+1 to removing LEGACY mode in Flink 2.0. Thanks for driving. Danny,
On Sat, 13 Jan 2024, 08:20 Yanfei Lei, <fredia...@gmail.com> wrote: > Thanks Zakelly for starting this discussion. > > Regardless of whether it is for users or developers, deprecating > RestoreMode#LEGACY makes the semantics clearer and lower maintenance > costs, and Flink 2.0 is a good time point to do this. > So +1 for the overall idea. > > Best, > Yanfei > > Zakelly Lan <zakelly....@gmail.com> 于2024年1月11日周四 14:57写道： > > > > > Hi devs, > > > > I'd like to start a discussion on FLIP-416: Deprecate and remove the > > RestoreMode#LEGACY[1]. > > > > The FLIP-193[2] introduced two modes of state file ownership during > > checkpoint restoration: RestoreMode#CLAIM and RestoreMode#NO_CLAIM. The > > LEGACY mode, which was how Flink worked until 1.15, has been superseded > by > > NO_CLAIM as the default mode. The main drawback of LEGACY mode is that > the > > new job relies on artifacts from the old job without cleaning them up, > > leaving users uncertain about when it is safe to delete the old > checkpoint > > directories. This leads to the accumulation of unnecessary checkpoint > files > > that are never cleaned up. Considering cluster availability and job > > maintenance, it is not recommended to use LEGACY mode. Users could choose > > the other two modes to get a clear semantic for the state file ownership. > > > > This FLIP proposes to deprecate the LEGACY mode and remove it completely > in > > the upcoming Flink 2.0. This will make the semantic clear as well as > > eliminate many bugs caused by mode transitions involving LEGACY mode > (e.g. > > FLINK-27114 [3]) and enhance code maintainability. > > > > Looking forward to hearing from you! > > > > [1] https://cwiki.apache.org/confluence/x/ookkEQ > > [2] https://cwiki.apache.org/confluence/x/bIyqCw > > [3] https://issues.apache.org/jira/browse/FLINK-27114 > > > > Best, > > Zakelly >
