Cloud computing

Moving IT out of the office

• Editore: BCS, The Chartered Institute for IT
• Anno: 2012
• ISBN:
  9781780171319
• Argomento: Informatique
• Categoria: Technologies de l'information

Cloud computing is considered to be one of the main business drivers for growth and innovation, and a global survey by Gartner listed cloud computing as one of the top three technology priorities for CIOs in 2012. Yet debate continues around its real benefits, security and data protection issues. The articles in this ebook look at different aspects of cloud computing, from strategic and infrastructure considerations to legal and security issues, aiming to provide practical advice and a clearer picture of its benefits and drawbacks.

SECTION 1:

WHAT IS THE CLOUD?

1 WHAT IS CLOUD COMPUTING?

An extract from a chapter in A Manager’s Guide to IT Law by Stuart Smith, a solicitor in the Information Technology Team of Bond Pearce.

Cloud computing is best described as ‘a model for enabling convenient, on-demand network access to a shared pool of configurable computing resources […] that can be rapidly provisioned and released with minimal management effort or service provider interaction’. National Institute of Standards and Technology (NIST).

Cloud computing consists of three different types of service provision. In each case the services are hosted remotely and accessed over a network (usually the internet) through a customer’s web browser, rather than being installed locally on a customer’s computer. Firstly, SaaS (software as a service) refers to the provision of software applications in the cloud. Secondly, PaaS (platform as a service) refers to the provision of services that enable customers to deploy, in the cloud, applications created using programming languages and tools supported by the supplier. Thirdly, IaaS (infrastructure as a service) refers to services providing computer processing power, storage space and network capacity, which enable customers to run arbitrary software (including operating systems and applications) in the cloud. These three elements are together referred to as the cloud computing ‘stack’. This article concentrates on the issues surrounding the provision of SaaS.

The supply of IT services in the cloud has been enabled both by the evolution of sophisticated data centres and widespread access to improved bandwidth. These technical advances mean that services may be hosted on machines across a wide range of locations but, from the customer’s perspective, they simply originate in the ‘cloud’.

The cloud model enables customers to access, from any computer connected to the internet (whether a desktop PC or a mobile device), a multitude of IT services rather than being limited to using locally installed software and being dependent on the storage capacity of their local computer network.

This model of IT service provision is one that is growing exponentially. It is estimated that one third of all revenue generated in the software market today relates to the delivery of cloud computing services, and that the value of the UK cloud computing market could reach around £10.5 billion in 2014, up from £6 billion in 2010.

THE SERVICES IN THE CLOUD

The multitude of IT services available in the cloud include familiar web-based email services such as Windows^® Live Hotmail^® (Microsoft^®), Yahoo!^® Mail, Gmail^® (Google), and the search engine facilities Google, Bing™ (Microsoft^®), Yahoo!^® and AltaVista^®. They also include the social networking services of Facebook, Twitter, Friends Reunited, Bebo, Flickr^®, YouTube, MySpace and LinkedIn^®, which provide chat, instant messaging and file sharing services. But there are a growing number of other services available. Two examples from different ends of the spectrum are Zynga^®, which provides online gaming services, and Wikileaks, which publishes and comments on leaked documents alleging government and corporate misconduct. These services are often provided free of charge to the user.

There are also a range of paid-for business-orientated IT services. These are provided by suppliers including Google, Microsoft^®, Amazon, Salesforce.com^® and Tempora. They offer a suite of services to assist with business management. Google offers Google Docs for word processing, Business Gmail for emails, Google Calendar for diary management and Google Sites for website management, and it even offers different editions of its applications for different sectors (education, governmental and ‘not for profit’). Microsoft^® offers Windows^® Azure that allows users to build and host applications on Microsoft^® servers (PaaS).

Amazon Web Services (AWS) offers its Elastic Compute Cloud (Amazon EC2), enabling customers to rent space on Amazon’s own computers from which they can run their own applications. Tempora provides a time recording and profitability analysis system for creative agencies and professional service firms, and Salesforce.com^® provides customer relationship management solutions.

THE EVOLUTION OF CLOUD COMPUTING

Long before the term cloud computing was coined, software suppliers were providing services to their customers from remote servers via internet-enabled computers. This was called Application Service Provision (ASP) and was the original platform of IT service delivery to emerge from the convergence of computing and communications in the mid-1990s. However, the ASP model ultimately was an experiment that failed. Firstly, it involved more complicated initial installation and configuration (at the customer end) than is involved with today’s on-demand cloud services. Secondly, it originated as a means of providing software on a one-to-one basis rather than on the one-to-many (multi-tenant) basis of cloud computing, where one supplier has many customers. Consequently, ASP lacked the huge advantage that cloud computing enjoys of being very scalable.

The emergence of software as a service (SaaS) in around 2001 signified the beginning of software delivery based on multi-tenant architecture involving network-based access to software managed from a central location and removing the need for customers to install patches or upgrades.

The term SaaS is useful because it highlights the principal difference between the internet-based model of software provision and the more orthodox licence and installation-based model. The latter involves a customer being granted a licence to use a software package, while the former involves the provision of a web-based service under a contract for services. There are considerable differences between a software licence and a contract for services.

CLOUD FORMATIONS

The cloud environment is subdivided into public, private, hybrid and community clouds.

• Public clouds are those in which services are available to the public at large over the internet in the manner already described in this chapter.
• A private cloud is essentially a private network used by one customer for whom data security and privacy is usually the primary concern. The downside of this type of cloud is that the customer will have to bear the significant cost of setting up and then maintaining the network alone.
• Hybrid cloud environments are often used where a customer has requirements for a mix of dedicated server and cloud hosting, for example if some of the data that is being stored is of a very sensitive nature. In such circumstances the organisation may choose to store some data on its dedicated server and less sensitive data in the cloud. Another common reason for using hybrid clouds is where an organisation needs more processing power than is available in-house and obtains the extra requirement in the cloud. This is referred to as ‘cloud bursting’. Additionally, hybrid cloud environments are often found in situations where a customer is moving from an entirely private to an entirely public cloud setup.
• Community clouds usually exist where a limited number of customers with similar IT requirements share an infrastructure provided by a single supplier. The costs of the services are spread between the customers so this model is better, from an economic point of view...