[MESOS-9015] Allow resources to be removed when updating the sorter.

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Done
• Fix Version/s: 1.7.0
• Component/s: allocation
• Labels: mesosphere storage
• Target Version/s: 1.7.0
• Epic Link: Resource Provider and CSI Tech Debt
• Sprint: Mesosphere Sprint 2018-22, Mesosphere Sprint 2018-23, Mesosphere Sprint 2018-24
• Story Points: 5
• Assignee: Chun-Hung Hsiao
• Reporter: Chun-Hung Hsiao
• Shepherd: Benjamin Bannier
• Created: 21/Jun/18 01:03
• Updated: 13/Jul/18 21:51
• Resolved: 13/Jul/18 21:51

Description

Currently we do not allow resource conversions to change the resource quantities when updating the sorter; we only allow the metadata for their consumed resources to be modified.

However, this restricts Mesos from supporting operations that remove resources. For example, when a CSI volume with a stale profile is destroyed, it would be better to convert it into an empty resource since the disk space is no longer available. See https://issues.apache.org/jira/browse/MESOS-8825.

To make the allocator more flexible, we should allow resource conversions to remove resources when updating the sorter.