Windows Worker

These configurations will be stored in the Windows Registry.

Let screensaver activate, or select Preview in screensaver settings to activate immediately.

Option B: Programatically (PowerShell)

For programmatic install and configuration, use a powershell script, a .reg file, a .keystore file, and optionally provide a bitmap image that will float around during compute.

1. Place the PowerShell script and all required resources in the same folder (e.g., C:\DCP\Resources).
2. Open PowerShell as Administrator
3. Run:

powershell

powershell -ExecutionPolicy Bypass -File

"C:\DCP\Resources\DCP-Worker-LocalInstall.ps1"

Monitoring a Running Worker

Option A: Foreground Mode (Text UI)

In a terminal:

"C:\Program Files\Distributive\DCP\dcp-evaluator.bat" && "C:\Program Files\Distributive\DCP\dcp-supervisor.bat"

Press Esc twice to exit.

Option B: Screensaver Mode

Let the screensaver activate, then use Event Viewer, Syslog, or a third-party logger like BetterStack to view worker logs.

To send logs to BetterStack, add the following registry entry:

[HKEY_LOCAL_MACHINE\SOFTWARE\Distributive\dcp-worker\dcp-config\worker\logging\syslog]
"url"="tls://<YOUR_SOURCE_TOKEN>.syslog.betterstack.com:6514"

Press Ctrl+C to exit log monitoring.

Configuring the Worker Service

Open Change Screensaver Settings and modify as desired to include desired parameters. Upon saving and exiting the configurator, the worker service automatically restarts.

Apply changes and restart the Worker.

Updating the Worker

Automatically updates using Google Omaha.

For advanced users using “frozen” machines:

During installation, the worker automatically creates windows task scheduler tasks.

apt list --upgradable | grep dcp-worker

There are several additional options, such as specifying allowed origins for routing data, functions, and results directly behind the firewall (e.g., for hospital genomics data processing), or setting target CPU and GPU loads to throttle device consumption, etc. Use --help to see the full list of options.

Process Model

All evaluator processes inherit a restricted security token and communicate only with the local Worker service over loopback TCP. No evaluator process accepts inbound network connections or executes with administrative privileges. The process tree for dcp-screensaver looks like this:

dcp-screensaver:
| node.exe (dcp-worker)
| dcp-evaluator (dispatcher) [listens on port 9000, locally]
    | dcp-evaluator (v8-evaluator)
    | dcp-evaluator (v8-evaluator)
    | dcp-evaluator (v8-evaluator)
    | ...

When the screensaver exits, the evaluator sandboxes terminate immediately, abandoning in-progress tasks. The Worker may submit completed results before returning to an idle state.

Service Accounts and Privilege Model

Component
Runs As
Purpose
Security Notes
dcp-worker (Node.js, launched by NSSM)
NT SERVICE\DCP Worker
Main Worker service that connects to the DCP Scheduler and manages Job lifecycle
Runs as a dedicated Windows service account with restricted privileges
dcp-screensaver.scr
OS-controlled desktop context (Winlogon pre-login or interactive user session)
Screensaver UI and idle trigger for task execution on evaluators
Managed by the Windows screensaver subsystem and executed without elevated privileges. When no user is logged in, configuration is sourced from HKEY_USERS.DEFAULT (Winlogon desktop), allowing Job execution in the pre-login state.
dcp-evaluator
Restricted token
Executes sandboxed JavaScript, WebAssembly, and WGSL workloads
Restricted token prevents filesystem, registry, and privileged API access

Operational Characteristics

Windows Screensaver Workers are typically used for:

• Individual or home users contributing idle CPU and GPU resources
• Institutional or enterprise deployments reclaiming idle CPU and GPU resources
• Interruptible batch workloads

They preserve the same core sandboxing and security properties as other DCP Worker variants, while leveraging the Windows screensaver subsystem as a native idle-state trigger for workload execution.