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.....
