Thursday, January 13, 2011

Class 1 - Application System & DNA Architecture

What is Application System???
System: it is combination of functional units.
Function Units: These are the necessary components for a operation which effect the target/goal.
For example:  Computer System
It has four functional units if anyone fails then system fails to achieve the goal.

Application System Functional Components
PL - Presentation Layer
BL – Business Layer/ Business Logic
DL – Data Link Layer
Presentation Layer:
User Interface called Presentation Layer. It is interface between Technical Person (Programmer)
and the Non-technical Person (User).

Technical Person tell the non technical person that how to work through their created User Interface.
If it is not correct then application is not successful.
It could be either windows forms or web forms in case of .Net.

Business Logic:

It deals in Software Development Cycle. It processes in various types of software development cycles
like water fall models etc..
Implementing business process called Business Logic.
Various types of logic available like here like:
Business Logic, Virtual Logic, Presentation Logic 

Data Link Layer:

This deals with backend databases to store the information.
This layer determined as the interaction b/w front end and back-end.
Fig 3
What is the Consumer Need?
In Current time consumer needs multiuser application. To achieve this here is few application architectures available.
That Uses DNA Architecture:
DNA (Distributed Network Architecture)
1.      1-tier
2.      2-tier
3.      3-tier
4.      N-tier

1-tier Architecture

fig 4

It is also called Monolithic approach. It has achieved DNA but demerit is that expansion is harmful in future for mainframe.
UNIX posses 1-tier architecture.

2-tier Architecture

Work Load is distributed in two layers. It is also called FAT Server if it is distributed as:
What is workload???

Max Number of instructions executed per unit time period on machine.

3-tier Architecture

It this workload is divided in layers as:

N-tier Architecture
Each Department has their own Business logic so they are divided in sub layer as in ERP System for company.
You cannot implement all departments BL at one site. So you have to divide it in sub layers.
This is N- tier arch. In which you can divided it in n number of sub layers according to the need.
Microsoft developed COM (Common/ Communication Object Model) for N- tier architecture.
 COM is for making communication between same type of technologies e.g. Microsoft to Microsoft.


For different type of technologies here is DCOM


It is all about DNA Architecture in Software Development.

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