Cloud Computing 101:

Defining Cloud Computing

Defining Cloud Computing

Many definitions of cloud computing are available. Unfortunately, many (perhaps most) are self-serving,

targeted by vendors, service providers, consultants, and other vested interests to advance their own

commercial agendas. Enterprises especially should be wary of these definitions.

Fortunately, there are independent organizations that are tasked with exactly this – such as the U.S. National

Institute for Standards and Technology (NIST).

The U.S. government and millions of people around the world trust NIST to define the official time for all of

the United States1, to calibrate instruments for NASA, and to supply industry, academia, government, and

other users with over 1100 reference materials2.

The U.S. government is using NIST to define cloud computing, as noted by U.S. Federal CIO, Vivek

Kundra3. Indeed, Kundra has strongly indicated that the U.S. government will be one of the strongest, largest,

and most important proponents, providers, and consumers of cloud computing (such as with sites like

apps.gov and data.gov). Other levels of government – and even other nations – will almost certainly follow

their lead, and the NIST definition of cloud computing.

NIST has a very elegant definition that is:

•

Intelligent – it has been through (to date) 15 iterations, and has accepted input from many of the

brightest minds in cloud computing

•

Independent – it is from a mature, well-established, and exceptionally talented U.S. government

agency, which is both apolitical and science-based

•

Commercially agnostic – it does not specify that anyone needs to be making money, nor does it

preclude it, allowing cloud to be B2B, B2C, B2G, G2C, or any other model

•

Accommodating – all established cloud vendors fit into this definition, as well as private and

government models.

•

Clear – it is not full of jargon or “cloudwash,” but rather has easily understood, plain English

concepts that are not only unambiguous but also usefully prescriptive

•

Comprehensive – it includes all the important core concepts such as self-service, resource pooling,

rapid elasticity, accessibility, usage costing, multiple use cases, and more

•

SMART – it does not try to create anything exceptional or outrageous, but does define a set of

Specific, Measurable, Achievable, Relevant, and Timely objectives

Given these antecedents, ENTERPRISE MANAGEMENT ASSOCIATES® (EMA™) analysts believe that

yet another new definition is neither helpful nor necessary, and have therefore adopted the NIST definition

of cloud computing as follows.

100-in-the-cloud/, retrieved 12/07/2009

EMA ADVISORY NOTE

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2

3

See http://time.gov

NIST Standard Reference Materials, http://ts.nist.gov/measurementservices/referencematerials/index.cfm

Kundra, V., The White House Blog, ‘Streaming at 1:00: In the Cloud’, http://www.whitehouse.gov/blog/streaming-at-

Cloud Computing 101:

Defining Cloud Computing

Core Definition of Cloud Computing

NIST defines cloud computing as4:

“a model for enabling convenient, on-demand network access to a shared pool of configurable

computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly

provisioned and released with minimal management effort or service provider interaction.”

Note that while this requires computing services must be accessible across a network, it does not necessarily

require that they be accessible across the public Internet. However, it does require resources be pooled and

reusable, rapidly reconfigurable, and accessible with little manual intervention from IT staff.

Essential Characteristics

NIST includes in its definition five essential characteristics:

On-Demand Self-Service

“A consumer can unilaterally provision computing capabilities, such as server time and network

storage, as needed automatically without requiring human interaction with each service’s provider.”

Note that this is really two characteristics – it must be on-demand, and also self-service. Self-service implies

user-accessible resources and/or services, but does not necessarily mean immediacy. On-demand, however,

almost certainly requires near-immediate resource or service provisioning, and by inference a reasonably

sophisticated level of IT automation.

Broad Network Access

“Capabilities are available over the network and accessed through standard mechanisms that promote

use by heterogeneous thin or thick client platforms (e.g., mobile phones, laptops, and PDAs).”

As noted, cloud services must be networked, but again does not require Internet access. Access to those

services must be somehow standardized, but the standardization is left open to include, for example, a Web

services interface, a “standard” API/SDK, an HTTP interface, etc. The key here is not necessarily the type of

access, but that it is transportable across multiple platforms, including especially mobile platforms.

Resource Pooling

“The provider’s computing resources are pooled to serve multiple consumers using a multi-tenant

model, with different physical and virtual resources dynamically assigned and reassigned according to

consumer demand. There is a sense of location independence in that the customer generally has no

control or knowledge over the exact location of the provided resources but may be able to specify

location at a higher level of abstraction (e.g., country, state, or datacenter). Examples of resources

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include storage, processing, memory, network bandwidth, and virtual machines.”

NIST, Cloud Computing, http://csrc.nist.gov/groups/SNS/cloud-computing/ , retrieved 12/17/2009