Hi, I have a scenario where a kafka topic is being written with different types of json records. I have to regroup the records based on the type and then fetch the schema and parse and write as parquet. I have tried structured programming. But dynamic schema is a constraint. So I have used DStreams and though I know the approach I have taken may not be good. If anyone can pls let me know if the approach will scale and possible pros and cons. I am collecting the grouped records and then again forming the dataframe for each grouped record. createKeyValue -> This is creating the key value pair with schema information.
stream.foreachRDD { (rdd, time) => val offsetRanges = rdd.asInstanceOf[HasOffsetRanges].offsetRanges val result = rdd.map(createKeyValue).reduceByKey((x,y) => x ++ y).collect() result.foreach(x=> println(x._1)) result.map(x=> { val spark = SparkSession.builder().config(rdd.sparkContext.getConf).getOrCreate() import spark.implicits._ import org.apache.spark.sql.functions._ val df = x._2 toDF("value") df.select(from_json($"value", x._1._2, Map.empty[String,String]).as("data")) .select($"data.*") //.withColumn("entity", lit("invoice")) .withColumn("year",year($"TimeUpdated")) .withColumn("month",month($"TimeUpdated")) .withColumn("day",dayofmonth($"TimeUpdated")) .write.partitionBy("name","year","month","day").mode("append").parquet(path) }) stream.asInstanceOf[CanCommitOffsets].commitAsync(offsetRanges) }