[YARN-1957] ProportionalCapacitPreemptionPolicy handling of corner cases...

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.4.0
• Fix Version/s: 2.4.1
• Component/s: resourcemanager
• Labels: capacity-scheduler preemption
• Hadoop Flags: Reviewed
• Assignee: Carlo Curino
• Reporter: Carlo Curino
• Created: 17/Apr/14 21:45
• Updated: 03/Sep/14 23:43
• Resolved: 13/May/14 23:16

Description

The current version of ProportionalCapacityPreemptionPolicy should be improved to deal with the following two scenarios:
1) when rebalancing over-capacity allocations, it potentially preempts without considering the maxCapacity constraints of a queue (i.e., preempting possibly more than strictly necessary)
2) a zero capacity queue is preempted even if there is no demand (coherent with old use of zero-capacity to disabled queues)

The proposed patch fixes both issues, and introduce few new test cases.