Bug 1915003

Summary: No estimate of average node readiness during lifetime of a cluster
Product: OpenShift Container Platform Reporter: Clayton Coleman <ccoleman>
Component: NodeAssignee: Ryan Phillips <rphillips>
Node sub component: Kubelet QA Contact: Sunil Choudhary <schoudha>
Status: CLOSED ERRATA Docs Contact:
Severity: high    
Priority: unspecified CC: aos-bugs
Version: 4.7   
Target Milestone: ---   
Target Release: 4.7.0   
Hardware: Unspecified   
OS: Unspecified   
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Last Closed: 2021-02-24 15:51:51 UTC Type: Bug
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description Flags
kube_node_ready.png
none
kube_schedulable_node_ready_reachable.png none

Description Clayton Coleman 2021-01-11 17:42:34 UTC 
The readiness of nodes in a cluster is a key measurement to assess the success of a rollout and upgrade. In general, in a working cluster nodes should always be ready unless they are rebooting, and always be reachable from metrics unless the node is down or the kubelet is being restarted. Tracking readiness allows us to estimate a bound on how often our nodes are being restarted or failing unexpectedly. This will give us information in the future to identify how we can more accurately detect, reflect, and measure service level objectives for node uptime.

Add two recording rules to telemetry that track:

* the average readiness and metrics reachability (to catch kubelet restarts) of schedulable nodes, which is our rough "how often is the kubelet running AND the node is ready from an API perspective, excluding maintenance systems"
* the average readiness as viewed in the API of all nodes, which is the rough "does a user think the node should be working" metric

This will give us rough fleet level measurements to begin quantifying sources of impact.
Comment 2 Sunil Choudhary 2021-01-19 10:25:28 UTC 
Verified on 4.7.0-0.nightly-2021-01-19-033533. I see cluster:usage:kube_schedulable_node_ready_reachable:avg5m & cluster:usage:kube_node_ready:avg5m metric being recorded.

$ oc get clusterversion
NAME      VERSION                             AVAILABLE   PROGRESSING   SINCE   STATUS
version   4.7.0-0.nightly-2021-01-19-033533   True        False         89m     Cluster version is 4.7.0-0.nightly-2021-01-19-033533

$ oc get nodes -o wide
NAME                                        STATUS   ROLES    AGE    VERSION           INTERNAL-IP   EXTERNAL-IP   OS-IMAGE                                                       KERNEL-VERSION                 CONTAINER-RUNTIME
ip-10-0-56-217.us-east-2.compute.internal   Ready    master   114m   v1.20.0+d9c52cc   10.0.56.217   <none>        Red Hat Enterprise Linux CoreOS 47.83.202101171239-0 (Ootpa)   4.18.0-240.10.1.el8_3.x86_64   cri-o://1.20.0-0.rhaos4.7.gitd9f17c8.el8.42
ip-10-0-59-181.us-east-2.compute.internal   Ready    master   114m   v1.20.0+d9c52cc   10.0.59.181   <none>        Red Hat Enterprise Linux CoreOS 47.83.202101171239-0 (Ootpa)   4.18.0-240.10.1.el8_3.x86_64   cri-o://1.20.0-0.rhaos4.7.gitd9f17c8.el8.42
ip-10-0-63-227.us-east-2.compute.internal   Ready    worker   104m   v1.20.0+d9c52cc   10.0.63.227   <none>        Red Hat Enterprise Linux CoreOS 47.83.202101171239-0 (Ootpa)   4.18.0-240.10.1.el8_3.x86_64   cri-o://1.20.0-0.rhaos4.7.gitd9f17c8.el8.42
ip-10-0-69-79.us-east-2.compute.internal    Ready    master   115m   v1.20.0+d9c52cc   10.0.69.79    <none>        Red Hat Enterprise Linux CoreOS 47.83.202101171239-0 (Ootpa)   4.18.0-240.10.1.el8_3.x86_64   cri-o://1.20.0-0.rhaos4.7.gitd9f17c8.el8.42
ip-10-0-70-235.us-east-2.compute.internal   Ready    worker   104m   v1.20.0+d9c52cc   10.0.70.235   <none>        Red Hat Enterprise Linux CoreOS 47.83.202101171239-0 (Ootpa)   4.18.0-240.10.1.el8_3.x86_64   cri-o://1.20.0-0.rhaos4.7.gitd9f17c8.el8.42
Comment 3 Sunil Choudhary 2021-01-19 10:26:06 UTC 
Created attachment 1748685 [details]
kube_node_ready.png
Comment 4 Sunil Choudhary 2021-01-19 10:26:56 UTC 
Created attachment 1748686 [details]
kube_schedulable_node_ready_reachable.png
Comment 7 errata-xmlrpc 2021-02-24 15:51:51 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 4.7.0 security, bug fix, and enhancement 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-2020:5633