Description of problem: Requests from Prometheus to kube-apiserver's /metrics endpoint aren't exempted from Priority and Fairness. When their assigned priority level (currently workload-high) becomes saturated, rejected metrics requests may result in missing samples. Version-Release number of selected component (if applicable): 4.10 How reproducible: Always Steps to Reproduce: 1. Note the UID of the "exempt" prioritylevel: $ oc get prioritylevelconfiguration exempt -o=jsonpath="{.metadata.uid}{'\n'}" 2. Query the metrics endpoint while impersonating the Prometheus ServiceAccount: $ oc --as=system:serviceaccount:openshift-monitoring:prometheus-k8s get --raw '/metrics' -v10 2>&1 | grep X-Kubernetes-Pf-Prioritylevel-Uid Actual results: The /metrics request isn't assigned to the exempt priority level. $ oc get prioritylevelconfiguration exempt -o=jsonpath="{.metadata.uid}{ '\n' }" afd92c7f-65df-48e3-ac6b-48d0a063cc33 $ oc --as=system:serviceaccount:openshift-monitoring:prometheus-k8s get --raw '/metrics' -v10 2>&1 | grep X-Kubernetes-Pf-Prioritylevel-Uid I1015 11:41:54.224598 163641 round_trippers.go:463] X-Kubernetes-Pf-Prioritylevel-Uid: 00e7fd91-9201-4ee6-8cfd-99fb0d6c0cc3 Expected results: The /metrics request is assigned to the exempt priority level.
oc get clusterversion NAME VERSION AVAILABLE PROGRESSING SINCE STATUS version 4.10.0-0.nightly-2021-10-19-210507 True False 14m Cluster version is 4.10.0-0.nightly-2021-10-19-210507 oc get prioritylevelconfiguration exempt -o=jsonpath="{.metadata.uid}{ '\n' }" c6370b8b-2f97-4a07-9ca6-448551bc8e3e oc --as=system:serviceaccount:openshift-monitoring:prometheus-k8s get --raw '/metrics' -v10 2>&1 | grep X-Kubernetes-Pf-Prioritylevel-Uid I1020 10:15:17.560268 44362 round_trippers.go:454] X-Kubernetes-Pf-Prioritylevel-Uid: c6370b8b-2f97-4a07-9ca6-448551bc8e3e The /metrics request is assigned to the exempt priority level.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (Moderate: OpenShift Container Platform 4.10.3 security update), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHSA-2022:0056