Evolution of the Cloud

Arcus Global

Arcus Global
December 5, 2009

Like Gas, Electricity or Water, Information Technology should be simple, ubiquitous, and cheap. Users / customers of the service should not enjoy or dislike using IT anymore that they do using the 220 volts of power from a socket. This is the key to Arcus’s methodology for advising and delivering cloud services to the public sector.

In recent years, huge investments have been made by both public and private organisations in data centres, with hundreds of thousands of servers providing services to tens of millions of users. The appearance of Platform Virtualisation technology such as Virtual Machines (VM) allowed the de-coupling of physical resources from their uses. The physical resources are shared between applications and users, and sophisticated technology governs how they are distributed and accessed. Seeking to improve utilisation, most of the providers who invested in data centres started offering their resources to anyone prepared to pay for them. There are several key flavours of such services:  Software as a Service, Platform as a Service and Infrastructure as service. Together, these can be described as “Cloud Computing. Our tools and pilots can help you to carefully evaluate the opportunities for each are of your infrastructure both in terms of savings, and service improvements.

It is important to examine each one of the above concepts in turn:

Software as a Service (SaaS) is where an application is offered to users on a “pay as you go basis”. For example, a user needs to use an application to perform a specific task – he or she then opens the application, usually through a web interface, and uses it for several hours. Once he or she has finished, the applications is closed. The user will then be billed for the specific use of the application either on the time basis of time, or another measure of usage. The application may be used entirely through a web browser, or may be installed on the user’s computer for offline use, but such installation is normally disabled after a period of time. The user does not have to pay an up-front cost of the software licence, but instead pays for the use.

Platform as a Service (PaaS) is where the user’s application is used on a virtual platform provided by an external provider. For example, a user has a software application that needs to synchronise with a server database. The user then “rents” the server (platform) on a per hour basis as necessary, scaling the amount of servers required dynamically, based on the demand for the application.

Infrastructure as a Service (IaaS) is similar to the above, but instead critical components of the infrastructure are “rented” from 3rd party providers. Such infrastructure may include communications hardware, firewalls, storage farms and other elements.

Clearly, cloud computing is a new industry, and as a result new concepts and methods appear all the time. The landscape of 3rd parties providing these services is also constantly evolving. Arcus Global provides a simple methodology for