[HADOOP-15481] Emit FairCallQueue stats as metrics

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.10.0, 3.0.4, 3.3.0, 3.2.1, 3.1.3
• Component/s: metrics, rpc-server
• Target Version/s: 3.0.2
• Assignee: Christopher Gregorian
• Reporter: Erik Krogen
• Created: 18/May/18 22:10
• Updated: 03/Jun/19 23:29
• Resolved: 11/Jan/19 22:02

Description

Currently FairCallQueue has some statistics which are exported via JMX: the size of each queue, and the number of overflowed calls per queue. These are useful statistics to track over time to determine, for example, if queues need to be resized. We should emit them via the standard metrics system.

Issue Links

• breaks: HADOOP-16345 Potential NPE when instantiating FairCallQueue metrics
• is related to: HADOOP-9640 RPC Congestion Control with FairCallQueue