
Cloud computing is all the rage. "It's become the phrase du jour," says
Gartner senior analyst Ben Pring, echoing many of his peers. The
problem is that (as with Web 2.0) everyone seems to have a different
definition.As a metaphor for the Internet, "the cloud", but
when combined with "computing," the meaning gets bigger and fuzzier.
Some analysts and vendors define cloud computing narrowly as an updated
version of utility computing: basically virtual servers available over the Internet. Others go very broad, arguing anything you
consume outside the firewall is "in the cloud," including conventional
outsourcing.
Organizations need flexible IT environments that help reduce costs,
accelerate processes and simplify management. Cloud computing
transforms the traditional server infrastructure into a dynamic
environment that expands and reduces capacity depending on
requirements. A cloud computing environment that expands and reduces
capacity depending on requirements. A cloud computing environment
combines the resources of a group of serves over a network. This group
of servers is the cloud that provides access to resources on demand.
Adopting a cloud-computing strategy helps businesses conduct their core
business activities with greater efficiency and flexibility. It enables
greater utilization of existing hardware while also providing the
ability to handle peaks in usage. Thousands of virtual machines and
applications can be managed more easily using a cloud-like environment.
Cloud computing comes into focus only when you
think about what IT always needs: a way to increase capacity or add
capabilities on the fly without investing in new infrastructure,
training new personnel, or licensing new software. Cloud computing
encompasses any subscription-based or pay-per-use service that, in real
time over the Internet, extends IT's existing capabilities.
Cloud
computing is at an early stage, with a motley crew of providers large
and small delivering a slew of cloud-based services, from full-blown
applications to storage services to spam filtering. Yes, utility-style
infrastructure providers are part of the mix, but so are SAAS( Software As A Services),
providers such as Salesforce.com. Today, for the most part, IT must
plug into cloud-based services individually, but cloud computing
aggregators and integrators are already emerging.InfoWorld
talked to dozens of vendors, analysts, and IT customers to tease out
the various components of cloud computing. Based on those discussions,
here's a rough breakdown of what cloud computing is all about:
SAAS
This
type of cloud computing delivers a single application through the
browser to thousands of customers using a multitenant architecture. On
the customer side, it means no upfront investment in servers or
software licensing; on the provider side, with just one app to
maintain, costs are low compared to conventional hosting.
Salesforce.com is by far the best-known example among enterprise
applications, but SAAS is also common for HR apps and has even worked
its way up the food chain to ERP, with players such as Workday. And who
could have predicted the sudden rise of SAAS " desktop" applications, such as Windows Azure, Google Apps and Zoho Office?
Comparisons
Cloud computing is often confused with grid computing ("a form of distributed computing whereby a 'super and virtual computer' is composed of a cluster of networked, loosely coupled computers, acting in concert to perform very large tasks"),utility computing (the "packaging of computing resources, such as computation and storage, as a metered service similar to a traditional public utility such as electricity")and autonomic computing ("computer systems capable of self-management").
Indeed many cloud computing deployments as of 2009[update] depend on grids, have autonomic characteristics and bill like utilities — but cloud computing can be seen as a natural next step from the grid-utility model.Some successful cloud architectures have little or no centralised infrastructure or billing systems whatsoever, including peer-to-peer networks such as BitTorrent and Skytype and volunteer computing.
Characteristics
The customers engaging in cloud computing do not own the physical
infrastructure serving as host to the software platform in question.
Instead, they avoid capital expenditure by renting usage from a third-party provider. They consume resources as a services paying instead for only the resources they use. Many cloud-computing offerings have adopted the utility computing model, which is analogous to how traditional utilities like electricity are consumed, while others are billed on a subscription basis. Sharing "perishable and intangible" computing power among mulitiple tenants
can improve utilization rates, as servers are not left idle, which can
reduce costs significantly while increasing the speed of application
development. A side effect of this approach is that overall computer
usage rises dramatically as customers do not have to engineer for peak
load limits.
Adoption has been enabled by "increased high-speed bandwidth" which
makes it possible to receive the same response times from centralized
infrastructure at other sites.
Companies
IBM, Microsoft, Amazon, Sun Microsystems, Google and Yahoo are some of the major cloud computing service providers. It is being adopted by individual users through large enterprises.
Legal issues
In March 2007, Dell applied to trademark the term "cloud computing"(U.S. Trademark 77,139,082) in theUnited States. The "Notice of Allowance" it received in July 2008 was canceled on August 6, resulting in a formal rejection of the trademark application less than a week later.
On September 30, 2008,USPTO issued a "Notice of Allowance" to CGactive LLC for "CloudOS". A cloud operating system is a generic operating system that "manage[s] the relationship between software inside the computer and on the Web", such as Microsoft Azure.
In November 2007, the Free Software Foundation released the Affero General Public License, a version of GPLv3 designed to close a perceived legal loophole associated with Free software designed to be run over a network, particularly SAAS. An application service provider is required to release any changes they make to Affero GPL open source code.
In early April of 2009, the FBI raided a data center in Texas. As
part of an ongoing investigation, they had a search warrant allowing
them to seize a particular cabinet of equipment. Unfortunately, the
hardware in that cabinet contained data for multiple companies, in
addition to the one involved in the investigation. The removal of their
data caused at least one of these companies to be unable to operate,
and the court denied their attempt to get their data back, although the
FBI did offer to copy it to blank tapes. This same type of co-location
of data for multiple entities on the same hardware could be a potential
risk and legal issue for companies considering hosting data or
applications in the cloud.
Types of Cloud Computing
- Public Cloud Computing
- Hybrid Cloud Computing
- Private Cloud Computing
References:
Wikipedia
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