[YARN-3298] User-limit should be enforced in CapacityScheduler

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Won't Fix
• Component/s: capacityscheduler, yarn
• Assignee: Wangda Tan
• Reporter: Wangda Tan
• Created: 05/Mar/15 22:50
• Updated: 01/May/15 21:35
• Resolved: 01/May/15 21:35

Description

User-limit is not treat as a hard-limit for now, it will not consider required-resource (resource of being-allocated resource request). And also, when user's used resource equals to user-limit, it will still continue. This will generate jitter issues when we have YARN-2069 (preemption policy kills a container under an user, and scheduler allocate a container under the same user soon after).

The expected behavior should be as same as queue's capacity:
Only when user.usage + required <= user-limit (1), queue will continue to allocate container.

(1), user-limit mentioned here is determined by following computing

current-capacity = queue.used + now-required (when queue.used > queue.capacity)
                   queue.capacity (when queue.used < queue.capacity)
user-limit = min(max(current-capacity / #active-users, current-capacity * user-limit / 100), queue-capacity * user-limit-factor)