Exception telemetry: Application Insights data model

In Application Insights, an instance of Exception represents a handled or unhandled exception that occurred during execution of the monitored application.

Problem Id

Identifier of where the exception was thrown in code. Used for exceptions grouping. Typically a combination of exception type and a function from the call stack.

Max length: 1024 characters

Severity level

Trace severity level. Value can be Verbose, Information, Warning, Error, Critical.

Exception details

(To be extended)

Custom properties

Name-value collection of custom properties: This collection is used to extend standard telemetry with the custom dimensions. Examples are the deployment slot that produced telemetry or the telemetry-item specific property like the order number.

  • Maximum key length: 150
  • Maximum value length: 8,192

Custom measurements

Collection of custom measurements. Use this collection to report named measurement associated with the telemetry item. Typical use cases are:

  • the size of Dependency Telemetry payload
  • the number of queue items processed by Request Telemetry
  • time that customer took to complete the step in wizard step completion Event Telemetry.

You can query custom measurements in Application Analytics:

| where customMeasurements != ""
| summarize avg(todouble(customMeasurements["Completion Time"]) * itemCount)


Custom measurements are associated with the telemetry item they belong to. They are subject to sampling with the telemetry item containing those measurements. To track a measurement that has a value independent from other telemetry types, use Metric telemetry.

Max key length: 150

Next steps