Hello Wenxuan, there reason of the Exception, by design the transaction Id must be unique per producer instance, this is from the Java docs:
https://kafka.apache.org/20/javadoc/org/apache/kafka/clients/producer/KafkaProducer.html "The purpose of the transactional.id is to enable transaction recovery across multiple sessions of a single producer instance. It would typically be derived from the shard identifier in a partitioned, stateful, application. As such, it should be unique to each producer instance running within a partitioned application." You must have a reason to instantiate multiple producers, however, have you try just to instantiate one producer? "The producer is *thread safe* and sharing a single producer instance across threads will generally be faster than having multiple instances." Hope that helps. Cheers, -- Jonathan On Fri, May 31, 2019 at 5:47 AM wenxuan <choose_h...@126.com> wrote: > Hey guys, > > I have problem in the below scenario. > > I hope to run multiple producer instances that send message concurrently > in the same transaction, and the transaction is committed when all the > producer send message successfully. Otherwise, if one producer failed, the > transaction is aborted and no message will be consumed. > > However, when multiple producer share the same txn id, throw the following > exception: > > org.apache.kafka.common.KafkaException: Cannot execute transactional > method because we are in an error state > > at > org.apache.kafka.clients.producer.internals.TransactionManager.maybeFailWithError(TransactionManager.java:784) > > at > org.apache.kafka.clients.producer.internals.TransactionManager.beginTransaction(TransactionManager.java:215) > > at > org.apache.kafka.clients.producer.KafkaProducer.beginTransaction(KafkaProducer.java:606) > > at > com.matt.test.kafka.producer.ProducerTransactionExample.main(ProducerTransactionExample.java:68) > > Caused by: org.apache.kafka.common.errors.ProducerFencedException: > Producer attempted an operation with an old epoch. Either there is a newer > producer with the same transactionalId, or the producer's transaction has > been expired by the broker. > > Please help us how to solve this, Thanks. > -- Santilli Jonathan
