Kafka Consumer 消费 多线程vs多实例

Kafka Consumer消费性能提升

针对一下两种方案进行对比，并通过代码检验。基于Kafka2.2.1版本

1. 方案一

在同一个Consumer Group中，创建多个Consumer，增加消费者性能。

创建Topic

bin/kafka-topics.sh --create --zookeeper master:2181 --replication-factor 1 --partitions 10 --topic mul_consumer_10

表格中展示出不同Consumer实例下的执行结果：

Consumer 实例	Partition	结果
8	10	Consumer数量小于partition数量时，某个分区数据被消费完之后，会让空闲Consumer继续消费未消费的partition中的数据。（partition数量大于Consumer数量，会将多出的partition分给同一个Consumer）
10	10	正常消费。每个Consumer实例分配一个partition，每个Consumer下的partition数据顺序消费。
12	10	Consumer数量大于partition数量时，空闲的Consumer啥事也不干。

对应Java API代码：

• Consumer Thread 实现类

  public class ConsumerThread implements Runnable {
       
      private KafkaConsumer<String,String> kafkaConsumer;
      private String topic ;
  
      public ConsumerThread(String brokers,String topicId ,  String topic) {
       
  
          Properties properties = buildKafkaProperty(brokers,topicId);
          this.kafkaConsumer = new KafkaConsumer<>(properties);
          this.topic = topic;
          this.kafkaConsumer.subscribe(Arrays.asList(this.topic));
      }
  
      private static Properties buildKafkaProperty(String brokers,String groupId){
       
  
          Properties properties = new Properties();
          properties.put("bootstrap.servers", brokers);
          properties.put("group.id", groupId);
          properties.put("enable.auto.commit", "true");
          properties.put("auto.commit.interval.ms", "1000");
          properties.put("session.timeout.ms", "30000");
          properties.put("auto.offset.reset", "earliest");
          properties.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
          properties.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
  
          return properties;
      }
  
      @Override
      public void run() {
       
  
          while (true){
       
              ConsumerRecords<String, String> records = kafkaConsumer.poll(Duration.ofMillis(100));
              for(ConsumerRecord<String,String> record : records){
       
                  System.out.print(Threa