I want to send Nifi flowfile to Spark and do some transformations in Spark and again send the result back to Nifi so that I can to further operations in Nifi. I don't want to write the flowfile written to database or HDFS and then trigger Spark job. I want to send flowfile directly to Spark and receive the result directly from Spark to Nifi. I tried using ExecuteSparkInteractive processor in Nifi but I am stuck. Any examples would be helpful