Major Description
Run the following code and check the UI
sc.makeRDD(1 to 1, 1).foreach { i => Thread.sleep(30000) }
You will see "Scheduler Delay" of a task is almost the same as "Duration" until the task finishes. That's really confusing.
In Spark 2.2, "Scheduler Delay" will be 0 until the task finishes. This is also not correct but less confusing.
