public long countServedRegions() {
    long count = 0;
    for (JVMClusterUtil.RegionServerThread rst : getLiveRegionServerThreads()) {
      count += rst.getRegionServer().getNumberOfOnlineRegions();
    }
    return count;
  }
Counts the total numbers of regions being served by the currently online region servers by
asking each how many regions they have. Does not look at hbase:meta at all. Count includes
catalog tables.
@return number of regions being served by all region servers
hbase-server/src/test/java/org/apache/hadoop/hbase/SingleProcessHBaseCluster.java