VMware Windows Memory hog

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

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

Use cases

• VMware Windows Memory hog determines the resilience of an application when stress is applied on the Memory resources of a VMware Windows virtual machine.
• VMware Windows Memory hog simulates the situation of lack of Memory for processes running on the application, which degrades their performance.
• It verifies the autopilot functionality of services or application on the VM.

Prerequisites

• Kubernetes > 1.16 is required to execute this fault.

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

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

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

• 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.

• Ensure installation of Testlimit on the target VM, a prerequisite for this experiment. Execute the fault using the built-in Administrator user to ensure permissions for memory stress testing. Instructions to enable the built-in Administrator in Windows.

• 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, win-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
MEMORY_CONSUMPTION	Amount of Memory to consume in MB.	Default: 0. For more information, go to memory consumption.
MEMORY_PERCENTAGE	Percentage of total Memory to consume.	Default: 50. For more information, go to memory percentage.
TOTAL_CHAOS_DURATION	Duration that you specify, through which chaos is injected into the target resource (in seconds).	Default: 60 s. For more information, go to duration of the chaos.
RAMP_TIME	Period to wait before and after injecting chaos (in seconds).	For example, 30 s. For more information, go to ramp time.
SEQUENCE	Sequence of chaos execution for multiple instances.	Default: parallel. Supports serial and parallel sequence. 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.
PATH_OF_TESTLIMIT	Path of “testlimit” binary (location of its download)

Memory consumption

The MEMORY_CONSUMPTION environment variable applies stress on the target Windows VM for a specific duration.

Use the following example to specify Memory consumption:

apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  chaosServiceAccount: litmus-admin
  experiments:
  - name: vmware-windows-memory-hog
    spec:
      components:
        env:
        # Name of the VM
        - name: VM_NAME
          value: 'test-vm-01'
       # Memory consumption in MB
        - name: MEMORY_CONSUMPTION 
          value: '1024'

Memory percentage

The MEMORY_PERCENTAGE environment variable applies stress on the target Windows VM for a specific duration. It consumes the specified percentage of the total Memory resources.

Use the following example to specify Memory percentage:

apiVersion: litmuschaos.io/v1alpha1
kind: ChaosEngine
metadata:
  name: engine-nginx
spec:
  engineState: "active"
  chaosServiceAccount: litmus-admin
  experiments:
  - name: vmware-windows-memory-hog
    spec:
      components:
        env:
        # Name of the VM
        - name: VM_NAME
          value: 'test-vm-01'
       # Memory percentage to consume
        - name: MEMORY_PERCENTAGE 
          value: '50'