metrics.asciidoc in elastic-apm-4.3.0

- old
+ new
@@ -139,5 +139,97 @@
 
 The total time spent in garbage collection.
 
 **NB:** You need to enable Ruby's GC Profiler for this to get reported.
 You can do this at any time when your application boots by calling `GC::Profiler.enable`.
+
+[float]
+[[metrics-jvm-metrics]]
+=== JVM Metrics
+
+The following metrics are available when using JRuby. They use the ruby java API to gather metrics via MXBean.
+
+[float]
+[[metric-jvm.memory.heap.used]]
+==== `jvm.memory.heap.used`
+
+* *Type:* Long
+* *Format:* Bytes
+
+The amount of used heap memory in bytes.
+
+[float]
+[[metric-jvm.memory.heap.committed]]
+==== `jvm.memory.heap.committed`
+
+* *Type:* Long
+* *Format:* Bytes
+
+The amount of heap memory in bytes that is committed for the Java virtual machine to use. This amount of memory is
+guaranteed for the Java virtual machine to use.
+
+[float]
+[[metric-jvm.memory.heap.max]]
+==== `jvm.memory.heap.max`
+
+* *Type:* Long
+* *Format:* Bytes
+
+The amount of heap memory in bytes that is committed for the Java virtual machine to use. This amount of memory is
+guaranteed for the Java virtual machine to use.
+
+[float]
+[[metric-jvm.memory.non_heap.used]]
+==== `jvm.memory.non_heap.used`
+
+* *Type:* Long
+* *Format:* Bytes
+
+The amount of used non-heap memory in bytes.
+
+[float]
+[[metric-jvm.memory.non_heap.committed]]
+==== `jvm.memory.non_heap.committed`
+
+* *Type:* Long
+* *Format:* Bytes
+
+The amount of non-heap memory in bytes that is committed for the Java virtual machine to use. This amount of memory is
+guaranteed for the Java virtual machine to use.
+
+[float]
+[[metric-jvm.memory.non_heap.max]]
+==== `jvm.memory.non_heap.max`
+
+* *Type:* Long
+* *Format:* Bytes
+
+The maximum amount of non-heap memory in bytes that can be used for memory management. If the maximum memory size is
+undefined, the value is -1.
+
+[float]
+[[metric-jvm.memory.heap.pool.used]]
+==== `jvm.memory.heap.pool.used`
+
+* *Type:* Long
+* *Format:* Bytes
+
+The amount of used memory in bytes of the memory pool.
+
+[float]
+[[metric-jvm.memory.heap.pool.committed]]
+==== `jvm.memory.heap.pool.committed`
+
+* *Type:* Long
+* *Format:* Bytes
+
+The amount of memory in bytes that is committed for the memory pool. This amount of memory is guaranteed for this
+specific pool.
+
+[float]
+[[metric-jvm.memory.heap.pool.max]]
+==== `jvm.memory.heap.pool.max`
+
+* *Type:* Long
+* *Format:* Bytes
+
+The maximum amount of memory in bytes that can be used for the memory pool.
\ No newline at end of file