Bug 1738831

Summary: parent MCP doesn't update machine count when there's another custom pool for a subset of the parent MCP
Product: OpenShift Container Platform Reporter: Antonio Murdaca <amurdaca>
Component: Machine Config OperatorAssignee: Antonio Murdaca <amurdaca>
Status: CLOSED ERRATA QA Contact: Micah Abbott <miabbott>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 4.2.0CC: mnguyen, nsu
Target Milestone: ---   
Target Release: 4.2.0   
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: 2019-10-16 06:35:15 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 Antonio Murdaca 2019-08-08 09:02:30 UTC 
Description of problem:

When using a custom pool for a subset of the worker nodes, the worker MCP shows an outdated machine count until the MCP is synced again (this can also be manually triggered by a worker MCP update like setting maxUnavailable).


Version-Release number of selected component (if applicable):

4.2


How reproducible:

100%


Steps to Reproduce:
1. set a node to be infra and create an infra MCP/MC inheriting from worker
2. oc describe mcp worker
3.

Actual results:

On a 3 nodes cluster and 1 infra node:

oc describe mcp worker
...
  Machine Count:              3
...


Expected results:

oc describe mcp worker
...
  Machine Count:              2
...

Additional info:
Comment 2 Michael Nguyen 2019-08-21 15:07:28 UTC 
Verified on 4.2.0-0.nightly-2019-08-20-162755

$ oc get clusterversion
NAME      VERSION                             AVAILABLE   PROGRESSING   SINCE   STATUS
version   4.2.0-0.nightly-2019-08-20-162755   True        False         11m     Cluster version is 4.2.0-0.nightly-2019-08-20-162755

cat mcpinfra.yaml
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfigPool
metadata:
  name: infra
spec:
  machineConfigSelector:
    matchExpressions:
      - {key: machineconfiguration.openshift.io/role, operator: In, values: [worker,infra]}
  maxUnavailable: null
  nodeSelector:
    matchLabels:
      node-role.kubernetes.io/infra: ""
  paused: false

$ oc create -f mcpinfra.yaml 
machineconfigpool.machineconfiguration.openshift.io/infra created

$ oc get machineconfigpool 
NAME     CONFIG                                             UPDATED   UPDATING   DEGRADED
infra    rendered-infra-0fbb7c0ce09edd8e04bf68881c95d62c    True      False      False
master   rendered-master-72b9921bcfbd8242bfb984850defee68   True      False      False
worker   rendered-worker-0fbb7c0ce09edd8e04bf68881c95d62c   True      False      False


$ oc get machineconfigpool worker -o yaml
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfigPool
metadata:
  creationTimestamp: "2019-08-21T14:26:46Z"
  generation: 2
  labels:
    machineconfiguration.openshift.io/mco-built-in: ""
  name: worker
  resourceVersion: "13234"
  selfLink: /apis/machineconfiguration.openshift.io/v1/machineconfigpools/worker
  uid: b46bbcb7-c41f-11e9-bb1a-0239f61aa074
spec:
  configuration:
    name: rendered-worker-0fbb7c0ce09edd8e04bf68881c95d62c
    source:
    - apiVersion: machineconfiguration.openshift.io/v1
      kind: MachineConfig
      name: 00-worker
    - apiVersion: machineconfiguration.openshift.io/v1
      kind: MachineConfig
      name: 01-worker-container-runtime
    - apiVersion: machineconfiguration.openshift.io/v1
      kind: MachineConfig
      name: 01-worker-kubelet
    - apiVersion: machineconfiguration.openshift.io/v1
      kind: MachineConfig
      name: 99-worker-ssh
  machineConfigSelector:
    matchLabels:
      machineconfiguration.openshift.io/role: worker
  nodeSelector:
    matchLabels:
      node-role.kubernetes.io/worker: ""
  paused: false
status:
  conditions:
  - lastTransitionTime: "2019-08-21T14:27:12Z"
    message: ""
    reason: ""
    status: "False"
    type: RenderDegraded
  - lastTransitionTime: "2019-08-21T14:27:15Z"
    message: ""
    reason: ""
    status: "False"
    type: NodeDegraded
  - lastTransitionTime: "2019-08-21T14:27:15Z"
    message: ""
    reason: ""
    status: "False"
    type: Degraded
  - lastTransitionTime: "2019-08-21T14:34:51Z"
    message: All nodes are updated with rendered-worker-0fbb7c0ce09edd8e04bf68881c95d62c
    reason: ""
    status: "True"
    type: Updated
  - lastTransitionTime: "2019-08-21T14:34:51Z"
    message: ""
    reason: ""
    status: "False"
    type: Updating
  configuration:
    name: rendered-worker-0fbb7c0ce09edd8e04bf68881c95d62c
    source:
    - apiVersion: machineconfiguration.openshift.io/v1
      kind: MachineConfig
      name: 00-worker
    - apiVersion: machineconfiguration.openshift.io/v1
      kind: MachineConfig
      name: 01-worker-container-runtime
    - apiVersion: machineconfiguration.openshift.io/v1
      kind: MachineConfig
      name: 01-worker-kubelet
    - apiVersion: machineconfiguration.openshift.io/v1
      kind: MachineConfig
      name: 99-worker-ssh
  degradedMachineCount: 0
  machineCount: 3
  observedGeneration: 2
  readyMachineCount: 3
  unavailableMachineCount: 0
  updatedMachineCount: 3

$ oc get nodes
NAME                                         STATUS   ROLES    AGE   VERSION
ip-10-0-140-224.us-west-2.compute.internal   Ready    master   19m   v1.14.0+f667219f4
ip-10-0-142-195.us-west-2.compute.internal   Ready    worker   12m   v1.14.0+f667219f4
ip-10-0-152-89.us-west-2.compute.internal    Ready    master   19m   v1.14.0+f667219f4
ip-10-0-157-197.us-west-2.compute.internal   Ready    worker   11m   v1.14.0+f667219f4
ip-10-0-167-57.us-west-2.compute.internal    Ready    master   19m   v1.14.0+f667219f4
ip-10-0-173-22.us-west-2.compute.internal    Ready    worker   12m   v1.14.0+f667219f4


$ oc describe node ip-10-0-173-22.us-west-2.compute.internal
Name:               ip-10-0-173-22.us-west-2.compute.internal
Roles:              worker
Labels:             beta.kubernetes.io/arch=amd64
                    beta.kubernetes.io/instance-type=m5.large
                    beta.kubernetes.io/os=linux
                    failure-domain.beta.kubernetes.io/region=us-west-2
                    failure-domain.beta.kubernetes.io/zone=us-west-2c
                    kubernetes.io/arch=amd64
                    kubernetes.io/hostname=ip-10-0-173-22
                    kubernetes.io/os=linux
                    node-role.kubernetes.io/worker=
                    node.openshift.io/os_id=rhcos
Annotations:        machine.openshift.io/machine: openshift-machine-api/mnguyen-w8rzg-worker-us-west-2c-8sfwr
                    machineconfiguration.openshift.io/currentConfig: rendered-worker-0fbb7c0ce09edd8e04bf68881c95d62c
                    machineconfiguration.openshift.io/desiredConfig: rendered-worker-0fbb7c0ce09edd8e04bf68881c95d62c
                    machineconfiguration.openshift.io/state: Done
                    volumes.kubernetes.io/controller-managed-attach-detach: true
CreationTimestamp:  Wed, 21 Aug 2019 10:32:46 -0400
Taints:             <none>
Unschedulable:      false
Conditions:
  Type             Status  LastHeartbeatTime                 LastTransitionTime                Reason                       Message
  ----             ------  -----------------                 ------------------                ------                       -------
  MemoryPressure   False   Wed, 21 Aug 2019 10:45:06 -0400   Wed, 21 Aug 2019 10:32:46 -0400   KubeletHasSufficientMemory   kubelet has sufficient memory available
  DiskPressure     False   Wed, 21 Aug 2019 10:45:06 -0400   Wed, 21 Aug 2019 10:32:46 -0400   KubeletHasNoDiskPressure     kubelet has no disk pressure
  PIDPressure      False   Wed, 21 Aug 2019 10:45:06 -0400   Wed, 21 Aug 2019 10:32:46 -0400   KubeletHasSufficientPID      kubelet has sufficient PID available
  Ready            True    Wed, 21 Aug 2019 10:45:06 -0400   Wed, 21 Aug 2019 10:33:46 -0400   KubeletReady                 kubelet is posting ready status
Addresses:
  InternalIP:   10.0.173.22
  InternalDNS:  ip-10-0-173-22.us-west-2.compute.internal
  Hostname:     ip-10-0-173-22.us-west-2.compute.internal
Capacity:
 attachable-volumes-aws-ebs:  25
 cpu:                         2
 hugepages-1Gi:               0
 hugepages-2Mi:               0
 memory:                      7861176Ki
 pods:                        250
Allocatable:
 attachable-volumes-aws-ebs:  25
 cpu:                         1500m
 hugepages-1Gi:               0
 hugepages-2Mi:               0
 memory:                      7246776Ki
 pods:                        250
System Info:
 Machine ID:                              ec2c8fea0f6a0f036773cf2dcb8b4134
 System UUID:                             ec2c8fea-0f6a-0f03-6773-cf2dcb8b4134
 Boot ID:                                 5f627768-c1ff-473c-9a09-c2e6d5e9d8e9
 Kernel Version:                          4.18.0-80.7.2.el8_0.x86_64
 OS Image:                                Red Hat Enterprise Linux CoreOS 42.80.20190816.2 (Ootpa)
 Operating System:                        linux
 Architecture:                            amd64
 Container Runtime Version:               cri-o://1.14.10-0.7.dev.rhaos4.2.git7e863dd.el8-dev
 Kubelet Version:                         v1.14.0+f667219f4
 Kube-Proxy Version:                      v1.14.0+f667219f4
ProviderID:                               aws:///us-west-2c/i-0a105357bc54d2199
Non-terminated Pods:                      (14 in total)
  Namespace                               Name                                        CPU Requests  CPU Limits  Memory Requests  Memory Limits  AGE
  ---------                               ----                                        ------------  ----------  ---------------  -------------  ---
  openshift-cluster-node-tuning-operator  tuned-wsgfp                                 10m (0%)      0 (0%)      50Mi (0%)        0 (0%)         12m
  openshift-dns                           dns-default-dl7hq                           110m (7%)     0 (0%)      70Mi (0%)        512Mi (7%)     12m
  openshift-image-registry                node-ca-dkhhs                               10m (0%)      0 (0%)      10Mi (0%)        0 (0%)         11m
  openshift-machine-config-operator       machine-config-daemon-wlns8                 20m (1%)      0 (0%)      50Mi (0%)        0 (0%)         11m
  openshift-monitoring                    alertmanager-main-0                         100m (6%)     100m (6%)   225Mi (3%)       25Mi (0%)      10m
  openshift-monitoring                    kube-state-metrics-6bdfd467f9-kmj2v         30m (2%)      0 (0%)      120Mi (1%)       0 (0%)         15m
  openshift-monitoring                    node-exporter-rdns2                         10m (0%)      0 (0%)      20Mi (0%)        0 (0%)         12m
  openshift-monitoring                    openshift-state-metrics-675c468964-fbc9m    120m (8%)     0 (0%)      190Mi (2%)       0 (0%)         15m
  openshift-monitoring                    prometheus-adapter-65bf8db64c-t4lrm         10m (0%)      0 (0%)      20Mi (0%)        0 (0%)         10m
  openshift-monitoring                    prometheus-k8s-0                            430m (28%)    200m (13%)  1134Mi (16%)     50Mi (0%)      10m
  openshift-monitoring                    prometheus-operator-8474479b67-kg98m        10m (0%)      0 (0%)      60Mi (0%)        0 (0%)         10m
  openshift-multus                        multus-t54rs                                10m (0%)      0 (0%)      150Mi (2%)       0 (0%)         12m
  openshift-sdn                           ovs-th5fc                                   200m (13%)    0 (0%)      400Mi (5%)       0 (0%)         12m
  openshift-sdn                           sdn-tttfp                                   100m (6%)     0 (0%)      200Mi (2%)       0 (0%)         12m
Allocated resources:
  (Total limits may be over 100 percent, i.e., overcommitted.)
  Resource                    Requests      Limits
  --------                    --------      ------
  cpu                         1170m (78%)   300m (20%)
  memory                      2699Mi (38%)  587Mi (8%)
  ephemeral-storage           0 (0%)        0 (0%)
  attachable-volumes-aws-ebs  0             0
Events:
  Type    Reason                   Age                From                                                Message
  ----    ------                   ----               ----                                                -------
  Normal  NodeHasSufficientMemory  12m (x8 over 13m)  kubelet, ip-10-0-173-22.us-west-2.compute.internal  Node ip-10-0-173-22.us-west-2.compute.internal status is now: NodeHasSufficientMemory
  Normal  NodeHasNoDiskPressure    12m (x8 over 13m)  kubelet, ip-10-0-173-22.us-west-2.compute.internal  Node ip-10-0-173-22.us-west-2.compute.internal status is now: NodeHasNoDiskPressure
$ oc edit node ip-10-0-173-22.us-west-2.compute.internal
node/ip-10-0-173-22.us-west-2.compute.internal edited
$ oc edit node ip-10-0-173-22.us-west-2.compute.internal

( s/node-role.kubernetes.io\/worker:/node-role.kubernetes.io\/infra:/ )

$ oc get  node 
NAME                                         STATUS   ROLES    AGE   VERSION
ip-10-0-140-224.us-west-2.compute.internal   Ready    master   20m   v1.14.0+f667219f4
ip-10-0-142-195.us-west-2.compute.internal   Ready    worker   13m   v1.14.0+f667219f4
ip-10-0-152-89.us-west-2.compute.internal    Ready    master   20m   v1.14.0+f667219f4
ip-10-0-157-197.us-west-2.compute.internal   Ready    worker   13m   v1.14.0+f667219f4
ip-10-0-167-57.us-west-2.compute.internal    Ready    master   20m   v1.14.0+f667219f4
ip-10-0-173-22.us-west-2.compute.internal    Ready    infra    13m   v1.14.0+f667219f4

$ oc describe machineconfigpool worker
Name:         worker
Namespace:    
Labels:       machineconfiguration.openshift.io/mco-built-in=
Annotations:  <none>
API Version:  machineconfiguration.openshift.io/v1
Kind:         MachineConfigPool
Metadata:
  Creation Timestamp:  2019-08-21T14:26:46Z
  Generation:          2
  Resource Version:    13234
  Self Link:           /apis/machineconfiguration.openshift.io/v1/machineconfigpools/worker
  UID:                 b46bbcb7-c41f-11e9-bb1a-0239f61aa074
Spec:
  Configuration:
    Name:  rendered-worker-0fbb7c0ce09edd8e04bf68881c95d62c
    Source:
      API Version:  machineconfiguration.openshift.io/v1
      Kind:         MachineConfig
      Name:         00-worker
      API Version:  machineconfiguration.openshift.io/v1
      Kind:         MachineConfig
      Name:         01-worker-container-runtime
      API Version:  machineconfiguration.openshift.io/v1
      Kind:         MachineConfig
      Name:         01-worker-kubelet
      API Version:  machineconfiguration.openshift.io/v1
      Kind:         MachineConfig
      Name:         99-worker-ssh
  Machine Config Selector:
    Match Labels:
      machineconfiguration.openshift.io/role:  worker
  Node Selector:
    Match Labels:
      node-role.kubernetes.io/worker:  
  Paused:                              false
Status:
  Conditions:
    Last Transition Time:  2019-08-21T14:27:12Z
    Message:               
    Reason:                
    Status:                False
    Type:                  RenderDegraded
    Last Transition Time:  2019-08-21T14:27:15Z
    Message:               
    Reason:                
    Status:                False
    Type:                  NodeDegraded
    Last Transition Time:  2019-08-21T14:27:15Z
    Message:               
    Reason:                
    Status:                False
    Type:                  Degraded
    Last Transition Time:  2019-08-21T14:34:51Z
    Message:               All nodes are updated with rendered-worker-0fbb7c0ce09edd8e04bf68881c95d62c
    Reason:                
    Status:                True
    Type:                  Updated
    Last Transition Time:  2019-08-21T14:34:51Z
    Message:               
    Reason:                
    Status:                False
    Type:                  Updating
  Configuration:
    Name:  rendered-worker-0fbb7c0ce09edd8e04bf68881c95d62c
    Source:
      API Version:            machineconfiguration.openshift.io/v1
      Kind:                   MachineConfig
      Name:                   00-worker
      API Version:            machineconfiguration.openshift.io/v1
      Kind:                   MachineConfig
      Name:                   01-worker-container-runtime
      API Version:            machineconfiguration.openshift.io/v1
      Kind:                   MachineConfig
      Name:                   01-worker-kubelet
      API Version:            machineconfiguration.openshift.io/v1
      Kind:                   MachineConfig
      Name:                   99-worker-ssh
  Degraded Machine Count:     0
  Machine Count:              3
  Observed Generation:        2
  Ready Machine Count:        3
  Unavailable Machine Count:  0
  Updated Machine Count:      3
Events:                       <none>
$ oc describe machineconfigpool infra
Name:         infra
Namespace:    
Labels:       <none>
Annotations:  <none>
API Version:  machineconfiguration.openshift.io/v1
Kind:         MachineConfigPool
Metadata:
  Creation Timestamp:  2019-08-21T14:45:04Z
  Generation:          2
  Resource Version:    17287
  Self Link:           /apis/machineconfiguration.openshift.io/v1/machineconfigpools/infra
  UID:                 42ca997d-c422-11e9-9cf0-0ab5045af90e
Spec:
  Configuration:
    Name:  rendered-infra-0fbb7c0ce09edd8e04bf68881c95d62c
    Source:
      API Version:  machineconfiguration.openshift.io/v1
      Kind:         MachineConfig
      Name:         00-worker
      API Version:  machineconfiguration.openshift.io/v1
      Kind:         MachineConfig
      Name:         01-worker-container-runtime
      API Version:  machineconfiguration.openshift.io/v1
      Kind:         MachineConfig
      Name:         01-worker-kubelet
      API Version:  machineconfiguration.openshift.io/v1
      Kind:         MachineConfig
      Name:         99-worker-b46bbcb7-c41f-11e9-bb1a-0239f61aa074-registries
      API Version:  machineconfiguration.openshift.io/v1
      Kind:         MachineConfig
      Name:         99-worker-ssh
  Machine Config Selector:
    Match Expressions:
      Key:       machineconfiguration.openshift.io/role
      Operator:  In
      Values:
        worker
        infra
  Node Selector:
    Match Labels:
      node-role.kubernetes.io/infra:  
  Paused:                             false
Status:
  Conditions:
    Last Transition Time:  2019-08-21T14:45:09Z
    Message:               
    Reason:                
    Status:                False
    Type:                  RenderDegraded
    Last Transition Time:  2019-08-21T14:45:14Z
    Message:               
    Reason:                
    Status:                False
    Type:                  NodeDegraded
    Last Transition Time:  2019-08-21T14:45:14Z
    Message:               
    Reason:                
    Status:                False
    Type:                  Degraded
    Last Transition Time:  2019-08-21T14:47:58Z
    Message:               
    Reason:                
    Status:                False
    Type:                  Updated
    Last Transition Time:  2019-08-21T14:47:58Z
    Message:               All nodes are updating to rendered-infra-0fbb7c0ce09edd8e04bf68881c95d62c
    Reason:                
    Status:                True
    Type:                  Updating
  Configuration:
    Name:  rendered-infra-0fbb7c0ce09edd8e04bf68881c95d62c
    Source:
      API Version:            machineconfiguration.openshift.io/v1
      Kind:                   MachineConfig
      Name:                   00-worker
      API Version:            machineconfiguration.openshift.io/v1
      Kind:                   MachineConfig
      Name:                   01-worker-container-runtime
      API Version:            machineconfiguration.openshift.io/v1
      Kind:                   MachineConfig
      Name:                   01-worker-kubelet
      API Version:            machineconfiguration.openshift.io/v1
      Kind:                   MachineConfig
      Name:                   99-worker-b46bbcb7-c41f-11e9-bb1a-0239f61aa074-registries
      API Version:            machineconfiguration.openshift.io/v1
      Kind:                   MachineConfig
      Name:                   99-worker-ssh
  Degraded Machine Count:     0
  Machine Count:              1
  Observed Generation:        2
  Ready Machine Count:        0
  Unavailable Machine Count:  0
  Updated Machine Count:      0
Events:                       <none>
$ oc describe machineconfigpool worker
Name:         worker
Namespace:    
Labels:       machineconfiguration.openshift.io/mco-built-in=
Annotations:  <none>
API Version:  machineconfiguration.openshift.io/v1
Kind:         MachineConfigPool
Metadata:
  Creation Timestamp:  2019-08-21T14:26:46Z
  Generation:          2
  Resource Version:    17284
  Self Link:           /apis/machineconfiguration.openshift.io/v1/machineconfigpools/worker
  UID:                 b46bbcb7-c41f-11e9-bb1a-0239f61aa074
Spec:
  Configuration:
    Name:  rendered-worker-0fbb7c0ce09edd8e04bf68881c95d62c
    Source:
      API Version:  machineconfiguration.openshift.io/v1
      Kind:         MachineConfig
      Name:         00-worker
      API Version:  machineconfiguration.openshift.io/v1
      Kind:         MachineConfig
      Name:         01-worker-container-runtime
      API Version:  machineconfiguration.openshift.io/v1
      Kind:         MachineConfig
      Name:         01-worker-kubelet
      API Version:  machineconfiguration.openshift.io/v1
      Kind:         MachineConfig
      Name:         99-worker-ssh
  Machine Config Selector:
    Match Labels:
      machineconfiguration.openshift.io/role:  worker
  Node Selector:
    Match Labels:
      node-role.kubernetes.io/worker:  
  Paused:                              false
Status:
  Conditions:
    Last Transition Time:  2019-08-21T14:27:12Z
    Message:               
    Reason:                
    Status:                False
    Type:                  RenderDegraded
    Last Transition Time:  2019-08-21T14:27:15Z
    Message:               
    Reason:                
    Status:                False
    Type:                  NodeDegraded
    Last Transition Time:  2019-08-21T14:27:15Z
    Message:               
    Reason:                
    Status:                False
    Type:                  Degraded
    Last Transition Time:  2019-08-21T14:34:51Z
    Message:               All nodes are updated with rendered-worker-0fbb7c0ce09edd8e04bf68881c95d62c
    Reason:                
    Status:                True
    Type:                  Updated
    Last Transition Time:  2019-08-21T14:34:51Z
    Message:               
    Reason:                
    Status:                False
    Type:                  Updating
  Configuration:
    Name:  rendered-worker-0fbb7c0ce09edd8e04bf68881c95d62c
    Source:
      API Version:            machineconfiguration.openshift.io/v1
      Kind:                   MachineConfig
      Name:                   00-worker
      API Version:            machineconfiguration.openshift.io/v1
      Kind:                   MachineConfig
      Name:                   01-worker-container-runtime
      API Version:            machineconfiguration.openshift.io/v1
      Kind:                   MachineConfig
      Name:                   01-worker-kubelet
      API Version:            machineconfiguration.openshift.io/v1
      Kind:                   MachineConfig
      Name:                   99-worker-ssh
  Degraded Machine Count:     0
  Machine Count:              2
  Observed Generation:        2
  Ready Machine Count:        2
  Unavailable Machine Count:  0
  Updated Machine Count:      2
Events:                       <none>
Comment 3 errata-xmlrpc 2019-10-16 06:35:15 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, 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-2019:2922
Comment 4 Nick Su 2021-03-09 06:17:24 UTC 
Hi 

I found this bug still exist in ocp4.5.4, before I have 6 worker nodes, but after I changed one of it to infra node, the machinecount of mcp is still 6

[student@workstation ~]$ oc get nodes -l node-role.kubernetes.io/worker
NAME       STATUS   ROLES    AGE    VERSION
worker01   Ready    worker   151d   v1.18.3+012b3ec
worker02   Ready    worker   151d   v1.18.3+012b3ec
worker03   Ready    worker   151d   v1.18.3+012b3ec
worker04   Ready    worker   19m    v1.18.3+012b3ec
worker05   Ready    worker   19m    v1.18.3+012b3ec
[student@workstation ~]$ oc get mcp worker
NAME     CONFIG                                             UPDATED   UPDATING   DEGRADED   MACHINECOUNT   READYMACHINECOUNT   UPDATEDMACHINECOUNT   DEGRADEDMACHINECOUNT   AGE
worker   rendered-worker-ecc5564cb238470a57fcdb8c49a9bc29   True      False      False      6              6                   6                     0                      151d

The only way I found to reflect the new machinecount is to recreate the MCP
[student@workstation ~]$ oc get clusterversion
NAME      VERSION   AVAILABLE   PROGRESSING   SINCE   STATUS
version   4.5.4     True        False         151d    Cluster version is 4.5.4