Systems Architecture

          It was evening time and I was about to do what I do the best i.e. sleep when someone banged my door. It was Enayath with my other class mates- Abhishek, Silky and Raj. They had missed the 1^st S.E. class and hence wanted me to explain what Dr. Mukerjee had taught.

Abhishek: Kartik, you very well know how good we are in IT so I want you to explain us Systems Architecture slide by slide.

Me: Okay I will try

Everyone opens Dr. Mukerjee’s presentation and I not so confidently start to explain.

Me: Just like a computer program has two parts- data structures and algorithms, an Information System has two parts- database and applications. And among the various architectures that we are about to learn, the basic or the primary architecture is one in which we separate the data from the applications.

Enayath: But Kartik, how do you separate these two?

Me: Take the example of a CLASS in a programming language which was taught by Dr. Mitra from HP. If you remember he taught us the concept of modular programming in which you have various classes and each class comprises attributes and operations as separate entities.

Enayath: Yes, now I got it.

Me: Now let us understand the various other architectures- two tier, three tier and multitier. A two tier also known as the client-server architecture is one in which the data resides in the server side and the applications are on the client side. For example our CMIE server which is the database lies on the server side and we have its frontend in our laptops. In three tier architecture you separate your business critical applications at the server side.

Silky: Kartik, I did not get the concept of this three tier architecture. Can you please elaborate on this?

Me: Okay, take an example of a banking application. A clerk would only require a simple frontend that has the accounting details. He does not have and is not supposed to a have a complex and a critical application like credit verification. So this application resides in the server which can only be accessed by the authorised person.

Silky: Okay now it is clear.

Me: Now if a company web-enables the entire process, the clients would only require a web-browser via which he would get his application. And for this the company would require a web server. This architecture is known as a multitier architecture.

Raj: But Kartik don’t you think that there will be security issues if opt for using internet?

  

Me: Yes Raj, you are right. Internet is a public network and is prone to hacker attacks and to counter this you would require firewalls, antivirus software etc. But we have already learned the huge benefits of web services to make up for these security issues. Moreover Dr. Mukerjee explained us the advantages of using an integrated database and ERP package.

Abhishek: Thank you Kartik, I think we already know the concepts of RDBMS and ERP which you taught us for ITM-2 end term exam. So let us not waste your precious time which I am sure you will spend for sleeping. So you can sleep happily now.

Me: Thank you Abhishek. You very well understand that I am a hardcore Garfield fan so I should sleep now.