ASP.NET Core Web API Interview Question #148

What is the difference between liveness and readiness checks?

Error Handling, Logging, Caching, Rate Limiting, CORS & Reliability Senior Advanced

Quick Interview Answer

A liveness check answers whether the application process is alive enough to continue running. A readiness check answers whether the instance is currently ready to receive traffic.

Detailed Explanation

A liveness check answers whether the application process is alive enough to continue running. A readiness check answers whether the instance is currently ready to receive traffic.

A temporary database outage may make an application unready without necessarily meaning the process should be restarted. Separating the two concepts helps infrastructure respond appropriately.

Code Example

// Example endpoint strategy:
app.MapHealthChecks("/health/live");
app.MapHealthChecks("/health/ready");

// Configure predicates/tags so each endpoint
// runs the checks appropriate to its purpose.