Made by – Uttam Kumar.

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Cloud Computing

Cloud Computing

Cloud computing is defined as the practice of using a network of remote servers hosted on the Internet to store, manage, and process data, rather than a local server or a personal computer.The Five Principles of Cloud Computing:-1. Resources pooling 2. Virtualization.3. Elasticity.4. Automatic/easy resource deployment.5. Metered billing.

Types of cloud computing providers

• There are three types of cloud computing providers-

• Infrastructure as a Service (IaaS)• Platform as a Service (PaaS).• Software as a Service (SaaS).

Infrastructure as a Service (IaaS)

• Infrastructure as a service provides companies with computing resources including servers, networking, storage, and data center space on a pay-per-use basis.

• IaaS providers offer hardware and the bare minimum software for users to develop on e.g. virtual servers, hard disk space. Users have broad control over the services offered by IaaS providers as they are able to configure settings to a very large extent and they are free to implement and utilize any form of software and programming environment on top of the services. An example of an IaaS provider is Rackspace

Platform as a Service (PaaS)

• For services offered by PaaS providers, users have very little control over their software and programming environment. This is because PaaS providers implement a software layer over the hardware they offer, forcing users to work with the providers' software layer. This is not necessarily a bad thing as PaaS providers reduce the technical expertise needed for users to create their own web application.

• Example – Google app engine.

Software as a Service (SaaS)

• SaaS providers basically offer software for users over the Internet through a web browser. An example of a SaaS is Google Docs, where one can edit documents through the software delivered over the Internet. The main advantage of using a SaaS is that you do not have to worry about installation, storage space, data loss due to PC crashes or patches - the cloud computing provider handles all that and simply delivers the software to you in your web browser.

Deployment models

• Public cloud :- Private cloud is cloud infrastructure operated solely for a single organization, whether managed internally or by a third-party and hosted internally or externally.

• Public cloud:- A cloud is called a "public cloud" when the services are rendered over a network that is open for public use. Technically there may be little or no difference between public and private cloud architecture

• Community cloud:- Community cloud shares infrastructure between several organizations from a specific community with common concerns (security, compliance, jurisdiction, etc.), whether managed internally or by a third-party and hosted internally or externally. The costs are spread over fewer users than a public cloud (but more than a private cloud), so only some of the cost savings potential of cloud computing are realized.

• Hybrid cloud :- Hybrid cloud is a composition of two or more clouds (private, community or public) that remain distinct entities but are bound together, offering the benefits of multiple deployment models. Hybrid cloud can also mean the ability to connect collocation, managed and/or dedicated services with cloud resources.

• To be effective, a management strategy for hybrid cloud deployment should address configuration management, change control, security, fault management and budgeting. Because a hybrid cloud combines public cloud and private data center principles, it's possible to plan a hybrid cloud deployment from either of these starting points.

ArchitectureCloud architecture, the systems architecture of the software systems involved in the delivery of cloud computing, typically involves multiple cloud components communicating with each other over a loose coupling mechanism such as a messaging queue. Elastic provision implies intelligence in the use of tight or loose coupling as applied to mechanisms such as these and others.

• The IntercloudThe Intercloud is an interconnected global "cloud of clouds" and an extension of the Internet "network of networks" on which it is based.

• Cloud engineeringCloud engineering is the application of engineering disciplines to cloud computing. It brings a systematic approach to the high-level concerns of commercialization, standardization, and governance in conceiving, developing, operating and maintaining cloud computing systems. It is a multidisciplinary method encompassing contributions from diverse areas such as systems, software, web, performance, information, security, platform, risk, and quality engineering.

Privacy issues• The increased use of cloud computing services such as

Gmail and Google Docs has pressed the issue of privacy concerns of cloud computing services to the utmost importance. The provider of such services lie in a position such that with the greater use of cloud computing services has given access to a plethora of data. This access has the immense risk of data being disclosed either accidentally or deliberately. Privacy advocates have criticized the cloud model for giving hosting companies' greater ease to control—and thus, to monitor at will—communication between host company and end user, and access user data (with or without permission). Instances such as the secret NSA program, working with AT&T, and Verizon, which recorded over 10 million telephone calls between American citizens, causes uncertainty among privacy advocates, and the greater powers it gives to telecommunication companies to monitor user activity.

• Cloud computing poses privacy concerns because the service provider can access the data that is on the cloud at any time. It could accidentally or deliberately alter or even delete information. This becomes a major concern as these service providers, who employ administrators which can leave room for potential unwanted disclosure of information on the cloud.

Privacy solutions

• Solutions to privacy in cloud computing include policy and legislation as well as end users' choices for how data is stored. The cloud service provider needs to establish clear and relevant policies that describe how the data of each cloud user will be accessed and used. Cloud service users can encrypt data that is processed or stored within the cloud to prevent unauthorized access.

The FutureAccording to Gartner's Hype cycle, cloud computing has reached a maturity that leads it into a productive phase. This means that most of the main issues with cloud computing have been addressed to a degree that clouds have become interesting for full commercial exploitation. This however does not mean that all the problems listed above have actually been solved, only that the according risks can be tolerated to a certain degree. Cloud computing is therefore still as much a research topic, as it is a market offering.• In 2012 the European Commission has issued an analysis of the

relevance of the open research issues for commercial stabilisation  in which various experts from industry and academia identify in particular the following major concerns:

• open interoperation across (proprietary) cloud solutions at IaaS, PaaS and SaaS levels

• managing multitenancy at large scale and in heterogeneous environments

• dynamic and seamless elasticity from inhouse clouds to public clouds for unusual (scale, complexity) and/or infrequent requirements data management in a cloud environment, taking the technical and legal constraints into consideration

These findings have been refined into a research roadmap proposed by the Cloud Computing Expert Group on Research in December 2012 which tries to lay out a timeline for the identified research topics according to their commercial relevance. With the 8th Framework Programmes for Research and Technological Development, the European Commission is trying to support the according research work along the lines of the Europe 2020 strategy.

Cloud Service Provide

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