Cloud computing is all the rage, the catchphrase du jour. The problem is that everyone seems to have a different definition. As a metaphor for the Internet, “the cloud” is a familiar cliché, but when combined with “computing,” the meaning gets bigger and fuzzier. And with so many vendors reinventing their marketing spin to bend the term to their own purposes, it’s no wonder there is massive confusion.

Increasingly, our clients are asking whether they need to replace their aging servers with new ones, or “just move to cloud computing”?

Sadly, with so many vendors working to own the space, there are few consistent answers and even fewer standards. Even Microsoft is devoting massive marketing budgets to convincing the world it is now a major cloud computing vendor! (See www.microsoft.com/cloud for an example of how to make an impression while saying absolutely nothing!)

So let’s see if we can demystify this phenomenon somewhat. This article draws on many sources, but for the definition, I found one given by Crikey.com.au the most accessible, and summarise it as follows.

Every business needs a shared location to store data, enable electronic communications and run business applications. A generation of businesses has installed servers in-house to perform these roles. With cloud computing, you instead rent capacity from a service provider and connect to it over the internet. The service provider installs, maintains and upgrades hardware and software as required. Typically you’ll rent each service, such as data storage or email or accounting, rather than ‘a server’ as such, and pay $X per user or business per month.

Amongst all the confusion, there are probably four major ways that vendors are rushing into this space, and (of course) acronyms to match!

HaaS – Hardware as a Service

This model simply provides a server in a rack off-site for you to manage. You are relieved of the costs and risks of an on-site computer room, and the power costs of running it. However, the server is still yours to populate with software, and to manage, in exactly the same way as you would with an in-house server. It’s just one less box to find space for at your place.

IaaS – Infrastructure as a Service

IaaS builds on HaaS by providing infrastructure services, such as an operating system, backup and recovery, monitoring and management tools and so forth, in effect replacing both an in-house box and much of the cost of managing an in-house server.

SaaS – Software as a Service

Taking this a step further, SaaS provides the application software needed for your business, whether that be mail services (e.g. Exchange), web services (e.g. Apache), file sharing, or specific applications such as accounting or business automation.

DaaS – Desktop as a Service (Desktop Virtualisation)

A specific form of SaaS, this provides a remotely-hosted desktop computer. I.e. not only your server(s) but also your desktops are hosted remotely. Typically, these are accessed through a remote desktop protocol from another computer (e.g. a laptop or thin client). Desktop management is outsourced as well as server management.

Often you access these resources through a web browser, rather than through specific desktop applications. In the case of virtual desktops, you will likely use a remote desktop protocol.

In all the above cases, you may in fact be sharing hardware with other clients of the service provider. Even HaaS may be a virtual server running with other virtual machines on common hardware. (See this article for a backgrounder on virtual machines.) In the case of SaaS or DaaS, almost certainly you will be sharing servers and services with many other clients.

By now it should be fairly obvious that there are major considerations afoot when thinking about computing in the cloud. Next newsletter we’ll consider the benefits and the issues inherent in cloud computing.