Spring Integration 的 DefaultMessageListenerContainer 和 JPA 中的事务

Question

Let's say I have simple IntegrationFlow which reads JMS messages in asynchronous manner, transforms, applies business logic, etc.

@Bean
public IntegrationFlow upstreamEventFlow() {
    return IntegrationFlows.from(
            Jms.messageDrivenChannelAdapter(jmsConnectionFactory)
                    .configureListenerContainer(container -> container.destinationResolver(destinationResolver))
                    .destination("myQueue")
                    .get()
    )
            .transform(xmlToObjectTransformer)
            .transform(upstreamTransformer)
            .handle(evaluationHandler)
            .transform(objectToXmlTransformer)
            .channel(downstreamEventChannel)
            .get();
}

evaluationHandler is GenericHandler which fetches data from database using JPA and applies some business logic

My question is related to transactions in Spring and Spring Integration

When I enable logging with following loggers:

<logger name="org.springframework.transaction" level="trace"/>
<logger name="org.springframework.jms.connection.JmsTransactionManager" level="debug"/>
<logger name="org.springframework.orm.jpa.JpaTransactionManager" level="debug"/>
<logger name="org.springframework.orm.hibernate5.HibernateTransactionManager" level="debug"/>
<logger name="org.springframework.jdbc.datasource.DataSourceTransactionManager" level="debug"/>
<logger name="org.springframework.integration" level="debug"/>
<logger name="org.springframework.messaging" level="debug"/>
<logger name="org.springframework.jms" level="debug"/>

I can see it all starts with JPA transaction, not transaction created by Spring Integration or at least JMS

from logs:

o.s.orm.jpa.JpaTransactionManager        : Creating new transaction with name ...: PROPAGATION_REQUIRED,ISOLATION_DEFAULT; ''
o.s.orm.jpa.JpaTransactionManager        : Opened new EntityManager ... for JPA transaction
o.s.orm.jpa.JpaTransactionManager        : Exposing JPA transaction as JDBC transaction ...

Why is that?

Could you elaborate on how transactions work in DefaultMessageListenerContainer and how it ties with JMS transactions, JMS transacted sessions, JPA transactions and so on?

Where is transaction boundary located?

What's the difference between transacted session and using transaction manager in DefaultMessageListenerContainer ?

If I throw RuntimeException in handler, I can see it is rolled back and see the message Execution of JMS message listener failed, and no ErrorHandler has been set. and activemq broker redelivers message multiple times

Should I set ErrorHandler ?

Answer 1

Best guess is one of your beans, eg evaluationHandler , or the method, is annotated @Transactional . That is when the JPA transaction starts. The transaction will commit (or rollback) when that method exits.

Since the MD channel adapter is transacted by default, the JMS (local) transaction wraps the entire flow and it will not commit (or rollback) until the entire flow completes (or aborts).

So, these two transactions are not really synchronized in any way; they are independent.

If you inject the JPA transaction manager into the adapter's listener container, the framework will provide "Best Efforts 1PC" transaction synchronization - see Dave Syer's Javaworld Article "Distributed transactions in Spring, with and without XA" .

The JPA transaction will be started by the container and both transactions will be committed back-to-back (DB first), effectively synchronizing them. This is not true JTA though and there is a small possibility that the DB Tx might commit while the JMS Tx rolls back - so you have to deal with the possibility of duplicate deliveries.