[YARN-3487] CapacityScheduler scheduler lock obtained unnecessarily when calling getQueue

• Type: Sub-task
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 2.6.0
• Fix Version/s: 2.6.1, 2.8.0, 2.7.1, 3.0.0-alpha1
• Component/s: capacityscheduler
• Labels: 2.6.1-candidate
• Target Version/s: 2.7.1
• Hadoop Flags: Reviewed
• Assignee: Jason Darrell Lowe
• Reporter: Jason Darrell Lowe
• Created: 14/Apr/15 21:30
• Updated: 06/Jan/17 00:49
• Resolved: 18/Apr/15 00:27

Description

Recently saw a significant slowdown of applications on a large cluster, and we noticed there were a large number of blocked threads on the RM. Most of the blocked threads were waiting for the CapacityScheduler lock while calling getQueueInfo.