GraphQL Hot Chocolate–Application Insights monitoring

If you use the default Application Insights configuration to monitor your GraphQL endpoint, there is not that much information you’ll get. For example, when a GraphQL request fails, it still results in a 200 response. Application Insights isn’t aware that you are using GraphQL and don’t flag this request as an exception.

Let’s see how we can improve our Application Insights logging by integrating it with Hot Chocolate.

Disclaimer: the code below has been written for Hot Chocolate 10. In Hot Chocolate 11, the diagnostics system is rewritten. I’ll write an update post when I have the chance to update one of my applications to Hot Chocolate 11.

• First thing we need to do is to create a class that implement the IDiagnosticObserver marker interface and inject the Application Insights TelemetryClient:

	public class ApplicationInsightsDiagnosticObserver:IDiagnosticObserver {
	private readonly TelemetryClient _telemetryClient;
	public ApplicationInsightsDiagnosticObserver(TelemetryClient telemetryClient)
	{
	_telemetryClient = telemetryClient;
	}
	}

view raw ApplicationInsightsDiagnosticObserver.cs hosted with ❤ by GitHub

• For every event that we want to track, we need to add a method and specify the corresponding Hot Chocolate event through the DiagnosticName attribute:

	[DiagnosticName("HotChocolate.Execution.Query.Start")]
	public void BeginQueryExecute(IQueryContext context)
	{
	}

view raw BeginQueryExecute.cs hosted with ❤ by GitHub

• We create a dictionary to hold all ongoing requests. This is necessary to update the correct TelemetryClient instance:

	private readonly TelemetryClient _telemetryClient;
	private Dictionary<string, IOperationHolder<RequestTelemetry>> _inFlightOperations = new Dictionary<string, IOperationHolder<RequestTelemetry>>();
	[DiagnosticName("HotChocolate.Execution.Query.Start")]
	public void BeginQueryExecute(IQueryContext 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 in the dictionary
	var operation = _telemetryClient.StartOperation(requestTelemetry);
	_inFlightOperations.Add(GetOperationIdFrom(httpContext), operation);
	}

view raw InFlightOperations.cs hosted with ❤ by GitHub

• Now we can see if our GraphQL request has errors and in that case mark the request as an exception:

	[DiagnosticName("HotChocolate.Execution.Query.Stop")]
	public void EndQueryExecute(IQueryContext context, IExecutionResult result)
	{
	var httpContext = GetHttpContextFrom(context);
	if (httpContext == null) return;
	if (_inFlightOperations.ContainsKey(GetOperationIdFrom(httpContext)))
	{
	var operation = _inFlightOperations[GetOperationIdFrom(httpContext)];
	_inFlightOperations.Remove(GetOperationIdFrom(httpContext));
	// handle any final request logging here (GraphQL query errors, success, etc)
	if (result.Errors.Count == 0)
	{
	operation.Telemetry.Success = true;
	operation.Telemetry.ResponseCode = "200";
	}
	else
	{
	HandleErrors(result.Errors);
	operation.Telemetry.Success = false;
	operation.Telemetry.ResponseCode = "500";
	}
	// Then stop the operation. This completes the request.
	_telemetryClient.StopOperation(operation);
	}
	}
	private void HandleErrors(IReadOnlyCollection<IError> errors)
	{
	foreach(var error in errors)
	{
	string path = string.Join("/",
	error.Path.Select(t => t.ToString()));
	if (error.Exception == null)
	{
	var exceptionTelemetry = new ExceptionTelemetry();
	exceptionTelemetry.Message = error.Message;
	_telemetryClient.TrackException(exceptionTelemetry);
	}
	else
	{
	_telemetryClient.TrackException(error.Exception);
	}
	}
	}

view raw EndQueryExecute.cs hosted with ❤ by GitHub

• As a last step we need to register our Observer on the ServiceCollection through the AddDiagnosticObserver extension method:

	public void ConfigureServices(IServiceCollection services)
	{
	services.AddDiagnosticObserver<ApplicationInsightsDiagnosticObserver>();
	services.AddApplicationInsightsTelemetry();
	}

view raw ConfigureServices.cs hosted with ❤ by GitHub

Here is the complete code:

	public class ApplicationInsightsDiagnosticObserver:IDiagnosticObserver {
	private readonly TelemetryClient _telemetryClient;
	private Dictionary<string, IOperationHolder<RequestTelemetry>> _inFlightOperations = new Dictionary<string, IOperationHolder<RequestTelemetry>>();
	public ApplicationInsightsDiagnosticObserver(TelemetryClient telemetryClient)
	{
	_telemetryClient = telemetryClient;
	}
	[DiagnosticName("HotChocolate.Execution.Query.Start")]
	public void BeginQueryExecute(IQueryContext 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 in the dictionary
	var operation = _telemetryClient.StartOperation(requestTelemetry);
	_inFlightOperations.Add(GetOperationIdFrom(httpContext), operation);
	}
	[DiagnosticName("HotChocolate.Execution.Query.Stop")]
	public void EndQueryExecute(IQueryContext context, IExecutionResult result)
	{
	var httpContext = GetHttpContextFrom(context);
	if (httpContext == null) return;
	if (_inFlightOperations.ContainsKey(GetOperationIdFrom(httpContext)))
	{
	var operation = _inFlightOperations[GetOperationIdFrom(httpContext)];
	_inFlightOperations.Remove(GetOperationIdFrom(httpContext));
	// handle any final request logging here (GraphQL query errors, success, etc)
	if (result.Errors.Count == 0)
	{
	operation.Telemetry.Success = true;
	operation.Telemetry.ResponseCode = "200";
	}
	else
	{
	HandleErrors(result.Errors);
	operation.Telemetry.Success = false;
	operation.Telemetry.ResponseCode = "500";
	}
	// Then stop the operation. This completes the request.
	_telemetryClient.StopOperation(operation);
	}
	}
	private void HandleErrors(IReadOnlyCollection<IError> errors)
	{
	foreach(var error in errors)
	{
	string path = string.Join("/",
	error.Path.Select(t => t.ToString()));
	if (error.Exception == null)
	{
	var exceptionTelemetry = new ExceptionTelemetry();
	exceptionTelemetry.Message = error.Message;
	_telemetryClient.TrackException(exceptionTelemetry);
	}
	else
	{
	_telemetryClient.TrackException(error.Exception);
	}
	}
	}
	private HttpContext GetHttpContextFrom(IQueryContext context)
	{
	// This method is used to enable start/stop events for query.
	if (!context.ContextData.ContainsKey("HttpContext"))
	return null;
	return context.ContextData["HttpContext"] as HttpContext;
	}
	private string GetOperationIdFrom(HttpContext context)
	{
	return context.TraceIdentifier;
	}
	}

view raw ApplicationInsightsDiagnosticObserver.cs hosted with ❤ by GitHub