Techniques for improved handling of queues of data units are described, such as queues of buffered data units of differing types and/or sources within a switch or other network device. When the size of a queue surpasses the state entry threshold for a certain state, the queue is said to be in the certain state. While in the certain state, data units assigned to the queue may be handled differently in some respect, such as being marked or being dropped without further processing. The queue remains in this certain state until its size falls below the state release threshold for the state. The state release threshold is adjusted over time in, for example, a random or pseudo-random manner. Among other aspects, in some embodiments, this adjustment of the state release threshold addresses fairness issues that may arise with respect to the treatment of different types or sources of data units.