Dynamic schema/supergraph selection per request (e.g. by header) in Hive Gateway

[Tolsee]

We’d like to know if Hive Gateway supports (or could support) choosing a different schema/supergraph per request, e.g. based on a request header.

For example: we wanna achieve something like this:

flowchart TD
    A[Client Request -- with header] --> B{Check x-schema header}
    B -->|default| C[Use Default Supergraph]
    B -->|next| D[Use Next Supergraph]
    C --> E[Execute Query]
    D --> E[Execute Query]
    E --> F[Return Response to Client]

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[enisdenjo]

Hive Gateway does not support switching the supergraph on/per requests. We don't have a plan of supporting this at the moment, can you elaborate on the use case?

Also, have you considered simply running 2 gateways and deciding between them instead (using a different URL or have a load-balancer that respects the header)?

[Tolsee]

Hi @enisdenjo! Thanks for the response.

We're experimenting with hot-swapping subgraphs on runtime (for example, a locally running subgraph) for better development experience. While we were able to swap upstream url per request based on header, we are looking if it is feasible to something similar for supergrapgh/schema.

We want to make it so that if I am testing something, the change should only reflect for me without affecting anyone else. So while we could in theory deploy multiple gateways, it's not ideal since we need per-developer isolation rather than environment-wide changes.

[ardatan]

Unfortunately Hive Gateway doesn't support it and won't support anytime soon. One of the reasons is that the gateway needs to do a lot of work while switching between supergraphs.

[Tolsee]

Good to know, thanks for quick response!