Transaction Synchronization in Spring Kafka

Question

I want to synchronize a kafka transaction with a repository transaction:

@Transactional
public void syncTransaction(){
  myRepository.save(someObject)
  kafka         


        

Answer 1

@Eike Behrends to have a db + kafka transaction, you can use ChainedTransactionManager and define it this way :

@Bean
public KafkaTransactionManager kafkaTransactionManager() {
    KafkaTransactionManager ktm = new KafkaTransactionManager(producerFactory());;
    ktm.setTransactionSynchronization(AbstractPlatformTransactionManager.SYNCHRONIZATION_ON_ACTUAL_TRANSACTION);
    return ktm;
}


@Bean
@Primary
public JpaTransactionManager transactionManager(EntityManagerFactory em) {
    return new JpaTransactionManager(em);
}

@Bean(name = "chainedTransactionManager")
public ChainedTransactionManager chainedTransactionManager(JpaTransactionManager jpaTransactionManager,
                                                           KafkaTransactionManager kafkaTransactionManager) {
    return new ChainedTransactionManager(kafkaTransactionManager, jpaTransactionManager);
}

You need to annotate your transactional db+kafka methods @Transactional("chainedTransactionManager")

(you can see the issue on spring-kafka project : https://github.com/spring-projects/spring-kafka/issues/433 )

You say :

From my perspective it looks weird that I send an event via kafkaTemplate, listen to my own event and forward the event using the kafkaTemplate again.

Have you tried this ? If so can you provide an example please ?