How to do it...

Perform the following steps:

1. Once the Application Insights account is created, navigate to the Overview tab and go to Instrumentation Key, as shown in the following screenshot:

2. Navigate to Function apps, for which you would like to enable monitoring and go to Application settings.

3. Add a new key with the name APPINSIGHTS_INSTRUMENTATIONKEY and provide the instrumentation key that you copied from the Application Insights account, shown as follows, then click on Save to save the changes:

4. That's it; you can start utilizing all the features of Application Insights to monitor the performance of your Azure functions. Open Application Insights and the RegisterUser function in two different tabs to test how Live Metrics Stream works:
   • Open Application Insights and click on Live Metrics Stream in the first tab of your browser, as shown in the following screenshot:

1. • Open any of your Azure functions (in my case, I have opened HTTP trigger) in another tab and run a few tests to ensure that it emits some logs to Application Insights.

5. After you have completed those tests, go to the tab that has Application Insights. You should see the live traffic going to your function app, as shown in the following screenshot: