Bug: Instance reported as down even if it's up

[cdprete]

Spring Boot Admin Server information

• Version: 3.5.2

• Spring Boot version: 3.5.5

• Configured Security: None

• Webflux or Servlet application: WebFlux

Client information

• Spring Boot versions: 3.5.3

• Used discovery mechanism: Eureka

• Webflux or Servlet application: Servlet

Description

Hello.
I've the weird behaviour that an application is reported as DOWN in SBA even if its health endpoint reports it as UP.

Moreover, I can see in the HTTP Exchanges view that the health has been indeed called and that it returned 200, but somehow it's not reflected in the status of the application.

[cdprete]

Hello.
Today I observed the same behaviour in our production instance with version 3.5.5:

What I observed is that in the journal the latest STATUS_CHANGED event is about the application migrating from UP to DOWN, which is potentially fine, but then a next STATUS_CHANGED event is basically missing there which would put the app from DOWN to UP:

This would explain to me why the app is then reported as DOWN, but that's then very bad, especially if the health reports the system as UP then.

[cdprete]

Indeed, the /applications call triggered while loading the homepage is returning the latest available status for all the registered applications, which explains why the issue - UI wise - occurs.
This doesn't explain why the backend is failing somehow, of course.