Kafka Producer Exactly-once

1. Idempotent producers

enable.idempotence=true yapılır. Böylece gönderilen mesajların birer birer artan ve ardışık olması garanti edilir. Producer Ayarları - idempotent yazısına bakabilirsiniz

2. Producer transactional guarantee

transactional.id alanına değer string değer atanır

Örnek

Şöyle yaparız

import org.apache.kafka.clients.producer.KafkaProducer;
import org.apache.kafka.clients.producer.Producer;
import org.apache.kafka.clients.producer.ProducerConfig;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.kafka.common.serialization.StringSerializer;

public class MyKafkaProducerForExactlyOnceDelivery {
  public static void main(String[] args) {
    Properties props = new Properties();
    props.put("bootstrap.servers", "localhost:9092"); 
    // enables idempotence
    props.put(ProducerConfig.ENABLE_IDEMPOTENCE_CONFIG, true); 
    // enables transaction guarantee
    props.put(ProducerConfig.TRANSACTIONAL_ID_CONFIG, "my-transaction-id"); 

    Producer<String, String> producer = new KafkaProducer<>(props, 
      new StringSerializer(), new StringSerializer());
    producer.initTransactions();
    try {
      // Start the transaction
      producer.beginTransaction();
      for (int i = 0; i <= 100; i++){
        producer.send(new ProducerRecord<>("my-producer-topic", 0, 
          Integer.toString(i), Integer.toString(i)));
      }
      // Commit the transaction
      producer.commitTransaction();
    } catch (Exception e) {
      // Abort the transaction on error
      producer.abortTransaction();
    } finally {
      producer.close();
    }
  }
}