See the explanation for Step by Step Solution and configuration.
Explanation:
Solution :
Step 1 : Create file in hdfs (We will do using Hue). However, you can first create in local filesystem and then upload it to hdfs.
Step 2 : Load data.csv file from hdfs and create PairRDDs
val name = sc.textFile("spark8/data.csv")
val namePairRDD = name.map(x=> (x.split(",")(0),x.split(",")(1)))
Step 3 : Now swap namePairRDD RDD.
val swapped = namePairRDD.map(item => item.swap)
Step 4 : Now combine the rdd by key.
val combinedOutput = namePairRDD.combineByKey(List(_), (x:List[String], y:String) => y ::
x, (x:List[String], y:List[String]) => x ::: y)
Step 5 : Save the output as a Text file and output must be written in a single file.
:ombinedOutput.repartition(1).saveAsTextFile("spark8/result.txt")