In 8.1.1, the user manual says (core)

Messages can be specified with a priority value between 0 and 9. 0 represents the highest priority and 9 represents
the lowest. HornetQ will attempt to deliver higher priority messages before lower priority ones.

But JMS message priority is just the reverse of that. It defines 0 as the lowest and 9 as the highest.

Any reason why we use a different priority order?