Introduction to Cloud Computing
Jul 5, 2012
Suresh Vasudev
6 minute read

Let us start with what Gartner, which is an internationally renowned IT research and advisory company, has to say about Cloud Computing.

  • The global market for cloud services would grow to $150.1 billion per year by 2013, almost a three-fold increase on their estimated market size for 2009 [2009]
  • 33 percent of user’s data will be stored in cloud by 2016 [2012 July]

Many of us are confused about what cloud computing is. The good thing is even the scenior managements of great companies are confused. Let us check some popular comments on Cloud Computing.

The interesting thing about cloud computing is that we’ve redefined cloud computing to include everything that we already do. I can’t think of anything that isn’t cloud computing with all of these announcements. The computer industry is the only industry that is more fashion-driven than women’s fashion. Maybe I’m an idiot, but I have no idea what anyone is talking about. What is it? It’s complete gibberish. It’s insane. When is this idiocy going to stop? [: Larry Ellison, CEO, Oracle 2008] ‘We’ll make cloud computing announcements. I’m not going to fight this thing. But I don’t understand what we would do differently in the light of cloud’ [Larry Ellison, 2008].

Now let us check the the one liner (non-understandable!!!) powerful definition available for cloud computing

  • Cloud computing is a style of computing where scalable and elastic IT-enabled capabilities are provided “as a service” to multiple external customers using Internet technologies [by Gartner]
  • Cloud computing enables businesses of all sizes to quickly procure and use a wide range of enterprise-class IT systems on a pay-per-use basis from anywhere at any time [Unknown]
  • 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. This cloud model promotes availability and is composed of FIVE essential characteristics, THREE service models, and FOUR deployment models [NIST :National Institute of Standards and Technology]

Three Service Models of Cloud Computing

To understand the cloud service model let us first check the structure of a normal PC or Laptop we use in our daily life.

Structure of a PC

Software Layer : Applications used by users like MS Office, Business applications like RevRemit / RevAudit etc.

Platform Layer : Operating System that interact with the Infrastructure, Developing Software like Oracle, VB, Ruby, Java etc

Infrastructure Layer: Physical Layer {CPU,Disk, Memory, Circuit etc}

Cloud computing provides three kinds for services corresponding toeach layer. They are

[1] Software as a Service – SaaS

This type of service provides complete business applications delivered over the web. Here customer directly uses the software

Example:, Google Apps

[2] Platform as a Service – PaaS

This type of service provide a stable online environment where customer can quickly create, test and deploy web applications using browser-based software development tools

*Example: Google App Engine*

[3] Infrastructure as a Service – IaaS

This type of service provides consumers with administrative, web-based access to fundamental computing resources such as processing power, storage and networks. All cloud infrastructures depend on virtualization

*Example: Amazon*

Five Essential Characteristics of Cloud Computing

On-Demand Self-Service

Consumers can log on to cloud computing website or use web services to access additional computing resources on demand, that is, whenever they want them, without talking to a sales representative or technical support staff

Broad Network Access

can access cloud computing services from any internet-connected device

Resource Pooling

In multi-tenanted computing clouds the customers (tenants) share a pool of computing resources with other customers, and these resources, which can be dynamically reallocated, may be hosted anywhere

Rapid Elasticity

Cloud computing enables computing resources or user accounts to be rapidly and elastically provisioned or released so that customers can scale their systems (and costs) up and down at any time according to their changing requirements.

Measured Service

Cloud computing providers automatically monitor and record the resources used by customers or currently assigned to customers, which makes possible the pay-per-use billing model that is fundamental to the cloud computing paradigm.

Four Deployment Models of Cloud Computing

[1] Private Cloud

Many large organizations prefer, or are legally obligated, to keep their servers, software and data within their own data centres; and private clouds enable them to achieve some of the efficiencies of cloud computing while taking responsibility for the security of their own data. By implementing cloud computing technologies behind their firewall, enterprises can enable pooling and sharing of computing resources across different applications, departments or business units. Unlike the pay-as-you-go model of public clouds, however, private clouds require significant up-front development costs, data centre costs, ongoing maintenance, hardware, software and internal expertise.

[2] Community Cloud

Community clouds are used by distinct groups (or ‘communities’) of organizations that have shared concerns such as compliance or security considerations, and the computing infrastructures may be provided by internal or third-party suppliers. The communities benefit from public cloud capabilities but they also know who their neighbours are so they have fewer fears about security and data protection.

[3] Public Cloud

The computing resources are shared with the provider’s other customers

[4] Hybrid Cloud

Many enterprises take the ‘hybrid cloud’ approach by using public clouds for general computing while customer data is kept within a private cloud, community cloud or a more traditional IT infrastructure.

Some Examples which are NOT Cloud

  1. Renting dedicated server hardware in a data centre for a single task, such as hosting a website, even if it is on a subscription basis;
  2. Server virtualization (running multiple virtual computers on a single server) in itself, unless servers can be deployed and destroyed in minutes by the consumer themselves rather than the provider
  3. Connecting to your home PC or office PC from anywhere using remote desktop or VPN (Virtual Private Network) technology

Benefits of Cloud Computing

Financial Benefits

  1. 1. Pay-per-use IT
    1. Operational expenditure than Capital Expenditure
    2. Reduced IT management costs

Technological Benefits

  1. 1. Rapid scalability on demand
    1. Access anywhere
    2. Future Proof (any technology that will not become outdated any time in the near future.)

Operational Features And Benefits

  1. 1. Someone else’s problem
    1. Business beyond buildings

Environmental Benefits

  1. 1. Sharing resources
    1. Reduced travel

Competitive Advantage

Risks of Cloud Computing

[1] Internal Security Risks

  1. 1. Insider Theft (account for 16% in US)
    1. Access to system by former employees
    2. Hacking
    3. Preventive Measure

Strict Internal Process, Two-factor Authentication and Single Sign-on are some approaches available to mitigate this.

[2] External Security Risks

  1. Security Technology Failures (Eg. Non-availability of GoogleDocs service in the past)
  2. Operational Security Failures (Weak Password and thus taking controller of Twitter in the past)

[3] Data Protection Risk

The data is it at risk as it is hosted outside in the cloud. The customer MUST be always aware of the following details to mitigate this risk

  1. What information is stored on a system?
  2. Where is the information stored?
  3. Who can access the system?
  4. What can they access?
  5. Is the access appropriate?

[4] Cloud Outages

[5] Data Loss

[6] Vendor Lock-in

[7] Vendor Failure

Business using Cloud Computing

  1. Charity – Oxfam America (PaaS)
  2. Education – The Open University (SaaS)
  3. Financial services – SunTrust Bank (SaaS)
  4. Media – The Guardian Media Group (SaaS)
  5. Media – The New York Times (IaaS)
  6. Professional services – Department 83 (SaaS)
  7. Retail – Alliance Boots (SaaS)
  8. Software services – LinkedIn (IaaS)
  9. (PaaS).