I have a producer to demonstrates a concurrency issue raising various exceptions uncontrollably on running parallel processing split block within which I try to execute inputs via JPA Camel component.

Please see the producer project below:
https://github.com/roman-hoher/parallel-processing-issue

The Example output:

#################################
ERROR SUMMARY
Exception types: 7
Total exception occurrences: 47
#################################
8 java.lang.IllegalStateException
4 org.hibernate.AssertionFailure
1 org.hibernate.sql.exec.ExecutionException
21 org.hibernate.exception.GenericJDBCException
1 org.hibernate.HibernateException
9 java.util.ConcurrentModificationException
3 java.lang.NullPointerException
#################################

Only when specify a single thread with the block, the test result would be ok without any exception.