sched: controller: set scheduler priority #979
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| @@ -55,7 +55,8 @@ import ( | |||
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| const ( | |||
| leaderElectionResourceName = "numa-scheduler-leader" | |||
| leaderElectionResourceName = "numa-scheduler-leader" | |||
| SystemNodeCriticalPriorityClass = "system-node-critical" | |||
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please make it private and rename to convey the intent, not the value. Maybe schedulerPriorityClassName
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In addition, please record in the commit message why system-node-critical and not system-cluster-critical (I'm fine with the decision, but let's record the reason)
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updated, thanks for raising
So far the scheduler priority is set to default which is 0 this is risky especially when the preemtion of pods is needed to fit more important pods. The NRS is important enough to deserve the most critical priority class system-node-critical which is the same priority for the kube-scheduler. We need this priority set always regardless how many replicas are set for the scheduler, and especially if we look to optimize the HA of the scheduler. We choose system-node-critical over system-cluster-critical because we don't want to allow SS preemption by higher-priority pods. If it was set to system-cluster-critical and an event is triggered that requires pod eviction, which would be for scheduling system-node-critical workloads, the SS would be at risk of being evicted. although this would be very rare and the evicted pod will be rescheduled, there is no convincing reason not to make it node-critical. addresses openshift-kni#974 Signed-off-by: Shereen Haj <[email protected]>
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[APPROVALNOTIFIER] This PR is APPROVED This pull-request has been approved by: ffromani, shajmakh The full list of commands accepted by this bot can be found here. The pull request process is described here
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@shajmakh: #979 failed to apply on top of branch "release-4.16": In response to this:
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Manual backport of openshift-kni#979 Signed-off-by: Shereen Haj <[email protected]>
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So far the scheduler priority is set to default which is 0 this is risky especially when the preemtion of pods is needed to fit more important pods.
The NRS is important enough to deserve the most critical priority class system-node-critical which is the same priority for the kube-scheduler.
addresses #974