Cloud Architecture Design Patterns

Architecting on AWS

All applications are broadly divided into two types. These are 2 tier or 3 tier architecture. Basically at high level we can say that 2-tier architecture is Client server application and 3-tier architecture is Web based application.

Two-Tier Architecture

The two-tier is based on Client Server architecture. The two-tier architecture is like client server application. The direct communication takes place between client and server. There is no intermediate between client and server. Because of tight coupling a 2 tiered application will run faster.

The above figure shows the architecture of two-tier. Here the direct communication happens between client and server, there is no intermediate layer between client and server. The Two-tier architecture is divided into two parts:

  • Client Application (Client Tier)
  • Database (Data Tier)

On client application side the code is written for saving the data in database server. Client sends the request to server and it process the request & send back with data. The main problem of two tier architecture is the server cannot respond multiple request same time, as a result it cause a data integrity issue. When the developers are not disciplined, the display logic, business logic and database logic are muddled up and/or duplicated in a 2tier client server system.


  • Easy to maintain and modification is bit easy.
  • Communication is faster.


  • In two tier architecture application performance will be degrade upon increasing the users.
  • Cost-ineffective.

Three-Tier Architecture