Cloud computing refers to the usage of IT resources delivered as a service over a network. It involves utilisation of shared services in terms of both hardware and applications. The concept is based on time-sharing of costly resources and harnessing advantages of the economies of scale. It is a result of exploring ways and means to ensure availability of computing power to users through shared resources and algorithms to optimise the usage of infrastructure, platform and applications. The common or pooled infrastructure contains multiple servers networked to distribute tasks pertaining to data processing amongst them. The power of cloud computing is maximised by usage of virtualization techniques, where end-users access the cloud through networked client devices for their applications merely through a web browser. Usage of Cloud enables an IT function to minimise their costs and issues associated with servers, network, applications, upgrades and maintenance.
Cloud computing has been adopted and propagated by major IT service providers and consulting companies. The concept originated in early 90s and has progressed significantly over time. The need was triggered by various factors, especially huge investment in data centers, which are highly capital intensive. Moreover, most of the data centers have a significantly high proportion of unutilised resources, with utilisation as low as 15% of their full capacity, which could be shared with others.
Deployment – Cloud can be deployed in the following models :
Private cloud – Cloud infrastructure created for exclusive use by an organisation, which may comprise of multiple business units. The cloud may be owned and supported by the user organisation, a third party, or a combination of these, and the Infrastructure could exist within the organisation’s premises, a service provider’s site or at a remote location.
Community cloud – a group of consumers that have certain common features and requirements create the infrastructure for their exclusive use. It may be owned and supported by one or more of the participating communities, a third party, or a combination of these.
Public cloud – The infrastructure is created for use by anyone. It may be owned and supported by a corporate, academic, public organisation, or a combination of these. The infrastructure is hosted at the premises of the provider.
Hybrid cloud – The infrastructure is a combination of two or more cloud infrastructures that continue to remain as separate clouds, but integrate seamlessly to enable portability of data and application across the clouds.
Benefits – Cloud computing results in several benefits to the customers as well as the service providers. Some of the benefits are :
Cost saving – Since the resources are shared across multiple applications hosted on the cloud, it reduces the costs. The benefits accrue from economies of scale, resource sharing and ‘pay per usage’ model.
Flexibility – Cloud computing enables faster set-up and ramp-down of resources. The Infrastructure can be easily scaled as per requirements, due to sharing and load balancing across resources. This leads to the end-customer getting a feeling of potential for infinite scalability.
Ease of maintenance – The service providers take care of application maintenance. They ensure the availability of applications with latest versions, updated patch sets and proper backups.
Platform Diversity – Cloud infrastructure offers support for a wide range of client platforms and operating systems.
Disaster Recovery – The service providers ensure business continuity and immediate recovery in case of any disaster.
Limitations – The limitations of Cloud Infrastructure are as follows:
- Privacy
- Security
- Possibility of Data Loss/ Leakage
- Geographical location of data – leading to regulatory violation in some countries.
Cloud computing is an on-demand service where shared resources like memory, storage, network, operating system and applications are provided to the customers as per their requirements, like the electricity grid, where a user pays for the service as per his consumption. A culmination of research on large scale computing with access to unlimited resources, it is an evolving paradigm based on time-sharing of costly resources and advantages of the economies of scale. Usage of cloud computing enables the IT function to minimise the costs and issues associated with servers, network, applications, upgrades and maintenance.
The author has three decades of industry experience and is currently acting as consulting advisor and mentor to several startups.