v1.3: Experimental API route

[guimachiavelli]

The engine team is working on creating a new API route to manage experimental features without the need for CLI flags and environment variables. The aim is to make it easier for users to turn experimental features on and off, something which will also benefit Meiliearch's cloud offering.

Not all experimental features will be editable via the new endpoint. We won't havetime to implement an interface for some (e.g. /metrics endpoint), and it is impossible to use the API to manage others (e.g. --experimental-reduce-indexing-memory-usage).

Tasks

• create new overview page under "Learn > Experimental" presenting experimental features, the experimental API, and which features can be configured via the API
• create new page under "Reference > API" describing the API route

References

• PRD (private): https://www.notion.so/meilisearch/Runtime-API-to-toggle-Experimental-Feature-a9e4053bbc6f42539983b782cd9b2a3b
• Slack discussion (private): https://meilisearch.slack.com/archives/C056WNAV3L2/p1687444578105049
• SME: @dureuill

[guimachiavelli]

@dureuill, question:

Changes made to an experimental feature using the API persist between launches. For example, if I activate vector search via the API, that feature will still be active after I interrupt and relaunch an instance.

What happens when changes made via the API conflict with e.g. a cli flag? For example, if I launch Meilisearch with --experimental-vector-search, disable vector search via the API, and relaunch the instance with --experimental-vector-search? I assume the cli flag takes precedence?

[guimachiavelli]

@dureill, another question on the interaction between experimental options and experimental API.

Do cli flags/env vars mark an experimental feature as active in the API?

For example, if I launch Meilisearch with --experimental-vector-search, then GET query the API, will the response show {"vectorSearch": true}?

[dureuill]

Hello @guimachiavelli,

We sidestepped this issue by making it so that features that can be toggled at runtime cannot be enabled by a command line flag, a configuration setting or an environment variable.

The PRD states "No CLI/env variable for the corresponding exp features"

[guimachiavelli]

duh, sorry, I missed that. Thanks for pointing it out 🙏

[dureuill]

You're welcome! It was a good question, hence why we decided to not answer it right away in this first iteration

[guimachiavelli]

Ok, another question, which I hopefully have not missed from the PR nor the PRD.

From what I'm seeing, we have implemented a POST endpoint for this route. Do we have a use case for it?

[dureuill]

hmmm, I think we don't have a good reason to provide a POST endpoint here. I'll check with people that know more about REST than I do