Hey Yuepeng, Thanks for putting this together.
I agree these are mostly legacy leftovers from Flink 1.x. Many were already deprecated there, and according to FLIP-321, they have had sufficient migration time and should be removable in the Flink 2.x series. For keys that had already been deprecated by the Flink 1.20.0 release on August 2, 2024[2], I don't see any compatibility risk in removing them now. +1 for systematically cleaning them up. [1] https://cwiki.apache.org/confluence/spaces/FLINK/pages/255072331/FLIP-321+Introduce+an+API+deprecation+process#FLIP321%3AIntroduceanAPIdeprecationprocess-ProposedChanges [2] https://flink.apache.org/2024/08/02/announcing-the-release-of-apache-flink-1.20/ Best, Rui On Sat, Sep 12, 2026 at 4:39 AM Yuepeng Pan <[email protected]> wrote: > Hi everyone, > > I would like to start a discussion on whether we could systematically > remove long-deprecated configuration keys in Flink 2.x series. > > As configuration options have been renamed and reorganized, Flink has > continued to support many old names through compatibility aliases. While > this helps users migrate, retaining these aliases indefinitely also > increases maintenance and testing costs and makes the configuration harder > to understand. > > I have compiled an inventory [1] of calls to > ConfigOption#withDeprecatedKeys and ConfigOption#withFallbackKeys, > including the actual configuration keys and their source locations. > Candidates worth reviewing include legacy akka.*, recovery.*, and > jobmanager.web.* keys, as well as older names for checkpointing, state > backend, and deployment settings. > > The inventory also includes commit dates from Git history for the > corresponding configuration code. These dates may help us prioritize the > cleanup chronologically and assess the compatibility risks of removing > individual keys. > > Looking forward to your thoughts and suggestions. > > [1] > > https://docs.google.com/document/d/1wHCIVX0zxu_0iCtyY2WWBb0gRkJk0UVKo2uuTcMQfDc/edit?usp=sharing > > Best regards, > Yuepeng Pan >
