[YARN-3388] Allocation in LeafQueue could get stuck because DRF calculator isn't well supported when computing user-limit

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.6.0, 2.8.0, 2.7.2, 3.0.0-alpha1
• Fix Version/s: 2.8.0, 3.0.0-alpha1
• Component/s: capacityscheduler
• Hadoop Flags: Reviewed
• Assignee: Nathan Roberts
• Reporter: Nathan Roberts
• Created: 23/Mar/15 15:02
• Updated: 14/Oct/19 15:37
• Resolved: 20/Aug/16 00:08

Description

When there are multiple active users in a queue, it should be possible for those users to make use of capacity up-to max_capacity (or close). The resources should be fairly distributed among the active users in the queue. This works pretty well when there is a single resource being scheduled. However, when there are multiple resources the situation gets more complex and the current algorithm tends to get stuck at Capacity.

Example illustrated in subsequent comment.