Characteristics of Cloud – Part I

In the coming posts, we’ll see some important characteristics of cloud computing. The first one being, On-Demand Self Service.

Let’s first see how data centers were used in traditional times.

Scenario: A data center established at a place is managed by a person named Bob who is the operations manager. Someone inside the data center handles the whole infrastructure, let that person be Sam. (Recall from the last post, description of IaaS – how we keep infrastructure in one room and one person to manage that). A user, who needs to use data center, let it be you, calls Bob and asks for let’s say one more Linux machine for his account, some more SSDs etc. Or you may be facing some networking problems, for which you call Bob to look into the matter.

So, every time you need something, you call Bob, who in turn instructs Sam to do the required operation. What we see here is, things are not much automated. You call Bob, demand something which may not be easily available. Sam may have to go out and buy some equipments for configuring what you want. This may add up some delay for a user. Also, Bob and Sam are humans. They’ll not be available 24X7 for responding to your calls. The situation is similar to calling the customer care for some problem, and waiting endless on the call listening, “Your call is valuable to us. All operators are currently busy. Please hold while we try to connect your call.”? This is a cumbersome process.


What we see above is the notion of the cloud. A user is provided with an interactive console using which he/she can request for machines. As he clicks on OK button or confirms his requirement, a process starts running on the data center side which automatically configures two machines with Linux OS (orange coloured in the above diagram) and assigns it to the user. What do we notice above? There is no human involvement, no waiting. Flexibility to do your things anytime in the day. Whenever customer feels the need, he can service himself at any point of time. Request will be automatically and immediately (in almost all cases) served.

As a proper definition, on-demand self service allows a consumer to unilaterally provision computing capabilities, such as server time and network storage, as needed automatically without requiring human interaction with the service provider.