VMware Windows CPU hog

VMware Windows CPU hog applies stress on the CPU resources on Windows OS based VMware VM.

• It checks the performance of the application running on the VMware Windows VMs.

Use cases

• VMware Windows CPU hog determines the resilience of an application when stress is applied on the CPU resources of a VMware Windows virtual machine.
• VMware Windows CPU hog simulates the situation of lack of CPU for processes running on the application, which degrades their performance.
• It also helps verify metrics-based horizontal pod autoscaling as well as vertical autoscale, that is, demand based CPU addition.
• It verifies the autopilot functionality of cloud managed clusters.

Prerequisites

• Kubernetes > 1.16 is required to execute this fault.

• Execution plane should be connected to vCenter and host vCenter on port 443.

• Adequate vCenter permissions should be provided to access the hosts and the VMs.

• VMware tool should be installed on the target VM with remote execution enabled.

• The VM should be in a healthy state before and after injecting chaos.

• Kubernetes secret has to be created that has the Vcenter credentials in the CHAOS_NAMESPACE.

• VM credentials can be passed as secrets or as a chaos enginer environment variable.

apiVersion: v1
kind: Secret
metadata:
  name: vcenter-secret
  namespace: litmus
type: Opaque
stringData:
    VCENTERSERVER: XXXXXXXXXXX
    VCENTERUSER: XXXXXXXXXXXXX
    VCENTERPASS: XXXXXXXXXXXXX

Mandatory tunables

Tunable	Description	Notes
VM_NAME	Name of the target VM.	For example, ubuntu-vm-1
VM_USER_NAME	Username of the target VM.	For example, vm-user.
VM_PASSWORD	User password for the target VM.	For example, 1234. Note: You can take the password from secret as well.

Optional tunables

Tunable	Description	Notes
CPU_CORES	Number of CPU cores subject to CPU stress.	Default: 0. Indicates that all the avaialble CPU resources are consumed. For more information, go to CPU cores.
TOTAL_CHAOS_DURATION	Duration that you specify, through which chaos is injected into the target resource (in seconds).	Default: 60s. For more information, go to duration of the chaos.
RAMP_TIME	Period to wait before and after injecting chaos (in seconds).	For example, 30s. For more information, go to ramp time.
SEQUENCE	Sequence of chaos execution for multiple instances.	Default: parallel. Supports serial sequence as well. For more information, go to sequence of chaos execution.
DEFAULT_HEALTH_CHECK	Determines if you wish to run the default health check which is present inside the fault.	Default: 'true'. For more information, go to default health check.

CPU cores

The CPU_CORE environment variable applies stress on the target Windows VM for a specific duration. If the variable is set to 0, the fault consumes all the available CPU resources.

Use the following example to specify CPU cores:

# CPU hog in the VMware VM
apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  chaosServiceAccount: litmus-admin
  experiments:
  - name: vmware-windows-cpu-hog
    spec:
      components:
        env:
        # Name of the VM
        - name: VM_NAME
          value: 'test-vm-01'
       # CPU cores for stress
        - name: CPU_CORES 
          value: '1'