KryoExperiment.scala

object KryoExperiment {

  case class SomeClass(x: String, v: String)
  case class BigClass(x: String, v: Long, k: Double)

  def main(args: Array[String]): Unit = {
    val sparkConf1 = new SparkConf()
      .set("spark.serializer", "org.apache.spark.serializer.KryoSerializer")
      .registerKryoClasses(Array())

    val kryo1 = new KryoSerializer(sparkConf1)
    test(kryo1)

    val sparkConf2 = new SparkConf()
      .set("spark.serializer", "org.apache.spark.serializer.KryoSerializer")
      .registerKryoClasses(Array(classOf[(String, String)], classOf[SomeClass], classOf[BigClass]))

    val kryo2 = new KryoSerializer(sparkConf2)
    test(kryo2)
  }

  def test(kryo: KryoSerializer) {
    val inst = kryo.newInstance()
    val k2 = inst.serialize(("Ok", "ok"))
    val l2 = inst.serialize(("Ok", 10000L, 0.1827383D))
    val m2 = inst.serialize(SomeClass("Ok", "ok"))
    val n2 = inst.serialize(BigClass("Ok", 10000L, 0.1827383D))
    println("tuple=" + k2.array().length +
      ", bigTuple=" + l2.array().length +
      ", class=" + m2.array().length +
      ", bigClass=" + n2.array().length)
  }

}