Young G1 GC Notification

[Rabi]

Hello,

I am new to this mailing list and I am reaching out here as it seemed like
a good place to ask this question. If this is the wrong place for this
question, I apologize.

I would like to get a notification for G1 Young GC pause events and report
the time to an external monitoring service. (See the code below where I
attempted to listen on a notification)

However, what I have noticed is that I never get a 'Notification' even
though I am seeing GC logs report the G1 Young GC pauses. Also, I can see
the same information in the JFR recording.
My application rarely does a full GC, so I am mostly interested in Young G1
GC events and I would like to overlay this information on top of other
application metrics.

Here is what I have attempted :

public class GCEventMonitor implements NotificationListener {

 public GCEventMonitor(MetricsRecorder metricsRecorder) {
        this.metricsRecorder = metricsRecorder; //external Service, where I
can send information
        registerGCBeans();
 }

  private void registerGCBeans() {
        for (GarbageCollectorMXBean gcbean :
ManagementFactory.getGarbageCollectorMXBeans()) { // I have noticed two
beans get registered here G1 Young and G1 Old through a debugger
            if (gcbean instanceof NotificationEmitter) {
                NotificationEmitter emitter = (NotificationEmitter) gcbean;
                emitter.addNotificationListener(this, null, null);
            }
        }
    }

   @Override
    public void handleNotification(Notification notification, Object
handback) { *//never gets called*
        if
(notification.getType().equals(GarbageCollectionNotificationInfo.GARBAGE_COLLECTION_NOTIFICATION))
{
                CompositeData cd = (CompositeData)
notification.getUserData();
                GarbageCollectionNotificationInfo info =
GarbageCollectionNotificationInfo.from(cd);
                processGCEvent(info, handback); // Extract info.getGcInfo()
here and send gcInfo.getDuration() to external service
            }
    }
}

I have set a debug point on handleNotification method, but this method
never gets called, even while I can actively see gc logs print the
following information. Why am I not getting a notification? Is my
configuration/registration/setup incorrect?
There is a comment on this stackoverflow question/answer that the VM does
not notify when Young GC happens. Is that true? If so, how does JFR record
that information?

Thanks for your help in advance!
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