On Wed, Dec 30, 2020 at 11:21 AM Jark Wu <imj...@gmail.com> wrote: Jark,
> If you are using the old planner in 1.9, and using the old planner in 1.11, > then a state migration is > needed because of the new added RowKind field. This is documented in the > 1.11 release note [1]. Yes - that's exactly the setup that we're using. Both versions currently use the old planner and state migration fails due to the "The new key serializer must be compatible" error. For testing I tried to patch the Flink source and to force usage of (only) the legacy mode in the RowSerializer (so that the state doesn't need to be migrated) and this seems to work. However, I'm not sure if this has any unintended side-effects so it seems that rebuilding the state is a much safer and more maintainable approach. - Guenther
