Bug 1951705

Summary: kube-apiserver needs alerts on CPU utlization
Product: OpenShift Container Platform Reporter: David Eads <deads>
Component: kube-apiserverAssignee: David Eads <deads>
Status: CLOSED ERRATA QA Contact: Ke Wang <kewang>
Severity: high Docs Contact:
Priority: high    
Version: 4.8CC: aos-bugs, mfojtik, xxia
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Target Release: 4.8.0   
Hardware: Unspecified   
OS: Unspecified   
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Last Closed: 2021-07-27 23:02:18 UTC Type: Bug
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description David Eads 2021-04-20 19:09:48 UTC
This will give us warning before an individual kube-apiserver fails under load and if the cluster cannot sustain the load if a single member fails.

Comment 4 Ke Wang 2021-05-06 03:54:06 UTC
$ oc get clusterversion
NAME      VERSION                             AVAILABLE   PROGRESSING   SINCE   STATUS
version   4.8.0-0.nightly-2021-04-30-201824   True        False         88m     Cluster version is 4.8.0-0.nightly-2021-04-30-201824

$ oc get prometheusrules.monitoring.coreos.com/cpu-utilization -n openshift-kube-apiserver -oyaml
apiVersion: monitoring.coreos.com/v1
kind: PrometheusRule
metadata:
  creationTimestamp: "2021-05-06T02:03:48Z"
  generation: 1
  managedFields:
  - apiVersion: monitoring.coreos.com/v1
    fieldsType: FieldsV1
    fieldsV1:
      f:spec:
        .: {}
        f:groups: {}
    manager: cluster-kube-apiserver-operator
    operation: Update
    time: "2021-05-06T02:03:48Z"
  name: cpu-utilization
  namespace: openshift-kube-apiserver
  resourceVersion: "17201"
  uid: ce838b0c-07b0-47e7-a915-4ab4ef4ce2a4
spec:
  groups:
  - name: control-plane-cpu-utilization
    rules:
    - alert: HighOverallControlPlaneCPU
      expr: |
        sum(
          100 - (avg by (instance) (rate(node_cpu_seconds_total{mode="idle"}[5m])) * 100)
          AND on (instance) label_replace( kube_node_role{role="master"}, "instance", "$1", "node", "(.+)" )
        )
        /
        count(kube_node_role{role="master"})
        > 60
      for: 10m
      labels:
        severity: warning
    - alert: ExtremelyHighIndividualControlPlaneCPU
      expr: |
        100 - (avg by (instance) (rate(node_cpu_seconds_total{mode="idle"}[5m])) * 100) > 90 AND on (instance) label_replace( kube_node_role{role="master"}, "instance", "$1", "node", "(.+)" )
      for: 5m
      labels:
        severity: critical

The HighOverallControlPlaneCPU has already been applied, also can be seen in web-console.

Comment 7 errata-xmlrpc 2021-07-27 23:02:18 UTC
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 4.8.2 bug fix and 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-2021:2438