[FLINK-15224] Resource requirements are not respected when fulfilling a slot request with unresolvedRootSlots from a SlotSharingManager

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Won't Do
• Affects Version/s: 1.11.0
• Component/s: Runtime / Coordination
• Assignee: Unassigned
• Reporter: Zhu Zhu
• Created: 12/Dec/19 12:33
• Updated: 20/Nov/20 13:55
• Resolved: 20/Nov/20 13:55

Description

In SchedulerImpl#allocateMultiTaskSlot, if a slot request cannot be fulfilled immediately with a resolved root slot(MultiTaskSlot that is fulfilled by an allocated slot) or with available slots, it will be assigned to a random unresolved root slot. It does not do resource requirements check in this case, so a large task slot can be assigned to a small shared slot (unresolved root slot) and when the shared slot received its physical slot offer, it will be recognized as oversubscribing and the slot would be released and related tasks would fail.

It's not a problem for now since specified resources are not used yet, but can be a problem in the future when we are to support specified resources.