Cloud Computing - What is it and how do you use it?
Cloud Computing generally refers to the provision of hosted services that are delivered using the Internet although some service providers also promote their more traditional services under the same banner, cloud services have three distinct characteristics that differentiate them from more traditional services:
They are sold on demand and are billed by the minute, the hour or per use
They are "elastic" the user can consume as much or as little as required
They are fully managed by the provider, the user simply connects to use them using a computer and of course an Internet connection
A cloud can be public or private. A public cloud is just that public and the provider provides this to anyone using the public Internet. A private cloud is provided to a limited number of users on a proprietary network. Organisations can also use public cloud services to provide some or all of their private cloud, this is called virtual private cloud. Regardless of what way cloud services are used the goal is the same, to provide easily accessible, scalable and reliable access to IT services.
Cloud services can be categorised as:
IAAS - Infrastructure as a Service - Provides organisations with server, storage and network elements. The service provider owns and manages the physical hardware and infrastructure. The organisation manages operating systems, server applications and databases. These services are generally billed on a per use basis.
PAAS - Platform as a Service - Delivers a hosted applications framework that organisations and developers can use to provide an application without the cost of providing the physical infrastructure. This typically involves a programming language, database and toolset. Customers who can most benefit from using PAAS are companies with large mobile workforces.
SAAS - Software as a Service - Provides a client or organisation with an application that is delivered through a web browser. The user typically does not need to install any software and does not need to manage any infrastructure the application is provided through a portal.
- DRaaS - More recently Disaster Recovery as a Service is gaining in adoption - Provides you with a copy of a physical or virtual server that is replicated to a hosted physical or virtual server in the providers datacentre.
Cloud Computing Deployment FAQ
Cloud Computing can provide services that greatly enhance your IT services and infrastructure but can also introduce issues that you may not have considered.
- Cost - Cloud services are 'elastic' which means that you in theory only pay for what you use, however this also means that you pay more when you use more. Data never gets smaller so if your usage increases so will your cost.
- Portability - Cloud Services are not generally portable between cloud providers or even to the Vendors own local version of the software. For example you may use a SAAS based CRM but it may not be possible to migrate this data to a local version.
- Application Suitability - Virtually any application could be installed on a cloud based server or service, however this does not mean that it should be. For example applications and data with privacy requirements should not be deployed in a public cloud and applications with specific hardware dependencies are also not suitable.
- Availability - If you commit to using cloud based applications then you must make sure you have fast reliable Internet connectivity. This means E-Fibre or large tier Internet connections preferably with an SLA.