@Subscribe
  public void onUpdateEvent(STOMPEvent STOMPEvent) {
    STOMPEvent.Type metricType = STOMPEvent.getType();
    events.put(metricType, events.get(metricType) + 1);
  }
Collects metrics about number of events by types and publishes to configured Metric Sink.
ambari-server/src/main/java/org/apache/ambari/server/metrics/system/impl/StompEventsMetricsSource.java