GraphQL HotChocolate 11 - Updated Application Insights monitoring

A few months ago, I blogged about integrating Application Insights in HotChocolate to monitor the executed GraphQL queries and mutations. In HotChocolate 11, the diagnostics system has been rewritten and the code I shared in that post no longer works.  Here is finally the updated post I promised on how to achieve this in HotChocolate 11.

Creating our own DiagnosticEventListener

• Starting from HotChocolate 11, your diagnostic class should inherit from DiagnosticEventListener. We still inject the Application Insights TelemetryClient in the constructor:

	public class ApplicationInsightsDiagnosticListener : DiagnosticEventListener
	{
	private readonly TelemetryClient _telemetryClient;
	public ApplicationInsightsDiagnosticListener(TelemetryClient telemetryClient)
	{
	_telemetryClient = telemetryClient;
	}
	}

view raw ApplicationInsightsDiagnosticListener.cs hosted with ❤ by GitHub

Remark: There seems to be a problem with dependency injection in HotChocolate 11. This problem was fixed in HotChocolate 12. I show you a workaround at the end of this article.

• In this class you need to override at least the ExecuteRequest method:

	public override IActivityScope ExecuteRequest(IRequestContext context)
	{
	return new RequestScope(_telemetryClient, context);
	}

view raw ExecuteRequest.cs hosted with ❤ by GitHub

• To track the full lifetime of a request, we need to implement a class that implements the IActivityScope interface. In the constructor of this class, we put all our initialization logic:

	private class RequestScope : IActivityScope
	{
	private TelemetryClient _telemetryClient;
	private IRequestContext _context;
	private IOperationHolder<RequestTelemetry> _operation;
	private bool _disposed=false;
	public RequestScope(TelemetryClient telemetryClient, IRequestContext context)
	{
	_telemetryClient = telemetryClient;
	_context = context;
	var httpContext = GetHttpContextFrom(context);
	if (httpContext == null) return;
	// Create a new request
	var requestTelemetry = new RequestTelemetry()
	{
	Name = $"{httpContext.Request.Method} {httpContext.Request.GetUri().GetLeftPart(UriPartial.Path)}",
	Url = new Uri(httpContext.Request.GetUri().AbsoluteUri)
	};
	requestTelemetry.Context.Operation.Id = GetOperationIdFrom(httpContext);
	requestTelemetry.Context.Operation.ParentId = GetOperationIdFrom(httpContext);
	requestTelemetry.Properties.Add("GraphQL Query", context.Request.Query.ToString());
	// Start the operation, and store it
	_operation = _telemetryClient.StartOperation(requestTelemetry);
	}
	}

view raw RequestScope.cs hosted with ❤ by GitHub

• I'm using 2 small helper methods GetHttpContextFrom and GetOperationIdFrom:

	private HttpContext GetHttpContextFrom(IRequestContext context)
	{
	if (!context.ContextData.ContainsKey("HttpContext"))
	return null;
	return context.ContextData["HttpContext"] as HttpContext;
	}
	private string GetOperationIdFrom(HttpContext context)
	{
	return context.TraceIdentifier;
	}

view raw HelperMethods.cs hosted with ❤ by GitHub

• In the Dispose() method, we clean up all resources and send the telemetry data to Application Insights for this request:

	public void Dispose()
	{
	if (_disposed)
	return;
	var httpContext = GetHttpContextFrom(_context);
	if (httpContext == null) return;
	// handle any final request logging here (GraphQL query errors, success, etc)
	if (_context.Result.Errors is null)
	{
	_operation.Telemetry.Success = true;
	_operation.Telemetry.ResponseCode = "200";
	}
	else
	{
	HandleErrors(_context.Result.Errors);
	_operation.Telemetry.Success = false;
	_operation.Telemetry.ResponseCode = "500";
	}
	// Then stop the operation. This completes the request.
	_telemetryClient.StopOperation(_operation);
	_disposed = true;
	}

view raw Dispose.cs hosted with ❤ by GitHub

• Here we are using 1 extra helper method HandleErrors:

	private void HandleErrors(IReadOnlyCollection<IError> errors)
	{
	foreach (var error in errors)
	{
	if (error.Exception == null)
	{
	var exceptionTelemetry = new ExceptionTelemetry();
	exceptionTelemetry.Message = error.Message;
	_telemetryClient.TrackException(exceptionTelemetry);
	}
	else
	{
	_telemetryClient.TrackException(error.Exception);
	}
	}
	}

view raw HandleErrors.cs hosted with ❤ by GitHub

Here is the full code:

	public class ApplicationInsightsDiagnosticListener : DiagnosticEventListener
	{
	private readonly TelemetryClient _telemetryClient;
	public ApplicationInsightsDiagnosticListener(TelemetryClient telemetryClient)
	{
	_telemetryClient = telemetryClient;
	}
	public override IActivityScope ExecuteRequest(IRequestContext context)
	{
	return new RequestScope(_telemetryClient, context);
	}
	private class RequestScope : IActivityScope
	{
	private TelemetryClient _telemetryClient;
	private IRequestContext _context;
	private IOperationHolder<RequestTelemetry> _operation;
	private bool _disposed=false;
	public RequestScope(TelemetryClient telemetryClient, IRequestContext context)
	{
	_telemetryClient = telemetryClient;
	_context = context;
	var httpContext = GetHttpContextFrom(context);
	if (httpContext == null) return;
	// Create a new request
	var requestTelemetry = new RequestTelemetry()
	{
	Name = $"{httpContext.Request.Method} {httpContext.Request.GetUri().GetLeftPart(UriPartial.Path)}",
	Url = new Uri(httpContext.Request.GetUri().AbsoluteUri)
	};
	requestTelemetry.Context.Operation.Id = GetOperationIdFrom(httpContext);
	requestTelemetry.Context.Operation.ParentId = GetOperationIdFrom(httpContext);
	requestTelemetry.Properties.Add("GraphQL Query", context.Request.Query.ToString());
	// Start the operation, and store it
	_operation = _telemetryClient.StartOperation(requestTelemetry);
	}
	public void Dispose()
	{
	if (_disposed)
	return;
	var httpContext = GetHttpContextFrom(_context);
	if (httpContext == null) return;
	// handle any final request logging here (GraphQL query errors, success, etc)
	if (_context.Result.Errors is null)
	{
	_operation.Telemetry.Success = true;
	_operation.Telemetry.ResponseCode = "200";
	}
	else
	{
	HandleErrors(_context.Result.Errors);
	_operation.Telemetry.Success = false;
	_operation.Telemetry.ResponseCode = "500";
	}
	// Then stop the operation. This completes the request.
	_telemetryClient.StopOperation(_operation);
	_disposed = true;
	}
	private HttpContext GetHttpContextFrom(IRequestContext context)
	{
	if (!context.ContextData.ContainsKey("HttpContext"))
	return null;
	return context.ContextData["HttpContext"] as HttpContext;
	}
	private string GetOperationIdFrom(HttpContext context)
	{
	return context.TraceIdentifier;
	}
	private void HandleErrors(IReadOnlyCollection<IError> errors)
	{
	foreach (var error in errors)
	{
	if (error.Exception == null)
	{
	var exceptionTelemetry = new ExceptionTelemetry();
	exceptionTelemetry.Message = error.Message;
	_telemetryClient.TrackException(exceptionTelemetry);
	}
	else
	{
	_telemetryClient.TrackException(error.Exception);
	}
	}
	}
	}
	}
	}

view raw ApplicationInsightsDiagnosticListener.cs hosted with ❤ by GitHub

Configuring the DiagnosticEventListener

Before we can use this listener, we need to register it in our Startup.cs file:

	public void ConfigureServices(IServiceCollection services)
	{
	services.AddApplicationInsightsTelemetry();
	services.AddGraphQLServer()
	.AddQueryType<QueryType>()
	.AddDiagnosticEventListener<ApplicationInsightsDiagnosticListener>((sp)=> new ApplicationInsightsDiagnosticListener(sp.GetService<TelemetryClient>()));
	}

view raw Startup.cs hosted with ❤ by GitHub

Remark:Notice that we are using an overload of the AddDiagnosticEventListener method to resolve and pass the TelemetryClient instance to the listener. If you don’t use this overload, nothing gets injected and you end up with an error. As mentioned, this code only works starting from HotChocolate 12. For Hot Chocolate 11, check out the workaround below.

Workaround for HotChocolate 11

In HotChocolate 11, when you try to use the ServiceProvider instance inside the listener, you don’t get access to the application level services. This means that you cannot resolve the TelemetryClient. As a hack we can build an intermediate  ServiceProvider instance and use that instead:

	public void ConfigureServices(IServiceCollection services)
	{
	services.AddApplicationInsightsTelemetry();
	// Build an intermediate service provider
	var intermediateProvider = services.BuildServiceProvider();
	services.AddGraphQLServer()
	.AddQueryType<QueryType>()
	.AddDiagnosticEventListener<ApplicationInsightsDiagnosticListener>((sp)=> new ApplicationInsightsDiagnosticListener(intermediateProvider.GetService<TelemetryClient>()));
	}

view raw Startup.cs hosted with ❤ by GitHub