title: Spark Streaming - Jobs run concurrently with default spark.streaming.concurrentJobs setting
body: <p>I have come across a wierd behaviour in Spark Streaming Job.
  We have used the default value for spark.streaming.concurrentJobs which is 1.
  The same streaming job was running for more than a day properly with the batch interval being set to 10 Minutes.
  Suddenly that same job has started running concurrently for all the batches that come in without putting them in Queue.</p>
  
  <p>Has anyone faced this before? 
  This would be of great help!</p>