Hi Rui, Agreed, I think we can have the deprecation and 'execution.checkpointing.file-merging.enabled' activated by default together. Let me do more testing to ensure an experience that is no worse than the previous approach.
Best, Zakelly On Sat, Sep 5, 2026 at 8:31 PM Rui Fan <[email protected]> wrote: > 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 > > >
