Hi Piotr, would it be possible to provide a table that shows the compatibility guarantees provided by the different snapshots going forward? Like type of change (Topology. State Schema, Parallelism, ..) in one dimension, and type of snapshot as the other dimension. Based on that, it would be easier to discuss those guarantees, I believe.
Cheers, Konstantin On Mon, Jan 3, 2022 at 9:11 AM David Morávek <d...@apache.org> wrote: > Hi Piotr, > > does this mean that we need to keep the checkpoints compatible across minor > versions? Or can we say, that the minor version upgrades are only > guaranteed with canonical savepoints? > > My concern is especially if we'd want to change layout of the checkpoint. > > D. > > > > On Wed, Dec 29, 2021 at 5:19 AM Yu Li <car...@gmail.com> wrote: > > > Thanks for the proposal Piotr! Overall I'm +1 for the idea, and below are > > my two cents: > > > > 1. How about adding a "Term Definition" section and clarify what "native > > format" (the "native" data persistence format of the current state > backend) > > and "canonical format" (the "uniform" format that supports switching > state > > backends) means? > > > > 2. IIUC, currently the FLIP proposes to only support incremental > savepoint > > with native format, and there's no plan to add such support for canonical > > format, right? If so, how about writing this down explicitly in the FLIP > > doc, maybe in a "Limitations" section, plus the fact that > > `HashMapStateBackend` cannot support incremental savepoint before > FLIP-151 > > is done? (side note: @Roman just a kindly reminder, that please take > > FLIP-203 into account when implementing FLIP-151) > > > > 3. How about changing the description of "the default configuration of > the > > checkpoints will be used to determine whether the savepoint should be > > incremental or not" to something like "the `state.backend.incremental` > > setting now denotes the type of native format snapshot and will take > effect > > for both checkpoint and savepoint (with native type)", to prevent concept > > confusion between checkpoint and savepoint? > > > > 4. How about putting the notes of behavior change (the default type of > > savepoint will be changed to `native` in the future, and by then the > taken > > savepoint cannot be used to switch state backends by default) to a more > > obvious place, for example moving from the "CLI" section to the > > "Compatibility" section? (although it will only happen in 1.16 release > > based on the proposed plan) > > > > And all above suggestions apply for our user-facing document after the > FLIP > > is (partially or completely, accordingly) done, if taken (smile). > > > > Best Regards, > > Yu > > > > > > On Tue, 21 Dec 2021 at 22:23, Seth Wiesman <sjwies...@gmail.com> wrote: > > > > > >> AFAIK state schema evolution should work both for native and > canonical > > > >> savepoints. > > > > > > Schema evolution does technically work for both formats, it happens > after > > > the code paths have been unified, but the community has up until this > > point > > > considered that an unsupported feature. From my perspective making this > > > supported could be as simple as adding test coverage but that's an > active > > > decision we'd need to make. > > > > > > On Tue, Dec 21, 2021 at 7:43 AM Piotr Nowojski <pnowoj...@apache.org> > > > wrote: > > > > > > > Hi Konstantin, > > > > > > > > > In this context: will the native format support state schema > > evolution? > > > > If > > > > > not, I am not sure, we can let the format default to native. > > > > > > > > AFAIK state schema evolution should work both for native and > canonical > > > > savepoints. > > > > > > > > Regarding what is/will be supported we will document as part of this > > > > FLIP-203. But it's not as simple as just the difference between > native > > > and > > > > canonical formats. > > > > > > > > Best, Piotrek > > > > > > > > pon., 20 gru 2021 o 14:28 Konstantin Knauf <kna...@apache.org> > > > napisał(a): > > > > > > > > > Hi Piotr, > > > > > > > > > > Thanks a lot for starting the discussion. Big +1. > > > > > > > > > > In my understanding, this FLIP introduces the snapshot format as a > > > > *really* > > > > > user facing concept. IMO it is important that we document > > > > > > > > > > a) that it is not longer the checkpoint/savepoint characteristics > > that > > > > > determines the kind of changes that a snapshots allows (user code, > > > state > > > > > schema evolution, topology changes), but now this becomes a > property > > of > > > > the > > > > > format regardless of whether this is a snapshots or a checkpoint > > > > > b) the exact changes that each format allows (code, state schema, > > > > topology, > > > > > state backend, max parallelism) > > > > > > > > > > In this context: will the native format support state schema > > evolution? > > > > If > > > > > not, I am not sure, we can let the format default to native. > > > > > > > > > > Thanks, > > > > > > > > > > Konstantin > > > > > > > > > > > > > > > On Mon, Dec 20, 2021 at 2:09 PM Piotr Nowojski < > pnowoj...@apache.org > > > > > > > > wrote: > > > > > > > > > > > Hi devs, > > > > > > > > > > > > I would like to start a discussion about a previously announced > > > follow > > > > up > > > > > > of the FLIP-193 [1], namely allowing savepoints to be in native > > > format > > > > > and > > > > > > incremental. The changes do not seem invasive. The full proposal > is > > > > > > written down as FLIP-203: Incremental savepoints [2]. Please > take a > > > > look, > > > > > > and let me know what you think. > > > > > > > > > > > > Best, > > > > > > Piotrek > > > > > > > > > > > > [1] > > > > > > > > > > > > > > > > > > > > > > > > > > > https://cwiki.apache.org/confluence/display/FLINK/FLIP-193%3A+Snapshots+ownership > > > > > > [2] > > > > > > > > > > > > > > > > > > > > > > > > > > > https://cwiki.apache.org/confluence/display/FLINK/FLIP-203%3A+Incremental+savepoints#FLIP203:Incrementalsavepoints-Semantic > > > > > > > > > > > > > > > > > > > > > -- > > > > > > > > > > Konstantin Knauf > > > > > > > > > > https://twitter.com/snntrable > > > > > > > > > > https://github.com/knaufk > > > > > > > > > > > > > > > -- Konstantin Knauf https://twitter.com/snntrable https://github.com/knaufk
