threetierarchitecture

THREE TIER ARCHITECTURE
Raveendran Krishnasamy
A n Easy Learning Series.
Three Tier Architecture
 Raveendran Krishnasamy



Table of Contents
Introduction What is Tier…? 1
What is 1-Tier………? …………………………………………… 2
What is 2-Tier………? 3
What is 3-Tier………?................................................................4
Mind
Mind Map …………………………………………………….5
Chapter
1

Introduction
What is Tier……?

Have you seen Movie Theatre’s arrangement….?

Fig 1.1

It is arranged in the following manner:

First Class
Second Class
Third Class

There is a border between each class. It seems like layer.

Have you seen wedding cake…..?
Fig 1.2 Wedding Cake.

It contains several layers…At the top of the cake; it is dressed with Cherry fruits.

Chapter
2
What is 1-Tier……?

We understood what is Tier. Okay fine. Now we can discuss about what is 1- tier….?

Let us take your stand alone PC. Your PC is stand alone. It means it is not connected with any other computers or net works. There you can create a word document and save it. You can read it whenever you need.


Fig2.1.This is a Stand Alone PC.

One thing we can understand here, your document is saved. ie Your Data is stored. But there is no Database Logic.

(What is Database….? A collection of information organized in such a way that a computer program can quickly select desired pieces of data. You can think of a database as an electronic filing system.).

No data sharing in Stand alone PC.

Stand Alone System is the best example for 1-Tier Architect. i.e.… there are no two layers. Like in Cinema Theatre only one class instead of several classes. One layer in cake. Direct access within your computer.





Chapter
3
What is 2-Tier…..?

Now we can discuss about 2-tier architecture.

Let us assume Mr.X is booking a Railway Reservation from Hyderabad to Chennai by Hyderabad Express at Counter No 1. In the same day, the same time Mr.Y also booking from Hyderabad to Chennai in the same train at Counter No 2.

Staff from Counter No 1. Keying the data into computer and checking the availability into their Database. What would happen if the staff from Counter No 2 keying in the same time of Counter No 1….? Surely, there might be a great chaos and confusion occurs. There is a chance to lock the record.

But practically we are seeing, we can book the tickets anywhere in India. How it is possible…?
Even there should be at least a Nano seconds difference between two staff in keying. Let us assume Counter No 1. Staff keying at first than Counter No 2. System locks that record. So the Counter No.2 staff is put into queue.

Here Staff is end user. He uses an Application Software. He feeds your data through this Application Software and sends requests to Server. Database and Server are integrated as a big computer. Such like this technology is called as “Client-Server Technology”
Fig 3.1 Sample Client-Server Technology.

Okay. What is Client-Server Technology…..?

- It is a Network Architecture
- It separates Client from Server. Client has an Application using GUI.
- Each Instance of Requests Client software can request to server.

Here we can understand the following facts:

1. Database runs on the server.
2. Need Database products like Oracle/DB2/Sybase/Informix/Ingress


Chapter
4

What is 3-Tier…..?


Here we can consider a different scenario. Let us assume a small Shop. All data are stored in a server/DB. The server is located at a separate computer room. There is 8 counter. Each terminal is connected with this server. All the requests are going to server and getting required data and you can update new transactions.

The above mentioned technology we can call it as “Client-Server Technology”.

Now the business is expanded. It has so many branches in various locations throughout the country.

All transactions through various locations should come under one database. It is not possible to do transactions through this Client-Server Technology.

What can we do…? Let us think…..

Huge transactions may occur in various locations and it is updated in one database…..Now is it okay…?

Again there is a chance to get damage on the database/locking records/getting chaos and confusions, because of number hits on the database.


So one thing we can understand. The number of hits should be minimized or organized, else problem will continue.


OK. Now what we can do….? Is there any solution to solve this problem…..?


Yes. Now we are introducing one layer between this client and server database. Speaking with terminologically, we are introducing a middle tier between client and server database.


This middle tier receives all the requests from client instead of server database. This tier organizes the requests and making queue to sending to database and retrieving from database. Thus the number of hits is organized and load is balanced.

This middle tier is called Application Tier or Application Server.

Here in 3-tier Architecture, the following tiers are available:

- Client Tier
- Application Tier
- Database Tier

For recalling purpose, here below I have given Mind Map for the above discussions for your easy memory.

The Art of Studying...

The Art of Studying-1

Dear Siddhas,

Recently one of our Siddha chatted me. She worried about her son's studies. Several Siddhas are worrying about their studies...and expecting proper guidance like

- How to study....fast...?
- How to recall....?
- How to focus on studies...?
- How to improve memory....?

If your child is an alphonian okay, he can apply all the amp techniques. Else, no need to worry. You can go thro' this serial. Sure your child/student will perform very well in their studies.

I didn't have any idea to write this article till this morning. Morning I had a chat with one of our Siddha. She worried about her son's studies. Her son also a 3rd level siddha, even unable to score good marks....
I am writing this article for that small boy....! and dedicate to all students who is suffering in studies .

Before discuss, I want to tell one thing.

Yes. To score high marks-
You no need to be a smart one/intelligent/coming from affluent background and etc.,

Have you observe many people expose themselves as born gick/suvvy ....? Their talks are more technical and they use more terminological words and they always try to expose themselves they are great and different from others...

If you stop them and ask them to explain...once again they try to talk Non-stop terminological phrases and try to make u fear and depression and they will declare, "You are fit for nothing..." Why...?

Because of poor self-confidence on them and poor understanding on subject. They are trying to escape by exposing they are computer gicks. You can understand these peters and you can find them mostly in IT profession. :):)

Digestion of study is very important. For Example we can take Three tier architecture.

Don't get fear when i am talking about Computer related things if you are not related with software. (Do u think that is a big issue...? )

Here many of IT professional, they can gimmicks and make you fear about what is 3 tier architecture...? They try to make you confuse ...Don't get fear. Read these two documents which I have attached with this mail.

One is Three tier architecture pdf document.
Second one is Mind Map for the above subject.

Now any one who is non-computer professional also can easily understand what is Three tier architecture by going thru' these documents.

Dear student, Now I am giving Home Work for you, till meet you in next episode of this serial.

Home Work:

Take a subject.
Read slow...very slow... line by line.
Underline each words by different colors.
Now draw the whole concept as a picture.
Share me your experience...
Take my documents as example. In that way, you can prepare your notes....

With Love
A Co-Passenger
Raveendran



Bibliography
Bobby Deporter with Mike Hernacki. Quantum Learning: Unleashing The Genius in You.
Buzan, T. (2006). MIND MAPPING. UK: BBC ACTIVE.
Buzan, T. (31-Dec-2006). The Buzan Study Skills Hand Book. UK: BBC AVTIVE.