System Architecture

“There are no strangers in this world; only friends who haven’t met.” I’m a firm believer of this saying and the origin of the conversation starts from this principle only.

2 days of holiday,135 kms of journey ,a rainy and dusky weather and a tiring 1^st week of MBA classes-Now I guess these are the reasons enough which compelled me to take the “Steel Express” from kharagpur to my beloved home town ,Jamshedpur. Normally I don’t suffer from this home sickness disease (well, for some that may be) but then meeting with some of the old pals coupled with reasons mentioned above did me in for the journey.

I’m a passionate traveler and I always make sure that I don’t miss the colourful world on the other side of the coach window but since it was dark in the evening I gave up the idea and started using all my energy in reading those heavily and exaggerated used financial terms which appears daily in the Financial Express newspaper. 30 Minutes into the newspaper and suddenly I had to adjust both my newspaper and my seat. There was this guy who asked me to move so that he could sit there. With the dress he had wear ,the attitude he was showing  and language he was using during his telephonic conversation with one of his friend, I could surely tell that he was an Engineer. Now, don’t get me wrong here. Engineers definitely are not aliens but then you could easily spot them in a horde of other human beings. Now, Once he got settled he started asking me questions regarding my life at IIT kharagpur and all other details about the institute. Now it was my turn to get shocked. I mean  I could guess him to be an engineer but how on earth he could with so confidence  tell me that I’m an MBA student of VGSOM. Then suddenly I looked towards my bag and it got all cleared (thanks VGSOM for providing with such a good laptop cum luggage bag with a visible logo).

As I had  guessed, his name was “Ranjan” and he was an Electrical Engineering Student from some engineering college of Bhubaneswar and was confused and baffled with all those jargons they use in DBMS class in 4^th semester .He asked me for some help regarding  System Architecture and I decided to make his life a bit easy by explaining this to him. So, here goes the conversation. 

Ranjan - Bhaiya,now since you’ve worked as a software engineer and are currently studying the System Architecture ,could you just tell me what exactly is system architecture and why do we need to study them.

Me – Well,Ranjan broadly we can say that System Architecture is all about computers, data and applications. It is the way in which system components interact. Architecture depicts the way in which different hardware components are interconnected and which software is running on which hardware.Now before you go to system architecture you need to understand some terms like platform and application.

 Ranjan – Ok, please explain these terms then.

Me -  Ok I’ll explain these terms one by one to you. A platform is a combination of hardware (RAM, ROM, INTEL/AMD chips, NVIDIA graphic card etc.) and the main operation system (like Unix, Windows Vista etc.) which facilitates as the name suggests a platform for the softwares to run.An application is nothing but a software, that runs on a platform and delivers the desired functionality. For example, Windows media player, MS office, Adobe reader etc. are all applications. An application processes on some kind of data. For example the file opened by MS Word, or the music file played by media player are all data for the respective application.

Ranjan – Ok,it seems interesting. Enlighten me.

Me - Now there are different types of computer architecture available. The simplest of them all is the Single-tier architecture. In a single-tier architecture, both data and application reside on the same platform.So, when you listen to any song in the vlc player installed in your system its an example of Single-tier Architecture.

Ranjan – So, I guess there must be more architectures…2 tier,3 tier and multitier.

Me – You’re absolutely correct. See,you’re getting all these terms with more ease then I thought.

In a two tier architecture, the data is separated from the application and stored on a different platform. Each user has a copy of the data on his own client machine and all the machines are connected together by a network – the Local Area Network (LAN) and and talk to each other.

Three  Tier architecture is a bit complex but then I think I could explain that easily to you. In a three tier architecture system, the application is split into two parts- One which handles the user interface like screens, menus etc. and the other which handles the complex business logic. Thus any significant change needs to be done only at the central server and not at each location. This is called as application server.Some examples of Three tier architecture syatem are An ERP product like SAP, BaaN, or Oracle eBusiness suite

Ranjan – God,its looks so complex when I read from the book but now I could really understand  all these complex  things.You didn’t told me about multi-architecture.

Me – Boss hold your horses. Let me go step by step or else I would sound you like another of those complex System Architecture books. Now, In a multi-tier architecture, an additional machine called the web browser is placed between the application server and the user. The web server acts as a translator between the client software on the user machine and the application server. Now a multitier Architecture has many advantages like there is no need for a specialist software at each client location. The web server thus converts the data traffic from the application server to a format that is understood by anyone who has a web browser.

Ranjan – Ok, what all you’re talking is great but then what about the security issues with multi-tier Architecture.

Me – That has been completely taken care of.There is an additional firewall server that will serve as gatekeepers between the public internet and company’s local area network. Unauthorized users trying to reach the company servers from an unauthorized computer would be denied  access and in fact would not be able to detect the presence of the servers at all.

Njan – Bhaiya,I didn’t even in my dreams could have though that I would be understanding these terms and that too with such ease. Could you refer some books for this?

Me – Well,there’s a lot of  e-books you could download but then I would suggest you to go through these slides  http://slidesha.re/mis-sysarch . These slides are prepared by our faculty, Prof .Prithwis Mukherjee. He teaches MIS at VGSOM, IIT Kgp.