Whats the difference between Unhealthy vs Degraded .NET health check status

I have an application running in Kubernetes. To take the advantage of rolling updates with no downtime, I have to implement the proper Health Checks, so the cluster can know when the application/container is ready to handle requests.

I'm trying to use the new ASP.NET Code 2.2 Healthchecks feature.

I should return a Microsoft.Extensions.Diagnostics.HealthChecks.HealthCheckResult struct with the status of the application.

Microsoft.Extensions.Diagnostics.HealthChecks.HealthCheckResult

This struct has 3 static methods that I can use to return this status:

In which situations that the app is not OK that I should use Unhealthy vs Degraded? A few examples would be good.

1 Answer
1

A "degraded" check could be used for checks that did succeed but are slow or unstable. E.g. a simple database query did succeed but took more than a second. Moving traffic to another instance is probably a good idea until the problem has resolved.

An "unhealthy" check means that the component does not work at all. E.g. a connection to the Redis cache could no be established. Restarting the instance could solve this issue.

Quoting the blog post:

A failed liveness probe says: The application has crashed. You should
shut it down and restart.

A failed readiness probe says: The application is OK but not yet ready
to serve traffic.

You could say that a "degraded" health check maps to the "readiness" probe and an "unhealthy" check maps to the "liveness" probe.

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.