void trackContainerCount(Gauge<Integer> gauge) {
    containerCountGauge = gauge;
    metricRegistry.register(MetricRegistry.name(MySqlAccountService.class, CONTAINER_COUNT), containerCountGauge);
  }
Tracks the total number of containers across all accounts.
@param gauge the function returning the container count.
ambry-account/src/main/java/com/github/ambry/account/AccountServiceMetrics.java