Tiers In Software Architecture

Question 1

What is a Tier?

Answer 1

A logical and physical separation of components in an application or a service at the Component level (not the code level)

Question 2

Why do software apps have different tiers?

Answer 2

• Creates a loosely coupled architecture.
• changes to a specific component does not impact the other components.
• components having designated roles makes management of whole system easier
• easier to add new features
• code changes in one component do not affect code in others

Question 3

How do I decide how many tiers my application should have?

Question 4

What are examples of application components?

Answer 4

Database, backend server, UI, messaging, caching

Question 5

What is a single-tier application?

Answer 5

In a single-tier application, the user interface, backend business logic, and the database reside in the same machine.

Question 6

Single-tier App Upsides

Answer 6

• No Network latency (every component on same machine). Improved performance if machine can support.
• Data/Privacy of highest order since user data always stays on one machine (doesn’t need to fly over network for persistence).

Question 7

2 Tier Application

Answer 7

Has Client and server. Client has UI+business logic, Server has DB on diff machine and is owned by the business.