一、kafka默认的发送一条消息的大小是1M，如果不配置，当发送的消息大于1M是，就会报错

[2018-07-03 14:49:38,411] ERROR Error when sending message to topic testTopic with key: null, value: 2095476 bytes with error: (org.apache.kafka.clients.producer.internals.ErrorLoggingCallback)
org.apache.kafka.common.errors.RecordTooLargeException: The message is 2095510 bytes when serialized which is larger than the maximum request size you have configured with the max.request.size configuration.

二、具体配置

1、 kafka topic

/bin/kafka-topics.sh --zookeeper 192.168.6.102:2181 --alter --topic testTopic --config max.message.bytes=52428800

2、server.properties中添加

message.max.bytes=5242880（5M）
replica.fetch.max.bytes=6291456（6M）每个分区试图获取的消息字节数。要大于等于message.max.bytes

3、producer.properties中添加

max.request.size = 5242880 （5M）请求的最大大小为字节。要小于 message.max.bytes

4、consumer.properties中添加

fetch.message.max.bytes=6291456（6M）每个提取请求中为每个主题分区提取的消息字节数。要大于等于message.max.bytes

5、在生产端使用java发送消息

public static void main(String[] args) {
        Properties props = new Properties();
        props.put("metadata.broker.list", "node1:9092");
        props.put("serializer.class", "kafka.serializer.StringEncoder");
        // key.serializer.class默认为serializer.class
        props.put("key.serializer.class", "kafka.serializer.StringEncoder");
        props.put("request.required.acks", "1");
        props.put("max.request.size", "52428800");
        ProducerConfig config = new ProducerConfig(props);
        Producer<String, String> producer = new Producer<String, String>(config);
            producer.send(new KeyedMessage<String, String>(
                    "testkafka", "jack",
                    "rose"));
        producer.close();
    }

三、重启

1、更改完配置要重启kafka server才能生效

1.1、先停止kafka.
a、通过命令：bin/kafka-server-stop.sh
b、找到kafka进程,命令：ps -ef | grep kafka，然后kill掉
1.2、启动kafka server：
nohup bin/kafka-server-start.sh config/server.properties&

2、重新执行生产端的命令

./bin/kafka-console-producer.sh  --broker-list 192.168.6.102:8997 --topic testTopic < /usr/local/test.txt --producer.config /usr/local/kafka10/config/producer.properties

注：在Linux控制台发送消息时，控制台有输入字数限制，不利于测试，所以将大的消息放在文本文件里test.txt，通过< /usr/local/test.txt追加到控制台

3、重新执行消费断的命令

./bin/kafka-console-consumer.sh --zookeeper 192.168.6.102:2181 --topic testTopic --consumer.config config/consumer.properties