Bug 1877943

Summary:	4.6 apiserver/etcd performance analysis with late switch to Golang 1.15
Product:	OpenShift Container Platform	Reporter:	Abu Kashem <akashem>
Component:	kube-apiserver	Assignee:	Abu Kashem <akashem>
Status:	CLOSED ERRATA	QA Contact:	Ke Wang <kewang>
Severity:	urgent	Docs Contact:
Priority:	urgent
Version:	4.6	CC:	aos-bugs, mfojtik, sttts, xxia
Target Milestone:	---
Target Release:	4.6.0
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-10-27 16:39:40 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Abu Kashem 2020-09-10 20:19:53 UTC

OpenShift 4.6 is migrating to (a default) of golang 1.15. Does this have any performance implications?

We want to understand if golang 1.15 introduces any performance regression. We can do the following:
- a simple test (maybe as simple as configmap create/update/get/delete), no pods churning so it does not need additional worker nodes.
- setup a cluster with latest 4.5 rc, run the test and establish a baseline.
- run the same test on 4.6 cluster, compare etcd/apiserver performance. check if there is any regression.

We can use the following test - https://github.com/tkashem/graceful/blob/master/cmd/loader/main.go

Comment 1 Abu Kashem 2020-09-25 17:33:47 UTC

Summary of the test results are captured here: https://hackmd.io/AG-8e7mgTv2Tgf-vyFMbag?edit. No noticeable performance regression detected at the specified apiserver load and test workload.

Comment 4 Ke Wang 2020-10-10 04:49:11 UTC

Per comment 1, we no need more performance tests for verification, just do below tests like description mentioned,
- a simple test (maybe as simple as configmap create/update/get/delete), no pods churning so it does not need additional worker nodes.

$ oc get clusterversion
NAME      VERSION                             AVAILABLE   PROGRESSING   SINCE   STATUS
version   4.6.0-0.nightly-2020-10-09-224055   True        False         157m    Cluster version is 4.6.0-0.nightly-2020-10-09-224055

$ oc create configmap special-config --from-literal=special.how=very --from-literal=special.type=charm
configmap/special-config created

$ oc get configmaps special-config -o yaml
apiVersion: v1
data:
  special.how: very
  special.type: charm
kind: ConfigMap
metadata:
  creationTimestamp: "2020-10-10T04:40:46Z"
  managedFields:
  - apiVersion: v1
    fieldsType: FieldsV1
    fieldsV1:
      f:data:
        .: {}
        f:special.how: {}
        f:special.type: {}
    manager: oc
    operation: Update
    time: "2020-10-10T04:40:46Z"
  name: special-config
  namespace: default
  resourceVersion: "73990"
  selfLink: /api/v1/namespaces/default/configmaps/special-config
  uid: daa66863-bc85-4fae-8e45-f5d9ff86193b

Add one new field, 
$ oc edit configmaps special-config
configmap/special-config edited

$ oc get configmaps special-config -o yaml
apiVersion: v1
data:
  special.how: very
  special.type: charm
kind: ConfigMap
metadata:
  creationTimestamp: "2020-10-10T04:40:46Z"
  managedFields:
  - apiVersion: v1
    fieldsType: FieldsV1
    fieldsV1:
      f:data:
        .: {}
        f:special.how: {}
        f:special.type: {}
        f:special.what: {}
    manager: oc
    operation: Update
    time: "2020-10-10T04:40:46Z"
  name: special-config
  namespace: default
  resourceVersion: "74185"
  selfLink: /api/v1/namespaces/default/configmaps/special-config
  uid: daa66863-bc85-4fae-8e45-f5d9ff86193b
  
$ oc delete configmaps special-config
configmap "special-config" deleted

$ oc get configmaps special-config
Error from server (NotFound): configmaps "special-config" not found

Cluster works as expected, so move the bug VERIFIED.

Comment 6 errata-xmlrpc 2020-10-27 16:39:40 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 (OpenShift Container Platform 4.6 GA Images), 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/RHBA-2020:4196