system architecture

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.