If you want to send across a "rich" data record, consider defining a schema and using a row coder since row coder is XLang compatible.
On Thu, Jul 16, 2020 at 9:28 AM Robert Bradshaw <rober...@google.com> wrote: > Note also that once you get the Bytes in Python, you can use whatever > coder (or Map) to decode them that you want. > > On Thu, Jul 16, 2020 at 9:21 AM Boyuan Zhang <boyu...@google.com> wrote: > > > > Hi Piotr, > > > > X-Lang uses TypedWithoutMetadata, which outputs the KV directly instead > of KafkaRecord: see here. Given the limit that x-lang can only work with > well-known coders, if you want to process the KV in python output from > KafkaIO, the coders of key and value should be well-known in beam. By > default, the key and value are bytes: see here. > > > > On Thu, Jul 16, 2020 at 8:48 AM Piotr Szuberski < > piotr.szuber...@polidea.com> wrote: > >> > >> I'm writing a python wrappers for KinesisIO and I encountered a problem > that Read transform creates a PCollection with KinesisRecord class which's > coder by default is assigned as 'beam:coders:javasdk:0.1'. I managed to > register this coder using CoderTranslatorRegistrar which adds the coder to > the KNOWN_CODER_URNS and therefore is sent with my custom urn. > >> > >> Kafka's cross language Write transform uses KV<>, is encoded by > default in beam. > >> > >> But I can't see how KafkaRecordCoder is translated in cross-language > usage to python? I can't see any place in code where it gets registered. > >> > >> I just don't get how KafkaIO.Read works in cross-language. Could > someone clarify me how does it work? > >> > >> Thanks in advance! >
