Hello all, I have recently been working on adding bulk iterations to the Python API of Flink in order to facilitate a research project I am working on. The current changes can be seen in this GitHub diff: https://github.com/apache/flink/compare/master...GEOFBOT:e8c9833b43675af66ce897da9880c4f8cd16aad0
This implementation seems to work for, at least, simple examples, such as incrementing numbers in a data set. However, with the transformations required for my project, I get an exception "java.lang.ClassCastException: [B cannot be cast to org.apache.flink.api.java.tuple.Tuple" thrown from the deserializers called by org.apache.flink.python.api.streaming.data.PythonReceiver.collectBuffer. I've created the following simplified Python plan by stripping down my research project code to the problem-causing parts: https://gist.github.com/GEOFBOT/abb7f81030aab160e6908093ebaa3b4a I have been working on this issue but I don't have any ideas on what might be the problem. Perhaps someone more knowledgeable about the interior of the Python API could kindly help? Thank you very much. Geoffrey Mon
