RocketMQ: Broker keeps adding file in index folder

Question

In window environment with JDK 1.8, I donwload Apache RocketMQ 5.1.4 binary source and start the namesrv and broker with command "start mqnamesrv.cmd" and "start mqbroker.cmd -n localhost:9876 autoCreateTopicEnable=true" respectively. Both shows boot success. However, when I use a Main.java to send the message to name server. The index file is keep adding 400MB file per second. Like this: enter image description here

Also, I have tried to config the "broker.conf" on changing fileReservedTime from 120 to 0.04. I want to avoid the full of disk but it fails. Also, I add "autoTopicEnable=true" in broker.conf is fail too. Is my Main.java casue this error? My purpose is to avoid the full of disk and let the nameserver and broker keep running.

Main.java's Source Code:

import org.apache.rocketmq.client.producer.DefaultMQProducer;
import org.apache.rocketmq.client.producer.SendResult;
import org.apache.rocketmq.common.message.Message;
import org.apache.rocketmq.remoting.common.RemotingHelper;

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// then press Enter. You can now see whitespace characters in your code.
public class Main {
    public static void main(String[] args) throws Exception {
        // 初始化一个producer并设置Producer group name
        DefaultMQProducer producer = new DefaultMQProducer("Info"); //（1）
        // 设置NameServer地址
        producer.setNamesrvAddr("localhost:9876");  //（2）
        // Set the messege resend times to 2
        producer.setRetryTimesWhenSendFailed(2);
        // Set messge timeout second to 3000ms
        producer.setSendMsgTimeout(3000);
        // 启动producer

        producer.start();
        for (int i = 0; i < 2; i++) {
            // 创建一条消息，并指定topic、tag、body等信息，tag可以理解成标签，对消息进行再归类，RocketMQ可以在消费端对tag进行过滤
            Message msg = new Message("Topic" +
                    "DeveloperTeam" /* Tag */,
                    ("CheckMsg" + i).getBytes(RemotingHelper.DEFAULT_CHARSET) /* Message body */
            );   //（3）
            // 利用producer进行发送，并同步等待发送结果
            SendResult sendResult = producer.send(msg);   //（4）
            System.out.printf("%s%n", sendResult);
        }
        // 一旦producer不再使用，关闭producer
        producer.shutdown();
    }
}

I have tried to config "broker.conf" and run the command "start mqbroker.cmd -n localhost:9876 messageIndexEnable=false fileReservedTime=0.004".