Hey Zakelly, Thank you for driving it!
> I would therefore like to propose: > > 1. Promoting the configurations introduced by FLIP-306 from @Experimental to @PublicEvolving. > 2. Deprecating the file-merging mechanism introduced under FLINK-26803 in favor of the unified mechanism. Sounds make sense to me. Only one minor comment here: is it possible to enable execution.checkpointing.file-merging.enabled by default while removing execution.checkpointing.unaligned.max-subtasks-per-channel-state-file? Since the default value is 5 right now. If we are confident in the unified file-merging feature, I think enabling it by default would be a good choice. It provides users with a production configuration that works right out of the box. Best, Rui On Thu, Sep 3, 2026 at 5:26 PM Zakelly Lan <[email protected]> wrote: > Hi everyone, > > The unified file merging mechanism introduced by FLIP-306 [1] has been > available since Flink 1.20.0, which was released on August 2, 2024 [2]. > Over the past two years, we have received much feedback from real-world use > cases and fixed a number of issues. The feature has now reached a good > level of stability. > > In the FLIP-600 discussion [3], Rui Fan suggested using FLIP-306 to handle > channel-state file merging as well, allowing us to deprecate the existing > mechanism introduced under FLINK-26803 [4]. With FLINK-39977 [5], the final > piece required to support merged channel-state recovery, now merged, I > believe we are ready to take the next step. > > I would therefore like to propose: > > 1. Promoting the configurations introduced by FLIP-306 from > @Experimental to @PublicEvolving. > 2. Deprecating the file-merging mechanism introduced under FLINK-26803 > in favor of the unified mechanism. > > FLIP-306 has now been available for more than two years and across multiple > release cycles, so this promotion would be consistent with Flink’s API > stability graduation process [6]. Consolidating on the unified mechanism > would also reduce duplication and provide a single file-merging solution > for both checkpoint data and channel state. > > Looking forward to your thoughts. > > > Best, > Zakelly > > [1] https://cwiki.apache.org/confluence/x/DwsNDw > [2] > > https://flink.apache.org/2024/08/02/announcing-the-release-of-apache-flink-1.20/ > [3] https://lists.apache.org/thread/qpztk0jdpcmhomszjx63l53xv26xnmwf > [4] https://issues.apache.org/jira/browse/FLINK-26803 > [5] https://issues.apache.org/jira/browse/FLINK-39977 > [6] https://cwiki.apache.org/confluence/x/J5eqCw >
