Client Server Architecture | System Design Tutorials | Part 3 | 2020

 Part 3 of Yogita Sharma System Design Tutorial.

• Taking a look at our first component: Client-Server Architecture
• Specifically: Client, Server, Thick Client, Thin Client, 2-Tier / 3-Ties / N-Tier

What is Client-Server Architecture?

Image courtesy of GeeksForGeeks

• Client initiates request from server to receive, for example, an image or a text file
• Servers sends back response with the requested information
• For some requests, data manipulation needs to be done on data. Logic is applied at the server to the request. For example, send filtered list houses within geographic and monetary range.
• The above diagram is represents basic 2 tier architecture.

Thick and Thin Clients

• Thick client means that (some of) the application programming logic is on the client side
• Thin client means that (most of) the application programming logic is on the server side
• Examples of thick clients where processing is done at client side include Outlook and video processing software.
• Examples of thin clients are streaming services such as Netflix and Youtube
• To summarise the 3 elements of client server architecture include: presentation, logic, and data
• Where the data is processed and logic applied, determines if it is a thick or thin client

2-Tier, 3-Ties, and N-Tier Architectures

• In setups where there is a lot of application logic or if the data is vast - then the server is broken up according to logic and data.
• Hence there are now 3 tiers: client, logic, and data.
• Once load-balancers are introduced between client and logic, cache is introduced between logic and data - the setup is now n-ties architecture.
• For simple streaming services or e-commerce sites - a thin client is best approach.
• For video editing apps, desktop games, or other processing intensive applications - thick client is best approach.
• For simple website for small business - 2-tier architecture is fine
• For application with more complex business logic - 3-tier architecture works better.
• When serving a large number of users - n-tier architecture is likely more suitable