The runners should be able to support Multimap User State portably over the FnApi already.
https://github.com/apache/beam/blob/master/model/fn-execution/src/main/proto/org/apache/beam/model/fn_execution/v1/beam_fn_api.proto#L937 How that's supported on each SDK is a different matter though. On Fri, Feb 24, 2023, 12:57 PM Alan Zhang <shuai....@gmail.com> wrote: > Appreciate it if anyone can help confirm and share thoughts. > > On Wed, Feb 22, 2023 at 11:46 PM Alan Zhang <shuai....@gmail.com> wrote: > >> Hi Beam devs. >> >> According to the Fn State API design doc[1], the state type >> MultimapUserState is intended for supporting MapState/SetState. And the >> implementation[2] for this state type is ready on the SDK harness side. >> Each runner will be responsible for integrating it if they want to leverage >> it. >> >> Today Beam uses StateRequestHandlers to define handler interfaces for >> other state types, e.g. MultimapSideInputHandler for >> MultimapSideInput, BagUserStateHandler for BagUserState, etc.[3] This is >> great since each runner can implement these handler interfaces then the Fn >> state API integration is done. >> >> In order to support MapState/SetState, I think we will need to provide >> a MultimapUserStateHandler interface in StateRequestHandlers and allow the >> runners to implement it. >> >> What do you think? >> >> Feel free to correct me if there is any incorrect understanding since I'm >> new to the Beam world. >> >> Btw, I saw Flink Python used MultimapSideInput to support MapState[4] but >> I think this is not recommended since MultimapUserState is available today. >> But please correct me if I'm wrong. >> >> >> [1] https://s.apache.org/beam-fn-state-api-and-bundle-processing >> <https://s.apache.org/beam-fn-state-api-and-bundle-processing> >> [2] https://github.com/apache/beam/pull/15238 >> [3] >> https://github.com/apache/beam/blob/master/runners/java-fn-execution/src/main/java/org/apache/beam/runners/fnexecution/state/StateRequestHandlers.java#L192 >> [4] >> https://cwiki.apache.org/confluence/display/FLINK/FLIP-153%3A+Support+state+access+in+Python+DataStream+API >> -- >> Thanks, >> Alan >> > > > -- > Thanks, > Alan >
