Issue with ITelemetryProcessor after migrating to aspnet core 2.1

[peter-bozovic]

I'm having different behavior since updated aspnet core project from 2.0 to 2.1 and AI library from 2.1.1 to 2.3
Not sure if this might be related to the new version of Entity Framework, but I'm having similar issue with filtering Azure Storage telemetry so I'm starting here.

Repro Steps

Im using following code to filter SQL requests so that they are not sent to Application Insights:

public class DefaultSqlFilter : ITelemetryProcessor {
	private ITelemetryProcessor Next { get; set; }
	public DefaultSqlFilter(ITelemetryProcessor next) {
		this.Next = next;
	}
	public void Process(ITelemetry item) {
		if (item is DependencyTelemetry dependency) {
			if (dependency.Type == "SQL") {
				return;
			}
		}
		this.Next.Process(item);
	}
}

And in my startup.cs Configure method:

var processorBuilder = TelemetryConfiguration.Active.TelemetryProcessorChainBuilder;
processorBuilder.Use((next) => new DefaultSqlFilter(next));
processorBuilder.Build();

Actual Behavior

My TelemetryProcessor is never hit with DependencyTelemetry of Type == "SQL".
Even when checking all items going trough the TelemetryProcessor, there is nothing related to the Entity Framework.
However, the Request details in Azure Portal is displaying calls done to the database, they are not filtered.

Expected Behavior

Telemetry related to SQL call is filtered and not sent to Application Insights and not displayed in Request Details

Version Info

SDK Version : aspnet core 2.1
.NET Version : net47
How Application was onboarded with SDK(VisualStudio/StatusMonitor/Azure Extension) : nuGet
OS : Windows 10
Hosting Info (IIS/Azure WebApps/ etc) : Azure AppService

[cijothomas]

https://github.com/Microsoft/ApplicationInsights-aspnetcore/wiki/Telemetry-Processors:-Sampling-and-Metrics-Stream#adding-a-custom-telemetry-processor-to-telemetry-pipeline

Can you follow this step for adding your custom telemetry processor?

Retrieving TelemetryConfiguration using TelemetryConfiguration.Active and modifying it is not recommended with newer version of the AI SDK.

[peter-bozovic]

Thanks Cijo, looks like that solved the problem !

I wasn't aware of the new method for loading TelemetryProcessors :(

[cijothomas]

Glad it helped. We are working to have this 'wiki' doc moved to official docs soon.

[kkdawkins]

This bit me too - What was confusing us was that in dev environment, our telemetry processor would hit a breakpoint but it appeared to still show in portal.

[peter-bozovic]

Question about registering Telemetry Processors that need parameters ?

I had before telemetry constructor like:

public RequestFilter(ITelemetryProcessor next, string[] paths) {
    ...
}

and with TelemetryConfiguration.Active.TelemetryProcessorChainBuilder

processorBuilder.Use((next) => new RequestFilter(next, new string[] { "/css", "/lib", "/dist", "/favicon" }));

I don't see how to pass my "paths" parameter with new

services.AddApplicationInsightsTelemetryProcessor<DependencyFilter>();

What would be the best method to pass parameters to my processor with the new method for registering the telemetry ?

[pharring]

@peter-bozovic You have a couple of options:

1. Create a custom class implementing ITelemetryProcessorFactory. In the Create method, call the constructor with the parameters you need. Then, instead of using the AddApplicationInsightsTelemetryProcessor extension method, use AddSingleton<ITelemetryProcessorFactory, MyTelemetryProcessorFactory>() (or similar).
2. If you can change the public signature of the RequestFilter constructor, instead of string[] for the paths, create and use a more precise type (e.g. RequestFilterConfiguration). Then you can inject an instance of that type with the paths you need into the DI services via AddSingleton. The code in AddApplicationInsightsTelemetryProcessor will use the appropriate public constructor with matching parameters.

For an example of the technique 1, see the Snapshot Debugger documentation here: https://docs.microsoft.com/en-us/azure/application-insights/app-insights-snapshot-debugger#configure-snapshot-collection-for-aspnet-core-20-applications
Note that this documentation was written before AddApplicationInsightsTelemetryProcessor was available but it's pretty close to technique 2 in that the SnapshotCollectorConfiguration object is found via the DI framework.

[cijothomas]

Keeping this open as a doc issue to include Pauls response to official docs.

[TimothyMothra]

Note to self: assign to M Bullwinkle

[TimothyMothra]

@mrbullwinkle any update?

[TimothyMothra]

note to self:
open equivalent issue in Docs repo, and assign to MB.
Will close this issue.

[TimothyMothra]

FYI: Paul's code samples were moved to here:
https://docs.microsoft.com/en-us/azure/azure-monitor/app/snapshot-debugger-vm#configure-snapshot-collection-for-applications-using-aspnet-core-20-or-above

[github-actions]

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