Research Publication Date: 4 June 2009 ID Number: G00168582 The What, Why and When of Cloud Computing David Mitchell Smith, Daryl C. Plummer, David W. Cearley Cloud computing continues to gain visibility. Our Special Report examines the realities and risks of cloud. Reproduction and distribution of this publication in any form without prior written permission is forbidden. The information contained herein has been obtained from sources believed to be reliable. Gartner disclaims all warranties as to the accuracy, completeness or adequacy of such information. Although Gartner's research may discuss legal issues related to the information technology business, Gartner does not provide legal advice or services and its research should not be construed or used as such. Gartner shall have no liability for errors, omissions or inadequacies in the information contained herein or for interpretations thereof. The opinions expressed herein are subject to change without notice.
ANALYSIS Awareness of cloud computing continues to increase, as does the subsequent confusion and a gradual understanding of the inevitability of many of the concepts. As cloud begins to move beyond the pure hype stage and into the beginning of mainstream adoption, the questions we are getting on the subject are changing. This Special Report illustrates the evolution of cloud computing. We are working on a Hype Cycle that explores many angles of cloud computing, as it is simplistic to only look at the high-level term itself in terms of hype. As aspects of the cloud begin to move into mainstream adoption, there will be doubts and disillusionment caused by a misunderstanding, overestimation and underestimation, misuse and miscommunication with regard to cloud computing. This is evident in the types of questions that we are getting from our clients. These questions range from "what is cloud computing?" (a reasonable question) to "how do I turn my data center into a cloud." Gartner makes the attempt to begin to not only answer the reasonable questions, but to also position the unreasonable ones into a context that can generate value for those seeking answers. This Special Report contains 29 pieces of research compiled by more than 20 analysts. In this research, we begin to establish what people should do about cloud computing and how it might help, or hurt, them. As such, our research on cloud computing continues to be multidisciplinary and wide-ranging. By its very nature, the subject is broad, exposing risks and opportunities throughout both the IT and the business worlds. The most common questions we get about cloud computing fall primarily into three buckets: "what, why, and when." What Is It? "What is cloud computing?" is the question that never seems to go away. No matter how much people try, a universally agreed-on definition remains elusive. However, Gartner's definition of cloud computing (put forth in "Five Refining Attributes of Public and Private Cloud Computing") remains the most consistently unchanged and explainable definition we have seen. But what we find to be most confusing for those approaching the subject of cloud computing is not, in fact, the definition. It is, instead, the words people use to describe the phenomenon. To help alleviate this concern, "Using the Right Words Will Ease Cloud Computing Confusion" provides some guidance that can help those discussing cloud computing to develop a consistent framework of understanding. However, a further challenge to a common understanding around the concept of cloud computing comes from the fact that different constituencies view the cloud from different perspectives. "Cloud Computing Constituencies and Inconsistent Perspectives" explores this issue in some detail. At a high level, understanding the relationship of global class and cloud (see "Global Class: The Inspiration for Cloud Computing") is also a good foundation for understanding. "Comparing Cloud Computing and Infrastructure Utility" deals with the differences and synergies between these two concepts. There are many ways to "slice" into cloud computing. A "horizontal" slicing along the lines of public vs. private and hybrid deployment models is one way. "The Spectrum of Public-to-Private Cloud Computing" takes into account the nuances introduced by the "private cloud" concept. Another way to slice it is "vertically," along the lines of somewhat-traditional layering approaches, but adjusted to meet the realities of the cloud. "Key Attributes Distinguish Cloud Computing Services" and "Cloud Computing Services: A Model for Categorizing and Characterizing Capabilities Delivered From the Cloud" introduce a taxonomy for looking at the various layers of Publication Date: 4 June 2009/ID Number: G00168582 Page 2 of 5
cloud computing. With this research and more (such as "Cloud Computing for Government Is Cloudy"), the "what" of cloud computing becomes more clear. Why Should I Consider It? We are often asked why enterprises are or should be considering cloud computing. Cloud provides two buckets of fundamentally dissimilar benefits. One (cost) is more evolutionary, and the other (capability) is more revolutionary. The first bucket, cost, is all about optimizing cost in positive ways. This often translates into a discussion of cost savings. Not surprisingly in today's economic climate, the desire to save money is part of many discussions. However, cloud computing does not always save money in fact it can drive cost up if it is used simply to replace on-premises work with an exact duplicate of that work in the cloud. Knowing when to redesign or when to avoid using cost savings as a justification for cloud computing is critical. Cost considerations are explored in "Save Money Now with Hosted and 'Cloud' Infrastructure" and "Cloud Storage: Benefits, Risks and Cost Considerations," Related system infrastructure research (dealing with the economies of scale, management, operations, and so on), including "How to Select a Cloud Computing Infrastructure Provider," "How to Ensure Infrastructure Providers Can Deliver Service Excellence" and "Using ITSM to Facilitate the Adoption of External Cloud-Computing Services" help round out the issues in this area. The second bucket, capability, is about the ability to do things that otherwise couldn't be done. Discussions focus on the desire to create new solutions that were not technically or economically feasible without the use of cloud services. These may include developing new applications. One of the main characteristics of cloud computing that enables these capabilities is elasticity, explored in detail in "Three Levels of Elasticity for Cloud Computing Expand Provider Options" and "Cloud Services Elasticity Is About Capacity, Not Just Load." A particular use of elasticity known as "cloudbursting" is described in "Anatomy of a Cloud 'Capacity Overdraft': One Way Elasticity Happens." Often, scenarios involving new capabilities require new design, development and integration methods. Application platform as a service (APaaS) is a major component of a new market (introduced in "Application Infrastructure for Cloud Computing: An Emerging Market") and described in detail in "APaaS: A Step to a 'Killer App' for Cloud Computing?" as a great example of the new capabilities and their potential. This market has many sub-components, some of which are described in "Portals in the Cloud Will Take Five Forms," "Managing Business Processes 'In the Cloud' and Outside the Cloud" and "Global-Class Persistence for Cloud-Based Web Applications." Many vendors provide offerings in the application infrastructure space. Clear divisions are not always obvious so we explore competition as it happens, even when the comparisons are not direct (as in "On Apples, Oranges, Amazon and Google") and in a broader sense in "Who's Who in Cloud-Computing/SaaS Integration, Volume 1." When Should I Implement and When Will It Be Ready? Discussions about "when" center on when it makes sense to move to cloud services, given the objections (see "Top Five Cloud-Computing Adoption Inhibitors") and new opportunities (for example, as described in "Three Types of Cloud Brokerages Will Enhance Cloud Services") may change the equations around those decisions. What does the future hold? "After the Next Big Thing: The Consequences of a Cloud Computing Scenario" gives a glimpse into that future, while "Forecast: Sizing the Cloud; Understanding the Opportunities in Cloud Services" gives a more quantitative twist to that answer while utilizing the Publication Date: 4 June 2009/ID Number: G00168582 Page 3 of 5
taxonomy introduced. Lastly, we outline some of our plans for future cloud research in "Key Issues for Cloud Computing, 2009." Conclusion Although confusion continues and shows no signs of abating, we remain committed to cutting through the hype, as well as illustrating opportunities for consumers and providers to take advantage of the cloud. This Special Report should serve as a useful repository of Gartner's current thinking and a starting point for discussions that get to the heart of your individual issues. Although cloud computing research does not stop here, this report is intended to begin to provide the answers to the questions of what a company or person should do next. From small beginnings, big things can grow. "After the Next Big Thing: The Consequences of a Cloud Computing Scenario" "Anatomy of a Cloud 'Capacity Overdraft': One Way Elasticity Happens" "APaaS: A Step to a 'Killer App' for Cloud Computing?" "Application Infrastructure for Cloud Computing: An Emerging Market" "Cloud Computing Constituencies and Inconsistent Perspectives" "Cloud Computing for Government Is Cloudy" "Cloud Computing Services: A Model for Categorizing and Characterizing Capabilities Delivered From the Cloud" "Cloud Services Elasticity Is About Capacity, Not Just Load" "Cloud Storage: Benefits, Risks and Cost Considerations" "Comparing Cloud Computing and Infrastructure Utility" "Five Refining Attributes of Public and Private Cloud Computing" "Forecast: Sizing the Cloud; Understanding the Opportunities in Cloud Services" "Global Class: The Inspiration for Cloud Computing" "Global-Class Persistence for Cloud-Based Web Applications" "How to Ensure Infrastructure Providers Can Deliver Service Excellence" "How to Select a Cloud Computing Infrastructure Provider" "Key Attributes Distinguish Cloud Computing Services" "Key Issues for Cloud Computing" "Managing Business Processes 'In the Cloud' and Outside the Cloud" "On Apples, Oranges, Amazon and Google" "Portals in the Cloud Will Take Five Forms" "Save Money Now With Hosted and 'Cloud' Infrastructure" "The Spectrum of Public to-private Cloud Computing" Publication Date: 4 June 2009/ID Number: G00168582 Page 4 of 5
"Three Levels of Elasticity for Cloud Computing Expand Provider Options" "Three Types of Cloud Brokerages Will Enhance Cloud Services" "Top Five Cloud-Computing Adoption Inhibitors" "Using ITSM to Facilitate the Adoption of External Cloud-Computing Services" "Using the Right Words Will Ease Cloud Computing Confusion" "Who's Who in Cloud-Computing/SaaS Integration, Volume 1" REGIONAL HEADQUARTERS Corporate Headquarters 56 Top Gallant Road Stamford, CT 06902-7700 U.S.A. +1 203 964 0096 European Headquarters Tamesis The Glanty Egham Surrey, TW20 9AW UNITED KINGDOM +44 1784 431611 Asia/Pacific Headquarters Gartner Australasia Pty. Ltd. Level 9, 141 Walker Street North Sydney New South Wales 2060 AUSTRALIA +61 2 9459 4600 Japan Headquarters Gartner Japan Ltd. Aobadai Hills, 6F 7-7, Aobadai, 4-chome Meguro-ku, Tokyo 153-0042 JAPAN +81 3 3481 3670 Latin America Headquarters Gartner do Brazil Av. das Nações Unidas, 12551 9 andar World Trade Center 04578-903 São Paulo SP BRAZIL +55 11 3443 1509 Publication Date: 4 June 2009/ID Number: G00168582 Page 5 of 5