title: How to make sure Spark master node is using the worker nodes? (Google cluster)
body: <p>I just created a Google Cloud cluster (1 master and 6 workers) and by default Spark is configured. </p>
  
  <p>I have a pure python code that uses NLTK to build the dependency tree for each line from a text file. When I run this code on the master <code>spark-submit run.py</code> I get the same execution time when I run it using my machine. </p>
  
  <p>How to make sure that the master is using the workers in order to reduce the execution time ?</p>