[YARN-9041] Performance Optimization of method FSPreemptionThread#identifyContainersToPreempt

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.1.1
• Fix Version/s: 3.2.1
• Component/s: fairscheduler, scheduler preemption
• Hadoop Flags: Reviewed
• Assignee: Wanqiang Ji
• Reporter: Wanqiang Ji
• Created: 21/Nov/18 00:05
• Updated: 04/Dec/18 18:27
• Resolved: 04/Dec/18 18:14

Description

In FSPreemptionThread#identifyContainersToPreempt method, I suggest if AM preemption, and locality relaxation is allowed, then the search space is expanded to all nodes changed to the remaining nodes. The remaining nodes are equal to all nodes minus the potential nodes.

Judging condition changed to:

1. rr.getRelaxLocality()
2. !ResourceRequest.isAnyLocation(rr.getResourceName())
3. bestContainers != null
4. bestContainers.numAMContainers > 0

If I understand the deviation, please criticize me. thx~