Introduction Cloud computing is a subscription-based service where you can obtain networked storage space and computer resources. One way to think of cloud computing is to consider your experience with email. Your email client, if it is Yahoo!, Gmail, Hotmail, and so on, takes care of housing all of the hardware and software necessary to support your personal email account.
When you want to access your email you open your web browser, go to the email client, and log in. The most important part of the equation is having internet access. Your email is not housed on your physical computer; you access it through an internet connection, and you can access it anywhere.
If you are on a trip, at work, or down the street getting coffee, you can check your email as long as you have access to the internet. Your email is different than software installed on your computer, such as a word processing program. When you create a document using word processing software, that document stays on the device you used to make it unless you physically move it. An email client is similar to how cloud computing works. Except instead of accessing just your email, you can choose what information you have access to within the cloud. History
The origin of the term cloud computing is obscure, but it appears to derive from the practice of using drawings of stylized clouds to denote networks in diagrams of computing and communications systems. The word cloud is used as a metaphor for the Internet, based on the standardized use of a cloud-like shape to denote a network on telephony schematics and later to depict the Internet in computer network diagrams as an abstraction of the underlying infrastructure it represents. The cloud symbol was used to represent the Internet as early as 1994. The underlying concept of cloud computing dates back to the 1950s, when large-scale mainframe became available in academic and corporations, accessible via thin clients / terminal computers.
Because it was costly to buy a mainframe, it became important to find ways to get the greatest return on the investment in them, allowing multiple users to share both the physical access to the computer from multiple terminals as well as to share the CPU time, eliminating periods of inactivity, which became known in the industry as time-sharing. In the 1990s, telecommunications companies, who previously offered primarily dedicated point-to-point data circuits, began offering virtual private network (VPN) services with comparable quality of service but at a much lower cost.
By switching traffic to balance utilization as they saw fit, they were able to utilize their overall network bandwidth more effectively. The cloud symbol was used to denote the demarcation point between that which was the responsibility of the provider and that which was the responsibility of the users. Cloud computing extends this boundary to cover servers as well as the network infrastructure. A
s computers became more prevalent, scientists and technologists explored ways to make large-scale computing power available to more users through time sharing, experimenting with algorithms to provide the optimal use of the infrastructure, platform and applications with prioritized access to the CPU and efficiency for the end users. John McCarthy opined in the 1960s that "computation may someday be organized as a public utility."
Almost all the modern-day characteristics of cloud computing (elastic provision, provided as a utility, online, illusion of infinite supply), the comparison to the electricity industry and the use of public, private, government, and community forms, were thoroughly explored in Douglas Parkhill's 1966 book, The Challenge of the Computer Utility.
Other scholars have shown that cloud computing's roots go all the way back to the 1950s when scientist Herb Grosch (the author of Grosch's law) postulated that the entire world would operate on dumb terminals powered by about 15 large data centers. Due to the expense of these powerful computers, many corporations and other entities could avail themselves of computing capability through time sharing and several organizations, such as GE's GEISCO, IBM subsidiary
The Service Bureau Corporation (SBC, founded in 1957), Tymshare (founded in 1966), National CSS (founded in 1967 and bought by Dun & Bradstreet in 1979), Dial Data (bought by Tymshare in 1968), and Bolt, Beranek and Newman (BBN) marketed time sharing as a commercial venture. The development of the Internet from being document centric via semantic data towards more and more services was described as "Dynamic Web". This contribution focused in particular in the need for better meta-data able to describe not only implementation details but also conceptual details of model-based applications.
The ubiquitous availability of high-capacity networks, low-cost computers and storage devices as well as the widespread adoption of hardware virtualization, service-oriented architecture, autonomic, and utility computing have led to a tremendous growth in cloud computing. After the dot-com bubble, Amazon played a key role in the development of cloud computing by modernizing their data centers, which, like most computer networks, were using as little as 10% of their capacity at any one time, just to leave room for occasional spikes.
Having found that the new cloud architecture resulted in significant internal efficiency improvements whereby small, fast-moving "two-pizza teams" (teams small enough to be fed with two pizzas) could add new features faster and more easily, Amazon initiated a new product development effort to provide cloud computing to external customers, and launched Amazon Web Service (AWS) on a utility computing basis in 2006.
In early 2008, Eucalyptus became the first open-source, AWS API-compatible platform for deploying private clouds. In early 2008, OpenNebula, enhanced in the RESERVOIR European Commission-funded project, became the first open-source software for deploying private and hybrid clouds, and for the federation of clouds. In the same year, efforts were focused on providing quality of service guarantees (as required by real-time interactive applications) to cloud-based infrastructures, in the framework of the IRMOS European Commission-funded project, resulting to a real-time cloud environment.
By mid-2008, Gartner saw an opportunity for cloud computing "to shape the relationship among consumers of IT services, those who use IT services and those who sell them" and observed that "organizations are switching from company-owned hardware and software assets to per-use service-based models" so that the "projected shift to computing... will result in dramatic growth in IT products in some areas and significant reductions in other areas." On March 1, 2011, IBM announced the Smarter Computing framework to support Smarter Planet. Among the various components of the Smarter Computing foundation, cloud computing is a critical piece. Definitions
Cloud computing is the use of computing resources (hardware and software) that are delivered as a service over a network (typically the Internet). The name comes from the use of a cloud-shaped symbol as an abstraction for the complex infrastructure it contains in system diagrams. Cloud computing entrusts remote services with a user's data, software and computation.
There are many types of public cloud computing: •Infrastructure as a service (IaaS) •Platform as a service (PaaS) •Software as a service (SaaS) •Network as a service (NaaS) •Storage as a service (STaaS) •Security as a service (SECaaS) •Data as a service (DaaS) •Database as a service (DBaaS) •Test environment as a service (TEaaS) •Desktop virtualization •API as a service (APIaaS) •Backend as a service (BaaS) In the business model using software as a service, users are provided access to application software and databases. The cloud providers manage the infrastructure and platforms on which the applications run. SaaS is sometimes referred to as “on-demand software” and is usually priced on a pay-per-use basis. SaaS providers generally price applications using a subscription fee. Proponents claim that the SaaS allows a business the potential to reduce IT operational costs by outsourcing hardware and software maintenance and support to the cloud provider.
This enables the business to reallocate IT operations costs away from hardware/software spending and personnel expenses, towards meeting other IT goals. In addition, with applications hosted centrally, updates can be released without the need for users to install new software. One drawback of SaaS is that the users' data are stored on the cloud provider’s server. As a result, there could be unauthorized access to the data. E
nd users access cloud-based applications through a web browser or a light-weight desktop or mobile app while the business software and user's data are stored on servers at a remote location. roponents claim that cloud computing allows enterprises to get their applications up and running faster, with improved manageability and less maintenance, and enables IT to more rapidly adjust resources to meet fluctuating and unpredictable business demand. Cloud computing relies on sharing of resources to achieve coherence and economies of scale similar to a utility (like the electricity grid) over a network. At the foundation of cloud computing is the broader concept of converged infrastructure and shared services. Process
Applications The first is backup and recovery. Clearly, it is more efficient to make use of a cloud computing service to provide backup and recovery. Investing in a ton of duplicate infrastructure makes no sense. The second area is also pretty obvious. Software-as-a-Service (SaaS) is a form of cloud computing. Whether it's a payroll or customer relationship management (CRM) system, there are times when delivering those applications as a service makes sense. A lot of times, the internal IT organization does not have the expertise required to run a particular application or that application may not be strategic enough to justify committing limited IT resources to managing it.
There's no doubt there are potential security issues when it comes to cloud computing, but like all things in life the risks need to be weighed against the potential benefits.\ The next big thing in cloud computing will be more specialized application services. A lot of IT organization can't afford to invest in supercomputer-class infrastructure. Yet, the business could benefit from access to some pretty compute-intensive analytic applications. An interesting example of how one of these services might work is WolframAlpha, a query service based on a new model for doing sophisticated searches and calculations.
WolframAlpha counts a company called Xignite, a provider of financial information via standard Web services protocols, as one of its partners. On a practical level, there are far too many existing applications that can't be cost-effectively rewritten to run on a public cloud. On a strategic level, there are hundreds of applications that are too fundamental to the business to run on a cloud. And finally, there are a number of legal and regulatory issues that may not make cloud computing practical in some cases. Advantages of Cloud Computing
1.Cost Efficient 2.Almost Unlimited Storage 3.Backup and Recovery 4.Easy Access to Information 5.Quick Deployment Disadvantages of Cloud Computing 1.Possible downtime. 2.Security issues. 3.Cost 4.Inflexibility 5.Lack of support.
Security The information housed on the cloud is often seen as valuable to individuals with malicious intent. There is a lot of personal information and potentially secure data that people store on their computers, and this information is now being transferred to the cloud. This makes it critical for you to understand the security measures that your cloud provider has in place, and it is equally important to take personal precautions to secure your data. The first thing you must look into is the security measures that your cloud provider already has in place. These vary from provider to provider and among the various types of clouds.
What encryption methods do the providers have in place? What methods of protection do they have in place for the actual hardware that your data will be stored on? Will they have backups of my data? Do they have firewalls set up? If you have a community cloud, what barriers are in place to keep your information separate from other companies? Many cloud providers have standard terms and conditions that may answer these questions, but the home user will probably have little negotiation room in their cloud contract.
A small business user may have slightly more room to discuss the terms of their contract with the provider and will be able to ask these questions during that time. There are many questions that you can ask, but it is important to choose a cloud provider that considers the security of your data as a major concern. No matter how careful you are with your personal data, by subscribing to the cloud you will be giving up some control to an external source.
This distance between you and the physical location of your data creates a barrier. It may also create more space for a third party to access your information. However, to take advantage of the benefits of the cloud, you will have to knowingly give up direct control of your data. On the converse, keep in mind that most cloud providers will have a great deal of knowledge on how to keep your data safe. A provider likely has more resources and expertise than the average user to secure their computers and networks. Conclusion
To summarize, the cloud provides many options for the everyday computer user as well as large and small businesses. It opens up the world of computing to a broader range of uses and increases the ease of use by giving access through any internet connection. However, with this increased ease also come drawbacks. You have less control over who has access to your information and little to no knowledge of where it is stored. You also must be aware of the security risks of having data stored on the cloud. The cloud is a big target for malicious individuals and may have disadvantages because it can be accessed through an unsecured internet connection.
If you are considering using the cloud, be certain that you identify what information you will be putting out in the cloud, who will have access to that information, and what you will need to make sure it is protected. Additionally, know your options in terms of what type of cloud will be best for your needs, what type of provider will be most useful to you, and what the reputation and responsibilities of the providers you are considering are before you sign up.
Information Sources 1.www.google.com 2.www.wikipedia.com 3.Lewis, Grace. Cloud Computing: Finding the Silver Lining, Not the Silver Bullet. http://www.sei.cmu.edu/newsitems/cloudcomputing.cfm (2009). 4. Lewis, Grace. Basics About Cloud Computing. http://www.sei.cmu.edu/library/abstracts/whitepapers/cloudcomputingbasics.cfm (2010). 5.Jansen, Wayne & Grance, Timothy. Guidelines on Security and Privacy in Public Cloud Computing. National Institute of Standards and Technology, 2011.