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Windows Chaos Infrastructure

This topic describes Windows Chaos Infrastructure, how you can enable and disable chaos on Windows Infrastructure.

Chaos experiments executed on Windows infrastructure inject chaos into Windows OS-based VM. This deteriorates the performance of the application for the duration of the chaos experiment. Depending on the type of instance the fault targets, Windows faults are categorized into various types.

Go to Windows-based Chaos faults to find the list of faults supported.

The diagram represents a high-level architecture of the interaction between the Windows execution plane and control plane components.

Configure with Flags​

The mandatory input required for the installation of the chaos infrastructure is the name. You can tune the other flags of the infrastructure with the following flags:

  1. admin user: Administrator used to execute commands on the terminal to install and manage the Windows chaos infrastructure. By default, the logs are stored at C:\\HCE\logs.

  2. task poll interval: Interval between subsequent poll queries to the server for a new experiment. The default value is 5 seconds.

  3. task update interval: Duration between subsequent status updates of an active fault to the server. The default value is 5 seconds.

  4. infrastructure liveness update interval: Interval between the chaos infrastructure liveness heartbeats. The default value is 5.

  5. update retries: Number of retries before the service fails.

  6. update retries interval seconds: Interval between the subsequent attempts to send a fault status or result, in case of a failure. The default value for it is 5 seconds.

  7. log file max size: Maximum size limit for the chaos infrastructure log file rotation. Upon breaching the size limit, a new log file is created to store the logs and the old log file is retired as a backup archive. The default value is 5 MB.

  8. log file max backups: Maximum number of backup archives to be retained at any given time. The oldest archive is deleted when a new log file is created. The default value is 2.

  9. experiment log file max age: Number of days after which the experiment log files will be deleted. The default value is 30.

  10. http proxy: HTTP proxy URL used to communicate with the control plane.

  11. http client timeout: HTTP client timeout for communicating with the control plane. The default value is 30s.

Infrastructure service​

The Windows chaos infrastructure is installed as an executable binary on your Windows VM. The service binary is present in C:\\HCE\windows-chaos-infrastructure.exe path. The config file is present in C:\\HCE\config.yaml path.

Logs​

Logs that are generated are stored in the C:\\HCE\logs directory by default.

There are two types of logs:

  1. Infrastructure logs: Infrastructure logs are generated as a result of any infrastructure operation that is not directly related to the execution of an experiment. Every experiment run has a new log folder with all connectivity logs.
  • The file is rotated based on its size; when the file size is a specified size, it is archived in a separate file with the timestamp of rotation suffixed to the file name. By default, this value is 5 MB.
  • Eventually, the old archives will be deleted. The maximum number of most recent archives that are retained at any given time can be specified. By default, this value is 2.
  1. Experiment logs: Experiment logs are stored in separate files, which are scoped to the faults of the experiment. It contains information about the various steps of the execution of that fault, including any errors caused during the execution of the fault. The files use the unique fault name mentioned in the experiment as their filename.

These files are rotated based on their age; where files older than a specific number of days are removed. By default, this value is 30 days.

Verify Windows infrastructure service status​

To verify the status of the service, navigate to the command prompt on your Windows. Search for Task Manager, select More details and check the status of WindowsChaosInfrastructure.

  1. If the status reads Running, it means the windows infrastructure is up and running.

  1. If it reads Stopped, right click and select Start.

  1. Any other status will be associated with logs which you can troubleshoot using our troubleshooting guide

Prerequisites to Install Infrastructure​

Ensure that you have fulfilled the prerequisites before connecting to a Windows chaos infrastructure.

Step 1: Create / Select Environment​

  1. Go to Environments and create a new environment or select an environment that already exists.

new environment

Step 2: Create Infrastructure​

  1. Select the Infrastructure Type as Windows and click New Infrastructure

  2. Provide a Name and other optional values based on your requirement. Select Next.

Step 3: Deploy Infrastructure​

  1. Copy the command generated. The prerequisites discusses how you can configure a password. If you have a password, replace it in the <your-password> placeholder. Execute this command on your terminal (remember to open the command prompt as an admin if you are not an admin by default). Click Done once you finish the execution.

This displays the following updates about the installation on your terminal.

    Directory: C:\


Mode                 LastWriteTime         Length Name
----                 -------------         ------ ----
d-----          3/7/2024   7:48 AM                HCE
Downloading Testlimit...
Extracting Testlimit...
Accepting Testlimit EULA...
Testlimit EULA accepted.
Downloading windows-chaos-infrastructure binary...
Config file created at C:\\HCE\config.yaml


    Directory: C:\HCE\Logs


Mode                 LastWriteTime         Length Name
----                 -------------         ------ ----
-a----          3/7/2024   7:51 AM              0 windows-chaos-infrastructure.log
[SC] CreateService SUCCESS
Service created and started successfully.

Validate Installation​

After adding chaos infrastructure, Harness takes some time to set up all the chaos infrastructure resources. On the UI, if you navigate to Environments -> Windows, you can see the connection status is CONNECTED.

That's it! Now you have a Windows chaos infrastructure and you're all set to inject chaos into your infrastructure.

Disable Infrastructure​

  1. To disable an infrastructure, go to Environments, select the Infrastructure type as Windows.

  2. Select the ⋮ icon against the chaos infrastructure name and select Disable.

    Delete Chaos Infra

  3. Copy the command displayed in the modal, and execute it in your Windows machine terminal to uninstall the chaos infrastructure components. Finally, select Confirm.

This disables your Windows infrastructure.

Resilience probes for Windows​

Harness CE allows you to create HTTP probe for Windows.