@After
  public void tearDown() throws Exception {
    if (hs2Conn != null) {
      hs2Conn.close();
    }
  }
This class is cloned from TestJdbcWithMiniMR, except use Namenode HA.
itests/hive-unit/src/test/java/org/apache/hive/jdbc/TestJdbcWithMiniHA.java