.NET Architecture & System Design Interview Question #143

What is health checking in a distributed application?

Resilience, Rate Limiting, Health Checks & Observability Senior Advanced

Quick Interview Answer

Health checking exposes or evaluates whether an application instance and its dependencies are in a condition suitable for a particular purpose.

Detailed Explanation

Health checking exposes or evaluates whether an application instance and its dependencies are in a condition suitable for a particular purpose.

Health checks can be used by load balancers, orchestrators, and monitoring systems. Checks should be fast and carefully scoped because an expensive health endpoint can itself become a source of load.

Code Example

Load Balancer
     |
GET /health
     |
Healthy -> route traffic
Unhealthy -> remove instance