HLDintermediate
Service Discovery
Service discovery helps dynamic services find each other without hardcoded addresses. It is essential in containerized and microservice environments where instances come and go frequently.
Reading time
9 min
service discoverydnsregistrymicroservices
Why Discovery Exists
In modern infrastructure, service instances are replaced often. Their IP addresses are not stable, so clients need a reliable way to discover where a service currently lives.
Approaches
- Registry-based discovery
- DNS-based discovery
- Service mesh sidecars
Client-Side vs Server-Side Discovery
Client-side discovery puts lookup logic in the client. Server-side discovery hides that behind a gateway or load balancer.
Interview Tip
Mention service discovery together with health checks and load balancing.