Ria:
Hello Meghana! How are you?
Me:
Hi, I am fine. You say any reason of calling me?
Ria:
Yes actually I have been given to prepare a presentation on “System
Architecture” and I have no idea about it can you help me out?
Me:
Ya sure. System Architecture is a very simple topic. System architecture is the conceptual model that defines the structure
and/or behavior of a system. Information System basically has two major parts: The Database and The Applications.
Ria: Can you tell me how these two are clubbed up in an
architecture?
Me: See in any Information System data has to be distinct
from Applications but to understand this in detail let me explain you the 3-tiers in
architecture:
1. Single-Tier Architecture: In
this all processing is done in a single computer and all resources are attached
to the same computer.
2. Two-Tier Architecture: It
is client-server architecture. The
client that runs the application and the server that handles the database
back-end. The client-server solution also allows multiple users to access the
database at the same time as long as they are accessing data in different parts
of the database. The client
machines where connected to the server using TCP/IP protocol. Example
of this is personal computers.
3. Three-Tier Architecture:
This has a third layer business logic tier/application server between the
previous two (client and database tier) layers. The application runs the traditional
client/server model but from the web server (middle tier). The client only displays
the GUI and data but does not play any role in producing result. Example is an
Internet Browser.
Similarly
the data layer can be split to form n-tier architecture.
Ria:
Oh this seems interesting. But I don’t understand why did one need to move from
single tier architecture to n-tier? :-(
Me:
Nice question. Each system had its drawbacks and so had to come up with a
higher version.
·
Single-tier architecture was simple and efficient
but as anyone could use the data it was not secure. Also the cost of the
central machine was very expensive. So we went for two-tier architecture.
·
Dual-tier execution was comparatively more
secure and faster but with clients more than 50 the speed of execution slowed
creating a need to go for a three-tier system.
·
In 3-tier architecture due to the
introduction of middle layer the client is handling only presentation logic.
Thus the traffic with the server reduces and speed increases. But these systems
are complex and costly.
Ria:
Cool. I have also heard about ERP system, can you throw some light on them too?
Me: An ERP
(Enterprise Resource Planning) is an integrated system that operates in real
time (or next to real time), without relying on periodic updates. It maintains
a common database, which supports all applications. It is faster to implement
and easier to manage.
Ria: Thank you
very much. I have one last question, these days data security is a very
important issue, is there anything that can protect your data?
Me: Yes your
concern is very right. In today’s world of malpractices security has become an
important issue. For this there are “firewall servers” which are basically a set of related programs, located at a network gateway server that protects the resources of a private network from
users from other networks. Basically, a firewall, working closely with a router program,
examines each network packet to determine whether to forward it toward its
destination.
Ria: Thank
you very much. Now I can very easily make my presentation. You have relieved me
of the tension.
Me: It was my
pleasure.