Simple Chronicle!

There is a lot of buzz around “cloud computing” in the tech space these days. Industry leaders have generally come to agree that cloud computing is a computing model where instantly (and hugely) scalable IT capabilities (software, hardware, services) are delivered in the form of a service over the internet.

The emphasis seems to be that cloud platforms have to be “scalable” but I want to argue that they have to be “elastic” as well. While scalability is key, without elasticity a platform cannot be truly considered a cloud platform.

Wikipedia defines scalability as:

In telecommunications and software engineering, scalability is a desirable property of a system, a network, or a process, which indicates its ability to either handle growing amounts of work in a graceful manner, or to be readily enlarged. For example, it can refer to the capability of a system to increase total throughput under an increased load.

The definition for elasticity is:

 (In Physics) Elasticity refers to continuum mechanics of bodies which deform reversibly under stress. Elastic refers to a reversible deformation of a material. In essence, Elasticity is the ability to grow and contract as needed.

So, while scalability ensures that the cloud platform can handle an increased load of users working on a ‘cloud’ application, elasticity makes sure that the cloud platform scales up or down based on need without stopping the way the business is handled. Without this, the economies of moving a business/application to the cloud do not make sense. In a typical enterprise, resources are only scaled up. When you want to handle more users, you buy more resources which idle at times of normal/low user load. This model can get pretty expensive over time and is the main reason why enterprises want to move to the cloud. A user scenario for this would be: target.com which is hosted in the cloud (EC2 I believe) can request more resources during the holiday season when more people visit the site and can release those resources when not needed at the end of the holiday season without changing the website or application. Elasticity of the cloud platform ensures this.

In fact, even Amazon EC2 is not truly elastic as the least unit of expansion there is a slice of compute power. In my view, “scale” indicates the size of a cloud computing provider while “elastic” indicates their agility. A small provider can be elastic and offer good cloud services as well.  So, when considering cloud platforms – dont just look at “scalability”, review how “elastic” the platform is as well.