starlingx/docs
Code Issues Proposed changes
47040fa69b
docs/doc/source/kube-virt/virtualmachineinstancereplicaset-8518d55de52b.rst
Elisamara Aoki Goncalves 1f91cd1ee0 Update documentation for Kubevirt 
Add Usage Examples sections.
Create KubeVirt Architecture section.
Fix minor editorial issues.
Fix grammar and formatting issues.

Story: 2010931
Task: 50286

Change-Id: I6118d0af848d07f3764eeae5ea8467864c65fceb
Signed-off-by: Elisamara Aoki Goncalves <elisamaraaoki.goncalves@windriver.com>
2024-09-04 22:08:20 +00:00

3.4 KiB
Raw Blame History

Virtual Machine Instance Replica Set

A tries to ensure that a specified number of replicas are running at any time. Meaning, a makes sure that a or a homogeneous set of is always up and ready.

Use VMIRS

The allows you to specify a Template in spec.template. It consists of ObjectMetadata in spec.template.metadata, and a spec in spec.template.spec. The specification of the is equal to the specification of the in the workload.

spec.replicas can be used to specify how many replicas are wanted. If unspecified, the default value is 1. This value can be updated anytime. The controller reacts to the changes.

Example manifest for replicaset:

apiVersion: kubevirt.io/v1
kind: VirtualMachineInstanceReplicaSet
metadata:
  name: testreplicaset
spec:
  replicas: 3
  selector:
    matchLabels:
      myvmi: myvmi
  template:
    metadata:
      name: test
      labels:
        myvmi: myvmi
    spec:
      domain:
        devices:
          disks:
          - disk:
            name: containerdisk
        resources:
          requests:
            memory: 64M
      volumes:
      - name: containerdisk
        containerDisk:
          image: kubevirt/cirros-container-disk-demo:latest

Configure Horizontal VM Autoscaler

[sysadmin@controller-0 ravi-test(keystone_admin)]$ cat hpa.yaml
---
apiVersion: autoscaling/v1
kind: HorizontalPodAutoscaler
metadata:
  name: test-hpa
spec:
  scaleTargetRef:
    kind: VirtualMachineInstanceReplicaSet
    name: testreplicaset
    apiVersion: kubevirt.io/v1
  minReplicas: 3
  maxReplicas: 5
  targetCPUUtilizationPercentage: 50
---

Verify :
[sysadmin@controller-0 (keystone_admin)]$ kubectl describe horizontalpodautoscaler.autoscaling
Name:                                   test-hpa
Namespace:                              default
Labels:                                 <none>
Annotations:                            autoscaling.alpha.kubernetes.io/conditions:
                                          [{"type":"AbleToScale","status":"True","lastTransitionTime":"2023-11-30T18:17:34Z","reason":"ScaleDownStabilized","message":"recent recomm...
                                        autoscaling.alpha.kubernetes.io/current-metrics:
                                          [\{"type":"Resource","resource":{"name":"cpu","currentAverageUtilization":1,"currentAverageValue":"2m"}}]
CreationTimestamp:                      Thu, 30 Nov 2023 19:17:19 +0100
Reference:                              VirtualMachineInstanceReplicaSet/testreplicaset
Target CPU utilization:                 50%
Current CPU utilization:                1%
Min replicas:                           3
Max replicas:                           5
VirtualMachineInstanceReplicaSet pods:  3 current / 3 desired
Events:                                 <none>

Note

Based on CPU usage in above example the autoscaler will scale up and down the replicaset.