Problem:
Bitbucket’s hosting ticket mechanism uses a semaphore that implements a FIFO queue. This means that if (for example) Bamboo submits 1000 clone requests for repository A and then someone comes along wanting to clone repository B once they have to wait for all of the clones of A to complete.

Solution:
Fair share scheduling of hosting operations. Instead of a FIFO queue, use a priority queue based approach where repositories or users that have not been very active are allowed to be prioritised over repositories or users that have been very active (either active currently, or in the recent past).