Invalidating tags in microservices and microfrontend architecture

[andreev-artem]

Hi everyone, let me describe my issue.

For example, I have general purpose microservice Documents and two microservices MS_A and MS_B which use Documents. Also I have two microfrontends - MF_A with api_A and MF_B and api_B. Both also use api_Documents. When I add document using api_Documents I would want to invalidate tags in other APIs but for MF_A I would want to invalidate tags in api_A and for MF_B - in api_B.

It seems that for now I can only invalidate in api_Documents.addMutation.onQueryStarted calling both api_A.util.invalidateTags and api_B.util.invalidateTags. It looks quite bad because api_Documents knows too much about MS_A and MS_B.

I wanted to write a middleware which would configured per microfrontend for resending api_Documents invalidated tags either to api_A or api_B using corresponding util.invalidateTags. But I can't get any info from actions or state - which tags are invalidated. Is something like that possible? Or does it make sense to fill a feature request?

[phryneas]

If they all access the same data and influence each other, it doesn't really matter if they are microsystems or a monolith - to the outside they are one system. So I would treat them as one api, not as three.

[andreev-artem]

If they all access the same data

I would say Documents microservice provides some data to MS_A and MS_B. Pretty common approach for microservices architecture.

influence each other

They do not influence each other. It's more like unidirectional flow.

it doesn't really matter if they are microsystems or a monolith - to the outside they are one system

I'm not sure what do you mean by "outside" here but It definitely matters for frontend.

So I would treat them as one api, not as three.

Actually it's not possible - three microservices have three urls. If it would be one url I would just use single createApi and API Slices/Code Splitting.

My point here is that such task is not rare nowadays. And it would be great if RTKQ would support such scenarios in some way.

[phryneas]

Fot the frontend it's the same dataset. The twitter api and a cookbook api are two different apis.

Twitter's "posts" api and twitter's "users" api are the same api from the perspective of any outside system (and a frontend is very much the definition of "outside"), as a user has posts, and posts can be liked by users. There's a relationship between the types. It doesn't matter if it's split up into microservices, that's an implementation detail.

three microservices have three urls.

Then you'll have to prefix your api endpoints with absolute urls and not work relative to one baseUrl.

[andreev-artem]

I see, thank you! Though something like ability to add baseUrl in injectEndpoints would be really convenient,