A custom TrackAvailability test can be used to test availability on an on-premises network without internet access. This is achieved by running custom code on a test server inside the private network that uses the TrackAvailability API to send results to Application Insights.
How it works
Run code on-premises: The test is performed by code that you write, which can be run as a background process or a scheduled job on a server located inside your private, on-premises network.
Send telemetry to Azure: The custom test code, when executed, sends the results of its availability checks (e.g., to an internal web server or API) to Application Insights using the TrackAvailability API from the core SDK.
View results in Application Insights: The results then appear in Application Insights alongside standard availability tests, and can be analyzed in the availability blade, Analytics, Search, and Metrics.
Note:
Types of availability tests
There are four types of availability tests:
* Standard test: A type of availability test that checks the availability of a website by sending a single request, similar to the deprecated URL ping test. In addition to validating whether an endpoint is responding and measuring the performance, Standard tests also include TLS/SSL certificate validity, proactive lifetime check, HTTP request verb (for example, GET,HEAD, and POST), custom headers, and custom data associated with your HTTP request.
*-> Custom TrackAvailability test: If you decide to create a custom application to run availability tests, you can use the TrackAvailability() method to send the results to Application Insights.
* (Deprecated) URL ping test: You can create this test through the Azure portal to validate whether an endpoint is responding and measure performance associated with that response. You can also set custom success criteria coupled with more advanced features, like parsing dependent requests and allowing for retries.
* (Deprecated) Multi-step web test
Reference:
https://learn.microsoft.com/en-us/azure/azure-monitor/app/availability