What are key performance metrics?

Requires Dynatrace version 1.144 or later.

Dynatrace offers an expanded selection of key performance metrics on which you can base your Real User Monitoring. Key performance metrics enable you to select the ideal user experience metric for each of your applications. These key metrics provide you with valuable performance insights that promote success in your digital business.

Choose the right performance metric for each application condition

For many traditional web applications, User action duration is considered the best metric available for web-performance optimization as it focuses on the amount of time from user input to complete page load. But Single Page Applications (SPAs) based on Angular, Ember, React, and other JavaScript frameworks don't depend on loading a new page following each click. So the race to be fast "above the fold" can lead to high overall user action duration times. As a result, other metrics such as Visually complete and Speed index can more accurately focus on the actual timings that reflect when the end user can take the next action. From the end user perspective, web applications can be usable after certain elements such as a date picker or autocomplete for a search are ready to use.

Then there are some applications where the UI is not as important as the interaction with the application. For example, a Call Center application or Help Desk application where the users are experts and work with short cuts and the time to interact with the application is more important than ensuring that all images are loaded. In these cases, JavaScript loading is important and DOM interactive may be the best metric to consider.

Choosing the right key performance metric also lets you adjust to varying performance levels for different features of one web application. For example, a customer may be satisfied waiting five seconds after clicking a button to confirm a booking, but be frustrated waiting five seconds for the autocomplete box of a search field to appear.

With key performance metrics and key user actions, you can now pick the ideal performance metric and expected performance goals that best fit each separate user action. Dynatrace key performance metrics enable you to respond to such variable conditions for each application you monitor. Additional key performance metrics you can select include:

  • Visually complete
  • Speed index
  • DOM interactive
  • Time to first byte
  • Load event end

Visually complete measures how long it takes for the visible portion of each user's browser screen to fully render. However a different metric may be more appropriate for your application, so you can select a different key performance metric. Selecting a different performance metric changes the performance analysis thresholds applied by the Dynatrace AI during automated problem detection.

Use key performance metrics to monitor application performance

Key performance metrics are activated by default, and Visually complete is selected as the key metric for load and XHR actions. User action duration is selected as the default metric for custom actions.

Once you enable key performance metrics for an application, you can select the right key performance metric for its load actions, XHR actions, and any custom actions.

To select key performance metrics for an application

  1. Click Applications from the navigation menu.
  2. Select the application you want to configure.
  3. Click the Browse [...] button and select Edit.
  4. Click General, and from the Load actions, XHR actions, and Custom actions tabs in the Select a key performance metric for this application section, select the key performance metric that best represents the user experience for each user action type.

Selecting a key performance metric - application

For situations where you want to tailor the key performance metric used for different features in one web application, you can select a different key performance metric for the application's different key user actions.

  1. Click Applications from the navigation menu, then select the application you want to configure.
  2. On the application's details page, select a key user action in the Top User Actions tile, or click View full details in the Top User Actions tile then select the desired user action from the Key user actions list.
  3. On the detail page for the selected key user action, click the Browse [...] button and select Edit.
  4. On the User Action settings page that appears, make sure Key performance metric is selected, then choose a key performance metric from the list box, as shown in the following image:

Set key performance metric for a user action

Key performance metric definitions

  • User action duration: Time spent from initial user input to complete page load. Includes load time of XHR requests initiated before loadEventEnd and load time of dynamic resources and script executions triggered by DOM modifications.

  • Visually complete: The point in time at which all content in the browser's visible area is fully rendered.

  • Speed index: The average amount of time before which all visible parts of a page are displayed. A low means that most parts of a page are rendering quickly.

Note: Speed index and Visually complete metrics are only available on browsers that support mutationobservers. This includes the following browsers:

  • Microsoft Internet Explorer 11 or later
  • Microsoft Edge 15 or later
  • Firefox 57 or later
  • Google Chrome 61 or later

Speed index is only available for load actions. Visually complete is available for all load actions, but not for AJAX requests, which don't affect the DOM.

  • DOM interactive: The amount of time it takes before a page's readiness status is set to interactive (ready to receive further user input).

  • Load event end: The amount of time it takes before the load event of the current page is completed.

  • Load event start: The amount of time it takes before the load event of the current page begins.

  • HTML downloaded: The amount of time it takes before the last byte of the current page is received, or before the transport connection is closed (whichever comes first).

  • Time to first byte: The amount of time it takes before the first byte of a response is received from the server, relevant application caches, or a local resource.

  • Response end (XHR actions): The elapsed time from when the first byte of the server response is received until either when the last byte of the current document of the response is received or when the response completes, whichever comes first.

See key performance metrics information for your applications

Several dashboard tiles such as the Worldmap, User Action, and Key user actions are affected based on the selected key performance metric. The metrics are also available for custom charting.

Key performance metrics in home dashboard tiles

The Application overview page shows Visually complete by default for load actions and XHR actions. User action duration is used for Custom actions.

Application overview showing key performance metric

The User action page, When speed index is selected as the key performance metric, reflects Speed index in all tiles and charts.

Speed index used in user action - key performance metric