Using Apdex

When application performance is monitored, organizations capture many metrics about the performance of IT applications. At first glance, these metrics often do not give a clear sense of how well these applications are performing from a business perspective. Reducing the metrics to a single, easy-to-understand metric is a simple way to determine the quality of the experience. This problem can be solved with the Apdex method. The Apdex method converts various metrics into a single number on a uniform scale of 0 to 1 (0 being frustrated, 1 being satisfied). The resulting Apdex value is a numerical measure of user satisfaction with the performance of the enterprise application.

Apdex widget

Instana enables users to create custom dashboard widgets for their Apdex configurations to display and analyze the performance of your application or website over time.

The following image presents an example of an Apdex widget called Robot Shop. The widget is configured to display the landing page performance index of a website called robot-shop with a threshold of 230 milliseconds for the last seven days. The threshold value indicates the optimal response time of the website.

Example Apdex widget

Adding Apdex widgets

You can set up an Apdex widget for any of your application perspectives or websites. To add an Apdex widget, go to one of your custom dashboards to open the dialog for adding a widget. Next, follow these steps:

  1. Click Apdex in the dialog sidebar, and click Next. The dialog shows the configuration section to set up an Apdex widget.
  2. Select whether you want to monitor an Application Perspective or website.
    • Apdex for Application Perspective excludes factors beyond your control such as poor internet connectivity of users, and might not accurately reflect user experience.
    • Apdex for website most accurately reflects user experience, and do not exclude factors beyond your control such as poor internet connectivity of users.
  3. Select the Application Perspective or website for the Apdex from the list.
  4. Select the Apdex configuration for the specific Apdex type from the list. If no Apdex configuration is available for the previously selected type, go to the Apdex configuration section to create an Apdex configuration.
  5. Enter a title for the widget.
  6. Verify your widget in the preview.
  7. If no preview is shown, click Highlight missing configuration to immediately see what is missing.
  8. To create the Apdex widget configuration, click Create.
  9. To save the Apdex widget configuration on your custom dashboard, click Save changes.

Apdex configuration

Managing Apdex configurations by using Instana UI

To create an Apdex configuration or clone an existing Apdex configuration, go to the Apdex Management dialog, which you can reach by either clicking Add widget or by editing an existing widget. Then, click Manage Apdex.

Example Apdex Configuration

Next, follow the steps to either create a configuration from scratch or by cloning an existing configuration.

Creating an Apdex configuration for application perspectives

  1. In the Apdex Management dialog, click Create Apdex Configuration.
  2. Enter a name for the Apdex configuration to identify the configuration uniquely.
  3. Select the boundary scope, either Inbound Calls or All Calls.
    • Inbound calls: Include only calls that are initiated from outside the application and where the destination service is part of the selected application perspective.
    • All calls: Include both inbound calls from outside the application and calls that occur within the application perspective itself.
  4. Optional: You can include internal calls or Synthetic calls. By default, both calls are excluded.
    • Internal calls: A particular type of calls that represents work that is done inside of a service. These calls can be created from intermediate spans that are sent through custom tracing. For more information about internal calls, see Concepts of Tracing.
    • Synthetic calls: Calls with a Synthetic endpoint as the destination, such as calls to the health-check endpoints.
  5. By applying an extra filter, you can further scope the configuration to a subset of application calls.
  6. Enter your application's optimal response time in milliseconds as the threshold for the selected metric.
  7. Click Create to save the new Apdex configuration.

Creating an Apdex configuration for websites

  1. In the Apdex Management dialog click Create Apdex Configuration.
  2. Enter a name for the Apdex configuration to identify the configuration uniquely.
  3. Select the beacon scope. For example, HTTP requests. By applying a beacon filter, you can further scope the configuration to a subset of website traffic, for example, by geolocation, browser, or user.
  4. Enter your website's optimal response time in milliseconds as the threshold for the selected metric.
  5. Click Create to save the new Apdex configuration.

The parameters of the Apdex configuration cannot be modified to prevent invalidation of the calculated spent budgets. For this reason, the Apdex configuration needs to be cloned when you change any parameter.

Clone an existing Apdex configuration

  1. From the Apdex Management dialog, click the View Apdex configuration or Clone Apdex configuration icon on the selected Apdex configuration that you want to clone.
  2. Edit the Apdex configuration details:
    • Change the name for the Apdex configuration to identify the configuration as a clone from the existing configuration.
    • Edit the configuration according to your needs.
  3. Click Clone to create a clone of the Apdex configuration.