Why my pessimistic Locking in JPA with Oracle is not working

Question

I\'m trying to implement some kind of semaphores for cron jobs that runs in different JBoss nodes. I\'m trying to use the database (Oracle 11g) as a locking mechanism using

Answer 1

I can confirm Ricardos observation. I have several Lock-Modes tested with a H2-Database, and all worked as expected. Neither of the pessimistic Lock-Modes worked correctly in combination with an Oracle database. I did not try optimistic locking, but it's amazing that there's a lockmode that doesn't work with the top dog at all.