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Kafka实战——简单易懂的生产者消费者demo_kafka demo

kafka demo

单线程版本适合本地调试,多线程版本适合做压测

1、引入maven依赖

  1. <dependency>
  2. <groupId>org.apache.kafka</groupId>
  3. <artifactId>kafka-clients</artifactId>
  4. <version>1.1.0</version>
  5. </dependency>

2、生产者代码

单线程版

  1. public class MsgProducer {
  2. public static void main(String[] args) throws InterruptedException, ExecutionException {
  3. Properties props = new Properties();
  4. props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "192.168.0.60:9092,192.168.0.60:9093,192.168.0.60:9094");
  5. /*
  6. 发出消息持久化机制参数
  7. 1)acks=0: 表示producer不需要等待任何broker确认收到消息的回复,就可以继续发送下一条消息。性能最高,但是最容易丢消息。
  8. 2)acks=1: 至少要等待leader已经成功将数据写入本地log,但是不需要等待所有follower是否成功写入。就可以继续发送下一条消息。这种情况下,如果follower没有成功备份数据,而此时leader
  9. 又挂掉,则消息会丢失。
  10. 3)acks=-1all: 这意味着leader需要等待所有备份(min.insync.replicas配置的备份个数)都成功写入日志,这种策略会保证只要有一个备份存活就不会丢失数据。
  11. 这是最强的数据保证。一般除非是金融级别,或跟钱打交道的场景才会使用这种配置。
  12. */
  13. props.put(ProducerConfig.ACKS_CONFIG, "1");
  14. //发送失败会重试,默认重试间隔100ms,重试能保证消息发送的可靠性,但是也可能造成消息重复发送,比如网络抖动,所以需要在接收者那边做好消息接收的幂等性处理
  15. props.put(ProducerConfig.RETRIES_CONFIG, 3);
  16. //重试间隔设置
  17. props.put(ProducerConfig.RETRY_BACKOFF_MS_CONFIG, 300);
  18. //设置发送消息的本地缓冲区,如果设置了该缓冲区,消息会先发送到本地缓冲区,可以提高消息发送性能,默认值是33554432,即32MB
  19. props.put(ProducerConfig.BUFFER_MEMORY_CONFIG, 33554432);
  20. //kafka本地线程会从缓冲区取数据,批量发送到broker,
  21. //设置批量发送消息的大小,默认值是16384,即16kb,就是说一个batch满了16kb就发送出去
  22. props.put(ProducerConfig.BATCH_SIZE_CONFIG, 16384);
  23. //默认值是0,意思就是消息必须立即被发送,但这样会影响性能
  24. //一般设置100毫秒左右,就是说这个消息发送完后会进入本地的一个batch,如果100毫秒内,这个batch满了16kb就会随batch一起被发送出去
  25. //如果100毫秒内,batch没满,那么也必须把消息发送出去,不能让消息的发送延迟时间太长
  26. props.put(ProducerConfig.LINGER_MS_CONFIG, 100);
  27. //把发送的key从字符串序列化为字节数组
  28. props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
  29. //把发送消息value从字符串序列化为字节数组
  30. props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class.getName());
  31. Producer<String, String> producer = new KafkaProducer<>(props);
  32. int msgNum = 5;
  33. CountDownLatch countDownLatch = new CountDownLatch(msgNum);
  34. for (int i = 1; i <= msgNum; i++) {
  35. Order order = new Order(i, 100 + i, 1, 1000.00);
  36. //指定发送分区
  37. ProducerRecord<String, String> producerRecord = new ProducerRecord<String, String>("order-topic"
  38. , 0, order.getOrderId().toString(), JSON.toJSONString(order));
  39. //未指定发送分区,具体发送的分区计算公式:hash(key)%partitionNum
  40. /*ProducerRecord<String, String> producerRecord = new ProducerRecord<String, String>("my-replicated-topic"
  41. , order.getOrderId().toString(), JSON.toJSONString(order));*/
  42. //等待消息发送成功的同步阻塞方法
  43. /*RecordMetadata metadata = producer.send(producerRecord).get();
  44. System.out.println("同步方式发送消息结果:" + "topic-" + metadata.topic() + "|partition-"
  45. + metadata.partition() + "|offset-" + metadata.offset());*/
  46. //异步方式发送消息
  47. producer.send(producerRecord, new Callback() {
  48. @Override
  49. public void onCompletion(RecordMetadata metadata, Exception exception) {
  50. if (exception != null) {
  51. System.err.println("发送消息失败:" + exception.getStackTrace());
  52. }
  53. if (metadata != null) {
  54. System.out.println("异步方式发送消息结果:" + "topic-" + metadata.topic() + "|partition-"
  55. + metadata.partition() + "|offset-" + metadata.offset());
  56. }
  57. countDownLatch.countDown();
  58. }
  59. });
  60. //送积分 TODO
  61. }
  62. countDownLatch.await(5, TimeUnit.SECONDS);
  63. producer.close();
  64. }
  65. }

多线程版

  1. package com.test.kafka;
  2. import org.apache.kafka.clients.producer.*;
  3. import org.apache.kafka.common.serialization.StringSerializer;
  4. import java.util.Properties;
  5. import java.util.concurrent.CountDownLatch;
  6. import java.util.concurrent.ExecutorService;
  7. import java.util.concurrent.Executors;
  8. public class MsgProducer {
  9. //发送消息的个数
  10. private static final int MSG_SIZE = 500000;
  11. //负责发送消息的线程池
  12. private static ExecutorService executorService = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors());
  13. private static CountDownLatch countDownLatch = new CountDownLatch(MSG_SIZE);
  14. /*发送消息的任务*/
  15. private static class ProduceWorker implements Runnable {
  16. private ProducerRecord<String, String> record;
  17. private KafkaProducer<String, String> producer;
  18. public ProduceWorker(ProducerRecord<String, String> record, KafkaProducer<String, String> producer) {
  19. this.record = record;
  20. this.producer = producer;
  21. }
  22. public void run() {
  23. final String id = Thread.currentThread().getId() + "-" + System.identityHashCode(producer);
  24. try {
  25. producer.send(record, new Callback() {
  26. public void onCompletion(RecordMetadata metadata, Exception exception) {
  27. if (null != exception) {
  28. exception.printStackTrace();
  29. }
  30. if (null != metadata) {
  31. System.out.println(id + "|"
  32. + String.format("偏移量:%s,分区:%s",
  33. metadata.offset(), metadata.partition()));
  34. }
  35. }
  36. });
  37. System.out.println(id + ":数据[" + record.key() + "-" + record.value() + "]已发送。");
  38. countDownLatch.countDown();
  39. } catch (Exception e) {
  40. e.printStackTrace();
  41. }
  42. }
  43. }
  44. public static void main(String[] args) {
  45. // 消费主题
  46. String topicName = "test_datax_kafka_read";
  47. Properties properties = new Properties();
  48. properties.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "10.254.21.6:59292,10.254.21.1:59292,10.254.21.2:59292");
  49. properties.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
  50. properties.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
  51. KafkaProducer<String, String> producer = new KafkaProducer(properties);
  52. try {
  53. //循环发送,通过线程池的方式
  54. for (int i = 0; i < MSG_SIZE; i++) {
  55. ProducerRecord<String, String> record = new ProducerRecord(
  56. topicName,
  57. null,
  58. "{\"data\":[{\"byteSize\":5,\"rawData\":28108,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":60,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":99,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":70,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":31,\"type\":\"LONG\"},{\"byteSize\":1,\"rawData\":0,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":82,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":94,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":70,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":22,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":10,\"type\":\"LONG\"},{\"byteSize\":1,\"rawData\":1,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":89,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":14,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":38,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":20,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":50,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":30,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":13,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":36,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":53,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":42,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":11,\"type\":\"LONG\"},{\"byteSize\":1,\"rawData\":4,\"type\":\"LONG\"},{\"byteSize\":1,\"rawData\":6,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":49,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":35,\"type\":\"LONG\"},{\"byteSize\":1,\"rawData\":4,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":48,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":46,\"type\":\"LONG\"},{\"byteSize\":1,\"rawData\":1,\"type\":\"LONG\"},{\"byteSize\":2,\"rawData\":73,\"type\":\"LONG\"},{\"byteSize\":1,\"rawData\":6,\"type\":\"LONG\"},{\"byteSize\":8,\"rawData\":1659515670000,\"subType\":\"DATETIME\",\"type\":\"DATE\"}],\"size\":34}\n"
  59. );
  60. executorService.submit(new ProduceWorker(record, producer));
  61. }
  62. countDownLatch.await();
  63. } catch (Exception e) {
  64. e.printStackTrace();
  65. } finally {
  66. producer.close();
  67. executorService.shutdown();
  68. }
  69. }
  70. }

3、消费者代码

单线程版

  1. public class MsgConsumer {
  2. public static void main(String[] args) {
  3. Properties props = new Properties();
  4. props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "192.168.0.60:9092,192.168.0.60:9093,192.168.0.60:9094");
  5. // 消费分组名
  6. props.put(ConsumerConfig.GROUP_ID_CONFIG, "testGroup");
  7. // 是否自动提交offset
  8. /*props.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, "true");
  9. // 自动提交offset的间隔时间
  10. props.put(ConsumerConfig.AUTO_COMMIT_INTERVAL_MS_CONFIG , "1000");*/
  11. props.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, "false");
  12. /*
  13. 心跳时间,服务端broker通过心跳确认consumer是否故障,如果发现故障,就会通过心跳下发
  14. rebalance的指令给其他的consumer通知他们进行rebalance操作,这个时间可以稍微短一点
  15. */
  16. props.put(ConsumerConfig.HEARTBEAT_INTERVAL_MS_CONFIG, 1000);
  17. //服务端broker多久感知不到一个consumer心跳就认为他故障了,默认是10
  18. props.put(ConsumerConfig.SESSION_TIMEOUT_MS_CONFIG, 10 * 1000);
  19. /*
  20. 如果两次poll操作间隔超过了这个时间,broker就会认为这个consumer处理能力太弱,
  21. 会将其踢出消费组,将分区分配给别的consumer消费
  22. */
  23. props.put(ConsumerConfig.MAX_POLL_INTERVAL_MS_CONFIG, 30 * 1000);
  24. props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
  25. props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
  26. KafkaConsumer<String, String> consumer = new KafkaConsumer<>(props);
  27. // 消费主题
  28. String topicName = "order-topic";
  29. //consumer.subscribe(Arrays.asList(topicName));
  30. // 消费指定分区
  31. //consumer.assign(Arrays.asList(new TopicPartition(topicName, 0)));
  32. //消息回溯消费
  33. consumer.assign(Arrays.asList(new TopicPartition(topicName, 0)));
  34. consumer.seekToBeginning(Arrays.asList(new TopicPartition(topicName, 0)));
  35. //指定offset消费
  36. //consumer.seek(new TopicPartition(topicName, 0), 10);
  37. while (true) {
  38. /*
  39. * poll() API 是拉取消息的长轮询,主要是判断consumer是否还活着,只要我们持续调用poll(),
  40. * 消费者就会存活在自己所在的group中,并且持续的消费指定partition的消息。
  41. * 底层是这么做的:消费者向server持续发送心跳,如果一个时间段(session.
  42. * timeout.ms)consumer挂掉或是不能发送心跳,这个消费者会被认为是挂掉了,
  43. * 这个Partition也会被重新分配给其他consumer
  44. */
  45. ConsumerRecords<String, String> records = consumer.poll(Integer.MAX_VALUE);
  46. for (ConsumerRecord<String, String> record : records) {
  47. System.out.printf("收到消息:offset = %d, key = %s, value = %s%n", record.offset(), record.key(),
  48. record.value());
  49. }
  50. if (records.count() > 0) {
  51. // 提交offset
  52. consumer.commitSync();
  53. }
  54. }
  55. }
  56. }

多线程版

  1. package com.test.kafka;
  2. import org.apache.kafka.clients.consumer.ConsumerConfig;
  3. import org.apache.kafka.clients.consumer.ConsumerRecord;
  4. import org.apache.kafka.clients.consumer.ConsumerRecords;
  5. import org.apache.kafka.clients.consumer.KafkaConsumer;
  6. import org.apache.kafka.common.serialization.StringDeserializer;
  7. import java.time.Duration;
  8. import java.util.Arrays;
  9. import java.util.Properties;
  10. import java.util.concurrent.ExecutorService;
  11. import java.util.concurrent.Executors;
  12. public class MsgConsumer {
  13. private static ExecutorService receiveMsgExecutorService = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors());
  14. public static void main(String[] args) {
  15. // 消费主题
  16. String topicName = "test_datax_kafka_read";
  17. int consumerThreadNum = 12;
  18. for (int i = 0; i < consumerThreadNum; i++) {
  19. receiveMsgExecutorService.submit(new KafkaConsumerThread(initConfig(), topicName));
  20. }
  21. }
  22. public static Properties initConfig() {
  23. Properties properties = new Properties();
  24. properties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "10.254.21.6:59292,10.254.21.1:59292,10.254.21.2:59292");
  25. // 消费分组名
  26. properties.put(ConsumerConfig.GROUP_ID_CONFIG, "local-test-2");
  27. // 是否自动提交offset
  28. properties.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, "true");
  29. // 自动提交offset的间隔时间
  30. properties.put(ConsumerConfig.AUTO_COMMIT_INTERVAL_MS_CONFIG, "1000");
  31. // 心跳时间,服务端broker通过心跳确认consumer是否故障,如果发现故障,
  32. // 就会通过心跳下发rebalance的指令给其他的consumer通知他们进行rebalance操作,这个时间可以稍微短一点
  33. properties.put(ConsumerConfig.HEARTBEAT_INTERVAL_MS_CONFIG, 1000);
  34. // 服务端broker多久感知不到一个consumer心跳就认为他故障了,默认是10
  35. properties.put(ConsumerConfig.SESSION_TIMEOUT_MS_CONFIG, 10 * 1000);
  36. // 如果两次poll操作间隔超过了这个时间,broker就会认为这个consumer处理能力太弱,
  37. // 会将其踢出消费组,将分区分配给别的consumer消费
  38. properties.put(ConsumerConfig.MAX_POLL_INTERVAL_MS_CONFIG, 30 * 1000);
  39. properties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
  40. properties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class.getName());
  41. return properties;
  42. }
  43. static class KafkaConsumerThread implements Runnable {
  44. private KafkaConsumer<String, String> kafkaConsumer;
  45. public KafkaConsumerThread(Properties properties, String topic) {
  46. this.kafkaConsumer = new KafkaConsumer<String, String>(properties);
  47. this.kafkaConsumer.subscribe(Arrays.asList(topic));
  48. }
  49. @Override
  50. public void run() {
  51. try {
  52. int consumerCount = 0;
  53. int lastConsumerCount = 0;
  54. long lastTime = System.currentTimeMillis();
  55. while (true) {
  56. ConsumerRecords<String, String> records = kafkaConsumer.poll(Duration.ofMillis(1000));
  57. for (ConsumerRecord<String, String> record : records) {
  58. //处理消息模块
  59. System.out.printf("收到消息:partition = %d, offset = %d, key = %s, value = %s%n", record.partition(), record.offset(), record.key(), record.value());
  60. consumerCount++;
  61. }
  62. System.out.println("consumerCount:" + consumerCount);
  63. long thisTime = System.currentTimeMillis();
  64. long speedTime = thisTime - lastTime;
  65. if (speedTime >= 1000L) {
  66. lastTime = thisTime;
  67. long speedCount = (consumerCount - lastConsumerCount)/(speedTime /1000L);
  68. lastConsumerCount = consumerCount;
  69. if (speedCount > 10) {
  70. System.out.println("消费速度:" + speedCount + "条/s");
  71. }
  72. }
  73. }
  74. } catch (Exception e) {
  75. e.printStackTrace();
  76. } finally {
  77. kafkaConsumer.close();
  78. }
  79. }
  80. }
  81. }

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