In Application Insights, using sampling is an effective way to reduce the amount of telemetry data that is sent to Application Insights. If you are worried about high storage costs if all telemetry data gets sent to Application Insights, you can make use of sampling in Application Insights.
By default Application Insights sampling is already enabled when you use the ASP.NET, ASP.NET Core software development kits.
For ASP.Net applications you can configure adaptive sampling by tuning parameters in the ApplicationInsights.config file. Some of the settings are
This will ensure to limit the number of items that are sent to Application Insights
This is the interval at which the current rate of telemetry is reevaluated
This is the amount of telemetry data that is sent when the application is started
In ASP.Net Core applications, there is no ApplicationInsights.config file, so the configuration is done via code.
Adaptive sampling is enabled by default for all ASP.NET Core applications
For more information on adaptive sampling, you can use the below link