ALTANAI BISHT .

VELTECH MULTITECH DR Rangarajan DR Sakunthala ENGINEERING COLLEGE

Dept of INFORMATION TECHNOLOGY , BTECH 1st YR

CLOUD COMPUTING

Abstract:

The term, cloud computing, has become one of the latest buzzwords in the IT industry. Cloud computing is an innovative approach that leverages existing IT infrastructure to optimize compute resources and manage data and computing workloads.. Cloud computing promises to increase the velocity with which applications are deployed, increase innovation, and lower costs, all while increasing business agility. cloud computing that allows it to support every facet, including the server, storage, network, and virtualization technology that drives cloud computing environments to the software that runs in virtual appliances that can be used to assemble applications in minimal time. The market-based resource management that cloud computing transforms the way we design, build, and deliver applications, and the architectural considerations that enterprises must make when adopting and using cloud computing technology.

Keywords: Cloud Computing, Data Centers, Utility Computing, Virtualization, Service Level Agreements (SLAs) Web Services.Introduction:

Computing is being transformed to a model consisting of services based on their requirements without regard to where the services are hosted or how

they are delivered. Cloud computing can be the ability to rent a server or a thousand servers and run on the most powerful systems available anywhere. It can be storing and securing immense amounts of data that is accessible only

by authorized applications and users to use applications on the Internet while providing a service — anything including email, sales force automation and tax preparation. It can be using a storage cloud to hold application, business, and personal data and it can be the ability to use a handful of Web services to integrate photos, maps. since cloud applications may be crucial to the core business operations of the consumers, it is essential that the consumers have guarantees from providers on service delivery. Typically, these are provided through Service Level Agreements (SLAs) brokered between the providers and consumers. Recent advances in microprocessor technology and software have led to the increasing ability of commodity hardware to run applications within Virtual Machines (VMs) efficiently. VMs allow both the isolation of applications from the underlying hardware and other VMs.

Cloud computing and characteristics:

"A Cloud is a type of parallel and distributed system consisting of a collection of inter-connected and virtualized computers that are dynamically provisioned and presented as one or more unified computing resources based on service-level agreements established through negotiation between the service provider and consumers.”

Cloud computing users can avoid capital expenditure on hardware, software, and services when they pay a provider only for what they use. Consumption is usually billed on a

utility or subscription basis with little or no upfront cost. Other benefits of this time sharing-style approach are low barriers to entry, shared infrastructure and costs, low management overhead, and immediate access to a broad range of applications. In general, users can terminate the contract at any time (thereby avoiding return on investment risk and uncertainty), and the services are often covered by service level agreements (SLAs) with financial penalties.

Architecture:

Cloud architecture, the systems architecture of the software systems involved in the delivery of cloud computing, comprises hardware and software designed by a cloud architect who typically works for a cloud integrator. It typically involves multiple cloud components communicating with each other over application programming interfaces, usually web services.

This closely resembles the Unix philosophy of having multiple programs each doing one thing well and working together over universal interfaces. Complexity is controlled and the resulting systems are more manageable than their monolithic counterparts.

Cloud architecture extends to the client, where web browsers and/or software applications access cloud applications.

Cloud computing architecture

Principles of Cloud Architecture:

1. Integrated Ecosystem Managem for Cloud:

For Vendors, Partnersand End users.2. Virtualization for Cloud Infrastructure:

Maintain Hardware and software resources availability in dynamic, on-demand manner.3. Service Orientation for Common Reusable Components:

Present reusable components as Web Services4. Extensible Provisioning and Subscription for Clouds:

How Cloud users easily access services. How cloud service providesProvision services.5. Configurable Enablement for Cloud Offerings:

Cloud offering levels(SaaS, IaaS, or PaaS).

6. Unified Information Representation and Exchange Framework:

How different Cloud Entities Exchange Messages.

7. Cloud Quality and Governance: Reliability, Security, Billing …etc

Cloud computing infrastructure models:

1. Public cloud:

Public cloud or external cloud describes cloud computing in the traditional mainstream sense, whereby resources are dynamically provisioned on a fine-grained, self-service basis over the Internet, via web applications/web services, from an off-site third-party provider who shares resources and bills on a fine-grained utility computing basis.

2. Hybrid cloud:

A hybrid cloud environment consisting of multiple internal and/or external providers "will be typical for most enterprises". A hybrid cloud can describe configuration combining a local device, such as a Plug computer with cloud services. It can also describe configurations combining virtual and physical, collocated assets.

3. Private cloud

Private cloud and internal cloud are neologisms that some vendors have recently used to describe offerings that emulate cloud computing on private networks. These products claim to "deliver some benefits of cloud computing without the pitfalls", capitalizing on data security, corporate governance, and reliability concerns.

Types of services:

Services provided by cloud computing can be split into three major categories

1. Infrastructure-as-a-Service (IaaS):

Infrastructure-as-a-Service like Amazon Web Services provides virtual servers with unique IP addresses and blocks of storage on demand. Customers

benefit from an API from which they can control their servers. Because customers can pay for exactly the amount of service they use, like for electricity or water, this service is also called utility computing.

2. Platform-as-a-Service (PaaS):

Platform-as-a-Service is a set of software and development tools hosted on the provider's servers. Developers can create applications using the provider's APIs. Google Apps is one of the most famous Platform-as-a-Service providers. Developers should take notice that there aren't any interoperability standards (yet), so some providers may not allow you to take your application and put it on another platform.

3. Software-as-a-Service (SaaS):

Software-as-a-Service is the broadest market. In this case the provider allows the customer only to use its applications. The software interacts with the user through a user interface. These applications can be anything from web based email, to applications like Twitter .

Market-Oriented Cloud:

Market-oriented resource management is necessary to regulate the supply and demand of Cloud resources to achieve market equilibrium (where supply = demand), providing feedback in terms of economic incentives for both Cloud consumers and providers, and mechanisms that differentiate service requests based on their utility.

M arket-oriented cloud architecture

Working:

1.Users/Brokers: Users or brokers acting on their

behalf submit service requests from anywhere in the world to the Data Center and Cloud to be processed.2.SLA Resource Allocator:

The SLA Resource Allocator acts as the interface between the Data Center/Cloud service provider and external users/brokers.3. Pricing:

The Pricing mechanism decides how service requests are charged. Pricing serves as a basis for managing the supply and demand of computing resources within the Data Center.4. Accounting:

The Accounting mechanism maintains the actual usage of resources by requests so that the final cost can be computed and charged to the users.5. VM Monitor:

The VM Monitor mechanism keeps track of the availability of VMs and their resource entitlements.6. Dispatcher:

The Dispatcher mechanism starts the execution of accepted service requests on allocated VMs.7. Service Request Monitor:

The Service Request Monitor mechanism keeps track of the executionprogress of service requests.8. VMs:

Multiple VMs can be started and stopped on-demand on a single physical

machine to meet accepted service requests, hence providing maximum flexibility to configure various partitions of resources on the same physical machine to different specific requirements of service requests. 9. Physical Machines:

The Data Center comprises multiple computing servers that provide resources to meet service demands.

Global Cloud Exchange and Markets:

The market directory allows participants to locate providers or consumers with the right offers. The banking system ensures that financial transactions pertaining to agreements between participants are carried out. Brokers perform mediate between consumers and providers by buying

capacity from the provider and sub-leasing these to the consumers.

A broker can accept requests from many users who have a choice of submitting their requirements to different brokers. Consumers, brokers and providers are bound to their requirements and related compensations through SLAs. An SLA specifies the details of the service to be provided in terms of metrics agreed upon by all parties, and penalties for meeting and violating the expectations, respectively.

Such markets can bridge disparate Clouds allowing consumers to choose a provider that suits their requirements by either executing SLAs in advance or by buying capacity on the spot. Providers can use the markets in order to perform effective capacity planning.

Global Cloud exchange and market infrastructure for trading services. Benefits of Cloud Computing:

Agility improves with users ability to rapidly and inexpensively re-provision technological infrastructure resources.

Cost is claimed to be greatly reduced and capital expenditure is converted to operational expenditure. Pricing on a utility computing basis is fine-grained with usage-based options and fewer IT skills are required for implementation.

Device and location independence enable users to access systems using a web browser regardless of their location or what device they are using (e.g., PC, mobile

Multi-tenancy enables sharing of resources and costs across a large pool of users thus allowing for:

o Centralization o Peak-load capacityo Utilization and

efficiency Reliability improves through the

use of multiple redundant sites, which makes cloud computing suitable for business continuity and disaster recovery.

Scalability via dynamic provisioning of resources on a fine-grained, self-service basis near real-time, without users having to engineer for peak loads.

Security could improve due to centralization of data, increased security-focused resources, etc., but concerns can persist about loss of control over certain sensitive data, and the lack of security for stored kernels.

Sustainability comes about through improved resource utilization, more efficient systems, and carbon neutrality.

Maintenance cloud computing applications are easier to maintain, since they don't have to be installed on each user's computer.

Increased StorageOrganizations can store more data than on private computer systems.

FlexibilityCloud computing offers much more flexibility than past isolated computing methods.

More Mobility: :Employees can access information wherever they are, rather than having to remain at their desks.

Clients:

A cloud client consists of computer hardware and/or computer software that relies on cloud computing for example:

Mobile - Palm Pre- Web’s Linux Kernel, Android-Linux Kernel, iPhone-Darwin Kernel, Microsoft based - Windows Mobile)

Thin client (CherryPal, Wyse, Zonbu, gOS-based systems)

Thick client / Web browser (Internet Explorer, Mozilla Firefox, Google Chrome, WebKit)

Servers:

The servers layer consists of computer hardware and/or computer software products for example:

Fabric computing .

Application:

A cloud application leverages cloud computing in software architecture, often eliminating the need to install and run the application on the customer's own computer, thus alleviating the burden of software maintenance, ongoing operation, and support. For example:

Peer-to-peer / volunteer computing (BOINC, Skype)

Web applications (Webmail, Face book, Twitter, You Tube, Yammer)

Security as a service (Message Labs, Pure wire, Scan Safe, Zscaler)

Software as a service (Google Apps)

Platform

Services o Identity (OAuth, OpenID)o Real-world (Amazon

Mechanical Turk) Solution stacks

o Java (Google App Engine)

o PHP (Rackspace Cloud Sites)

o Python Django (Google App Engine)

o Ruby on Rails (Engine Yard, Heroku)

Storage [Structured] o Databases (Amazon

SimpleDB, Big Table)o Queues (Amazon SQS)

Conclusion:

Cloud computing is a new and promising paradigm delivering IT services as computing utilities. As Clouds are designed to provide services to external users, providers need to be compensated for sharing their resources and capabilities. In this paper, we have proposed architecture for market-oriented allocation of resources within Clouds. We have discussed some representative platforms for Cloud computing covering the state-of-the-art. As Cloud platforms become ubiquitous, we expect the need for internetworking them to create a market oriented global Cloud exchange for trading services. Several challenges need to be addressed to realize this vision. They include: market-maker for bringing service providers and consumers; market registry for publishing and discovering Cloud service providers and their services; clearing house and brokers for mapping service requests to providers who can meet QoS expectations; and payment management and accounting infrastructure for trading services. Finally, we need to address regulatory and legal issues, which go beyond technical issues.