@Override
  protected void chore() {
    final long start = System.nanoTime();
    try {
      _chore();
    } finally {
      if (metrics != null) {
        metrics.incrementRegionSizeReportingChoreTime(
          TimeUnit.MILLISECONDS.convert(System.nanoTime() - start, TimeUnit.NANOSECONDS));
      }
    }
  }
A Chore which sends the region size reports on this RegionServer to the Master.
hbase-server/src/main/java/org/apache/hadoop/hbase/quotas/RegionSizeReportingChore.java