public static int netty_io_ratio() {
        return getInt(Configs.NETTY_IO_RATIO, Configs.NETTY_IO_RATIO_DEFAULT);
    }
get configs through system properties prior to default value

@author tsui
@version $Id: ConfigManager.java, v 0.1 2017-08-03 19:21 tsui Exp $
src/main/java/com/alipay/remoting/config/ConfigManager.java