public synchronized void addMetricSet(IMetricSet metricSet) {
    if (!metricSets.contains(metricSet)) {
      metricSet.bindTo(this);
      metricSets.add(metricSet);
    }
  }
Bind metrics and store metric set.
iotdb-core/metrics/interface/src/main/java/org/apache/iotdb/metrics/AbstractMetricService.java