Hi In our streaming pipeline, we have two pubsub sources. PCollection<OurType> A and PCollection<OurType> B is created from the two pubsub sources respectively.
In this case, both A and B is unbounded PCollection. Can we do something like: PCollection<OurType> C = PCollectionList.of(A).and(B).apply(Flatten. pCollections()) ? When we try to flatten them into one PCollection like above, basically the pipeline stopped working by repeatedly throwing message "GetData failed: status: APPLICATION_ERROR(3): Computation S6does not have state family S4 for value read". Anyone know what this error msg mean? Alternatively, if we transform A and B into KV<OurType, Integer> and flatten them into C and do a GroupByKey with a 1 second window then transform it back to PCollection<OurType>, the pipeline seems working correctly. -- Richard Tian Software Engineer Snap Inc.
