Happy New Year! I am looking forward to the year of 2012.
Lately, I have been involved in Cloud Computing forums and I have been reading articles on Cloud Computing. I even took up a 5-day course on Cloud Computing in order to prepare myself for the inevitable. Yes, Cloud Computing is here to stay, but we joke about it, don’t we? I think the fun word of Cloud Computing is “cloudy“, which is indeed very true.
As I ingest more and more information about Cloud Computing, the definition of how different people has different perspective or opinion about Cloud Computing has never been “cloudier“. It is fuzzy, hazy, and confusing. And in the forums, many were saying that virtualization is Cloud Computing. What do you think?
I found that one definition of Cloud Computing very definitive, yet simple. This definition comes from the National Institute of Standards and Technology (NIST) of the US Department of Commerce. In its publication #800145, NIST defines Cloud Computing to have the following 5 essential characteristics (duplicated in verbatim):
- 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 provider.
- 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, tablets, laptops, and workstations).
- 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 include storage, processing, memory, and network bandwidth.
- Rapid elasticity. Capabilities can be elastically provisioned and released, in some cases automatically, to scale rapidly outward and inward commensurate with demand. To the consumer, the capabilities available for provisioning often appear to be unlimited and can be appropriated in any quantity at any time.
- Measured service. Cloud systems automatically control and optimize resource use by leveraging a metering capability1 at some level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth, and active user accounts). Resource usage can be monitored, controlled, and reported, providing transparency for both the provider and consumer of the utilized service.
The 5 essential characteristics are very important in determining whether Virtualization = Cloud Computing, and I know there are a lot of people out there that says that Virtualization equates Cloud Computing. Let’s see the table below:
Some readers might argue about the “YES” or “NO” in the above comparison, but I do not want to dwell on the matter. Yes, I believe that many of these things are doable in their own right but with different level of complexity and costs. The objective is to settle the arguments and confusions of Cloud Computing, accept some definitive terms and move on.
As you can see from the table above, Virtualization does not equate to Cloud Computing. We can say that Virtualization enables Cloud Computing to happen. It is the pre-cursor to Cloud Computing.
In Cloud Computing, there are different Service Models. NIST defines 3 different Service Models. They are:
- Software as a Service (SaaS). The capability provided to the consumer is to use the provider’s applications running on a cloud infrastructure2. The applications are accessible from various client devices through either a thin client interface, such as a web browser (e.g., web-based email), or a program interface. The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, storage, or even individual application capabilities, with the possible exception of limited user-specific application configuration settings.
- Platform as a Service (PaaS). The capability provided to the consumer is to deploy onto the cloud infrastructure consumer-created or acquired applications created using programming languages, libraries, services, and tools supported by the provider.3 The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, or storage, but has control over the deployed applications and possibly configuration settings for the application-hosting environment.
- Infrastructure as a Service (IaaS). The capability provided to the consumer is to provision processing, storage, networks, and other fundamental computing resources where the consumer is able to deploy and run arbitrary software, which can include operating systems and applications. The consumer does not manage or control the underlying cloud infrastructure but has control over operating systems, storage, and deployed applications; and possibly limited control of select networking components (e.g., host firewalls).
And NIST went on to define the Deployment Models of Cloud Computing as listed below:
- Private cloud. The cloud infrastructure is provisioned for exclusive use by a single organization comprising multiple consumers (e.g., business units). It may be owned, managed, and operated by the organization, a third party, or some combination of them, and it may exist on or off premises.
- Community cloud. The cloud infrastructure is provisioned for exclusive use by a specific community of consumers from organizations that have shared concerns (e.g., mission, security requirements, policy, and compliance considerations). It may be owned, managed, and operated by one or more of the organizations in the community, a third party, or some combination of them, and it may exist on or off premises.
- Public cloud. The cloud infrastructure is provisioned for open use by the general public. It may be owned, managed, and operated by a business, academic, or government organization, or some combination of them. It exists on the premises of the cloud provider.
- Hybrid cloud. The cloud infrastructure is a composition of two or more distinct cloud infrastructures (private, community, or public) that remain unique entities, but are bound together by standardized or proprietary technology that enables data and application portability (e.g., cloud bursting for load balancing between clouds).
There! Cloud Computing by the definition of NIST. It is simple, easily understood and most importantly, it give us the context of what we are looking for in the sea of confusion. Here’s the link to NIST’s PDF.
We can argue till the cows come home but it is best to stick to a simple definition of Cloud Computing and focus on other more important aspects of the cloud.
I hope to share more of my Cloud Computing experience with you and storage will have a big part to play in it.
