public final AccumuloIndexScanner createScanner() throws AccumuloIndexScannerException {
    AccumuloIndexScanner handler;

    String classname = conf.get(INDEX_SCANNER);
    if (classname != null) {
      try {
        handler = (AccumuloIndexScanner) Class.forName(classname).newInstance();
      } catch (ClassCastException | InstantiationException |  IllegalAccessException
          | ClassNotFoundException e) {
        throw new AccumuloIndexScannerException("Cannot use index scanner class: " + classname, e);
      }
    } else {
      handler = new AccumuloDefaultIndexScanner();
    }
    if (handler != null) {
      handler.init(conf);
    }
    return handler;
  }
Accumulo Index Parameters for Hive tables.
accumulo-handler/src/java/org/apache/hadoop/hive/accumulo/serde/AccumuloIndexParameters.java