Cloud computing

Cloud computing means using multiple server computers via a digital network, as though they were one computer. Often, the services available are considered part of cloud computing.

Traditionally, without a cloud, a web server runs as a single computer or a group of privately owned computers. The computer(s) are powerful enough to serve a given amount of requests per minute and can do so with a certain amount of latency per request. If the computer's website or web application suddenly becomes more popular, and the amount of requests are far more than the web server can handle, the response time of the requested pages will be increased due to overloading. On the other hand, in times of low load much of the capacity will go unused.

If the website, service, or web application is hosted in a cloud, however, additional processing and compute power is available from the cloud provider. The website would share those servers with perhaps thousands of other websites of varying size and memory. If the website suddenly becomes more popular, the cloud can automatically direct more individual computers to work to serve pages for the site, and more money is paid for the extra usage. If it becomes unpopular, however, the amount of money due will be less. Cloud computing is popular for its pay-as-you-go pricing model.

Cloud computing visual diagram

Clouds are sometimes set up within large corporations, or other institutions, so that many users all share the same server power. As computer power gets cheaper, many different applications are provided and managed by the cloud server. In many cases, users might not download and install applications on their own device or computer; all processing and storage is maintained by the cloud server.

Introduction

In the past computing tasks such as word processing were not possible without the installation of application software on a user's computer. A user bought a license for each application from a software vendor and obtained the right to install the application on one computer system. With the development of local area networks (LAN) and more networking capabilities, the client-server model of computing was born, where server computers with enhanced capabilities and large storage devices could be used to host application services and data for a large workgroup. Typically, in client-server computing, a network-friendly client version of the application was required on client computers which utilized the client system's memory and CPU for processing, even though resultant application data files (such as word processing documents) were stored centrally on the data servers. Multiple user licenses of an application were purchased for use by many users on a network.

Cloud computing differs from the classic client-server model by providing applications from a server that are executed and managed by a client's web browser, with no installed client version of an application required. Centralization gives cloud service providers complete control over the versions of the browser-based applications provided to clients, which removes the need for version upgrades or license management on individual client computing devices. The phrase "software as a service" (SaaS) is sometimes used to describe application programs offered through cloud computing. A common shorthand for a provided cloud computing service (or even an aggregation of all existing cloud services) is "The Cloud".

Any computer or web-friendly device connected to the Internet may access the same pool of computing power, applications, and files in a cloud-computing environment. Users may remotely store and access personal files such as music, pictures, videos, and bookmarks; play games; or do word processing on a remote server. Data is centrally stored, so the user does not need to carry a storage medium such as a DVD or USB flash drive. Desktop applications that connect to internet-host email providers may be considered cloud applications, including web-based Gmail, Hotmail, or Yahoo! email services. Private companies may also make use of their own customized cloud email servers for their employees.

Cloud computing technologies are regarded by some analysts as a technological evolution, or may be seen as a marketing trap by others such as Richard Stallman.

Consumers now routinely use data-intensive applications driven by cloud technology that may have been previously unavailable due to cost and deployment complexity. In many companies, employees and company departments are bringing a flood of consumer technology into the workplace, which raises legal compliance and security concerns for the corporation which may be relieved by cloud computing.

It should be stated that the phrase "cloud computing" is currently a theory. Eventually perhaps twenty years from now the internet will be a single ubiquitous "always on" network with unlimited resources and zero down time. Currently to my knowledge there are no true "unlimited" web based applications with millions of physical processors and physical memory in reserve waiting to pick up the slack for a specific served application. In other words, there are no current live on-demand applications available complete with viable charge-back solution that can be cited anywhere as a true "cloud" service as described in this document. It is a work in progress and there requires a lot more development before the "theory" is actually publicly implemented as a viable business services strategy. Even the claim by Amazon that it has a "cloud" solution is just that, a "claim" and has yet to be proven. As far as anyone can tell, they are just providing VPS and collocation services just like all the other large over-extended infrastructure networks such as SAVVIS, Google, eBay and others who have hundreds of thousands of servers running at 12% utilization leaving a large percentage of its processing footprint untouched and underutilized. There are many who are of the opinion that Amazon is riding a "marketing" wave for "cloud" services when in fact all they are doing is running VPS services just like everyone else. There has been no proof that they have resolved the continuing issues with: 1. Charge-back 2. Change-management 3. Security All of which still need to be resolved before "public cloud" services will become readily available. I've seen no proof that Amazon has resolved any one of these issues. Just because they claim to be selling "cloud services" does not mean they have the same definition of "cloud" as is stated here in this paper.

How it works

A cloud user needs a client device such as a laptop or desktop computer, pad computer, smart phone, or other computing resource with a web browser (or other approved access route) to access a cloud system via the World Wide Web. Typically the user will log into the cloud at a service provider or private company, such as their employer. Cloud computing works on a client-server basis, using web browser protocols. The cloud provides server-based applications and all data services to the user, with output displayed on the client device. If the user wishes to create a document using a word processor, for example, the cloud provides a suitable application running on the server which displays work done by the user on the client web browser display. Memory allocated to the client system's web browser is used to make the application data appear on the client system display, but all computations and changes are recorded by the server, and final results including files created or altered are permanently stored on the cloud servers. Performance of the cloud application is dependent upon the network access, speed and reliability as well as the processing speed of the client device.

Since cloud services are web-based, they work on multiple platforms, including Linux, Macintosh, and Windows computers. Smart phones, pads and tablet devices with Internet and World Wide Web access also provide cloud services to telecommuting and mobile users.

A service provider may pool the processing power of multiple remote computers in a cloud to achieve routine tasks such as backing up of large amounts of data, word processing, or computationally intensive work. These tasks might normally be difficult, time consuming, or expensive for an individual user or a small company to accomplish, especially with limited computing resources and funds. With cloud computing, clients require only a simple computer, such as netbooks, designed with cloud computing in mind, or even a smartphone, with a connection to the Internet, or a company network, in order to make requests to and receive data from the cloud, hence the term "software as a service" (SaaS). Computation and storage is divided among the remote computers in order to handle large volumes of both, thus the client need not purchase expensive hardware or software to handle the task. The outcome of the processing task is returned to the client over the network, dependent on the speed of the Internet connection.

Technical description

The National Institute of Standards and Technology (NIST) provides a concise and specific definition:

Cloud computing is a model for enabling convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction.

Cloud computing provides computation, software, data access, and storage services that do not require end-user knowledge of the physical location and configuration of the system that delivers the services. Parallels to this concept can be drawn with the electricity grid, wherein end-users consume power without needing to understand the component devices or infrastructure required to provide the service.

Cloud computing describes a new supplement, consumption, and delivery model for IT services based on Internet protocols, and it typically involves provisioning of dynamically scalable and often virtualized resources It is a byproduct and consequence of the ease-of-access to remote computing sites provided by the Internet. This may take the form of web-based tools or applications that users can access and use through a web browser as if they were programs installed locally on their own computers.

Cloud computing providers deliver applications via the internet, which are accessed from a Web browser, while the business software and data are stored on servers at a remote location. In some cases, legacy applications (line of business applications that until now have been prevalent in thin client Windows computing) are delivered via a screen-sharing technology such as Citrix XenApp, while the computing resources are consolidated at a remote data center location; in other cases, entire business applications have been coded using web-based technologies such as AJAX.

Most cloud computing infrastructures consist of services delivered through shared data-centers. The Cloud may appear as a single point of access for consumers' computing needs; notable examples include the iTunes Store and the iOS App Store. Commercial offerings may be required to meet service level agreements (SLAs), but specific terms are less often negotiated by smaller companies.

Risks

Cloud computing's users are exposed to risks mainly associated with:

1) Information security and users' privacy

• Using a service of cloud computing to store data may expose the user to potential violation of privacy. Possession of a user's personal information is entrusted to a provider that can reside in a country other than the user's. In the case of a malicious behavior of the cloud provider, it could access the data in order to perform market research and user profiling.
• In the case of wireless cloud computing, the safety risk increases as a function of reduced security offered by wireless networks. In the presence of illegal acts like misappropriation or illegal appropriation of personal data, the damage could be very serious for the user, with difficulty to reach legal solutions and/or refunds if the provider resides in a state other than the user's country.
• In the case of industries or corporations, all the data stored in external memories are seriously exposed to possible cases of international or cyber espionage.

2) International, political and economic problems

• May arise when public data are freely collected and privately stored from cloud's archives located in a country other than those of the cloud's users. Crucial and intellectual productions and large amounts of personal informations are increasingly stored in private, centralized and partially accessible archives in the form of digital data. No guarantee is given to the users for a free future access.
• Issues are related with the location of the cloud's archives in a few rich countries. If not governed by specific international rules:

1. it could increase the digital divide between rich and poor nations (if the access to the stored knowledge will be not freely ensured to all).
2. being the intangible property considered as a strategic factor for the modern knowledge-based economies it could favor big corporations with "polycentric bodies" and "monocentric minds" only located in the "cloud's countries".

3) Continuity of service

• Delegating their data-managing and processing to an external service, users are severely limited when these services are not operating. A malfunction also affects a large number of users at once because these services are often shared on a large network. As the service provided is supported by a high-speed Internet connection (both in download and upload), even in the event of an interruption of the line connection due to the user's Internet Service Provider (ISP) he or she will face a complete paralysis of the work.

4) Data migration problems when changing the cloud provider

• Another issue is related with the data migration or porting when a user wants to change his cloud provider. There is no defined standard between the operators and such a change is extremely complex. The case of bankruptcy of the company of the cloud provider could be extremely dangerous for the users.

Overview

Comparisons

Cloud computing shares characteristics with:

1. Autonomic computing — computer systems capable of self-management."
2. Client–server model – client–server computing refers broadly to any distributed application that distinguishes between service providers (servers) and service requesters (clients).
3. Grid computing — "a form of distributed computing and parallel computing, whereby a 'super and virtual computer' is composed of a cluster of networked, loosely coupled computers acting in concert to perform very large tasks."
4. Mainframe computer — powerful computers used mainly by large organizations for critical applications, typically bulk data processing such as census, industry and consumer statistics, enterprise resource planning, and financial transaction processing.
5. Utility computing — the "packaging of computing resources, such as computation and storage, as a metered service similar to a traditional public utility, such as electricity."
6. Peer-to-peer – distributed architecture without the need for central coordination, with participants being at the same time both suppliers and consumers of resources (in contrast to the traditional client–server model).
7. Service-oriented computing – Cloud computing provides services related to computing while, in a reciprocal manner, service-oriented computing consists of the computing techniques that operate on software-as-a-service.

Characteristics

The key characteristic of cloud computing is that the computing is "in the cloud"; that is, the processing (and the related data) is not in a specified, known or static place(s). This is in contrast to a model in which the processing takes place in one or more specific servers that are known. All the other concepts mentioned are supplementary or complementary to this concept.

Architecture

Cloud computing sample architecture

Cloud 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 loose coupling mechanism such as messaging queue.

The two most significant components of cloud computing architecture are known as the front end and the back end. The front end is the part seen by the client, i.e., the computer user. This includes the client’s network (or computer) and the applications used to access the cloud via a user interface such as a web browser. The back end of the cloud computing architecture is the cloud itself, comprising various computers, servers and data storage devices.

History

The term "cloud" is used as a metaphor for the Internet, based on the cloud drawing used in the past to represent the telephone network, and later to depict the Internet in computer network diagrams as an abstraction of the underlying infrastructure it represents.

Cloud computing is a natural evolution of the widespread adoption of virtualization, service-oriented architecture, autonomic, and utility computing. Details are abstracted from end-users, who no longer have need for expertise in, or control over, the technology infrastructure "in the cloud" that supports them.

The underlying concept of cloud computing dates back to the 1960s, when John McCarthy opined 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.

The actual term "cloud" borrows from telephony in that telecommunications companies, who until the 1990s 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 user. Cloud computing extends this boundary to cover servers as well as the network infrastructure. The first scholarly use of the term “cloud computing” was in a 1997 lecture by Ramnath Chellappa.

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" 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. The first exposure of the term Cloud Computing to public media is by GoogleEx CEO Eric Schmidt at SES San Jose 2006. It was reported in 2011 that Amazon has thousands of corporate customers, from large ones like Pfizer and Netflix to start-ups. Among them also include many corporations that live on Amazon's web services, including Foursquare, a location-based social networking site; Quora, a question-and-answer service; Reddit, a site for news-sharing and BigDoor, a maker of game tools for Web publishers.

In 2007, Google, IBM and a number of universities embarked on a large-scale cloud computing research project. 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 QoS guarantees (as required by real-time interactive applications) to cloud-based infrastructures, in the framework of the IRMOS European Commission-funded project. 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 "[o]rganisations are switching from company-owned hardware and software assets to per-use service-based models" so that the "projected shift to cloud computing ... will result in dramatic growth in IT products in some areas and significant reductions in other areas."

Key characteristics (from a business perspective)

Taking into account the serious risks listed in the Risk section above, there are some advantages for a company that decides to benefit of a cloud computing service:

• Agility improves with users' ability to re-provision technological infrastructure resources.
• Application Programming Interface (API) accessibility to software that enables machines to interact with cloud software in the same way the user interface facilitates interaction between humans and computers. Cloud computing systems typically use REST-based APIs.
• Cost is claimed to be reduced and in a public cloud delivery model capital expenditure is converted to operational expenditure. This is purported to lower barriers to entry, as infrastructure is typically provided by a third-party and does not need to be purchased for one-time or infrequent intensive computing tasks. Pricing on a utility computing basis is fine-grained with usage-based options and fewer IT skills are required for implementation (in-house).
• 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 phone). As infrastructure is off-site (typically provided by a third-party) and accessed via the Internet, users can connect from anywhere.
• Multi-tenancy enables sharing of resources and costs across a large pool of users thus allowing for:
  • Centralization of infrastructure in locations with lower costs (such as real estate, electricity, etc.)
  • Peak-load capacity increases (users need not engineer for highest possible load-levels)
  • Utilization and efficiency improvements for systems that are often only 10–20% utilized.
• Reliability is improved if multiple redundant sites are used, which makes well-designed cloud computing suitable for business continuity and disaster recovery.
• Scalability via dynamic ("on-demand") provisioning of resources on a fine-grained, self-service basis near real-time, without users having to engineer for peak loads.
• Performance is monitored, and consistent and loosely coupled architectures are constructed using web services as the system interface.
• 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. Security is often as good as or better than under traditional systems, in part because providers are able to devote resources to solving security issues that many customers cannot afford. However, the complexity of security is greatly increased when data is distributed over a wider area or greater number of devices and in multi-tenant systems that are being shared by unrelated users. In addition, user access to security audit logs may be difficult or impossible. Private cloud installations are in part motivated by users' desire to retain control over the infrastructure and avoid losing control of information security.
• Maintenance of cloud computing applications is easier, because they do not need to be installed on each user's computer. They are easier to support and to improve, as the changes reach the clients instantly.

Layers

Once an Internet Protocol connection is established among several computers, it is possible to share services within any one of the following layers.

Provider

A cloud provider mpany responsible for providing the cloud service.

Client

See also: Category:Cloud clients

A cloud client consists of computer hardware and ccvc/or computer software that relies on cloud computing for application delivery, or that is specifically designed for delivery of cloud services and that, in either case, is in essence useless without it. Examples include some computers, phones and other devices, operating systems, and browsers."Microsoft's cloud operating system, Windows Azure, to go live in January". Geek.com. 2009-11-18. Retrieved 2010-08-22.</ref> Cloud Desktop as a Service or Hosted Desktop, is a term often used to refer to a container of a collection of virtual objects, software, hardware, configurations etc., residing on the cloud, used by a client to interact with remote services and perform computer related tasks.

Application

See also: Category:Cloud applications

Cloud application services or "Software as a Service (SaaS)" deliver software as a service over the Internet, eliminating the need to install and run the application on the customer's own computers and simplifying maintenance and support. People tend to use the terms "SaaS" and "cloud" interchangeably, when in fact they are two different things. Key characteristics include:

• Network-based access to, and management of, commercially available (i.e., not custom) software
• Activities that are managed from central locations rather than at each customer's site, enabling customers to access applications remotely via the Web
• Application delivery that typically is closer to a one-to-many model (single instance, multi-tenant architecture) than to a one-to-one model, including architecture, pricing, partnering, and management characteristics
• Centralized feature updating, which obviates the need for downloadable patches and upgrades

Platform

See also: Category:Cloud platforms

Cloud platform services, also known as Platform as a Service (PaaS), deliver a computing platform and/or solution stack as a service, often consuming cloud infrastructure and sustaining cloud applications. It facilitates deployment of applications without the cost and complexity of buying and managing the underlying hardware and software layers.

Infrastructure

See also: Category:Cloud infrastructure

Cloud infrastructure services, also known as Infrastructure as a Service (IaaS), deliver computer infrastructure – typically a platform virtualization environment – as a service. Rather than purchasing servers, software, data-center space or network equipment, clients instead buy those resources as a fully outsourced service. Suppliers typically bill such services on a utility computing basis; the amount of resources consumed (and therefore the cost) will typically reflect the level of activity. IaaS evolved from virtual private server offerings.

Cloud infrastructure often takes the form of a tier 3 data center with many tier 4 attributes, assembled from hundreds of virtual machines.

Server

The servers layer consists of computer hardware and/or computer software products that are specifically designed for the delivery of cloud services, including multi-core processors, cloud-specific operating systems and combined offerings.

Deployment models

Cloud computing types

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 bills on a fine-grained utility computing basis.

Note: Some companies describe Public Cloud as Shared Hardware where multiple customers share the same hardware and Private Cloud as Dedicated Hardware for the client. The correct name for this interpretation should be Dedicated Cloud when you are reffering to Dedicated Hardware (Private vs. Public Cloud)

Community cloud

A community cloud may be established where several organizations have similar requirements and seek to share infrastructure so as to realize some of the benefits of cloud computing. The costs are spread over fewer users than a public cloud (but more than a single tenant). This option may offer a higher level of privacy, security, and/or policy compliance. In addition, it can be economically attractive as the resources (storage, workstations) utilized and shared in the community are already exploited and have reached their return of investment. Examples of community clouds include Google's "Gov Cloud".

Hybrid cloud and hybrid IT delivery

The main responsibility of the IT department in a non-IT company is to deliver services to the business. With the proliferation of cloud computing (both private and public) and the fact that IT departments must also deliver services via traditional, in-house methods, the newest catch-phrase has become “hybrid cloud computing”. Hybrid cloud is also called hybrid delivery by the major vendors including HP, IBM, Oracle, VMware and Fujitsu who offer technology to manage the complexity in managing the performance, security and privacy concerns that results from the mixed delivery methods of IT services. Hybrid delivery is expected to become the norm in data centers.

A hybrid storage cloud uses a combination of public and private storage clouds. Hybrid storage clouds are often useful for archiving and backup functions, allowing local data to be replicated to a public cloud.

Another perspective on deploying a web application in the cloud is using Hybrid Web Hosting, where the hosting infrastructure is a mix between cloud hosting and managed dedicated servers – this is most commonly achieved as part of a web cluster in which some of the nodes are running on real physical hardware and some are running on cloud server instances.

Combined cloud

Two clouds that have been joined together are more correctly called a "combined cloud". A combined cloud environment consisting of multiple internal and/or external providers "will be typical for most enterprises". By integrating multiple cloud services, users may be able to ease the transition to public cloud services while avoiding issues such as PCI compliance.

Private cloud

Douglas Parkhill first described the concept of a "private computer utility" in his 1966 book The Challenge of the Computer Utility. He based the idea on direct comparison with other industries (e.g., the electricity industry) and on the extensive use of hybrid supply models to balance and mitigate risks.

"Private cloud" and "internal cloud" have been described as neologisms, but the concepts themselves pre-date the term "cloud" by 40 years. Even within modern utility industries, hybrid models still exist, despite the formation of reasonably well-functioning markets and the ability to combine multiple providers.

Some vendors have used the terms to describe offerings that emulate cloud computing on private networks. These (typically virtualization automation) products offer the ability to host applications or virtual machines in a company's own set of hosts. These provide the benefits of utility computing – shared hardware costs, the ability to recover from failure, and the ability to scale up or down depending upon demand.

Private clouds have attracted criticism because users "still have to buy, build, and manage them" and thus do not benefit from lower up-front capital costs and less hands-on management, essentially "[lacking] the economic model that makes cloud computing such an intriguing concept". Enterprise IT organizations use their own private cloud(s) for mission-critical and other operational systems to protect critical infrastructures. Therefore, for all intents and purposes, "private clouds" are not an implementation of cloud computing at all, but are in fact an implementation of a technology subset: the basic concept of virtualized computing.

Cloud engineering

Main article: Cloud engineering

Cloud engineering is the application of a systematic, disciplined, quantifiable, and interdisciplinary approach to the ideation, conceptualization, development, operation, and maintenance of cloud computing, as well as the study and applied research of the approach, i.e., the application of engineering to cloud. It is a maturing and evolving discipline to facilitate the adoption, strategization, operationalization, industrialization, standardization, productization, commoditization, and governance of cloud solutions, leading towards a cloud ecosystem. Cloud engineering is also known as cloud service engineering.

Cloud storage

Main article: Cloud storage

See also: Cloud storage gateway

Cloud storage is a model of networked computer data storage where data is stored on multiple virtual servers, in general hosted by third parties, rather than being hosted on dedicated servers. Hosting companies operate large data centers; and people who require their data to be hosted buy or lease storage capacity from them and use it for their storage needs. The data center operators, in the background, virtualize the resources according to the requirements of the customer and expose them as virtual servers, which the customers can themselves manage. In the physical sense, the resource may span across multiple servers.

The Intercloud

Main article: Intercloud

The Intercloud is an interconnected global "cloud of clouds" and an extension of the Internet "network of networks" on which it is based. The term was first used in the context of cloud computing in 2007 when Kevin Kelly stated that "eventually we'll have the intercloud, the cloud of clouds. This Intercloud will have the dimensions of one machine comprising all servers and attendant cloudbooks on the planet.". It became popular in 2009 and has also been used to describe the datacenter of the future.

The Intercloud scenario is based on the key concept that each single cloud does not have infinite physical resources. If a cloud saturates the computational and storage resources of its virtualization infrastructure, it could not be able to satisfy further requests for service allocations sent from its clients. The Intercloud scenario aims to address such situations, and in theory, each cloud can use the computational and storage resources of the virtualization infrastructures of other clouds. Such form of pay-for-use may introduce new business opportunities among cloud providers if they manage to go beyond theoretical framework. Nevertheless, the Intercloud raises many more challenges than solutions concerning cloud federation, security, interoperability, quality of service, vendor's lock-ins, trust, legal issues, monitoring and billing.

The concept of a competitive utility computing market that combined many computer utilities together was originally described by Douglas Parkhill in his 1966 book, the "Challenge of the Computer Utility". This concept has been subsequently used many times over the last 40 years and is identical to the Intercloud.

Issues

Privacy

The cloud model has been criticized by privacy advocates for the greater ease in which the companies hosting the cloud services control, and, thus, can monitor at will, lawfully or unlawfully, the communication and data stored between the user and the host company. Instances such as the secret NSA program, working with AT&T, and Verizon, which recorded over 10 million phone calls between American citizens, causes uncertainty among privacy advocates, and the greater powers it gives to telecommunication companies to monitor user activity. While there have been efforts (such as US-EU Safe Harbor) to "harmonize" the legal environment, providers such as Amazon still cater to major markets (typically the United States and the European Union) by deploying local infrastructure and allowing customers to select "availability zones."

Compliance

In order to obtain compliance with regulations including FISMA, HIPAA, and SOX in the United States, the Data Protection Directive in the EU and the credit card industry's PCI DSS, users may have to adopt community or hybrid deployment modes that are typically more expensive and may offer restricted benefits. This is how Google is able to "manage and meet additional government policy requirements beyond FISMA" and Rackspace Cloud are able to claim PCI compliance. Customers in the EU contracting with cloud providers established outside the EU/EEA have to adhere to the EU regulations on export of personal data. Many providers also obtain SAS 70 Type II certification (e.g., Amazon, Salesforce.com, Google and Microsoft), but this has been criticised on the grounds that the hand-picked set of goals and standards determined by the auditor and the auditee are often not disclosed and can vary widely. Providers typically make this information available on request, under non-disclosure agreement.

Legal

In March 2007, Dell applied to trademark the term "cloud computing" (U.S. Trademark 77,139,082) in the United States. The "Notice of Allowance" the company received in July 2008 was canceled in August, resulting in a formal rejection of the trademark application less than a week later. Since 2007, the number of trademark filings covering cloud computing brands, goods, and services has increased rapidly. As companies sought to better position themselves for cloud computing branding and marketing efforts, cloud computing trademark filings increased by 483% between 2008 and 2009. In 2009, 116 cloud computing trademarks were filed, and trademark analysts predict that over 500 such marks could be filed during 2010.

Other legal cases may shape the use of cloud computing by the public sector. On October 29, 2010, Google filed a lawsuit against the U.S. Department of Interior, which opened up a bid for software that required that bidders use Microsoft's Business Productivity Online Suite. Google sued, calling the requirement "unduly restrictive of competition." Scholars have pointed out that, beginning in 2005, the prevalence of open standards and open source may have an impact on the way that public entities choose to select vendors.

Open source

Open source software has provided the foundation for many cloud computing implementations, one prominent example being the Hadoop framework. In November 2007, the Free Software Foundation released the Affero General Public License, a version of GPLv3 intended to close a perceived legal loophole associated with free software designed to be run over a network. There are many open source platform offerings including AppScale, CloudFoundry, OpenShift, and Heroku.

Open standards

See also: Category:Cloud standards

Most cloud providers expose APIs that are typically well-documented (often under a Creative Commons license) but also unique to their implementation and thus not interoperable. Some vendors have adopted others' APIs and there are a number of open standards under development, including the OGF's Open Cloud Computing Interface. The Open Cloud Consortium (OCC) is working to develop consensus on early cloud computing standards and practices.

Security

Main article: Cloud computing security

As cloud computing is achieving increased popularity, concerns are being voiced about the security issues introduced through the adoption of this new model. The effectiveness and efficiency of traditional protection mechanisms are being reconsidered as the characteristics of this innovative deployment model differ widely from those of traditional architectures.

The relative security of cloud computing services is a contentious issue that may be delaying its adoption. Issues barring the adoption of cloud computing are due in large part to the private and public sectors unease surrounding the external management of security based services. It is the very nature of cloud computing based services, private or public, that promote external management of provided services. This delivers great incentive among cloud computing service providers in producing a priority in building and maintaining strong management of secure services. Security issues have been categorized into sensitive data access, data segregation, privacy, bug exploitation, recovery, accountability, malicious insiders, management console security, account control, and multi-tenancy issues. Solution to various cloud security issues vary through cryptography, particularly public key infrastructure (PKI),use of multiple cloud providers, standardization of APIs, improving virtual machines support and legal support.

Organizations have been formed to provide standards for a better future in cloud computing services. One organization in particular, the Cloud Security Alliance is a non-profit organization formed to promote the use of best practices for providing security assurance within cloud computing.

Availability and performance

In addition to concerns about security, businesses are also worried about acceptable levels of availability and performance of applications hosted in the cloud. Technologies such as ADN (Application Delivery Network), CDN (Content Delivery Network) and TCP acceleration are commonly leveraged to mitigate these issues at the transport level.

There are also concerns about a cloud provider shutting down for financial or legal reasons, which has happened in a number of cases.

Data usage

Since data that was, in the past, stored locally on a user's computer would now be stored remotely in a data center, an individual's internet usage would soar as large files are sent via the internet between the user's computer and the data center. For instance, a purchased movie needs to be downloaded only once if stored on a user's computer. But, if the same movie is stored in cloud storage, it would, in essence, have to be downloaded every time it is viewed in its entirety. If the user's internet service has a monthly data usage cap, this cap could easily be exceeded if large, frequently accessed files are stored remotely. This would cause the user to incur potentially large overage charges.

Sustainability and siting

Although cloud computing is often assumed to be a form of "green computing", there is as of yet no published study to substantiate this assumption. Siting the servers affects the environmental effects of cloud computing. In areas where climate favors natural cooling and renewable electricity is readily available, the environmental effects will be more moderate. Thus countries with favorable conditions, such as Finland, Sweden and Switzerland, are trying to attract cloud computing data centers.

SmartBay, marine research infrastructure of sensors and computational technology, is being developed using cloud computing, an emerging approach to shared infrastructure in which large pools of systems are linked together to provide IT services.

Use by crackers

As with privately purchased hardware, crackers posing as legitimate customers can purchase the services of cloud computing for nefarious purposes. This includes password cracking and as a means of launching attacks. In 2009, a banking trojan illegally used the popular Amazon service as a command and control channel that issued software updates and malicious instructions to PCs that were infected by the malware.

Research

Many universities, vendors and government organizations are investing in research around the topic of cloud computing.

Joint government, academic and vendor collaborative research projects include the IBM/Google Academic Cloud Computing Initiative (ACCI). In October 2007 IBM and Google announced the multi-university project designed to enhance students' technical knowledge to address the challenges of cloud computing. In April 2009, the National Science Foundation joined the ACCI and awarded approximately million in grants to 14 academic institutions.

In July 2008, HP, Intel Corporation, and Yahoo! announced the creation of a global, multi-data-center, open-source test bed, called Open Cirrus, designed to encourage research into all aspects of cloud computing, service and data center management. Open Cirrus partners include the NSF, the University of Illinois (UIUC), Karlsruhe Institute of Technology, the Infocomm Development Authority (IDA) of Singapore, the Electronics and Telecommunications Research Institute (ETRI) in Korea, the Malaysian Institute for Microelectronic Systems(MIMOS), and the Institute for System Programming at the Russian Academy of Sciences (ISPRAS). In Sept. 2010, more researchers joined the HP/Intel/Yahoo Open Cirrus project for cloud computing research. The new researchers are China Mobile Research Institute (CMRI), Spain's Supercomputing Center of Galicia (CESGA by its Spanish acronym), Georgia Tech's Center for Experimental Research in Computer Systems (CERCS) and China Telecom.

In July 2010, HP Labs India announced a new cloud-based technology designed to simplify taking content and making it mobile-enabled, even from low-end devices. Called SiteonMobile, the new technology is designed for emerging markets where people are more likely to access the internet via mobile phones rather than computers. In November 2010, HP formally opened its Government Cloud Theatre, located at the HP Labs site in Bristol, England. The demonstration facility highlights high-security, highly flexible cloud computing based on intellectual property developed at HP Labs. The aim of the facility is to lessen fears about the security of the cloud. HP Labs Bristol is HP’s second-largest central research location and currently is responsible for researching cloud computing and security.

The IEEE Technical Committee on Services Computing in IEEE Computer Society sponsors the IEEE International Conference on Cloud Computing (CLOUD). CLOUD 2010 was held on July 5–10, 2010 in Miami, Florida

On March 23, 2011, Google, Microsoft, HP, Yahoo, Verizon, Deutsche Telekom, and 17 other companies formed a nonprofit organization called Open Networking Foundation, focused on providing support for a new cloud initiative called Software-Defined Networking. The initiative is meant to speed innovation through simple software changes in telecommunications networks, wireless networks, data centers and other networking areas.

Criticism of the term

Some have come to criticize the term as being either too unspecific or even misleading. CEO Larry Ellison of Oracle Corporation asserts that cloud computing is "everything that we already do", claiming that the company could simply "change the wording on some of our ads" to deploy their cloud-based services. Forrester Research VP Frank Gillett questions the very nature of and motivation behind the push for cloud computing, describing what he calls "cloud washing"—companies simply relabeling their products as "cloud computing", resulting in mere marketing innovation instead of "real" innovation. GNU's Richard Stallman insists that the industry will only use the model to deliver services at ever increasing rates over proprietary systems, otherwise likening it to a "marketing hype campaign".

See also

• Cloud backup
• Cloud engineering
• Cloud gaming
• Apache Hadoop
• Data center
• Green computing
• High-performance computing
• List of cloud computing providers
• Open Data Center Alliance
• Hosted desktop
• Cloud Computing Modeling Notation (CCMN)
• SOMF Cloud computing modeling capabilities
• ADN (Application Delivery Network)
• CDN (Content Delivery Network)
• TCP acceleration

External links

• Cloud Computing Dashboard and Resources on Academic Room
• Grail Research - Cloud Computing: Fact versus Fog