JBPAPP-7464 was fixed by using synchronized to control access to the properties, but the synchronization is wider than it needs to be. The entire ManagedConnectionFactory.createManagedConnection() method is synchronized, when in reality only the part touching the properties needs to be. This causes a bottleneck where only one connection can be created at once, which impacts early use when the pool is filling.

Backporting the relevant changes which are part of https://github.com/ironjacamar/ironjacamar/commit/e2db9c25fff32207c733c0945e825cd126f34ffb would remove the bottleneck.