[MESOS-9975] Sorter may leak clients allocations.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.9.1, 1.10.0
• Component/s: allocation
• Labels: resource-management
• Target Version/s: 1.9.1
• Sprint: Resource Mgmt: RI-18 55
• Story Points: 2
• Assignee: Meng Zhu
• Reporter: Meng Zhu
• Created: 18/Sep/19 23:09
• Updated: 25/Sep/19 20:28
• Resolved: 23/Sep/19 20:44

Description

In MESOS-9015, we allowed resource quantities to change when updating an existing allocation. When the allocation is updated to empty, however, we forget to remove the client in the map in the `sorter::update()` if the `newAllocation` is `empty()`.

https://github.com/apache/mesos/blob/master/src/master/allocator/mesos/sorter/drf/sorter.hpp#L382-L384

The above case could happen, 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.