Identify performance regressions by comparing load test runs

In this article, learn how to identify performance regressions by visually comparing multiple load test runs in the Azure Load Testing Preview dashboard.

A test run contains client-side and server-side metrics. The test engine reports client-side metrics, such as the number of virtual users. The server-side metrics provide application- and resource-specific information.

By overlaying multiple metrics charts you can more easily pinpoint performance changes, and identify which application component is causing problems.

There are two entry points for comparing load test runs in the Azure portal:

• Starting from the test runs page, select multiple results to compare.
• Starting from a specific test run, select other results to compare that run with.

Prerequisites

• An Azure account with an active subscription. If you don't have an Azure subscription, create a free account before you begin.

• An Azure Load Testing resource with a test plan that has multiple test runs. To create a Load Testing resource, see Create and run a load test.

  Note

  A test run needs to be in the Done, Stopped, or Failed state to compare it.

Compare test runs from the test runs page

In this section, you'll compare multiple results by selecting runs from the test runs page.

1. Sign in to the Azure portal by using the credentials for your Azure subscription.

2. Navigate to your Azure Load Testing resource, and select Tests from the left navigation to view the list of tests.

   

   You can also use the filters to find your load test.

3. Select the test whose runs you want to compare from the list of tests.

4. Select multiple test runs from the list by using the checkboxes, and then select Compare.

   

   Note

   You can choose a maximum of five test runs to compare.

   The selected test runs are presented in the dashboard. Each run is shown as an overlay in the different charts.

   

   You can use filters to customize the graphs. There are separate filters for the client and the server metrics.

   Tip

   The time filter is based on the relative duration of the tests. A value of zero indicates the beginning of the test and the maximum value marks the duration of the longest test run. For client-side metrics, test runs will show only data for the duration of the test.

Compare test runs from the run details page

In this section, you'll use the test run details page and add other test runs to compare them.

1. Navigate to the test run details page, and then select Compare.

   

2. Select the test runs you want to compare by using the checkboxes.

   

   Note

   You can choose a maximum of five test runs to compare.

3. Select Compare.

   The selected test runs are presented in the dashboard. Each run is shown as an overlay in the different charts.

   

   You can use filters to customize the graphs. There are separate filters for the client and the server metrics.

Next steps

• For information about high-scale load tests, see Set up a high-scale load test.

• To learn about performance test automation, see Configure automated performance testing