The queue fails in Confluence or Jira: "No Hibernate Session bound to thread, and configuration does not allow creation of non-transactional one here"

In Confluence

The queue says “No Hibernate Session bound to thread” in Confluence, because we access the database without starting a transaction (getDescriptors() is made outside a transaction since the last rework on jobs).

I have reviewed a few places where we could need a transaction and added them.

In Jira

Since 3.2.0, some messages from Confluence were rejected depending on the configuration.