The 3-tier architecture document discusses the evolution and benefits of the 3-tier architecture model. It defines the 3-tier architecture as having the user interface stored on the client, business logic stored on application servers, and data stored in a database server. This allows for improved scalability, reusability, security, and availability compared to earlier single-tier and dual-tier architectures. An example is also provided of implementing a 3-tier architecture application in ASP.NET using C#, with distinct presentation, business, and data access layers.

1. 3- tier Architecture
Sanjeev Sarma, Webx
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2. Topics Covered
• What is 3-tier Architecture?
• Evolution of 3-tier Architecture Development.
• What does 3-tier Architecture Offer You?
▫ Advantages & Disadvantages
• An Example of how to implement 3-tier
Architecture in .Net Platform Using C#
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3. What is 3-tier Architecture?
• A three-way interaction in a client/Server
environment
▫ The User Interface is stored in the Client.
▫ The Business Application Logic is Stored in one or
more Servers.
▫ The Data is Stored in a Database Server.
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5. Evolution to the 3-tier Architecture
Tiers we are going to
study
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6. Single Tier Architecture
• Time of Huge “Mainframe”
• All Processing in Single
Computer
• All Resources Attached to
the same Computer
• Access Via Dumb Terminals
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7. Single Tier – Advantages & Disadvantages
• Advantages
▫ Simple
▫ Efficient
▫ Uncomplicated
• Disadvantages
▫ Very Expensive
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8. Dual Tier Architecture
• The Personal Computer
• Necessity of Providing
Personal Software
• The Client Server Model
was Born!!
• Logical System
Components – Most of
which are on the Client
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9. Dual Tier – Advantages & Disadvantages
• Advantages
▫ Less Expensive than Mainframe
• Disadvantages
▫ The Connections to the Database Server are very
Expensive
▫ One can only connects a limited number of users to a
server before Database Server spends more time
managing connections than processing requests
▫ Cost-ineffective. Many users only use their
connections 2-3% of the time.
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10. 3-Tier Architecture
• These Applications runs on
the Traditional Client/Server
Model But from a Application
server.
• Client only Displays the GUI
and data, but has no part in
producing results
• Database Server Serves to
few Connections
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11. 3-Tier Advantages
• Scalability
▫ The Application Servers can be deployed on many
machines
▫ The Database no longer requires a connection from
every client.
• Reusability
▫ If a standard object is employed, the specific language
of implementation of middle tier can be made
transparent.
• Data Integrity
▫ The middle tier can ensure that only valid data is
allowed to be updated in the database.
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12. 3-Tier Advantages
• Improved Security
▫ Since the client doesn’t have direct access to the database,
Data layer is more secure.
▫ Business Logic is generally more secure since it is placed on
a secured central server.
• Reduced Distribution
▫ Changes to business logic only need to be updated on
application servers and need not to distributed on clients
• Improved Availability
▫ Mission Critical Applications can make use of redundant
application servers and redundant application servers, so it
can recover from network of server failures.
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13. 3-Tier Disadvantages
• Increased Complexity / Effort
▫ In General 3-tier Architecture is more complex to
build compared to 2-tier Architecture.
▫ Point of Communication are doubled.
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14. Conclusions
• Complex business rules easy to implement in application
server layer.
• Business Logic off-loaded from database server and
client, which improve performance
• Changes to business logic automatically enforce by
server.
• All tiers can be platform independent.
• Superior Performance for medium to High Volume
Environments
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15. 3-Tier Application in ASP.NET
• The Program is organised into three major
distinctive tiers or layers:
▫ Presentation Layer (User Interface)
▫ Business Layer (Business Access Layer)
▫ Data Layer (Data Access Layer)
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16. User Interface Layer
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17. Presentation Layer
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18. Business Access Layer - Properties
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19. Business Access Layer
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20. Data Access Layer
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21. Presentation Layer
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Creating an Object of
Property Layer

22. Presentation Layer
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Creating an Object of
Business Layer

23. Presentation Layer
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Data Object to Receive Data
sent by Business Layer

24. Presentation Layer
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Obtaining ID from Property
Layer

25. Presentation Layer
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Calling Business Layer
Function

26. Business Access Layer
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Calling Data Layer Function

27. Data Access Layer
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Result Object Declaration

28. Data Access Layer
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SQL Query Definition

29. Data Access Layer
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Creating Object to receive
data

30. Data Access Layer
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Query Execution

31. Data Access Layer
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Returning the Information
of the Database

32. Business Access Layer
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Retuning the Information of
Data Layer

33. Presentation Layer
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Returning Data From
Business Layer

34. Presentation Layer
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Displaying Result

35. Questions & Answers
If Any?
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36. Thank You!
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