Corrective mechanisms for rebalancing NM container queues

Bad queuing decisions by the LocalRMs (e.g., due to the distributed nature of the scheduling decisions or due to having a stale image of the system) may lead to an imbalance in the waiting times of the NM container queues. This can in turn have an impact in job execution times and cluster utilization.
To this end, we introduce corrective mechanisms that may remove (whenever needed) container requests from overloaded queues, adding them to less-loaded ones.