Q&A: The Many Aspects of Private Cloud Computing

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1 Research Publication Date: 22 October 2009 ID Number: G Q&A: The Many Aspects of Private Cloud Computing Thomas J. Bittman Cloud computing is at the Peak of Inflated Expectations on the Gartner "Hype Cycle for Cloud Computing, 2009." The idea of private cloud computing is appealing, extremely confusing, and very misleading. We discuss common questions and answers. 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.

2 ANALYSIS What is private cloud computing? Gartner defines private cloud computing as: "A style of computing where scalable and elastic ITenabled capabilities are delivered as a service to internal customers using Internet technologies." In practice, a private cloud-computing service behaves just like an external (public) cloudcomputing service, except the implementation is internal to an organization, and access is limited to internal users. However, private cloud computing still requires a service interface that gives it a similar look and feel to the end user of an external service. The implementation, which is hidden from the user, still needs to be scalable, shared, automated and elastic (see "Private Cloud Computing: The Steppingstone to the Cloud"). What are the benefits of private cloud computing? Like public cloud services, private cloud services are easy for customers to start using (a low barrier to entry) startup time for the user of the service is short, and the process is straightforward and does not require implementation details. It is scalable so that the end user does not perceive limits in physical scaling, and it is elastic that is, growing and shrinking with usage. The end user pays for a private cloud service based on usage (or the service is subsidized for example, by advertisers), and is not based on fixed implementation costs. Finally, a private cloud service enables an easier migration to public cloud services at some point in the future. Is private cloud computing just a well-run data center? While this is a common question, it is comparing the wrong things. Private cloud computing is a style of architecture and delivery of a service. A well-run data center has many services that may include private cloud services or may not. The only time these two can be equated is for a data center (such as Google) that is designed around a very small number of services. Large, well-run IT organizations eventually will manage and deliver private cloud services (cost-effectively), source some services from the public cloud, and retain well-run but noncloud architectures for services not suited to the cloud-computing style (for example, services that are business differentiators, and possibly changing often as the business changes). Why build a private cloud service rather than buy public cloud services? While cloud computing holds tremendous promise, only a limited number of services and service levels are available today. Most enterprises manage many services, most of which cannot be addressed by today's external offerings. Some cloud services have a business model predicated on very high volume, consumers or advertising (such as Google), rather than on enterprise requirements. Services that have specific performance, availability, security, regulatory or legal requirements may not be served by public cloud services for some time or ever. The current situation is that: The technologies needed to develop robust public cloud offerings are often immature or do not yet exist. The ability to move virtual machines to and from service providers is just becoming a reality. Pricing and licensing models for public cloud computing are immature. Publication Date: 22 October 2009/ID Number: G Page 2 of 6

3 The cloud service provider market also is extremely immature, and will result in new providers emerging quickly, while others fail. Remediation for failed services is another immature area, and interoperability standards to make recovery from a failed provider possible don't yet exist. For all of these reasons, there will be many cases where private cloud services make good business sense, at least until public cloud services mature. Is private cloud computing right for enterprises of all sizes? No. A key benefit and rationale of cloud computing is having shared resources and economies of scale. Small businesses that do not have enough resources to share will not be able to derive the cost savings benefit from a private cloud-computing style. They will usually be better served by focusing on operational improvements and consolidation, and leveraging external cloud services as soon as they mature (this is especially true for startups). However, "economies of scale" is a relative term, and there will be many examples of midsize businesses (with hundreds of servers, for example) that will be able to build a business case for private cloud computing, at least in the near term (see "Cloud Computing Doesn't Require Massive Providers"). The business case will always depend on the cost, the return on the investment, and an evaluation of the maturity of public cloud service offerings. Are there cloud-computing styles between fully public and fully private? Of course, and these "hybrid" styles will probably be the most common (see "The Spectrum of Public-to-Private Cloud Computing"). Two dimensions to describe the range of options between fully public and fully private cloud computing are access (Is it limited, or can anyone access the service?) and ownership/control (Do users control and own the implementation, or is it completely controlled and owned by a third party?). Impressive examples include the virtual private cloud (where a third party limits access to certain IT resources to a single user), a targeted industry service (where a third party provides a service to a limited and possibly proprietary market), a community cloud (as defined by the U.S. National Institute of Standards and Technology [NIST] as a cloud infrastructure shared by several organizations to support a specific community) and a supply-chain cloud service (where an enterprise opens up its cloud services to specific business partners). What are examples of private cloud services? There are examples of actual private cloud services, and there are examples of the term being abused to describe something else. Many early private cloud services are custom-built by Type A technology adopters, where an agile compute capability, for example, gives them a competitive market edge. Many enterprises may have shared services that fit the definition in many ways, but don't really have a service-oriented (or self-service) interface, or are only partially automated in implementation. The most promising technologies being used as a basis for private cloud services are virtual servers, virtual storage and virtual networking, together with the automation to make them behave like an infrastructure service. In almost all cases, these are not yet "private cloud" services. As improved automation tools and self-service interfaces emerge, there will be a rapid growth in private cloud services at the infrastructure level. A prominent example of private cloud services using virtualization is self-service development and test environments (for example, using VMware's Lab Manager). Publication Date: 22 October 2009/ID Number: G Page 3 of 6

4 Will private cloud services exist at all levels of the IT stack? Theoretically, yes; but they will be heavily skewed toward system infrastructure services (storage, servers, networking and desktops). Application platform services, and especially application services (software as a service [SaaS] in the cloud), will emerge and mature faster than system infrastructure services that meet all service needs. Enterprises will tend to deploy traditional applications on private cloud system infrastructure services. However, very large enterprises (such as the federal government) may build SaaS solutions for government-specific custom applications shared between government agencies. But these will be the exceptions. What are the basic elements of a private cloud service? There are four key elements to a private cloud service. A private cloud service has a self-service interface (a graphical user interface or an application programming interface) that also presents cost estimates and actuals (metered use). Below the interface, service delivery is managed through automation, and metered use is tracked. Operational processes to support the service are automated as much as possible, reducing the need for manual intervention. And IT resources are pooled and reallocatable in some way (usually through some virtualization technique), ensuring shared and efficient use of resources. How does private cloud computing compare with Gartner's realtime infrastructure? Gartner introduced the real-time infrastructure (RTI) vision in 2001, prior to there being similar vendor strategies such as On Demand (IBM), Adaptive Enterprise (HP) and Dynamic Systems (Microsoft). An RTI architecture is the foundation of private cloud computing for an infrastructure (a policy-based interface producing results that meet service needs, with IT resources automatically provisioned, optimized and maintained to meet those needs). An RTI can support several private cloud services; however, it can also support services that are not necessarily private cloud services (for example, they may not do usage metering, or they may not be entirely self-service). RTI does not equal "private cloud," but RTI and RTI concepts will be required foundations for cloud and private cloud services. RTI remains as Gartner's vision for the architecture of infrastructure and operations. Cloud computing, however, is the vision for the style of various services that will leverage RTI architectures, whether those services are public or private. How does a company start with private cloud computing? Rather than first buying technologies to build a "private cloud," a company needs to understand the services the company provides, its service-level requirements and its current service costs. Not every service is appropriate for the cloud-computing style. Every service is different, and companies should evaluate public cloud offerings to determine if a sufficient service already exists, or will exist soon. Private cloud services should be built if there is sufficient return on investment to warrant building a service, rather than waiting and buying it as a public cloud service later. Will every IT service become a cloud service private or public? No. The cloud-computing style is ideal for services that are relatively standardized, common among other businesses, not business differentiators, not customized and separate from the end customers. The goal for these services is to eliminate unneeded customizations, and make them Publication Date: 22 October 2009/ID Number: G Page 4 of 6

5 more independent from the business, with a standard interface that abstracts the details of the service from the business the cloud-computing style. There are other services that IT organizations provide that might be business differentiators, that might change based on business change, and that tend to be heavily customized. The goal for these services is to improve integration and intimacy between the service and the business, and to enable dynamic change. These services are not suited for cloud computing, although they may leverage private or public cloud services deeper in their supply chain (for example, for storage backup). How will private cloud services evolve? At a high level, a private cloud service will go through three stages: An early private cloud service will tend to be stand-alone, monolithic and customized due to lack of packaged technologies. Over time, more private cloud services will be built using packaged technologies and add-ons. Private cloud services will become more shared and layered in a large enterprise (two private cloud services using a lower-level private cloud service, for example). As technologies become more common and standards improve, hybrid models will become possible, where a private cloud can federate with public cloud services (for example, "overdrafting" of server resources during peaks). During this stage, enterprises will have a fluid choice of staying fully private, going fully public, or retaining a hybrid model. RECOMMENDED READING "Private Cloud Computing: The Steppingstone to the Cloud" "Five Refining Attributes of Public and Private Cloud Computing" "The Spectrum of Public-to-Private Cloud Computing" "Cloud Computing Doesn't Require Massive Providers" Publication Date: 22 October 2009/ID Number: G Page 5 of 6

6 REGIONAL HEADQUARTERS Corporate Headquarters 56 Top Gallant Road Stamford, CT U.S.A European Headquarters Tamesis The Glanty Egham Surrey, TW20 9AW UNITED KINGDOM Asia/Pacific Headquarters Gartner Australasia Pty. Ltd. Level 9, 141 Walker Street North Sydney New South Wales 2060 AUSTRALIA Japan Headquarters Gartner Japan Ltd. Aobadai Hills, 6F 7-7, Aobadai, 4-chome Meguro-ku, Tokyo JAPAN Latin America Headquarters Gartner do Brazil Av. das Nações Unidas, andar World Trade Center São Paulo SP BRAZIL Publication Date: 22 October 2009/ID Number: G Page 6 of 6