Cloud Computing

Introduction Cloud computing is Internet-based computing, where shared resources, software and information are provided to computers and other devices on-demand, like the electricity grid. It is the culmination of numerous attempts at large scale computing with seamless access to virtually limitless resources. On-demand computing, utility computing, ubiquitous computing, autonomic computing, platform computing, edge computing, elastic computing, grid computing. B. Ramamurthy & K. Madurai [email protected] & [email protected] Cloud computing is internet based computing where virtual shared servers provide software, infrastructure, platform, devices and other resources and hosting to customers on a pay as you use basis.

Cloud computing models provide all the information that a digitized system offers as a service. User can access these services on the internet without any prior knowledge on managing the resources involved, thus allowing them to focus more on their core business processes instead of first acquiring the requisite knowledge . Cloud computing customers do not own the physical infrastructure but rent the usage from third party providers.

This avoids the large costs that would be incurred in purchasing the hardware and such. The customer only consumes the resources that they require and as such only pay for what they use. Cloud computing systems come in four models to meet requirements: 1.platform (PaaS), (SaaS), 3.infrastructure (IaaS), 4.Services-based application programming interface (API)

Development Cloud computing came to be due to these challenges and factors: •The need to provide for the alignment of the needs of the business, user, non-computer specialists, community and society. •The need to address the scalability issue: large scale data, high performance computing, automation, response time, rapid prototyping, and rapid time to production •Need to effectively address the ever shortening cycle of obsolescence, the heterogeneity and rapid changes in requirements of industry.

•The transformation of data from diverse sources into intelligence and delivery of the intelligence to the right people, user and systems.

•Emergence of enabling technology. •The evolution of distributed systems and the Internet. •The availability of middleware supporting networks of systems that facilitate sharing, standardization and openness. •Move towards delivering “computing” to masses similar to other utilities (electricity and voice communication). B. Ramamurthy & K. Madurai [email protected] & [email protected]

Architecture Cloud computing is divided into a front end and a back end. The front is comprised of the client’s devices which have some systems which allow them to access the cloud. The back refers to the cloud itself which usually comprises of various computers, data storage systems and servers. A group of these clouds make up a whole cloud computing system. The whole systems administrated and monitored by a central server which also overlooks client’s demands and traffic in order to insure smooth functioning of the system.

Middleware is software that is used to allow computers that are connected on the network to communicate with each other. The system provides redundancy as it keeps a copy of the clients data which is used to restore the service in the event of a device malfunction. The four development models of cloud computing are:

•Public cloud •Community cloud •Hybrid cloud •Private cloud

Public clouds are the traditional cloud computing system where resources are dynamically provisioned on a self-service basis over the internet or through a third party provider. Community clouds are established when several organisations with similar requirements share infrastructure to realise benefits. This option provides higher security and privacy at the expense of an increased cost as the costs are spread between fewer users.

Hybrid clouds mean that several clouds have been joined or that it’s a collection of virtualised cloud server instances used together with real physical hardware. Private clouds describe offerings that deploy cloud computing on private networks. htt:// They consist of applications or virtual machines on a company’s own set of hosts thus providing benefits such as: 1.Utility computing.

2.Shared hardware costs. 3.Failure recovery. 4.Scalability.

Cloud computing programming models. The context Big data. Data mining huge amounts of data collected in a wide range of domains has become essential for planning and performance. Data has become an important asset to an organization. The discovery of knowledge; enabling the discovery of the annotation of complex data and computational models. Google file system

The internet introduced a new challenge in the form web logs, web crawler’s data: large scale, peta byte scale data which has a uniquely different characteristic to transactional data in that it writes once and is read many times WORM. These forms of data are maintained privacy protected healthcare and patient information, historical financial data and other historical data. Google exploits these characteristics in its Google file system (GFS). Hadoop

At Google MapReduce operation are run on a special file system called Google File System (GFS) that is highly optimized for this purpose. GFS is not open source but Doug Cutting and others at Yahoo! reverse engineered the GFS and called it Hadoop Distributed File System (HDFS). The software framework that supports HDFS, MapReduce and other related entities is called the project Hadoop or simply Hadoop. This is open source and distributed by Apache. Cloud computing services and vendors

SaaS (Software As A Service) Is the most widely known and widely used form of cloud computing. It provides all the functions of a sophisticated traditional application to many customers and often thousands of users, but through a Web browser, not a "locally-installed" application. Little or no code is running on the Users local computer and the applications are usually tailored to fulfill specific functions.

SaaS eliminates customer worries about application servers, storage, application development and related, common concerns of IT. Highest-profile examples are, Google's Gmail and Apps, instant messaging from AOL, Yahoo and Google, and VoIP from Vonage and Skype. PaaS (Platform as a Service)

Delivers virtualized servers on which customers can run existing applications or develop new ones without having to worry about maintaining the operating systems, server hardware, load balancing or computing capacity. These vendors provide APIs or development platforms to create and run applications in the cloud – e.g. using the Internet.

Managed Service providers with application services provided to IT departments to monitor systems and downstream applications such as virus scanning for e-mail are frequently included in this category. Well known providers would include Microsoft's Azure, Salesforce's, Google Maps, ADP Payroll processing, and US Postal Service offerings. IaaS (Infrastructure as a Service)

Delivers utility computing capability, typically as raw virtual servers, on demand that customers configure and manage. Here Cloud Computing provides grids or clusters or virtualized servers, networks, storage and systems software, usually (but not always) in a multitenant architecture. IaaS is designed to augment or replace the functions of an entire data center. This saves cost (time and expense) of capital equipment deployment but does not reduce cost of configuration, integration or management and these tasks must be performed remotely.

An example is Windows Azure which provides enterprise level on demand capacity builder fabric of cycles and storage available on-request for a cost. Azure API is used to work with the infrastructure offered by Microsoft. Its chief significant features are web role, worker role, blob storage, table and drive-storage. Another example is Amazon’s EC2 which is a large complex web service. EC2 provided an API for instantiating computing instances with any of the operating systems supported. It can also facilitate computations through Amazon Machine Images (AMIs) for various other models. Its signature features are S3, Cloud Management Console, MapReduce Cloud and Amazon Machine Image (AMI).

It also has excellent distribution, load balancing and cloud monitoring tools. The Google App Engine is more a web interface for a development environment that offers a universal facility for design, development and deployment Java and Python-based applications in Java, Go and Python. Google offers the same reliability, availability and scalability which are on par with Google’s own applications. The interface is software programming based and offers a comprehensive programming platform irrespective of the size of the project. Its signature features are templates and appspot and an excellent monitoring and management console.

Failure recovery is a service provided because failure is the norm rather than exception. A HDFS instance may consist of thousands of server machines, each storing part of the file system’s data, since we have huge number of components and that each component has non-trivial probability of failure means that there is always some component that is non-functional. Benefits Cloud computing provides several benefits for the enterprise. The first benefit is the reduction of upfront capital expenditure.

This is opposed to consumption which is usually billed as a utility or subscription. The second is that it provides location independence to anywhere there is internet access. The third is that it increases the flexibility and market agility. Fourthly is that it allows the enterprise to focus on its care business. Fifthly is that it increases the competitive advantage. Sixth is it increases security at a fraction of the cost of the traditional method due to centralisation Seventh is that it is easier to maintain as programs

Conclusion Cloud computing is an important technology that will shape the business world as well as peoples everyday lives. The proliferation of the internet and the availability of improved services will make the difference and will open new and exciting markets. Cloud computing provides a platform for true globalisation as companies can operate in different countries on the same information as though they all shared an office.

Cloud computing’s negatives are security and access to the internet. Security will have to be improved as the current level of security available will not stop a determined hacker and so only none sensitive information can be stored as it would be too risky to leave valuable information. The second problem affects the less developed countries which have intermittent slow internet access. This means that though it is novel the developing wordkxd.

Reference B. Ramamurthy & K. Madurai [email protected] & [email protected] htt:// [email protected]