title: Spark: driver/worker configuration. Does driver run on Master node?
body: <p>I am starting a spark cluster on AWS, with one master and 60 cores:</p>
  
  <p><a href="https://i.stack.imgur.com/2UKa2.png" rel="noreferrer"><img src="https://i.stack.imgur.com/2UKa2.png" alt="enter image description here"></a></p>
  
  <p>Here is the command to start up, basically 2 executors per core, totally 120 executors:</p>
  
  <pre><code>spark-submit --deploy-mode cluster --master yarn-cluster --driver-memory 180g --driver-cores 26 --executor-memory 90g --executor-cores 13 --num-executors 120
  </code></pre>
  
  <p>However, in the job tracker, there is only 119 executors:</p>
  
  <p><a href="https://i.stack.imgur.com/bOT9j.png" rel="noreferrer"><img src="https://i.stack.imgur.com/bOT9j.png" alt="enter image description here"></a></p>
  
  <p>I thought there should be 1 driver + 120 worker executors. However, what I saw was 119 executors, which including 1 driver + 118 working executors.</p>
  
  <p>Does that mean my Master node was not used? Is the driver running on the Master node or Core node? Can I make the driver run on the Master node and let the 60 Cores hosting 120 working executors?</p>
  
  <p>Thanks!</p>