title: spark.executor.extraClassPath option setting programmatically through SparkConf
body: <p>My project jars are conflicting with jars which are on EMR so to fix this 
  I have copied all my advanced jars to custom location of nodes through bootstrap script. I have verified jars got copied on to all executor nodes.  </p>
  
  <p>It is working fine with spark-submit , my <code>code</code> referring new jars which are in custom folder of all nodes.</p>
  
  <pre><code>/usr/bin/spark-submit --conf="spark.driver.extraClassPath=/usr/customJars/*" --conf="spark.executor.extraClassPath=/usr/customJars/*"  
  </code></pre>
  
  <p>Same thing I want to implement programmatically in the code by updating sparkconf object. </p>
  
  <pre><code>sparkConf.set("spark.driver.extraClassPath", "/usr/customJars/*");
  sparkConf.set("spark.executor.extraClassPath", "/usr/customJars/*"); 
  </code></pre>
  
  <p>it is not working when I want to implement programmatically. my <code>code</code> is not referring updated jars in custom location .</p>
  
  <p>Any suggestion?</p>