This endpoint gathers and publishes information of the OS, JVM, and application-level metrics. By default, the /actuator/metrics endpoint will return all the names of the metrics that are supported, for example, if it has a metric such as "jvm.memory.used". We can query the details by using /actuator/metrics/jvm.memory.used and get a result similar to the following:

{
  "name": "jvm.memory.used",
  "description": "The amount of used memory",
  "baseUnit": "bytes",
  "measurements": [{
    "statistic": "VALUE",
    "value": 2.13495176E8
  }],
  "availableTags": [{
    "tag": "area",
    "values": ["heap", "nonheap"]
  }, {
    "tag": "id",
    "values": ["Compressed Class Space", "PS Survivor Space", "PS Old 
    Gen", "Metaspace", "PS Eden Space", "Code Cache"]
  }]
}

As you can see, the application has used 213 megabytes of memory.