title: Increase Spark Executors on Zeppelin
body: <p>I'm setting up a cluster with Hortnworks (HDP 2.4). I have a 4 nodes cluster each having (16Gb-RAM, 8-CPUs). I also have Spark installed with Zeppelin Notebook in order to use python (pyspark).</p>
  
  <p>My problem is: I started with a configuration of 3 nodes and later I added another new node (so totally 4 as said before), anyway the number of executors on Spark remains "3". </p>
  
  <p>I see on the web that the number of executors is settable in <code>SPARK_EXECUTOR_INSTANCES</code>, but this param is present only in <code>spark-env template</code> of the config page of Spark in Ambari UI. Seems it demand to YARN the decision about executors, but in YARN I haven't found anything about this.</p>
  
  <p><a href="https://i.stack.imgur.com/Oq71v.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Oq71v.png" alt="enter image description here"></a></p>
  
  <p>Definitively, How I can increase the number of executor in my Hortonworks Hadoop Cluster using Ambari?</p>