Can KafkaTransactionManager usable with a ReactiveTransactionManager ?

[xnart]

I have a project which use R2dbc and spring-kafka altogether. I want to commit the Kafka transaction after R2dbc transaction. Normally it can be achieved as documentation suggests :

@Transactional("dstm")
public void someMethod(String in) {
    this.kafkaTemplate.send("topic2", in.toUpperCase());
    this.jdbcTemplate.execute("insert into mytable (data) values ('" + in + "')");
}

But when using R2dbcTransactionManager, KafkaTemplate throws No transaction is in process; possible solutions: run the template operation within the scope of a template.executeInTransaction() operation, start a transaction with @Transactional before invoking the template method, run in a transaction started by a listener container when consuming a record

I guess KafkaTransactionManager uses ThreadLocal while ReactiveTransactionManager uses Reactor Context. So they do not know each other's transactions. How can i adapt the KafkaTransactionManager to use Reactor Context ? Should i completely rewrite it ?

Thanks in advance.

[artembilan]

Right, the KafkaTemplate and its KafkaProducer are not Reactor-aware.
Therefore you cannot use them with ReactiveTransactionManager.

You may consider to use Rector Kafka instead: https://projectreactor.io/docs/kafka/release/reference/ 6.9. Transactional send.