Since the early days, Hadoop has provided Interface classification annotations to represent the scope and stability for downstream applications to select Hadoop APIs carefully. After some time, these annotations (InterfaceAudience and InterfaceStability) have been migrated to Apache Yetus. As of today, with increasing number of Hadoop ecosystem applications using (or starting to use) Yetus stability annotations for their own downstreamers, we should also consider using IA/IS annotations provided by *org.apache.yetus.audience *directly in our codebase and retire our *org.apache.hadoop.classification* package for the better separation of concern and single source.
I believe we can go with this migration to maintain compatibility for Hadoop downstreamers: 1. In Hadoop trunk (3.4.0+ releases), replace all usages of o.a.h.c stability annotations with o.a.y.a annotations. 2. Deprecate o.a.h.c annotations, and provide deprecation warning that we will remove o.a.h.c in 4.0.0 (or 5.0.0) release and the only source for these annotations should be o.a.y.a. Any thoughts?
