[YARN-9464] Support "Pending Resource" metrics in RM's RESTful API

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.3.0
• Assignee: Prabhu Joseph
• Reporter: Zhankun Tang
• Created: 09/Apr/19 03:43
• Updated: 23/Oct/19 16:15
• Resolved: 12/Aug/19 09:02

Description

Knowing only the "available", "used" resource is not enough for YARN management tools like auto-scaler. It would be helpful to diagnose the cluster resource utilization if it gets "Pending Resource" from RM RESTful APIs. In a certain extent, it represents how starving the applications are.

Initially, we can add "pending resource" information in below two RM REST APIs:

RMnode:port/ws/v1/cluster/metrics
RMnode:port/ws/v1/cluster/nodes