A number of issues have been reported with respect to preemption in FairScheduler along the lines of:
- FairScheduler preempts resources from nodes even if the resultant free resources cannot fit the incoming request.
- Preemption doesn't preempt from sibling queues
- Preemption doesn't preempt from sibling apps under the same queue that is over its fairshare
Filing this umbrella JIRA to group all the issues together and think of a comprehensive solution.