MP metrics does not correctly rescale distributions (e.g., timers, histograms)

[tjquinno]

Environment Details

• Helidon Version: 2.x
• Helidon SE or Helidon MP MP
• JDK version:
• OS:
• Docker version (if applicable):

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Problem Description

In MP applications, the periodic calculation of the current time in seconds does not occur properly.

Steps to reproduce

(easiest way)

1. Generate the Helidon MP QuickStart app. Add a @Timed annotation to the GreetResource#getMessage method.
2. Build the project with mvn package
3. Run with the debugger: java -agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=4000 -jar target/helidon-quickstart-mp.jar
4. Using an IDE, set a breakpoint at ExponentiallyDecayingReservoir#updateTimeInSeconds and connect to the paused server to allow it to continue.
5. You will hit the breakpoint once as the system initializes but not after that. The breakpoint should fire a few times each second.

• 2.x PR Move scheduling of metrics periodic updater so it is run in MP as well as in SE (2.x) #3732
• 3.x PR Move scheduling of metrics periodic updater so it is run in MP as well as in SE (3.x) #3733