It was a gloomy sultry evening, and my mood gave a tough competition to the weather outside. From morning we had a power cut due to some grid failure and to add to that the drizzle never seemed to stop making it more humid and pathetic. “Welcome to VGSOM , IIT Kharagpur “, this is what rang through my ears . I was wondering what kind of a welcome were the seniors talking about ? ?? No Fresher’s party yet, and to add to our misfortune went on the clubs selections, sitting all night through to get done with our presentations for the club interviews and not to leave the sessions and events even on the weekends.......
10 subjects, lakhs of assignments, surprise quizzes were waiting to devour us in the days to come. Keeping worries aside I went to Dipanjan’s room (who is pursuing MTECH in Computer Science out here in IIT Kharagpur and happens to be in his final year) room to have a break. He was busy explaining system architecture to 1st year UG guy. Now we had a subject called management information system which I knew would require fundamental computer hardware and software knowledge. So I thought it will be prudent enough for me to sit and listen to their discussion so the MIS gets easily tackled.
UG guy - what is system architecture and what does it contain ??
Dipanjan – A computer system architecture consists of four major components. Storage, processor, peripherals, and input/output. The storage system is used to keep data and programs, the processor is the unite that controls the operation of the system and carries out various computations; the peripheral devices are used to communicate with the outside world; and the input/output system allows the previous components to communicate with one another.
UG guy – so how is this storage and processing done ??
Dipanjan - have you heard of data structures and algorithms??
UG guy –Yaa, do have some vague idea, data structure is a way of organising data so that operations on the data are done in most effective way. I mean operations such as creation insertion , deletion , traversal , search , displays etc. and algorithms represent how this process is done.
Dipanjan – As you understand the fundamental process, I will tell you about single tier architecture which means that the data and the application exist on the same machine, for example both the word processor and the document which you create by using the word processor lie on your desktop only.
UG guy – But when there exists a large number of users and all of the want to access the access application ?
Dipanjan – that can be taken care by the 2-tier architecture. Here each user has a copy of the application in his own machine, but the common data that is used by all is stored in a common machine called the server. Since there is only one copy of the data available to all users, hence there will be no inconsistency when the data is modified by any user. It also ensured that individual machines are not loaded beyond their capacity because the application logic is placed on different machines.
UG guy - But again, I think using this architecture becomes a huge challenge when hundreds and thousands of users are involved because high bandwidth will be required to cater to such a large number of users.
Dipanjan - You are correct. This can be resolved by the Three-Tier architecture where the application is divided into two parts. One part, which handles only the user interface, is on the client machine and the other part containing the complex business logic is stored at a central location. This common location is known as the application server. Hence, any kind of changes to the application can be done once at the central server only. An ERP product like SAP or Oracle e-Business Suite is a suitable example of a well designed three-tier application where the database server exists at the back, an application server runs the ERP software in the middle and the ERP client software resides on every user’s machine.
UG guy – In that case the ERP software has be to installed in each and every user’s machine.
Dipanjan –Internet comes up with a solution for this, an additional machine called the web server can be placed between the application server and the user. Here the client software on the user machine has been replaced by the web browser which cannot communicate with the application server directly but needs an intermediate server for this purpose. This need is fulfilled by a web browser which converts the data traffic from the application server to a recognizable format. Firewall ensures that datas are safe denying access to unauthorized computers.
Suddenly the power was back. The grid failure had been resolved. We started to head towards the mess to have dinner. On the way I thought “ MIS first chapter covered”
