https://micrometer.io/

https://micrometer.io/docs
https://micrometer.io/docs/concepts
https://micrometer.io/docs/registry/prometheus
https://github.com/micrometer-metrics/micrometer

https://micrometer.io/docs/ref/jvm
https://micrometer.io/docs/ref/cache

https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#production-ready-metrics
https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#production-ready-endpoints-exposing-endpoints

exposing endpoint
management:
  server:
    port: 9090
    security:
      enabled: false
  endpoints:
    web:
      base-path: /application
      exposure:
        include: info,health,prometheus

2018
https://dzone.com/articles/using-micrometer-with-spring-boot-2
https://spring.io/blog/2018/03/16/micrometer-spring-boot-2-s-new-application-metrics-collector

extras
https://github.com/mweirauch/micrometer-jvm-extras
http://www.ryantenney.com/metrics-spring/
https://github.com/ryantenney/metrics-spring