Cloud Computing and Virtualization
What is cloud computing?
The last years have reinforced the concept that information processing and storing can be done more efficiently, centrally, on large spaces(farms or servers) of computing and storage systems accessible via the Internet. When computing resources in distant data centers and computing spaces are used rather than local computing systems (in the local hard drives and storages), we talk about network-centric computing and network-centric content.
We will discuss this concept in detail in this article. Advancements in networking and other areas such as massive online storages are responsible for the acceptance of the two new computing models and led to the grid computing movement in the early 1990s and, since 2005, to utility computing concept and cloud computing concept.
In utility computing the hardware and software resources are based primarily on large data centers and users can pay as they consume computing, storage, and communication resources. Utility computing often requires a cloud-like infrastructure, but it differs from cloud computing, since focus is on the business model for providing the computing services.
Cloud computing is a path to utility computing embraced by major IT companies around the world, such as Amazon, Apple, HTC, Google, HP, IBM, Microsoft, Oracle, Autodesk and others.
Cloud computing delivery models are shown in the picture. There are three cloud delivery models: Software-as-a-Service (SaaS), Platform-as-a-Service (PaaS), and Infrastructure-as-a-Service (IaaS), deployed as public, private, community and hybrid clouds.
The defining characteristics of the new philosophy for delivering computing services in a cloud computing are listed below:
• Cloud computing uses Internet technologies to offer flexible services. The term elastic computing refers to the ability to dynamically acquire computing resources, services and support a variable workload. A cloud service provider maintains a massive infrastructure to support elastic services. So that it can provide large number of services and can acquire different user requirements.
• The resources used for these services are metered and the users are charged only for the resources they use. There is no such a thing like a flat rate for the usage, but it will always depend upon the type of service that the user demands.
• Maintenance, security and privacy are ensured by service providers.
• Economies of scale from large number of users demanding similar type of services, allows service providers to operate more efficiently and productively due to specialization and centralization.
• Cloud computing uses resource multiplexing which makes it cost effective; lower costs for the service provider are passed on to the cloud users who experience a great service at a lower cost.
• The application data is stored in cloud closer to the site where it is used in a device – and location-independent manner; potentially, this data storage strategy has increased reliability and security of the cloud, resulting lower communication cost to the service provider.
Cloud computing is a social and technical reality and a popular emerging technology. At this time, one can only give his opinion on how the infrastructure for this new concept will evolve and what applications will migrate to it. The economic, ethical, legal and social implications of this trend in technology, in which users rely on services provided by large data farms and store private data and software on systems which are controlled and maintained by third parties, are likely to be significant.
Research and engineering applications, data mining, financing, gaming, and social networking as well as many other computational and data-intensive activities can benefit from cloud computing. A broad range of data, from the results of high-energy scientific experiments to financial or enterprise management data to personal and social data such as photos, videos, notes and movies, can be stored on the cloud.
Microsoft integrated Windows 8 with OneDrive, a network centric alternative for storing any content such as documents, notes, music, videos, movies, and personal information; this content was previously confined only to personal devices such as workstations, laptops, or tablets. The obvious advantage of network- centric information is the accessibility of information from any place where user can connect to internet.
With this function Windows users abled to format their computers without any prior backups and all. If useful content has been synched to OneDrive, then there is no loss of data. Clearly, information stored on a cloud can be shared easily; you only need to share the link to your data block, so that other users can access them from the internet.
This approach saves lot of data, time and space. But this approach raises major issues: Is the information safe and secure? Is it accessible whenever we need it? Do we still own it? Can others get access to them without permission?
In the next few decades, the focus of cloud computing is expected to change from building the infrastructure and physical storages, today’s main front of competition among the IT vendors, to the application domain.
This change in focus is reflected by Google’s plan to build a dedicated cloud for government organizations in the USA. Google states: “We recognize that government agencies and departments have unique legislation and compliance requirements for IT systems, and cloud computing is no exception.
So we have invested a lot of finance and time in understanding government’s requirements and how they can get the best from cloud computing.”
Definition of a cloud
The cloud itself is a group of hardware, networks, storage, services, and platforms that enable the delivery of distant computing as a service. Cloud services include the delivery of software such as notebook software (tool) in OneDrive, infrastructure, and space storage over the Internet (either as separate components or an integrated platform) based on user requirement.
The world of the cloud has lots of participants:
• The end user is the person who is getting the service done from the cloud. He doesn’t really need to know anything about the underlying technology. In small businesses, for example, the cloud provider becomes the de facto data center. In larger organizations, the IT organization oversees the inner workings of both internal resources and external cloud resources.
• Business management needs to be responsibility for overall governance of data or services provided in a cloud. Cloud service providers must provide a uniform and guaranteed service level and security to all their customers.
• The cloud service provider is responsible for IT assets in the cloud and its maintenance.
Network-centric computing and content
Network – centric computing and network – centric contents are the basis for the cloud computing. So it is vital to understand concepts used in it and its key characteristics.
Some of the key concepts and technologies for network-centric computing and content evolved through the years and led to development of cloud computing are:
• The Web and the semantic Web are believed to support composition of services (not need to be computational services) available on the Web. 1
• The Grid, implemented in the early 1990s by National Laboratories and Universities, is used basically for applications in the area of science and engineering.
• Computer clouds, promoted since 2005 as a form of service-oriented computing by leading IT companies such as google, yahoo, are used for enterprise management, high-performance computing, Web hosting, and storage for network-centric content.
Network-centric computing and network-centric content share a number of characteristics:
• Most of the applications are data-intensive. Computer simulation has become a powerful tool for scientific researches in virtually all areas of science, from physics, engineering, biology, and chemistry to archeology. Sophisticated tools for CAD, such as Catia (Computer Aided Three dimensional Interactive Application), are widely used in all engineering disciplines including aerospace and automotive industries. The widespread application of sensors contributes to increases in the volume of data.
Multimedia applications are becoming increasingly popular; the ever-larger media increase the load placed on storage, networking, and processing systems.
• Virtually all apps are network-intensive. Indeed, transferring large volumes of data requires high-bandwidth network transmission; parallel computing, computation steering and data streaming are methods of applications that can only run effectively on low-latency networks.
• The systems are accessed using thin clients running on systems with limited assets. In June 2011 Google released Google Chrome browser, designed to run on primitive devices and based on the browser with the same user account.
• The infrastructure supports some form of workflow management. Obviously, complex computational tasks require coordination of several apps; integration of services is a basic principle of Web2.0.
Several types of cloud
The term computer cloud can be given to several different infrastructures. Since it covers infrastructures of different sizes, with different management techniques and different user pools, number of different types of cloud is envisioned:
• Private cloud
• Community cloud
• Public cloud
• Hybrid cloud
Why could cloud computing be successful?
The reasons that cloud computing could be successful can be categorized into several general groups: basically they are technological advances, a realistic system model, user convenience, and financial advantages.
• Cloud computing is in a better position to leverage recent advances in software, storage, networking and processor technologies. Cloud computing is promoted and developed by large IT companies where these new technological advancements take place, and these companies have lot of interest in promoting the new technologies.
• A cloud has a homogeneous set of hardware and software assets in a single administrative domain. In this environment, security, resource management, uniformity, fault tolerance, and quality of service are less challenging than in a heterogeneous environment with different types of resources in multiple administrative domains having differences.
• Cloud computing is heavily focused on enterprise computing; its adoption by business organizations, financial institutions, healthcare organizations, and so on has a potentially massive impact on the economy.
• A cloud provides the illusion of unlimited computing assets; its elasticity frees app designers from the confinement of a single system.
• A cloud eliminates the requirement for up-front financial commitment, and it is based on a pay-as-you-use approach. This has the tendency to attract new apps and new users for existing apps, fomenting a new era of industry wide technological improvements.
Major obstacles for cloud computing
In spite of the technological advancements that have made cloud computing feasible, there are still major obstacles for this new emerging technology; these obstacles give a chance for research. I list a few of the most obvious hurdles are:
• Availability of service. What happens when the service provider has to temporally shut down? Can a large company such as TOYOTA move its IT to the cloud and have assurances that its future activity will not be negatively affected by cloud overload? Incomplete answer to this question is given by service-level agreements (SLAs).
A temporary fix with negative economic implications is over provisioning, that is, having enough assets to satisfy the largest projected demand by the user.
• Vendor lock-in. Once a customer is hooked to one provider, it is hard to move to another provider or to initiate it.
• Data confidentiality and security.
• Data transfer bottlenecks. Many applications are data driven. So it is very important to store the data as near as possible to the site where it is needed. Transferring 1 TB of data on a 1 Mbps network needs 8 million seconds, or nearly 10 days; it is faster and economical to use courier service and transfer data recoded on some media than to transfer it over the network.
Very high-speed networks will minimize this problem in the near future; for example, a 2 Gbps network would reduce this time to 4,000 s, or slightly more than 1 h.
Cloud computing is yet an emerging technology or I may call it the ‘next generation of internet’ which still needs lot of technological breakthroughs to evolve. It is an area in which lot of researches are being carried out. Lot of major IT conglomerates are moving their focus from their general specialization to cloud computing.
New SEO of Microsoft has stated that their key business will get shifted from operating systems to cloud computing.
With all these advancements and trends in IT field, we have a positive hope that we will be able to experience tremendous benefits of cloud computing in near future. It will eventually give birth to a culture in which people no longer use devices with bulk storage capacity. There will only be a very little storage to run cloud applications.