Are modern REST-Applications 3-Tier-Architecture or 4-Tier-Architecture?

4
votes

I am currently learning UML and Deployment/Component Diagrams and want to model my existing application into a 3- or 4-Tier-Architecture. My App has the following instances:

  1. Angular Application
  2. Java Spring Boot Application as REST-Webservice
  3. Database

All three instances can be deployed on different servers. In my mind, this is a 3-Tier-Architecture. But now I am confused, because I am not sure, if the Client with the Web Browser is the 4th tier of my architecture. Can the webbrowser and the angular application be in the presentation layer, like this:

enter image description here

I am thinking and confused about this, because in this post:

Is this okay to use UML component diagram for a 3-tier Architecture?

he summarizes the application and the browser in the presentation layer.

EDIT: This is how I would realize it as a 4-Tier-Architecture Deployment Diagram:

enter image description here

1
architectureuml3-tiercomponent-diagram
does that answer to your question (not really linked to UML if I understand well) : stackoverflow.com/questions/10761440/… – bruno

1 Answers

4
votes

Your application has a 3-tier architecture. The browser is simply an execution environment that is running part of your front-end application code.

The front-end application is split between deployment on the web server (at a minimum, hosting the static files that comprise your front-end even if (because you are using angular) it is doing nothing more) and the web browser.

The API is the second tier. Your angular app is connecting to this to invoke logic and access data.

The Database is the third tier.

I would go with your top diagram, but put your angular app nested inside the browser.