Authentication at gateway level in Microservices - Architecture Diagram

System Overview - Authentication at gateway level

This system handles user requests by verifying their identity at the API Gateway before allowing access to backend microservices. It ensures only authenticated users can reach services, improving security and reducing load on services.

Architecture Diagram

User
  |
  v
Load Balancer
  |
  v
API Gateway (Auth Check)
  |
  v
Microservices Cluster
  |
  v
Database

Cache (for tokens) connected to API Gateway

Components

User

client

Sends requests to the system

Load Balancer

load_balancer

Distributes incoming requests evenly to API Gateway instances

API Gateway

api_gateway

Performs authentication and routes requests to microservices

Cache

cache

Stores authentication tokens for quick validation

Microservices Cluster

service

Handles business logic after authentication

Database

database

Stores user data and service data

Request Flow - 10 Hops

User → Load Balancer

Load Balancer → API Gateway

API Gateway → Cache

Cache → API Gateway

API Gateway → Microservices Cluster

Microservices Cluster → Database

Database → Microservices Cluster

Microservices Cluster → API Gateway

API Gateway → Load Balancer

Load Balancer → User

Failure Scenario

Component Fails:API Gateway

Impact:All incoming requests fail authentication and cannot reach microservices, causing service outage.

Mitigation:Deploy multiple API Gateway instances behind the load balancer for redundancy and failover.

Architecture Quiz - 3 Questions

Where is the user authentication checked in this system?

A Inside each microservice

B Directly in the database

C At the API Gateway before routing to microservices

D At the load balancer

Design Principle

This design centralizes authentication at the API Gateway to secure all requests before they reach microservices. Using a cache for tokens speeds up validation and reduces database load. Load balancer redundancy ensures availability and scalability.