Rename process.runtime.jvm.cpu.utilization to process.runtime.jvm.cpu.recent_utilization

[trask]

process.runtime.jvm.cpu.utilization is defined as

Returns the "recent cpu usage" for the Java Virtual Machine process. This value is a double in the [0.0,1.0] interval. A value of 0.0 means that none of the CPUs were running threads from the JVM process during the recent period of time observed, while a value of 1.0 means that all CPUs were actively running threads from the JVM 100% of the time during the recent period being observed. Threads from the JVM include the application threads as well as the JVM internal threads. All values betweens 0.0 and 1.0 are possible depending of the activities going on in the JVM process and the whole system.

The current definition of .utilization is vague enough to fit this:

an instrument that measures the fraction of usage
out of its limit should be called entity.utilization. For example,
system.memory.utilization for the fraction of memory in use. Utilization
values are in the range [0, 1].

but it doesn't match the system.cpu.utilization usage, since it's not specifically for the time since last measurement:

Difference in system.cpu.time since the last measurement, divided by the elapsed time and number of CPUs

[trask]

we are planning to emit process.runtime.jvm.cpu.time (open-telemetry/opentelemetry-specification#3490)

three options:

• process.runtime.jvm.cpu.utilization
  • CONS: doesn't match "utilization since last measurement"
• process.runtime.jvm.cpu.recent_utilization
• process.runtime.jvm.cpu.load
  • CONS: doesn't match definition of linux load

decision from WG:

• process.runtime.jvm.cpu.recent_utilization