I have Stateles bean with method:
...
 @TransactionAttribute(TransactionAttributeType.REQUIRES_NEW)
 public void addUser(User user) throws Exception {
 try {
 em.persist(user);
 } catch (Exception e) {
 throw e;
 }
 }
...
java.lang.RuntimeException: org.jboss.tm.JBossRollbackException: Unable to commit, tx=TransactionImpl:XidImpl[FormatId=257, GlobalId=lserver/662, BranchQual=, localId=662] status=STATUS_NO_TRANSACTION; - nested throwable: (org.hibernate.exception.ConstraintViolationException: Could not execute JDBC batch update)
the tx actually rollback hence the exception