|Buyer's guide to cloud computing|
Salesforce.com's recent announcement of its VMforce platform for deploying Java applications is the latest in a long line of announcements from a wide range of IT suppliers of such on-demand(or cloud-based) offerings. IT departments may be confused about the range of products and the terminology used to describe them. They may also be unsure of the risk and benefits.
What's in the cloud?
Essentially there are three levels of on-demand offerings. These mirror the way IT is increasingly deployed internally.
The lowest level is infrastructure-as-a-service (IaaS). This is where pre-configured hardware is provided via a virtualised interface or hypervisor. There is no high-level infrastructure software provided such as an operating system, this must be provided by the buyer embedded with their own virtual applications.
IaaS is particularly useful for organisations that are running virtualised applications internally, but may want to make use of additional capacity when their own resources are stretched. On-demand storage is also considered as IaaS.
Platform-as-a-service (PaaS) goes a stage further and includes the operating environment with the operating system and application services. PaaS suits organisations that are committed to a given development environment for a specific application but like the idea of someone else maintaining the deployment platform for them.
Software-as-a-Service (SaaS) goes the whole hog, providing fully functional applications on-demand to deliver specific services such as e-mail management, CRM, ERP, web conferencing and an increasingly wide range of other applications. Many independent software vendors (ISVs) are now turning to the SaaS model and making on-demand versions of their applications available. To do so they are often using IaaS or PaaS for deployment.
Cloud service providers
Much of the coverage of on-demand products focuses on a few high-profile IT companies and it is easy to think the market is limited to them. This is simply not true; many managed hosting providers are now providing IaaS and PaaS as an alternative to their traditional dedicated infrastructure hosting services. Add to this the number of ISVs now offering full or partial SaaS and the aggregated market these organisations represent is easily as big as that of their higher profile counterparts.
Choosing a supplier will depend on the type of platform required, the service levels on offer and the guarantees that can be provided on security and governance.
Perhaps the most high-profile IaaS platform is the Amazon Elastic Compute Cloud (EC2). Other examples are Attenda's RTI and Rackspace's Cloud Servers (currently in beta and due to be launched in the next few months).
PaaS suppliers include Microsoft with its Windows and .net-based Azure and Google with its Java-based AppEngine. Some PaaS offerings have a particular focus; force.com (the original salesforce.com platform) only supports applications developed using its proprietary Apex language. It was mainly aimed at customers wanting to extend their salesforce.com CRM deployments and ISVs wanting to sell their applications to existing salesforce.com customers. The new VMforce product allows them to do that with Java as well. Rackspace's Cloud Sites is used primarily for websites, although some use it for applications.
SaaS includes a wide range of products including enterprise applications such as CRM and ERP, utility services including e-mail, web conferencing and content security. The range of suppliers is huge.
Working out the benefits
So why all the fuss? What is actually in it for the buyer? If you focus on the cost of the platform, it does not seem to add up. If you buy your own hardware and software after eight quarters it is quite possible that the cumulative spending on an on-demand subscription could outstrip that of an on-premise deployment.
But this only looks at hardware and software costs. The point is that by using an on-demand supplier you are also buying access to highly secure enterprise datacentre facilities, skilled staff specifically trained to support given applications and infrastructure, regularly scheduled back-ups, built-in redundancy and easily shared applications for supporting cross organisational business processes to mention just some of the benefits.
Add all this in and for many the cost is easily outweighed by the reduced risk and added value of on-demand services. And don't forget, at some point all that on-premise hardware and software will need replacing; with on-demand providers that is part of the service, or at least it should be.
For many small and medium sized businesses the business continuity option offered by on-demand services should be irresistible. For many enterprises, running utility IT applications via on-demand services also makes sense, freeing IT departments to focus on the applications that deliver unique value to their businesses.
Bob Tarzey is analyst and director at Quocirca
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This was first published in June 2010