SpringBoot - Atomikos - Warning of missing transaction in latest 2.0.x snapshot

[manuel-sousa]

When a repository has a method findBy... spring boot outputs the warning bellow on initialization

2017-07-03 17:29:56.147  WARN 29034 --- [           main] c.a.icatch.jta.TransactionManagerImp     : This method needs a transaction for the calling thread and none exists.
Possible causes: either you didn't start a transaction,
it rolledback due to timeout, or it was committed already.
ACTIONS: You can try one of the following: 
1. Make sure you started a transaction for the thread.
2. Make sure you didn't terminate it yet.
3. Increase the transaction timeout to avoid automatic rollback of long transactions;
   check http://www.atomikos.com/Documentation/JtaProperties for how to do this.

To reproduce this I cloned the spring-boot repo and used the sample spring-boot-sample-jta-atomikos adding findByUsername (diff bellow)

$ git diff
diff --git a/spring-boot-samples/spring-boot-sample-jta-atomikos/src/main/java/sample/atomikos/AccountRepository.java b/spring-boot-samples/spring-boot-sample-jta-atomikos/src/main/java/sample/atomikos/AccountRepository.java
index 6b88cb4..477710a 100644
--- a/spring-boot-samples/spring-boot-sample-jta-atomikos/src/main/java/sample/atomikos/AccountRepository.java
+++ b/spring-boot-samples/spring-boot-sample-jta-atomikos/src/main/java/sample/atomikos/AccountRepository.java
@@ -19,5 +19,5 @@ package sample.atomikos;
 import org.springframework.data.jpa.repository.JpaRepository;
 
 public interface AccountRepository extends JpaRepository<Account, Long> {
-
+    public Account findByUsername(String username);
 }

[wilkinsona]

I presume you must have also called that method somehow to trigger the warning? Can you please provide a complete sample that reproduces the warning?

[manuel-sousa]

After adding any findByMethod this error shows up just by doing mvn spring-boot:run at startup, in this case just using the sample and adding that method should show up the warning.

From what i could tell this happens while searching/creating named queries for these methods.

The repository methods do work later when called so i don't know if there's any other side effect besides the warning output.

[wilkinsona]

Thanks for the additional explanation. I don't think this has anything to do with Spring Boot specifically so it'll need to be addressed elsewhere.

During the processing of the findByUsername method, Spring Data JPA calls EntityManager.createNamedQuery(String) to look up a named query. This fails as a query with the given name hasn't been defined. As a result, Spring Data JPA will create a query based on the method name.

As part of the lookup failing, Hibernate attempts to mark the current JTA transaction as rollback only. There isn't one, which, per the JTA specification, causes an IllegalStateException to be thrown. Unfortunately, in addition to throwing the IllegalStateException, Atomikos also logs the warning message mentioned above.

I can see two possible ways to fix this:

1. Update Spring Data JPA so that it performs the look up of the named query in a transaction. There's obviously a cost to this and I don't know what other, unwanted side-effects it may have. @olivergierke would know more. It's also a general change for an Atomikos-specific problem.
2. Change Atomikos so that it doesn't log the warning message (which, without the exception stack trace, isn't helpful as it doesn't tell you which method was called without a transaction or what called it)

A workaround for the log message would be to set to level of the com.atomikos.icatch.jta.TransactionManagerImp logger to ERROR but that would lose other, more useful, warning messages.

[wilkinsona]

I just checked if the same problem occurs with 1.5 and it does not. The reason for that is a change in Hibernate. Spring Boot 1.5 uses Hibernate 5.0 while Spring Boot 2.0 uses Hibernate 5.2. Both attempt to mark the current transaction as rollback only, but Hibernate 5.0 is much more defensive.

In Hibernate 5.0 it checks for an active Hibernate transaction and, if there is an active transaction, it marks it roll back only. If there's no Hibernate transaction it looks for JTA being configured and if it is, and the status of the transaction manager is not STATUS_NO_TRANSACTION, it marks the JTA transaction rollback only.

In Hibernate 5.2 it attempts to mark the transaction rollback only no matter what, relying on the IllegalStateException if there's no transaction active.

[manuel-sousa]

@wilkinsona first of all thanks for your work and assistance. I had also followed the problem to that method but wasn't sure if it would be a spring data issue, atomikos, or something in between. This was the reason i reported here and since it was easily reproducible with a sample.

Yes this didn't happen in 1.5 but i lacked the skills to relate it to hibernate.
With no visible side effects later on i'll just ignore the message. I was more worried that something might be failing to be created, despite stuff working.

[nniesen]

I logged HHH-12571 because as far as I can tell, Hibernate should not be calling javax.persistence.EntityTransaction#setRollbackOnly if there is not an active transaction or they should be throwing an ISE. Since Hibernate is doing neither, the Atomikos TransactionManagerImp is forced to throw the ISE as imposed by javax.persistence.TransactionManager#setRollbackOnly().