概述

kafka中有个 micro batch 的概念，为了提高Producer 发送的性能。

不同于RocketMQ 提供了一个可以批量发送多条消息的 API 。 Kafka 的做法是：提供了一个 RecordAccumulator 消息收集器，将发送给相同 Topic 的相同 Partition 分区的消息们，缓冲一下，当满足条件时候，一次性批量将缓冲的消息提交给 Kafka Broker 。

参数设置

https://kafka.apache.org/24/documentation.html#producerconfigs

主要涉及的参数，三个条件，满足任一即会批量发送：

batch-size ：超过收集的消息数量的最大量。默认16KB

buffer-memory ：超过收集的消息占用的最大内存 , 默认32M

linger.ms ：超过收集的时间的最大等待时长，单位：毫秒。

Code

POM依赖

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

		<!-- 引入 Spring-Kafka 依赖 -->
		<dependency>
			<groupId>org.springframework.kafka</groupId>
			<artifactId>spring-kafka</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

配置文件

spring:
  # Kafka 配置项，对应 KafkaProperties 配置类
  kafka:
    bootstrap-servers: 192.168.126.140:9092 # 指定 Kafka Broker 地址，可以设置多个，以逗号分隔
    # Kafka Producer 配置项
    producer:
      acks: 1 # 0-不应答。1-leader 应答。all-所有 leader 和 follower 应答。
      retries: 3 # 发送失败时，重试发送的次数
      key-serializer: org.apache.kafka.common.serialization.StringSerializer # 消息的 key 的序列化
      value-serializer: org.springframework.kafka.support.serializer.JsonSerializer # 消息的 value 的序列化
      batch-size: 16384 # 每次批量发送消息的最大数量   单位 字节  默认 16K
      buffer-memory: 33554432 # 每次批量发送消息的最大内存 单位 字节  默认 32M
      properties:
        linger:
          ms: 10000 # 批处理延迟时间上限。[实际不会配这么长，这里用于测速]这里配置为 10 * 1000 ms 过后，不管是否消息数量是否到达 batch-size 或者消息大小到达 buffer-memory 后，都直接发送一次请求。
    # Kafka Consumer 配置项
    consumer:
      auto-offset-reset: earliest # 设置消费者分组最初的消费进度为 earliest
      key-deserializer: org.apache.kafka.common.serialization.StringDeserializer
      value-deserializer: org.springframework.kafka.support.serializer.JsonDeserializer
      properties:
        spring:
          json:
            trusted:
              packages: com.artisan.springkafka.domain
    # Kafka Consumer Listener 监听器配置
    listener:
      missing-topics-fatal: false # 消费监听接口监听的主题不存在时，默认会报错。所以通过设置为 false ，解决报错

logging:
  level:
    org:
      springframework:
        kafka: ERROR # spring-kafka
      apache:
        kafka: ERROR # kafka

生产者

package com.artisan.springkafka.producer;

import com.artisan.springkafka.constants.TOPIC;
import com.artisan.springkafka.domain.MessageMock;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.kafka.core.KafkaTemplate;
import org.springframework.kafka.support.SendResult;
import org.springframework.stereotype.Component;
import org.springframework.util.concurrent.ListenableFuture;

import java.util.Random;
import java.util.concurrent.ExecutionException;

/**
 * @author 小工匠
 * @version 1.0
 * @description: TODO
 * @date 2021/2/17 22:25
 * @mark: show me the code , change the world
 */

@Component
public class ArtisanProducerMock {


    @Autowired
    private KafkaTemplate<Object,Object> kafkaTemplate ;


    /**
     * 同步发送
     * @return
     * @throws ExecutionException
     * @throws InterruptedException
     */
    public SendResult sendMsgSync() throws ExecutionException, InterruptedException {
        // 模拟发送的消息
        Integer id = new Random().nextInt(100);
        MessageMock messageMock = new MessageMock(id,"artisanTestMessage-" + id);
        // 同步等待
       return  kafkaTemplate.send(TOPIC.TOPIC, messageMock).get();
    }



    public ListenableFuture<SendResult<Object, Object>> sendMsgASync() throws ExecutionException, InterruptedException {
        // 模拟发送的消息
        Integer id = new Random().nextInt(100);
        MessageMock messageMock = new MessageMock(id,"messageSendByAsync-" + id);
        // 异步发送消息
        ListenableFuture<SendResult<Object, Object>> result = kafkaTemplate.send(TOPIC.TOPIC, messageMock);
        return result ;

    }

}

消费者

package com.artisan.springkafka.consumer;

import com.artisan.springkafka.domain.MessageMock;
import com.artisan.springkafka.constants.TOPIC;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.kafka.annotation.KafkaListener;
import org.springframework.stereotype.Component;

/**
 * @author 小工匠
 * @version 1.0
 * @description: TODO
 * @date 2021/2/17 22:33
 * @mark: show me the code , change the world
 */

@Component
public class ArtisanCosumerMock {


    private Logger logger = LoggerFactory.getLogger(getClass());
    private static final String CONSUMER_GROUP_PREFIX = "MOCK-A" ;

    @KafkaListener(topics = TOPIC.TOPIC ,groupId = CONSUMER_GROUP_PREFIX + TOPIC.TOPIC)
    public void onMessage(MessageMock messageMock){
        logger.info("【接受到消息][线程:{} 消息内容：{}]", Thread.currentThread().getName(), messageMock);
    }

}

package com.artisan.springkafka.consumer;

import com.artisan.springkafka.domain.MessageMock;
import com.artisan.springkafka.constants.TOPIC;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.kafka.annotation.KafkaListener;
import org.springframework.stereotype.Component;

/**
 * @author 小工匠
 * @version 1.0
 * @description: TODO
 * @date 2021/2/17 22:33
 * @mark: show me the code , change the world
 */

@Component
public class ArtisanCosumerMockDiffConsumeGroup {


    private Logger logger = LoggerFactory.getLogger(getClass());

    private static final String CONSUMER_GROUP_PREFIX = "MOCK-B" ;

    @KafkaListener(topics = TOPIC.TOPIC ,groupId = CONSUMER_GROUP_PREFIX + TOPIC.TOPIC)
    public void onMessage(MessageMock messageMock){
        logger.info("【接受到消息][线程:{} 消息内容：{}]", Thread.currentThread().getName(), messageMock);
    }

}

单元测试

package com.artisan.springkafka.produceTest;

import com.artisan.springkafka.SpringkafkaApplication;
import com.artisan.springkafka.producer.ArtisanProducerMock;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.kafka.support.SendResult;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.util.concurrent.ListenableFuture;
import org.springframework.util.concurrent.ListenableFutureCallback;

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;

/**
 * @author 小工匠
 *  * @version 1.0
 * @description: TODO
 * @date 2021/2/17 22:40
 * @mark: show me the code , change the world
 */

@RunWith(SpringRunner.class)
@SpringBootTest(classes = SpringkafkaApplication.class)
public class ProduceMockTest {

    private Logger logger = LoggerFactory.getLogger(getClass());


    @Autowired
    private ArtisanProducerMock artisanProducerMock;



    @Test
    public void testAsynSend() throws ExecutionException, InterruptedException {
        logger.info("开始发送");

        for (int i = 0; i < 2; i++) {
            artisanProducerMock.sendMsgASync().addCallback(new ListenableFutureCallback<SendResult<Object, Object>>() {
                @Override
                public void onFailure(Throwable throwable) {
                    logger.info(" 发送异常{}]]", throwable);

                }
                @Override
                public void onSuccess(SendResult<Object, Object> objectObjectSendResult) {
                    logger.info("回调结果 Result =  topic:[{}] , partition:[{}], offset:[{}]",
                         objectObjectSendResult.getRecordMetadata().topic(),
                            objectObjectSendResult.getRecordMetadata().partition(),
                            objectObjectSendResult.getRecordMetadata().offset());
                }
            });
            //  发送2次 每次间隔5秒， 凑够我们配置的 linger:  ms:  10000
            TimeUnit.SECONDS.sleep(5);
        }

        // 阻塞等待，保证消费
        new CountDownLatch(1).await();

    }

}

异步发送2条消息，每次发送消息之间， sleep 5 秒，以便达到配置的 linger.ms 最大等待时长10秒。

测试结果

2021-02-18 10:58:53.360  INFO 24736 --- [           main] c.a.s.produceTest.ProduceMockTest        : 开始发送
2021-02-18 10:59:03.555  INFO 24736 --- [ad | producer-1] c.a.s.produceTest.ProduceMockTest        : 回调结果 Result =  topic:[MOCK_TOPIC] , partition:[0], offset:[30]
2021-02-18 10:59:03.556  INFO 24736 --- [ad | producer-1] c.a.s.produceTest.ProduceMockTest        : 回调结果 Result =  topic:[MOCK_TOPIC] , partition:[0], offset:[31]
2021-02-18 10:59:03.595  INFO 24736 --- [ntainer#0-0-C-1] c.a.s.consumer.ArtisanCosumerMock        : 【接受到消息][线程:org.springframework.kafka.KafkaListenerEndpointContainer#0-0-C-1 消息内容：MessageMock{id=6, name='messageSendByAsync-6'}]
2021-02-18 10:59:03.595  INFO 24736 --- [ntainer#1-0-C-1] a.s.c.ArtisanCosumerMockDiffConsumeGroup : 【接受到消息][线程:org.springframework.kafka.KafkaListenerEndpointContainer#1-0-C-1 消息内容：MessageMock{id=6, name='messageSendByAsync-6'}]
2021-02-18 10:59:03.595  INFO 24736 --- [ntainer#1-0-C-1] a.s.c.ArtisanCosumerMockDiffConsumeGroup : 【接受到消息][线程:org.springframework.kafka.KafkaListenerEndpointContainer#1-0-C-1 消息内容：MessageMock{id=94, name='messageSendByAsync-94'}]
2021-02-18 10:59:03.595  INFO 24736 --- [ntainer#0-0-C-1] c.a.s.consumer.ArtisanCosumerMock        : 【接受到消息][线程:org.springframework.kafka.KafkaListenerEndpointContainer#0-0-C-1 消息内容：MessageMock{id=94, name='messageSendByAsync-94'}]