Reverse proxy concept in HLD - Architecture Diagram

System Overview - Reverse proxy concept

A reverse proxy acts as a middleman between users and backend servers. It receives user requests, forwards them to the appropriate server, and then returns the server's response to the user. This helps improve security, load distribution, and caching.

Architecture Diagram

User
  |
  v
Reverse Proxy
  |
  +------------+------------+
  |                         |
Backend Server 1       Backend Server 2
  |                         |
Database                Database

Components

User

client

Sends requests to the system

Reverse Proxy

reverse_proxy

Receives user requests, forwards to backend servers, and returns responses

Backend Server 1

service

Processes requests and generates responses

Backend Server 2

service

Processes requests and generates responses

Database

database

Stores persistent data for backend servers

Request Flow - 5 Hops

User → Reverse Proxy

Reverse Proxy → Backend Server 1

Backend Server 1 → Database

Backend Server 1 → Reverse Proxy

Reverse Proxy → User

Failure Scenario

Component Fails:Reverse Proxy

Impact:All user requests fail because the reverse proxy is the single entry point

Mitigation:Use multiple reverse proxy instances with load balancing and failover

Architecture Quiz - 3 Questions

What is the main role of the reverse proxy in this system?

A Directly serve static files to users

B Store user data permanently

C Forward user requests to backend servers and return responses

D Replace the database for faster queries

Design Principle

The reverse proxy centralizes incoming traffic, enabling load balancing, security control, and simplified client access to multiple backend servers.