Major Description
When the persistence unit starts aries creates the EntityManagerFactory by calling the PersistenceProvider (hibernate). Hibernate then tries to access the jndi DataSource as it wants to check some db details.
If the DataSource is not yet up then this call will hang for a long time. This then blocks the startup of the pu bundle. So in effect this can then also block the startup of the DataSource bundle.
We could either use a separate thread for the EMF creation or only start the creation when the DataSource is actually present.