Allows resource reservations at the QoS level preventing pods at lower QoS levels

[pacoxu]

• owner: @sjenning

// Allows resource reservations at the QoS level preventing pods at lower QoS levels from
// bursting into resources requested at higher QoS levels (memory only for now)
QOSReserved featuregate.Feature = "QOSReserved"

The feature gate was added in v1.11 kubernetes/kubernetes#62509.

No enhancement or KEP is tracking this, and I opened this issue to track this feature gate.

/sig node

• Responsible SIGs: sig-node
• Enhancement target (which target equals to which milestone):
  • Alpha release target (x.y): 1.11
  • Beta release target (x.y): ??
  • Stable release target (x.y):
• Alpha
  • KEP (k/enhancements) update PR(s): None
  • Code (k/k) update PR(s): kubelet: move QOSReserved from experimental to alpha feature gate kubernetes#62509
  • Docs (k/website) update PR(s): None

[pacoxu]

cc @SergeyKanzhelev @haircommander
Do you have some context on this FG?
As this FG kept in alpha since 1.11 and no feedback, should we deprecated it?

[haircommander]

+1 to deprecating

[pacoxu]

I think there are two choices

1. deprecated it: remove the qosReserved setting.
2. deprecated it: respect the qosReserved setting

Currently, I prefer to promote it since this FG is merely a gate and you need to additionally specify the qosReserved to use this feature.

https://github.com/kubernetes/kubernetes/blob/d36322f8d76c8e2a456e381bcc6bb43e4bbe602c/pkg/kubelet/cm/qos_container_manager_linux.go#L348-L377

[haircommander]

@pacoxu were you planning on working on this?

[pacoxu]

@pacoxu were you planning on working on this?

@haircommander Does this need a KEP?

I submit a PR kubernetes/kubernetes#130022.