https://micrometer.io/docs/observation
    https://micrometer.io/docs/concepts
    https://github.com/micrometer-metrics/micrometer/wiki/Migrating-to-new-1.10.0-Observation-API

https://github.com/eugenp/tutorials/tree/master/spring-boot-modules/spring-boot-3-observation

2024
https://medium.com/javarevisited/tracing-in-spring-boot3-097205dc08f4
2023
https://www.baeldung.com/spring-boot-3-observability
https://tanzu.vmware.com/developer/guides/observability-reactive-spring-boot-3/
    https://github.com/marios-code-path/path-to-springboot-3/tree/main/manual-observation

https://mvnrepository.com/artifact/io.micrometer/micrometer-observation-test