Request-scoped DataLoaderRegistry blows up

[kijanowski]

I have given a try the code introduced by #12
I used version 1.0 and created a CustomGraphQLInvocation class based on https://github.com/graphql-java/graphql-java-spring/pull/12/files#diff-cb93f026b7b911f1cdfa731e56caa39f

The comment in this PR says:
I think it's overkill to create a ExecutionInputCustomizer for this, simply defining a (request-scoped) @bean should be sufficient.

I've create that bean like this:

    @Bean
    @Scope(value = WebApplicationContext.SCOPE_REQUEST, proxyMode = ScopedProxyMode.TARGET_CLASS)
    public DataLoaderRegistry dataLoaderRegistry() {...}

And it fails with:

{
  "timestamp": "2019-09-29T11:07:42.456+0000",
  "status": 500,
  "error": "Internal Server Error",
  "message": "Error creating bean with name 'scopedTarget.dataLoaderRegistry': Scope 'request' is not active for the current thread; consider defining a scoped proxy for this bean if you intend to refer to it from a singleton; nested exception is java.lang.IllegalStateException: No thread-bound request found: Are you referring to request attributes outside of an actual web request, or processing a request outside of the originally receiving thread? If you are actually operating within a web request and still receive this message, your code is probably running outside of DispatcherServlet: In this case, use RequestContextListener or RequestContextFilter to expose the current request.",
  "path": "/graphql"
}

If I change the scope to WebApplicationContext.SCOPE_APPLICATION then it doesn't throw an error. How should this be approached to have a request scoped DataLoaderRegistry?

A working workaround is to change the DefaultGraphQLInvocation and remove:

    @Autowired(required = false)
    DataLoaderRegistry dataLoaderRegistry;

and replace:

        if (dataLoaderRegistry != null) {
            executionInputBuilder.dataLoaderRegistry(dataLoaderRegistry);
        }

with:

        DataLoaderRegistry dataLoaderRegistry = new DataLoaderRegistry();

        // Loader specific configuration
        DataLoader<String, CountryTO> countryLoader = DataLoader.newDataLoader(dataFetchers.countryBatchLoader());
        dataLoaderRegistry.register("countries", countryLoader);
        // Loader specific configuration end
        
        executionInputBuilder.dataLoaderRegistry(dataLoaderRegistry);
        executionInputBuilder.context(dataLoaderRegistry); // add it to the context to use it later in fetchers

[kijanowski]

The whole thing can be checked out from https://github.com/kijanowski/graphql-springboot-scope-issue

[marceloverdijk]

I think we need to remove the DataLoaderRegistry from the DefaultGraphQLInvocation. Spring Request-scoped beans will not work when creating new threads.

I think it's better to create a custom ExecutionInputCustomizer which creates the DataLoaderRegistry and attaches it to the ExecutionInput.

[smacktoid]

Can I ask the status of this? Is it possible to configure the DataLoaderRegistry to be request scoped as things stand?

[selliera]

Hello,
I had this working with request scoped dataloader, by removing the async. Not great, but at least I can have batch compute and avoid the 1+N request issue.
For this, I simply use return CompletableFuture.completedFuture(value); in the DataLoader load method.
This way, my loader function can access all request scoped beans that are needed.

[Arka-Bandyopadhyay]

We can user Spring Async Executor Framework for DataLoaderRegistery

[andimarek]

This project is now archived in favor of the official Spring GraphQL integration.