SPARK-18560

##### Receiver data can not be dataSerialized properly.

```
// :: ERROR executor.Executor: Exception in task 4.3 in stage 6.0 (TID )
com.esotericsoftware.kryo.KryoException: Encountered unregistered class ID:
    at com.esotericsoftware.kryo.util.DefaultClassResolver.readClass(DefaultClassResolver.java:)
    at com.esotericsoftware.kryo.Kryo.readClass(Kryo.java:)
    at com.esotericsoftware.kryo.Kryo.readClassAndObject(Kryo.java:)
    at org.apache.spark.serializer.KryoDeserializationStream.readObject(KryoSerializer.scala:)
    at org.apache.spark.serializer.DeserializationStream$$anon$.getNext(Serializer.scala:)
    at org.apache.spark.util.NextIterator.hasNext(NextIterator.scala:)
    at org.apache.spark.util.Utils$.getIteratorSize(Utils.scala:)
    at org.apache.spark.rdd.RDD$$anonfun$count$.apply(RDD.scala:)
    at org.apache.spark.rdd.RDD$$anonfun$count$.apply(RDD.scala:)
    at org.apache.spark.SparkContext$$anonfun$runJob$.apply(SparkContext.scala:)
    at org.apache.spark.SparkContext$$anonfun$runJob$.apply(SparkContext.scala:)
    at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:)
    at org.apache.spark.scheduler.Task.run(Task.scala:)
    at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:)
    at java.lang.Thread.run(Thread.java:)
```
This problem stems from SPARK-, a patch to have Spark automatically pick the "best" serializer when caching RDDs.

```
Affects Version/s:
2.0.
Fix Version/s:
2.0., 2.1.
```

SPARK-18560