Change schema in runtime

[pkese]

I'm adding or replacing some data (tables) in runtime and I'm wondering if I can inform GraphQL layer that the schema has changed rather than restarting the whole server process.

Is that possible?

[pkese]

I've noticed that there's a few extensions for services.AddGraphQL that accept
executorFactory : Func<IServiceProvider, Executor<'Root>>
rather than just
executor : Executor<'Root>
so technically I should be able to pass a factory to GraphQL executor instead of a fixed (unmodifiable) executor instance...

... however all extension methods accepting executorFactory are marked internal in that file.

I assume there's probably a reason for that (that I don't know), but nevertheless ... is it possible to pass new schema / schema executor at runtime without

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FSharp.Data.GraphQL/src/FSharp.Data.GraphQL.Server.AspNetCore/StartupExtensions.fs

Line 99 in 26b13f1

executorFactory : Func<IServiceProvider, Executor<'Root>>,

[xperiandri]

We can open them public if you need

[xperiandri]

https://github.com/fsprojects/FSharp.Data.GraphQL/blob/dev/src/FSharp.Data.GraphQL.Server.AspNetCore/GraphQLRequestHandler.fs

This is the other extension point. But I also have not made the HandleAsync overridable.

What do you think?

[pkese]

@xperiandri

thanks for your help and effort... I'm trying to understand that code that you are pointing me to as well as your hint "This is the other extension point".

There's an IOptionsMonitor implying that I could possibly somehow change the options and fire OnChange event. Is it possible to get a handle to these options on a running instance, or change them in some other way?

Was this the hint?

Btw, for the moment, I'm just instantiating and populating a new WebHost at the top level, wait until it is ready, then shutting down the old WebHost and then starting again with the new one immediately after.
So yes, I close the socket and drop some connections, which is not ideal, but at least the downtime is just milliseconds.

[xperiandri]

That is more a question where exactly you prefer an extension point.
Because I have not thought about any scenario like yours

[pkese]

I think having an option to pass a new executor through IOptionsMonitor would probably make more sense.

Exposing services.AddGraphQL<Root> with executor as a factory still leaves it open when this factory needs to be called (i.e. a new executor instantiated).

[pkese]

Aha ...

I think I misunderstood:
if the services.AddGraphQL<Root> can be called by supplying the executor as a factory
... and if this factory gets called on each request
... and I if I get to cache the executor and keep supplying the same executor instance from that factory (until change),
then everything works fine as well.

Therefore IOptionsMonitor or supplying an executor factory to services.AddGraphQL<Root> both provide the same functionality and both are fine.

[xperiandri]

@pkese I've made SchemaExecutor and RootFactory mutable
Try the latest GitHub package