You should be able to use a WindowInto with any of the common windowing operations (e.g. global, fixed, sliding, sessions) in an external transform. You should also be able to window into an arbitrary WindowFn as long as it produces standards window types, but if there's a bug here you could possibly work around it by windowing into a more standard windowing fn before returning.
What is the full traceback? On Tue, Aug 25, 2020 at 5:02 PM Boyuan Zhang <[email protected]> wrote: > > Hi team, > > I'm trying to create an External transform in Java SDK, which expands into > several ParDo and a Window.into(FixWindow). When I use this transform in > Python SDK, I get an pipeline construction error: > > apache_beam/utils/urns.py", line 186, in from_runner_api > parameter_type, constructor = cls._known_urns[fn_proto.urn] > KeyError: 'beam:window_fn:serialized_java:v1' > > Is it expected that I cannot use a Window.into when building External > Ptransform? Or do I miss anything here? > > > Thanks for your help!
