Querying custom data in Application Insights

Using Application Insights Analysis is a really powerful way to query the telemetry data from your system. Using a simple, but powerful query language you can get interesting data:

requests
| where duration  > 500ms

Logging custom data

Using the ApplicationInsights SDK, you can publish custom telemetry events:

var client = new TelemetryClient();
Map<String, String> properties = new HashMap<>();
properties.put("updateVersion", updateVersion);

//send the event
telemetry.trackEvent("VersionReceived", properties);

Querying custom data

You can query custom properties using the customDimensions value.

customEvents
| where customDimensions.updateVersion == "12.2"

Querying structured data

If you want do trace more complex data, you can serialize objects to json before storing them:

properties.put("dataReceived", jsonReceived.ToString());

//send the event
telemetry.trackEvent("VersionReceived", properties);

This can be queried using the extractjson function:

customEvents
|extend productnumber = extractjson("$.Product.ProductNumber", 
   tostring(customDimensions.json))
| project productnumber, timestamp