private JVMClusterUtil.RegionServerThread startRegionServer(Configuration configuration)
    throws IOException {
    User rsUser = HBaseTestingUtil.getDifferentUser(configuration, ".hfs." + index++);
    JVMClusterUtil.RegionServerThread t = null;
    try {
      t =
        hbaseCluster.addRegionServer(configuration, hbaseCluster.getRegionServers().size(), rsUser);
      t.start();
      t.waitForServerOnline();
    } catch (InterruptedException ie) {
      throw new IOException("Interrupted adding regionserver to cluster", ie);
    }
    return t;
  }
Starts a region server thread running
@return New RegionServerThread
hbase-server/src/test/java/org/apache/hadoop/hbase/SingleProcessHBaseCluster.java