[YARN-5077] Fix FSLeafQueue#getFairShare() for queues with zero fairshare

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.9.0, 3.0.0-alpha1
• Hadoop Flags: Reviewed
• Assignee: Yufei Gu
• Reporter: Yufei Gu
• Created: 12/May/16 18:27
• Updated: 30/Aug/16 01:02
• Resolved: 18/Jun/16 05:31

Description

1) When a queue's weight is set to 0.0, FSLeafQueue#getFairShare() returns <memory:0, vCores:0>
2) When a queue's weight is nonzero, FSLeafQueue#getFairShare() returns <memory:16384, vCores:8>
In case 1), that means no container ever gets allocated for an AM because from the viewpoint of the RM, there is never any headroom to allocate a container on that queue.

For example, we have a pool with the following weights:

• root.dev 0.0
• root.product 1.0

The root.dev is a best effort pool and should only get resources if root.product is not running. In our tests, with no jobs running under root.product, jobs started in root.dev queue stay stuck in ACCEPT phase and never start.