Mar 12 18:52:24.937 - 58s E namespace/openshift-kube-apiserver alert/KubeAPIErrorBudgetBurn alertstate/firing severity/critical ALERTS
{alertname="KubeAPIErrorBudgetBurn", alertstate="firing", long="1h", namespace="openshift-kube-apiserver", prometheus="openshift-monitoring/k8s", severity="critical", short="5m"}

Issue 16854930: alert/KubeAPIErrorBudgetBurn should not be at or above info
Description: Description of problem:
 {code:none}
 While working on making IPsec upgrade as a mandatory jobs for OCP releases with PR: https://github.com/openshift/release/pull/63528, KubeAPIErrorBudgetBurn alert is seen for the 4.17 and 4.16 rehearsal jobs. Looks like this is seen sporadically.
 
 : [bz-kube-apiserver][invariant] alert/KubeAPIErrorBudgetBurn should not be at or above info expand_less0s{  KubeAPIErrorBudgetBurn was at or above info for at least 4m58s on platformidentification.JobType{Release:"4.17", FromRelease:"4.17", Platform:"aws", Architecture:"amd64", Network:"ovn", Topology:"ha"} (maxAllowed=0s): pending for 1h35m32s, firing for 4m58s:
 
 Apr 25 14:27:34.665 - 298s  E namespace/openshift-kube-apiserver alert/KubeAPIErrorBudgetBurn alertstate/firing severity/critical ALERTS{alertname="KubeAPIErrorBudgetBurn", alertstate="firing", long="6h", namespace="openshift-kube-apiserver", prometheus="openshift-monitoring/k8s", severity="critical", short="30m"}}
 
 https://prow.ci.openshift.org/view/gs/test-platform-results/pr-logs/pull/openshift_release/63528/rehearse-63528-pull-ci-openshift-cluster-network-operator-release-4.16-e2e-aws-ovn-ipsec-upgrade/1915748137436188672
 
 https://prow.ci.openshift.org/view/gs/test-platform-results/pr-logs/pull/openshift_release/63528/rehearse-63528-pull-ci-openshift-cluster-network-operator-release-4.17-e2e-aws-ovn-ipsec-upgrade/1915748145673801728{code}
 Version-Release number of selected component (if applicable):
 {code:none}
     {code}
 How reproducible:
 {code:none}
     {code}
 Steps to Reproduce:
 {code:none}
     1.
     2.
     3.
     {code}
 Actual results:
 {code:none}
     {code}
 Expected results:
 {code:none}
     {code}
 Additional info:
 {code:none}
 Reference: https://issues.redhat.com/browse/OCPBUGS-42083   {code}
Status: New

We have many guards making sure that there are always at least two instances of the kube-apiserver. If we ever reach a single kube-apiserver and it causes disruption for the clients, other alerts such as KubeAPIErrorBudgetBurn will fire.
KubeAPIDown is here to make sure that Prometheus and really any client can reach the kube-apiserver, which they can even when there is only one instance of kube-apiserver running. If they can't or that availability is disrupted, `KubeAPIErrorBudgetBurn` will fire.
Comment 23058588 by Marcel Härri at 2023-09-19T06:57:07.949+0000

# [bz-kube-apiserver][invariant] alert/KubeAPIErrorBudgetBurn should not be at or above pending
KubeAPIErrorBudgetBurn was at or above pending for at least 1m58s on platformidentification.JobType{Release:"4.14", FromRelease:"", Platform:"aws", Architecture:"amd64", Network:"sdn", Topology:"ha"} (maxAllowed=0s): pending for 1m58s, firing for 0s:
Jul 04 17:44:15.046 - 118s  I alert/KubeAPIErrorBudgetBurn namespace/openshift-kube-apiserver ALERTS{alertname="KubeAPIErrorBudgetBurn", alertstate="pending", long="3d", namespace="openshift-kube-apiserver", prometheus="openshift-monitoring/k8s", severity="warning", short="6h"}