A talk with a Friend

Day before yesterday my friend called me to teach her System Architecture. Her name is Pallavi. She is also doing her MBA from Pune.

The conversation between us went as follow:

Pallavi:  Yaar thoda urgent hai.. Please can you teach me this topic "System Architecture".

Me:        Ok.. What happen? Why so urgent?

Pallavi:  Are we have a test tomorrow, so need to learn now only..

Me:        Why don't you ask your faculty to teach you the subject?

Pallavi:  If I would have understood what he teaches in the class I would not have asked you the same question. And since you have Prithwis Sir teaching you in your college, I knew that calling you will serve the purpose.

 Me:       Ohhh... got it now...Yeah we are really lucky to have him here...

Pallavi:  So now please teach me na...

Me:        Okay... Let's go... I will teach you..

Me:        See.. System Architecture is a model which that defines its structure, components and the relation between them.

The system architecture can be classified into different types of architectures which I will be telling u one be one.

Firstly We have an architecture called "Integrated Architecture" or "Single Tier Architecture" , just like we have our laptops at home. The basic principle is that the data must be logically distinct from applications. Here we don't need to separate data from applications even if they are on the same physical hardware.

Then we have "Two Tier Architecture" or "Client Server Architecture" where the data resides in the server. The server can be Oracle, mySQL, SQL Server etc. Here the application is stored in different machine unlike the integrated system. The application has a presentation and business logic. It communicate to the client machine on Local area network (LAN) via TCP/IP. It has certain Advantages and Disadvantages. The main advantage is that the server no needs to bear the processing burden when hundreds of users are using it. But the disadvantage is that it requires a high bandwidth which slows down the application....

Then we have one more type of architecture named "Three Tier Architecture" where the application itself is partitioned. Here the business logic is kept centrally so that changes need to be done only at one system which has the application on it. Presentation logic will be there on the clients on that the data transfer over the network is minimized.

Then the last one is "Multi Tier Architecture". Unlike other architectures we use internet over WAN as a communication media. Anyways both internet and WAN are TCP/IP based. The only difference is that internet is public and WAN is private. The internet is inexpensive but insecure. We don't need any specialized software for Clients but the application has to be web enabled.

Now the various types of Architectures are over. There are various other things to ponder when you design a particular architecture.

In order to manage the complexity of the data for example banks, offices etc we came make use of RDBMS that is Relational Database Management System. It has certain advantage that there won't be duplication of data. Also there won't be inconsistency of data across locations and time periods. It is also easier to manage and you can always take the backup and restore the system in case of emergency. It is quite secure and requires user authentication.

To manage even more complex databases we have ERP systems. It has very tight integration between the functions. No separate activity required to synchronize data. It can be purchased as a combined package from the same reputed vendor. It is faster to implement and easier to manage and maintain.

In order to protect data from hackers and intruders, we can make use of firewalls in the network. Placing the firewall doesn't guarantee complete protection. We can only try to configure it in such a manner so that we can protect our network to the maximum possible.

So that's it.. I am done..

Pallavi:  Nice yaar... Now it sounds so easy.. Well thanks a lot Kamya..

Me:        It okay yaar...Chal then I have to leave. Bye Bye and Take care...

Pallavi:  Bye.....