Hello everyone, For accessing metrics and traces, there were metaclass interfaces, called `Stats` and `Trace` respectively. Each interface was reading the config and then initializing the instance of the appropriate implementation. Each metaclass was acting like a singleton cache and in all consecutive calls after the first one, it would always access the same existing instance.
Daniel Standish has been leading an effort to simplify the OTel traces code. He was able to remove the `Trace` interface and add a single configuration when initializing all the airflow settings in core. Traces were simpler because they have a single supported implementation while metrics have multiple. But after discussions, we think that we can follow a similar approach and remove the stats interface. The reason is that there is too much complexity that increases with every new addition or refactoring. It's going to be easier to maintain if simplified. The question is whether `airflow.metrics` and `airflow.stats` are public interfaces. They have been around since airflow 2.7 but as far as I know, no one from the community has talked about adding user-defined metrics from under dags. Additionally, there are no docs saying how users can do it. The only public info is for enabling the project's internal metrics. I'm considering these modules as private and I'm assuming that users aren't aware of them or using them. I think they are safe to remove. I would like to call for a lazy consensus vote which will run for 72 hours. If no one votes -1 during the voting period, the vote will be considered passed. Thank you! Regards, Christos
