Windows

Windows Chaos Infrastructure runs chaos experiments against Windows VMs. The installer registers a single binary as the WindowsChaosInfrastructure service on the target VM, which then polls the Harness control plane for experiments.

This page walks through the in-product create wizard, configurable options, and how to validate or disable the infrastructure.

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Before you begin

• A Windows VM with administrator privileges (or an account that can run the installer as administrator).

• A Harness environment to attach the infrastructure to. Go to Create an environment if you do not have one.

• Windows fault prerequisites. Go to Windows fault prerequisites for the per-fault setup (passwords, tools, etc.).

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Resource requirements

The Windows Chaos Infrastructure runs as the WindowsChaosInfrastructure Windows service. It is idle between experiments and adds fault-specific load only while an experiment is executing.

Resource	Idle usage on a 2 vCPU / 4 GB reference VM
CPU	~0.14% average (0–1.5% instantaneous; brief 5s poll spikes)
Memory	~15 MB working set (≈ 0.5% of 4 GB)
Disk	~45 MB installed (binary + bundled tools); ~60 MB ceiling with log rotation
Network bandwidth	Minimal (HTTP poll + heartbeat every 5s; no persistent connections)

Reference measurement was taken on an AWS EC2 t3.medium instance (2 vCPU, 4 GB memory) running Windows Server 2025 Datacenter.

Minimum recommended host: Windows Server 2016+ or Windows 10+ (64-bit) with 50 MB free RAM, 100 MB free disk, and outbound HTTPS to the Harness control plane. No inbound ports are required.

HOST SIZING

The agent's idle cost is negligible, so size the host for the workload the agent will inject chaos against, not for the agent itself. Per concurrent fault, the service adds roughly +0.7 MB RAM and +1.5% CPU on top of idle; faults that target disk or network may load additional bundled tools (diskspd) or kernel drivers (WinDivert) for the duration of the experiment.

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Create a Windows infrastructure

In Harness, go to Resilience Testing → Project Settings → Resilience Testing Infrastructures, switch to the Windows tab, and click + New Infrastructure. The create wizard has three steps.

Step 1. Overview

Enter the infrastructure metadata and pick an environment.

Field	Required	Notes
Name	Yes	Display name for the infrastructure.
Description	No	Free-form context.
Tags	No	Searchable labels.
Environment	Yes	Pick from the dropdown or click + New Environment.

Windows wizard: Overview step

Click Configure Details to continue.

Step 2. Configure Options

All options on this step are optional. Defaults work for most setups, expand a section only if you need to change a value.

Section	Field	Default	Purpose
Setup	Admin user	Administrator	Administrator used to install and manage the infrastructure.
Interval	Task poll interval	5s	Interval between poll queries for a new experiment.
Interval	Task update interval	5s	Interval between status updates for an active fault.
Interval	Infrastructure liveness update interval	5s	Heartbeat interval to the control plane.
Retry	Update retries (count)	5	Maximum retries before the service treats the call as failed.
Retry	Update retries interval	5s	Wait between status or result retries.
Logs	Log file max size	5 MB	Log file size threshold for rotation.
Logs	Log file max backups	2	Number of rotated log archives to retain.
Logs	Experiment log file max age	30 days	Age after which experiment log files are deleted.
HTTP Proxy	HTTP Proxy	unset	Proxy URL used to communicate with the control plane.
HTTP Client Timeout	HTTP Client Timeout	30s	Timeout for HTTP calls to the control plane.

Windows wizard: Configure Options step

For restricted networks, set HTTP Proxy to the proxy URL the VM should use for outbound calls to the Harness control plane.

Click Next to continue.

Step 3. Deploy the setup

Harness generates a PowerShell command that downloads the installer, registers WindowsChaosInfrastructure as a service, and connects it to your account.

Windows wizard: Deploy the setup step

1. Copy the PowerShell command shown on screen.

2. Open PowerShell as Administrator on the target Windows VM.

3. Paste and run the command.

4. Click Done in the wizard.

ONE-TIME ACCESS KEY

The access key embedded in the command is single use. If you close the wizard before running the command, reopen the deploy step to generate a new one.

The installer prints output similar to:

    Directory: C:\

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

    Directory: C:\HCE\Logs

[SC] CreateService SUCCESS
Service created and started successfully.

The default install paths are:

• Binary: C:\HCE\windows-chaos-infrastructure.exe

• Config: C:\HCE\config.yaml

• Logs: C:\HCE\logs\

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Validate the installation

After running the install command, Harness takes a few moments to register the infrastructure. Go to Resilience Testing → Project Settings → Resilience Testing Infrastructures → Windows and confirm the status is CONNECTED.

To verify the service on the VM:

1. Open Task Manager and switch to More details.

2. Find WindowsChaosInfrastructure under the Services tab. The state should be Running.

3. If the state is Stopped, right-click the service and select Start.

Logs

Logs are written under the log directory (default C:\HCE\logs).

• Infrastructure logs capture connectivity, startup, and polling errors. Files are rotated when they reach Log file max size (default 5 MB); the most recent Log file max backups archives (default 2) are kept.

• Experiment logs are written one file per fault, named after the fault's unique name. Each experiment run also creates its own folder with the connectivity logs for that run. Files are deleted after Experiment log file max age (default 30 days).

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Disable the infrastructure

1. Go to Resilience Testing → Project Settings → Resilience Testing Infrastructures → Windows.

2. Click the ⋮ menu next to the infrastructure and select Disable.

3. Copy the uninstall command, run it in PowerShell as Administrator on the VM, and click Confirm.

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Next steps

• Upgrade Windows infrastructure: apply the latest binary to an existing install.

• Windows fault prerequisites: per-fault setup before running experiments.

• Overview: compare against the Kubernetes and Linux infrastructure types.