Locust + Azure = High Performance

I’m happy to announce that Microsoft is now backing my work maintaining the **Locust** open source load testing project!

Since a little over a year ago Azure has offered the ability to run cloud hosted Locust performance tests using **Azure Load Testing**, and now we’re partnering to make the experience even better. For “self-hosted” Locust users as well as as Azure users!

Azure Load Testing at a glance

If you used Locust Cloud before you’ll be right at home, as ALT has many of the same key features (managed infrastructure, advanced reporting, etc), but it also gives some additional ones:

• **Cost-Efficient:** No fixed monthly fees — Azure operates on a pure pay-as-you-go model.
• **Global Scale:** Simulate traffic from multiple regions simultaneously.
• **VNet Injection:** Securely test private endpoints or on-premises applications.
• **Native CI/CD:** Seamlessly embed load tests into GitHub Actions or Azure Pipelines.
• **Deep Insights:** Access AI-powered actionable insights and detailed server-side metrics.

How to Get Started (In Two Ways)

Getting your existing Locust scripts up and running in Azure is incredibly simple (and you’ll find more information in the documentation). You have two broad choices for your workflow:

Option 1: The VS Code Extension (Developer-First)

If you love staying in your editor, you can use the **Azure Load Testing extension** paired with GitHub Copilot:

1. Validate Locally: Open your script in VS Code, open the command palette, and run Load Testing: Run load test (local) to test via the standard Locust UI.
2. Deploy to Azure: Run Load Testing: Run load test (Azure Load Testing).
3. Follow the quick prompts to sign into Azure, and a loadtest.config.yaml file will be automatically generated in your workspace. Copilot will validate it, upload your artifacts, and trigger the cloud test instantly.

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Option 2: The Azure Portal (UI-Driven)

If you prefer a visual, step-by-step setup directly in the browser, follow the official instructions here. But basically it boils down to:

1. Creating an Azure Load Testing Resource (Go to the Azure Portal, search for Azure App Testing)
2. Uploading Your Script (Under the Tests tab, click + Create and choose Create Test)
3. Configuring the Test (Go to the Test plan, select Locust as your framework, upload your locustfile (along with any requirements.txt or CSV data files your test needs), and set your target virtual users and duration)
4. Run and Monitor the Test (Hit Review + create, run the test, and watch real-time client metrics and tabular sampler statistics populate right in your dashboard)

Looking Ahead

This collaboration is all about keeping the developer-friendly spirit of Locust alive while backing it with the enterprise-grade reliability and scale of Azure.

Both me and the Azure team are very interested in your feedback! Leave a comment or reach out to me on LinkedIn! And clap for this story if you found it useful, as it helps with the algorithm!

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// Lars Holmberg