Load test with the Azure portal
Check your web app's performance before you launch it or deploy updates to production by running load tests. That way, you can better assess whether your app is ready for release. Feel more confident that your app can handle the traffic during peak use or at your next marketing push.
Prepare your environment
You'll need an Azure subscription. You can get one free through Visual Studio Dev Essentials.
You'll need a VSTS subscription to keep your performance test history. A suitable subscription will be created automatically when you set up your performance test. Or you can create a new subscription or use an existing subscription if you're the owner.
Deploy your app for testing in a non-production environment. Have your app use an App Service plan other than the plan used in production. That way, you don't affect any existing customers or slow down your app in production.
Set up and run your performance test
Sign in to the Azure Portal. To use a VSTS subscription that you own, sign in as the owner.
Go to your web app.
In the DEVELOPMENT TOOLS section choose Performance test.
Now you'll link a VSTS subscription to keep your performance test history. Choose Set Account.
If you have a VSTS subscription to use, select that. If you don't, create a new one.
Choose + New to create a new performance test.
Set the details and run the test. Your web app's default URL is added automatically. You can change the URL to test other pages (HTTP GET requests only). To simulate local conditions and reduce latency, select a location closest to your users for generating load.
You simulate load on your app by generating virtual users (customers) who visit your web site at the same time. This will show how many requests are failing or responding slowly.
As an example, suppose you have an app that gave out coupons at last year's holiday sale. This event lasted 15 minutes with a peak load of 100 concurrent customers. You want to double the number of customers this year. You also want to improve customer satisfaction by reducing the page load time from 5 seconds to 2 seconds. So, you can test your updated app's performance with 250 users for 15 minutes.
Watch the progress in real time while the test runs. During the first minute, the page loads slower than is required.
After the test is done, view the final results. You can see that the page loads much faster after the first minute. This helps identify where you might start troubleshooting the problem.
Test multiple URLs
You can also run performance tests incorporating multiple URLs that represent an end-to-end user scenario by uploading a Visual Studio Web Test file. Some of the ways you can create a Visual Studio Web Test file are:
- Capture traffic using Fiddler and export as a Visual Studio Web Test file
- Create a load test file in Visual Studio
To upload and run a Visual Studio Web Test file:
Follow the steps above to open the New performance test blade. In this blade, choose the CONFIGFURE TEST USING option to open the Configure test using blade.
Check that the TEST TYPE is set to Visual Studio Web Test and select your HTTP Archive file. Use the icon to open the file selector dialog.
After the file has been uploaded, you see the list of URLs to be tested in the URL DETAILS section.
Specify the user load and test duration, then choose Run test.
After the test has finished, view the results in the two panes. The left pane shows the performance information as a series of charts.
The right pane shows a list of failed requests, with the type of error and the number of times it occurred.
Rerun the test by choosing the Rerun icon at the top of the right pane.