static String getMetastoreJdbcUser(Configuration conf) {
    return MetastoreConf.getVar(conf, MetastoreConf.ConfVars.CONNECTION_USER_NAME);
  }
@param hdpConfig
@return subset of properties prefixed by a connection pool specific substring
standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/datasource/DataSourceProvider.java