REFERENCE: Cloud Computing: Web – Based Applications that change the way you work and Collaborate Online”, by Michael Miller, “

Cloud computing – What it is and What it isn’t

Cloud computing portends a major change in how we store information and run applications. Instead of running programs and data on an individual desktop computer,

Everything is hosted in the “cloud”—a nebulous assemblage of computers and servers accessed via the Internet.

Cloud computing lets you access all your applications and documents from anywhere in the world.

The emergence of cloud computing is the computing equivalent of the electricity revolution of a century ago.

Desktop computing and cloud computingWith traditional desktop computing, you run copies of software

programs on each computer you own. The documents you create are stored on the computer they can’t be accessed by computers outside the network.

“The whole scene is PC-centric”With cloud computing, the software programs are rather stored

on servers and accessed via the Internet.

If your computer crashes, the software and documents is still available for others to use. They’re stored on a collection of servers accessed via the Internet.

Anyone with permission can not only access the documents, but can also edit and collaborate on those documents in real time.

“cloud computing model isn’t PC centric, it’s document-centric”

What Cloud Computing Isn’t

Network Computing Cloud Computing

Applications/documents are hosted on a single company’s server.

It encompasses multiple companies, multiple servers, and multiple networks.

Access is over the company’s network only.

Cloud services and storage are accessible from anywhere in the world over an Internet connection

First, cloud computing isn’t network computing

Cloud computing also isn’t traditional outsourcing

What Cloud Computing IsThe applications and data served by the cloud are available

to broad group of users, cross-enterprise and cross-Platform.

Any authorized user can access these docs and apps from any computer over any Internet connection.

And, to the user, the technology and infrastructure behind the cloud is invisible.

It isn’t apparent (and, in most cases doesn’t matter)whether cloud services are based on HTTP, HTML, XML, JavaScript, or other specific technologies.

Six key properties - Google’s perspective of cloud computingCloud computing is user-centric. Once you as a user are

connected to the cloud, whatever is stored there—documents, messages, images, applications, whatever—becomes yours

Cloud computing is task-centric. Instead of focusing on the application and what it can do, the focus is on what you need to do and how the application can do it for you.,

Cloud computing is powerful. Connecting hundreds or thousands of computers together in a cloud creates a wealth of computing power impossible with a single desktop PC.

Cloud computing is accessible. Because data is stored in the cloud, users can instantly retrieve more information from multiple repositories.

Cloud computing is intelligent. With all the various data stored on the computers in a cloud, data mining and analysis are necessary to access that information in an intelligent manner.

Cloud computing is programmable. Many of the task is necessary with cloud computing must be automated. For example, to protect the integrity of the data, information stored on a single computer in the cloud must be replicated on other computers in the cloud. If that one computer goes offline, the cloud’s programming automatically redistributes that computer’s data to a new computer in the cloud.

A Short History of Cloud ComputingCloud computing has as its antecedents both client/server

computing and peer-to-peer distributed computing. It’s all a matter of how centralized storage facilitates collaboration and how multiple computers work together to increase computing power.

Client/Server Computing: Centralized Applications and Storage

Peer-to-Peer Computing: Sharing Resources

Distributed Computing: Providing More Computing Power

Collaborative Computing: Working as a Group

Client/Server ComputingIn the pre-1980 everything operated on the

client/server model. All the software applications, all the data,

and all the control resided on huge mainframe computers, otherwise known as servers.

If a user wanted to access specific data or run a program, he had to connect to the mainframe, gain appropriate access, and then do his business while essentially “renting” the program or data from the server.

Users connected to the server via a computer terminal, sometimes called a workstation or client. This computer was sometimes called a dumb terminal because it didn’t have a lot (if any!) memory, storage space, or processing power.

It was merely a device that connected the user to and enabled him to use the mainframe computer.

Access was not immediate, nor could two users access the same data at the same time.

The fact is, when multiple people are sharing a single computer, even if that computer is a huge mainframe, you have to wait your turn.

So the client/server model, while providing similar centralized storage, differed from cloud computing in that it did not have a user-centric focus;

with client/server computing, all the control rested with the mainframe—and with the guardians of that single computer.

It was not a user-enabling environment.

Peer-to-Peer ComputingP2P computing defines a network architecture in

which each computer has equivalent capabilities

and responsibilities. This is in contrast to the traditional client/server

network architecture, in which one or more computers are dedicated to serving the others.

P2P was an equalizing concept. In the P2P environment, every computer is a client and a server; there are no masters and slaves.

By recognizing all computers on the network as peers, P2P enables direct exchange of resources and services.

There is no need for a central server, because any computer can function in that capacity when called on to do so.

P2P was also a decentralizing concept. Control is decentralized, with all computers functioning as equals.

Content is also dispersed among the various peer computers. No centralized server is assigned to host the available resources and services.

Perhaps the most notable implementation of P2P computing is the Internet.

Many of today’s users forget (or never knew) that the Internet was initially conceived, under its original ARPAnet guise, as a peer-to-peer system that would share computing resources across the United States.

The various ARPAnet sites—and there weren’t many of them—were connected together not as clients and servers, but as equals.

The P2P nature of the early Internet was best exemplified by the Usenet network.

Usenet, which was created back in 1979, was a network of computers (accessed via the Internet), each of which hosted the entire contents of the network.

Messages were propagated between the peer computers; users connecting to any single Usenet server had access to all (or substantially all) the messages posted to each individual server.

Although the users’ connection to the Usenet server was of the traditional client/server nature, the relationship between the Usenet servers was definitely P2P—and presaged the cloud computing of today.

Usenet is a collection of user-submitted notes or messages on various subjects that are posted to servers on a worldwide network. Each subject collection of posted notes is known as a newsgroup.

There are thousands of newsgroups and it is possible for you to form a new one. Most newsgroups are hosted on Internet-connected servers, but they can also be hosted from servers that are not part of the Internet. Usenet's original protocol was UNIX-to-UNIX Copy (UUCP), but today the Network News Transfer Protocol (NNTP) is used.

A diagram of Usenet servers and clients

The blue, green, and red dots on the servers represent the groups they carry. Arrows between servers indicate newsgroup group exchanges (feeds). Arrows between clients and servers indicate that a user is subscribed to a certain group and reads or submits articles.

With the development of the World Wide Web came a shift away from P2P back to the client/server model. On the web, each website is served up by a group of computers, and sites’ visitors use client software (web browsers) to access it.

Almost all content is centralized, all control is centralized, and the clients have no autonomy or control in the process.

NNTP (Network News Transfer Protocol)It is the predominant protocol used by computer

clients and servers for managing the notes posted on Usenet newsgroups.

NNTP replaced the original Usenet protocol, UNIX-to-UNIX Copy Protocol (UUCP) some time ago.

NNTP servers manage the global network of collected Usenet newsgroups and include the server at your Internet access provider.

An NNTP client is included as part of a Netscape, Internet Explorer, Opera, or other Web browser or you may use a separate client program called a newsreader.

Network News Transfer Protocol (NNTP)It is an Internet application protocol used for

transporting Usenet news articles (netnews) between news servers and for reading and posting articles by end user client applications.

Usenet was originally designed based on the UUCP network, with most article transfers taking place over direct point-to-point telephone links between news servers, which were powerful time-sharing systems.

Readers and posters logged into these computers reading the articles directly from the local disk

As local area networks and Internet participation proliferated, it became desirable to allow newsreaders to be run on personal computers connected to local networks.

Because distributed file systems were not yet widely available, a new protocol was developed based on the client-server model.

It resembled the Simple Mail Transfer Protocol (SMTP), but was tailored for exchanging newsgroup articles

A newsreader, also known as a news client, is a software application that reads articles on Usenet, either directly from the news server's disks or via the NNTP.

The well-known TCP port 119 is reserved for NNTP. When clients connect to a news server with Transport Layer Security (TLS), TCP port 563 is used. This is sometimes referred to as NNTPS

Distributed Computing: Providing More Computing Power

One of the most important subsets of the P2P model is that of distributed computing, where idle PCs across a network or across the Internet are tapped to provide computing power for large, processor-intensive projects.

It’s a simple concept, all about cycle sharing between multiple computers.

A personal computer, running full-out 24 hours a day, 7 days a week, is capable of tremendous computing power. Most people don’t use their computers 24/7, however, so a good portion of a computer’s resources go unused. Distributed computing uses those resources.

When a computer is enlisted for a distributed computing project, software is installed on the machine to run various processing activities during those periods when the PC is typically unused.

The results of that spare-time processing are periodically uploaded to the distributed computing network, and combined with similar results from other PCs in the project.

The result, if enough computers are involved, simulates the processing power of much larger mainframes and supercomputers—which is necessary for some very large and complex computing projects.

For example, genetic research requires vast amounts of computing power. It might take years to solve essential mathematical problems.

By connecting together thousands (or millions) of individual PCs, more power is applied to the problem, and the results are obtained that much sooner.

Many distributed computing projects are conducted within large enterprises, using traditional network connections to form the distributed computing network.

Other, larger, projects utilize the computers of everyday Internet users, with the computing typically taking place offline, and then uploaded once a day via traditional consumer Internet connections.

Collaborative Computing: Working as a GroupFrom the early days of client/server computing

through the evolution of P2P, there has been a desire for multiple users to work simultaneously on the samecomputer-based project.

This type of collaborative computing is the driving force behind cloud computing, but has been around for more than a decade.

Early group collaboration was enabled by the combination of several different P2P technologies. The goal was (and is) to enable multiple users to collaborate on group projects online, in real time.

To collaborate users must first be able to talk to one another.Achieved using

- instant messaging, voice and picture communication,

- multi user video conferencing.

Users must be able to share files and have multiple users work on the same document simultaneously

Real-time white boarding is also common, especially in corporate and education

(White boarding is where one or more users “draw” on a virtual whiteboard that is viewable by all the members of the group )

Early group collaboration systems ranged from the relatively simple (Lotus Notes and Microsoft NetMeeting) to the extremely complex (the building-block architecture of the Groove Networks system).

Most were targeted at large corporations,

and limitedto operation over the companies’ private networks.

Cloud Computing: The Next Step in CollaborationWith the growth of the Internet, there was no need to limit

group collaboration to a single enterprise’s network environment.

Users from multiple locations within a corporation, and from multiple organizations, desired to collaborate on projects that crossed company and geographic boundaries.

To do this, projects had to be housed in the “cloud” of the Internet, and accessed from any Internet-enabled location.

Today, people are using cloud services and storage to create, share, find, and organize information of all different types.

Tomorrow, this functionality will be available not only to computer users, but to users of any device that connects to the Internet—mobile phones, portable music players, even automobiles and home television sets.

Cloud Architecture

The key to cloud computing is the “cloud”—a massive network of servers or even individual PCs interconnected in a grid. These computers run in parallel, combining the resources of each to generate supercomputing-like power.

Individual users connect to the cloud from their own personal computers or portable devices, over the Internet. To these individual users, the cloud is seen as a single application, device, or document.

The hardware in the cloud (and the operating system that manages the hardware connections) is invisible.

Cloud Architecture

Flow of events in cloud computing systemFirst the users select a task or service (either starting an

application or opening a document). The user’s request then gets passed to the system

management, which finds the correct resources and then calls the system’s appropriate provisioning services.

These services carve out the necessary resources in the cloud, launch the appropriate web application, and either creates or opens the requested document.

After the web application is launched, the system’s monitoring and metering functions track the usage of the cloud so that resources are apportioned and attributed to the proper user(s).

Key to the notion of cloud computing is the automation of many management tasks.

Flow of events in cloud computing system

Understanding Cloud Storage With cloud storage, data is stored on multiple third-party servers, rather

than on the dedicated servers used in traditional networked data storage.

The actual storage location may even differ from day to day or even minute to minute, as the cloud dynamically manages available storage space. But even though the location is virtual, the user sees a “static” location for his data

Cloud storage has both financial and security-associated advantages.

Financially, virtual resources in the cloud are typically cheaper than dedicated physical resources connected to a personal computer or network.

As for security, data stored in the cloud is secure from accidental erasure or hardware crashes, because it is duplicated across multiple physical machines; since multiple copies of the data are kept continually, the cloud continues to function as normal even if one or more machines go offline. If one machine crashes, the data is duplicated on other machines in the cloud.

Understanding Cloud Services Any web-based application or service offered via cloud computing is

called a cloud service.

Cloud services can include anything from calendar and contact applications to word processing and presentations.

With a cloud service, the application itself is hosted in the cloud.

An individual user runs the application over the web browser.

The browser accesses the cloud service and an instance of the application is opened within the browser window.

Once launched, the web-based application operates and behaves like a standard desktop application.

The only difference is that the application and the working documents remain on the host’s cloud servers.

Advantages Cloud services1. If the user’s PC crashes, it doesn’t affect either the host

application or the open document; both remain unaffected in the cloud .

2. An individual user can access his applications and documents from any location on any PC.

3. Multiple users can collaborate on the same document in real time, using any available Internet connection

4. Documents are no longer machine-centric. Instead, they’re always available to any authorized user.

Companies in the Cloud: Cloud Computing Today

We’re currently in the early days of the cloud computing revolution.

Although many cloud services are available today, more and more interesting applications are still in development.

That said, cloud computing today is attracting the best and biggest companies from across the computing industry, all of whom hope to establish profitable business models based in the cloud.

The most noticeable company currently embracing the cloud computing model is Google.

Google offers a powerful collection of web-based applications, all served via its cloud architecture.

Whether you want cloud-based word processing (Google Docs), presentation software (Google Presentations), email (Gmail), or calendar/scheduling functionality (Google Calendar), Google has an offering.

And best of all, Google is adept in getting all of its web-based applications to interface with each other; their cloud services are interconnected to the user’s benefit.

Other major companies are also involved in the development of cloud services.

Microsoft, offers its Windows Live suite of web-based applications, as well as the Live Mesh initiative that promises to link together all types of devices, data, and applications in a common cloud-based platform.

Amazon has its Elastic Compute Cloud (EC2), a web service that provides cloud-based resizable computing capacity for application developers.

IBM has established a Cloud Computing Center to deliver cloud services and research to clients.

And numerous smaller companies have launched their own web based applications, primarily (but not exclusively) to exploit the collaborative nature of cloud services.

Why Cloud Computing Matters

There are many implications of cloud technology, for both developers and end users.

For developers, cloud computing provides increased amounts of storage and processing power to run the applications they develop.

Cloud computing also enables new ways to access information, process and analyze data, and connect people and resources from any location anywhere in the world.

In essence, it takes the lid off the box; with cloud computing, developers are no longer boxed in by physical constraints.

For end users, cloud computing offers all those benefits and more. A person using a web-based application isn’t physically bound to a single PC, location, or network.

His applications and documents can be accessed wherever he is, whenever he wants. Gone is the fear of losing data if a computer crashes.

Documents hosted in the cloud always exist, no matter what happens to the user’s machine.

And then there’s the benefit of group collaboration. Users from around the world can collaborate on the same documents, applications, and projects, in real time.

It’s a whole new world of collaborative computing, all enabled by the notion of cloud computing

And cloud computing does all this at lower costs, because the cloud enables more efficient sharing of resources than does traditional network computing.

With cloud computing, hardware doesn’t have to be physically adjacent to a firm’s office or data center. Cloud infrastructure can be located anywhere, including and especially areas with lower real estate and electricity costs.

In addition, IT departments don’t have to engineer for peak-load capacity, because the peak load can be spread out among the external assets in the cloud.

And, because additional cloud resources are always at the ready, companies no longer have to purchase assets for infrequent intensive computing tasks. If you need more processing power, it’s always there in the cloud—and accessible on a cost-efficient basis.

Cloud Computing: AdvantagesLower-Cost Computers for UsersImproved PerformanceLower IT Infrastructure CostsFewer Maintenance IssuesLower Software CostsInstant Software UpdatesIncreased Computing PowerUnlimited Storage CapacityIncreased Data SafetyImproved Compatibility Between Operating SystemsImproved Document Format CompatibilityEasier Group CollaborationUniversal Access to DocumentsLatest Version AvailabilityRemoves the Tether to Specific Devices

Cloud Computing: DisadvantagesRequires a Constant Internet ConnectionDoesn’t Work Well with Low-Speed ConnectionsCan Be SlowFeatures Might Be LimitedStored Data Might Not Be Secure

Cloud Computing is more than a technology. It is more than a platform. It is more than just a hosting provider. It is more than just an application hosted as a

service. It is more than providing storage services on

the Internet. It is a combination of all the above

Cloud as an IT strategyIn today’s economic environment as Enterprises try to

balance out and optimize their IT budgets, Cloud computing can be an effective strategy to

reduce the IT operations and management costs and free up critical resources and budget for innovative projects.

Typically, Enterprises have a 80/20 split between regular ongoing IT operations cost which includes

hardware, software licensing costs, development, data center maintenance etc

Vs new investment for solving critical business needs which

is critical for businesses to survive in these challenging times.

Cloud as an IT strategyCloud Computing can have a significant impact in this by

reducing the footprint of IT operations by taking out the upfront capital investments needed for hardware and software licensing.

It enables a Use what you Need and Pay for what you Use cost model.

This will enable businesses to invest on innovative solutions that will help them address key customer challenges instead of worrying about operational details

CLASSIFICATION OF CLOUDThis cloud model promotes availability and is

composed of five essential characteristics,three service models, and Four deployment models.

The Five Essential Characteristics1. On-demand Self Service. A consumer can unilaterally provision computing

capabilities, such as server time and network storage, as needed automatically without requiring human interaction with each service’s provider.

2. Broad Network Access. Capabilities are available over the network and accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms (e.g., mobile phones, laptops, and PDAs).

3. Resource Pooling. The provider’s computing resources are pooled to serve multiple consumers using a multi-tenant model with different physical and virtual resources dynamically assigned and reassigned according to consumer demand. There is a sense of location independence in that the customer generally has no control or knowledge over the exact location of the provided resources but may be able to specify location at a higher level of abstraction (e.g., country, state, or data center). Examples of resources include storage, processing, memory, network bandwidth, and virtual machines.

The Five Essential Characteristics ….4. Rapid Elasticity. Capabilities can be rapidly and elastically provisioned, in some

cases automatically, to quickly scale out, and rapidly released to quickly scale in. To the consumer, the capabilities available for provisioning often appear to be unlimited and can be purchased in any quantity at any time.

5. Measured Service. Cloud systems automatically control and optimize resource use by leveraging a metering capability at some level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth, and active user accounts). Resource usage can be monitored, controlled, and reported providing transparency for both the provider and consumer of the utilized service.

The Three Service Models Cloud Infrastructure as a Service (IaaS). The capability provided to the consumer is to

provision processing, storage, networks, and other fundamental computing resources where the consumer is able to deploy and run arbitrary software, which can include operating systems and applications. The consumer does not manage or control the underlying cloud infrastructure but has control over Operating systems, storage, deployed applications, and possibly limited control of select networking components (e.g., host firewalls).

Cloud Software as a Service (SaaS). The capability provided to the consumer is to use the provider’s applications running on a cloud infrastructure. The applications are accessible from various client devices through a thin client interface such as a web browser (e.g., web based email). The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, storage, or even individual application capabilities, with the possible exception of limited user specific application configuration settings.

Cloud Platform as a Service (PaaS). The capability provided to the consumer is to deploy onto the cloud infrastructure consumer-created or acquired applications created using programming Languages and tools supported by the provider. The consumer does not manage or control the underlying cloud infrastructure including network, servers, operating systems, or storage, but has control over the deployed applications and possibly application hosting environment configurations.

The Four Deployment Models Private Cloud. The cloud infrastructure is operated solely for an organization. It may be

managed by the organization or a third party and may exist on premise or off premise.

Community Cloud. The cloud infrastructure is shared by several organizations and supports a specific community that has shared concerns (e.g., mission, security requirements, policy, and compliance considerations). It may be managed by the organizations or a third party and may exist on premise or off premise.

Public Cloud. The cloud infrastructure is made available to the general public or a large industry group and is owned by an organization selling cloud Services.

Hybrid Cloud. The cloud infrastructure is a composition of two or more clouds (private, community, or public) that remain unique entities but are bound together by standardized or proprietary technology that enables data and application portability (e.g., cloud bursting for load-balancing between clouds).

The Benefits of Cloud ComputingAs cloud computing begins to take hold, several major benefits have become evident: Costs. The cloud promises to reduce the cost of acquiring, delivering, and maintaining

computing power, a benefit of particular importance in times of fiscal uncertainty. By enabling agencies to purchase only the computing services needed, instead of investing in complex and expensive IT infrastructures, agencies can drive down the costs of developing, testing, and maintaining new and existing systems.

Access. The cloud promises universal access to high-powered computing and storage resources for anyone with a network access device. By providing such capabilities, cloud computing helps to facilitate telework initiatives, as well as bolster an agency’s continuity of operations (COOP) demands.

Scalability and Capacity. The cloud is an always-on computing resource that enables users to tailor consumption to their specific needs. Infinitely scalable, cloud computing allows IT infrastructures to be expanded efficiently and expediently without the necessity of making major capital investments. Capacity can be added as resources are needed and completed in a very short period of time. Thus, agencies can avoid the latency, expense, and risk of purchasing hardware and software that takes up data center space -- and can reduce the traditional time required to scale up an application in support of the mission. Cloud computing allows agencies to easily move in the other direction as well, removing capacity, and thus expenses, as needed.

The Benefits of Cloud Computing … Resource Maximization. Cloud computing eases the burden on IT resources

already stretched thin, particularly important for agencies facing shortages of qualified IT professionals.

Collaboration. The cloud presents an environment where users can develop software-based services that enhances collaboration and fosters greater information sharing, not only within the agency, but also among other government and private entities.

Customization. Cloud computing offers a platform of tremendous potential for creating and amending applications to address a diversity of tasks and challenges. Its inherent agility means that specific processes can be easily altered to meet shifting agency needs, since those processes are typically changeable by making a configuration change, and not by driving redevelopment from the back-end systems

Companies in cloud