You can use Kryo by doing the following settings in your SparkConf:

1. Start the Spark shell by setting Kryo as a serializer:

        $ spark-shell --conf spark.serializer=org.apache.spark.serializer.KryoSerializer

2. Kryo automatically registers most of the core Scala classes, but if you would like to register your own classes, you can use the following command:

        scala> sc.getConf.registerKryoClasses(Array(classOf[com.infoobjects.CustomClass1],classOf[com.infoobjects.CustomClass2])