public JVMClusterUtil.RegionServerThread stopRegionServer(int serverNumber,
    final boolean shutdownFS) {
    JVMClusterUtil.RegionServerThread server = hbaseCluster.getRegionServers().get(serverNumber);
    LOG.info("Stopping " + server.toString());
    server.getRegionServer().stop("Stopping rs " + serverNumber);
    return server;
  }
Shut down the specified region server cleanly
@param serverNumber Used as index into a list.
@param shutdownFS   True is we are to shutdown the filesystem as part of this regionserver's
                    shutdown. Usually we do but you do not want to do this if you are running
                    multiple regionservers in a test and you shut down one before end of the
                    test.
@return the region server that was stopped
hbase-testing-util/src/main/java/org/apache/hadoop/hbase/MiniHBaseCluster.java