How can I log resolver/operation name and duration in HotChocolate?

Question

I'm trying to log some basic gql method details - resolver/operation name and duration. I've started looking at using .AddHttpRequestInterceptor((context, executor, builder, ct) and getting the info from the builder, but even though I can see it in the debugger, the method name is buried in private members like: ((HotChocolate.Execution.QueryRequestBuilder)builder)._query.Document.Definitions[0].SelectionSet.Selections[0].Name.Value

I'm sure there's an easier and better way to hook into the pipeline to get the method name and log it with the call duration.

I found an article written about GraphQL.Net that uses DefaultGraphQLExecuter - public class GraphQLExecutorWithDiagnostics<TSchema> : DefaultGraphQLExecuter<TSchema> which provides an operationName parameter within the Task<ExecutionResult> ExecuteAsync( , which looks ideal.

I'll be logging to AppInsights, but that's not relevant for now, I just want to get the info first. I'm using v11.0.8

Answer 1

What you are looking for is the DiagnosticEventListener

You can just extend this base class and override the methods that you need for you logging.

public class CustomDiagnosticListener : DiagnosticEventListener
{
    public override IActivityScope ExecuteRequest(IRequestContext context)
    {
        return EmptyScope;
    }

    public virtual IActivityScope ResolveFieldValue(IMiddlewareContext context)
    {
        return EmptyScope;
    }
}

To use this diagnostic listener you have to add it to the schema

services.AddGraphQLServer()
    ...
   .AddDiagnosticEventListener<CustomDiagnosticListener>()

In case you have dependencies that you listener has to reslove you have to reslove them manually:

services.AddGraphQLServer()
    ...
   .AddDiagnosticEventListener<CustomDiagnosticListener>(
         sp => new CustomDiagnosticListener(
                sp.GetApplicationService<MyDependency>()))