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| Jim and Mary |
Jim : Hey Mary !! How are you ? How was your day?
Mary : Don't ask me Jim. I am really upset with the Mrs Jane (neighbour). She mocked at me saying I unaware of the famous client server model. Since then I have been waiting for you. I want to know the entire story today. That is it !!! You look tired by the way.
Jim : (Sighs) , Mary, give me five minutes and I'll be right back .
Mary : No way Jim, you have to enlighten me right here , right now !!
Jim : Since I have no option ...here you go. Lets go back 60 years in time. We had something called Data Structures(DS) and we had algorithms which is now popularly called database and applications respectively. DS described what is to be processed and the algorithms gave the logic behind the method of processing the DS.
Mary : Ok ...so ?
Jim : The basic objective was to separate the data from the applications, even though they were a part of the same hardware.
Mary : What is "Two Tier Client Server Architecture" ?
Jim : This is a modification of the single tier architecture, wherein the data is stored on a central server and is connected to different machines(clients) through TCP/IP protocols. The entire set up is called a LAN.
Mary : Big deal !! Are there any positives out of this ?
Jim : Yeah !! The main idea is to place the data on a central server and place the presentation and business logic separately on each client. The positives are convenient graphics interface and the reduction of burden on the server when there are many users.
Mary : Interesting !! Did people stop there or were there any negatives to it ?
Jim : The biggest disadvantage was high usage of bandwidth which slowed down application speed on individual machines. Then there is always the problem of maintenance in case of distributed software.
Mary : Got it ....So they must have thought of a "Three tier architecture". Didn't they ?
Jim : (Sighs) Who says women are low on IQ ? Yes darling, then came the next edition- "Three tier architecture". Here the business logic was kept centrally, so that the changes in business logic can be done centrally at one location. The presentation logic resided on individual systems.
Mary : I am impressed. but Jim tell me one thing- Can we employ internet in this system ?
Jim : (In doubt) Have you read this somewhere?
Mary : (Laughs) No Jim, do you think I am a fool to ask you all over again ?
Jim : Nowadays every system has a default web browser. This can be connected to the centrally located internet server to access the presentation and the business logic along with the data from the database. This helps us in eliminating the installation of special software at each client location. We only need to make sure that the business logic server is web enabled.
Mary : Can you cite an example in the present times?
Jim : For example, any organisation would be having its - Sales Data in the Sales Server, Finance Data in the Finance Server and HR Data in the HR server with offices in different locations as different clients. An integrated database system would combine all the three servers into a single Corporate Database. The respective locations can access their respective data from the integrated corporate database.
Mary : Ok !! Mr. Jane works in the ERP department of his organisation. What is ERP ?
Jim : Enterprise Resource Planning , is an integrated powerful software that combines various functional modules in a project and eliminates separate activity for synchronisation of data. There are various vendors of the ERP package - SAP & Oracle Apps. We can use this ERP Package in the example that I cited now. This package combines all the Finance Data, HR Data and Sales Data from the corporate database in a single ERP Server and eliminates the use of different software on each of the clients. We can simply use ERP client software on every client. It is easy to manage and maintain and also faster to implement.
I hope this works !!!
Mary : O Jim , that was so nice of you !!! I am really tired Jim , can we go out for dinner ?
(Laughs)
Jim : (Sighs) Women will always be women !!
Balajee Rao
11BM60042
systems architecture as a stepping stone to social status :-) nice thought
ReplyDeletethank you Sir
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