than two years of research and analysis of the commercial cloud computing industry, cloud computing vendor platforms, and further innovation and contributions made by cloud computing industry standards organizations and practitioners. The purpose of this book is to break down proven and mature cloud computing technologies and practices into a series of well-defined concepts, models, and technology mechanisms and architectures. The resulting chapters establish concrete, academic coverage of fundamental aspects of cloud computing concepts and technologies. The range of topics covered is documented using vendor-neutral terms and descriptions, carefully defined to ensure full alignment with the cloud computing industry as a whole.

1.2. What This Book Does Not Cover Due to the vendor-neutral basis of this book, it does not contain any significant coverage of cloud computing vendor products, services, or technologies. This book is complementary to other titles that provide product-specific coverage and to vendor product literature itself. If you are new to the commercial cloud computing landscape, you are encouraged to use this book as a starting point before proceeding to books and courses that are proprietary to vendor product lines.

1.3. Who This Book Is For This book is aimed at the following target audience:

• IT practitioners and professionals who require vendor-neutral coverage of cloud computing technologies, concepts, mechanisms, and models

• IT managers and decision makers who seek clarity regarding the business and technological implications of cloud computing • professors and students and educational institutions that require well- researched and well-defined academic coverage of fundamental cloud computing topics • business managers who need to assess the potential economic gains and viability of adopting cloud computing resources • technology architects and developers who want to understand the different moving parts that comprise contemporary cloud platforms

1.4. How This Book Is Organized The book begins with Chapters 1 and 2 providing introductory content and background information for the case studies. All subsequent chapters are organized into the following parts:

• Part I: Fundamental Cloud Computing • Part II: Cloud Computing Mechanisms • Part III: Cloud Computing Architecture • Part IV: Working with Clouds • Part V: Appendices

Part I: Fundamental Cloud Computing The four chapters in this part cover introductory topics in preparation for all subsequent chapters. Note that Chapters 3 and 4 do not contain case study content. Chapter 3: Understanding Cloud Computing

Following a brief history of cloud computing and a discussion of business drivers and technology innovations, basic terminology and concepts are introduced, along with descriptions of common benefits and challenges of cloud computing adoption. Chapter 4: Fundamental Concepts and Models

Cloud delivery and cloud deployment models are discussed in detail, following sections that establish common cloud characteristics and roles and boundaries. Chapter 5: Cloud-Enabling Technology

Contemporary technologies that realize modern-day cloud computing platforms and innovations are discussed, including data centers, virtualization, and Web-

based technologies. Chapter 6: Fundamental Cloud Security