https://www.quora.com/Why-do-people-integrate-Spark-with-TensorFlow-even-if-there-is-a-distributed-TensorFlow-framework
https://www.quora.com/What-is-the-difference-between-TensorFlow-on-Spark-and-the-default-distributed-TensorFlow-1-0
https://www.quora.com/How-will-the-distributed-version-of-TensorFlow-affect-Apache-Spark-and-MLlib
https://www.quora.com/unanswered/How-is-the-distributed-performance-of-Apache-Spark-different-from-Distributed-TensorFlow