Every program manager loves metrics. In fact, a popular company (Netflix) is so well known in this arena that people describe it as a metrics-gathering company that happens to stream video.

When it comes to Spring Boot, metrics are a prime piece of Spring Boot Actuator functionality. If we visit /application/metrics, we can see a list of metrics:

    {
      "names": [
        "jvm.buffer.memory.used",
        "jvm.memory.used",
        "jvm.buffer.count",
        "logback.events",
        "process.uptime",
        "jvm.memory.committed",
        "http.server.requests",
        "jvm.buffer.total.capacity",
        "jvm.memory.max",
        "process.starttime"
      ]
    }

This lists all sorts of stuff--memory, garbage collection, heap versus nonheap, threads...