Configuration changes take affect immediately

open-feature / flagd

A feature flag daemon with a Unix philosophy

https://openfeature.dev

Apache License 2.0

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Configuration changes take affect immediately #22

Closed beeme1mr closed 2 years ago

beeme1mr commented 2 years ago

Summary

One of the main benefits of feature flags is the ability to change values at runtime. Flagd needs to watch for feature flag configuration changes and update its internal state. This should happen without downtime to Flagd.

Considerations

File system watcher overhead should be minimal
Change events may be added to the OpenFeature spec in the future

Questions

How should invalid feature flag configuration changes be handled in a running process?

Resources

AlexsJones commented 2 years ago

The current implementation is more or less on request, would this satisfy the requirement?

beeme1mr commented 2 years ago

Yeah, that's fine for now. Long term I think we would want to only reload the config if the file has changed.

beeme1mr commented 2 years ago

A downside of reloading the file per request besides overhead is that flagd wouldn't be able to push events. That's currently out of scope but will likely be added to the OpenFeature spec soon.

AlexsJones commented 2 years ago

Okay, so the sync could be reworked into an informer/watcher then each implementation has to do what it will with that.

AlexsJones commented 2 years ago

This has been reworked with notifiers