如果我从c++应用程序或从本地计算机的命令行生成和使用kafka服务器，那么我的kafka服务器工作得很好。
但是它在外部ip地址上工作不好：创建主题时，我看到使用tcpdump和acks的网络流量（意味着kafka正在应答），但是我在队列中没有发现消息，java也没有给出错误。日志上什么也找不到。或者谷歌。这是我的应用程序：

public class KafkaPBJProducer {
    private static String KAFKA_TOPIC = "test";

    public static void main(String[] args) {
        Properties properties = new Properties();
        properties.put("bootstrap.servers", "192.168.1.131:9092");
        properties.put("acks", "all");
        properties.put("retries", 0);
        properties.put("batch.size", 16384);
        properties.put("linger.ms", 1);
        properties.put("buffer.memory", 33554432);
        properties.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
        properties.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");

        properties.put("kafka.topic", KAFKA_TOPIC);
        runMainLoop(properties);
    }

    static void runMainLoop(Properties properties) {
        @SuppressWarnings("resource")
        KafkaProducer<String, String> producer = new KafkaProducer<String, String>(properties);
        for (int count = 0; count < 10; count++) {
            String msg = getMsg(String.valueOf(count));
            System.out.println("Producing message: " + msg);
            producer.send(new ProducerRecord<String, String>(KAFKA_TOPIC, 0, "dev-" + count, msg));
            producer.flush();
        }
    }

    public static String getMsg(String id) {
        JsonObject obj = new JsonObject();
        try {
            obj.addProperty("id", id);
            obj.addProperty("timestamp", new Timestamp(System.currentTimeMillis()).toString());
            obj.addProperty("data", Base64.getEncoder().encodeToString("Hello, World!".getBytes("utf-8")));
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return new Gson().toJson(obj);
    }
}

当它运行时，每一条消息都会阻塞一分钟（不会显示错误，它们只是需要很长时间才能被发送）：

Producing message: {"id":"0","timestamp":"2018-08-21 13:49:10.697","data":"SGVsbG8sIFdvcmxkIQ\u003d\u003d"}
Producing message: {"id":"1","timestamp":"2018-08-21 13:50:10.794","data":"SGVsbG8sIFdvcmxkIQ\u003d\u003d"}
Producing message: {"id":"2","timestamp":"2018-08-21 13:51:10.797","data":"SGVsbG8sIFdvcmxkIQ\u003d\u003d"}
Producing message: {"id":"3","timestamp":"2018-08-21 13:52:10.813","data":"SGVsbG8sIFdvcmxkIQ\u003d\u003d"}

我可以看到主题是：

> bin/kafka-topics.sh --list --zookeeper localhost:2181
__consumer_offsets
test

我可以使用命令行手动向主题添加内容：

$ bin/kafka-console-producer.sh --broker-list localhost:9092 --topic test
>one
>two
>four

但如果我选中主题，则只列出手动发送的消息：

$ bin/kafka-console-consumer.sh --bootstrap-server 192.168.1.131:9092 --topic test --from-beginning
one
two
four

(after several minutes, I press CTRL-C)
^CProcessed a total of 3 messages

这里发生了什么？为什么创建了主题，但服务器上不接受任何消息？为什么Kafka没有报告任何错误？
蒂亚！