title: How to access monitoring web UI when running spark on AWS
body: <p>I'm running spark from AWS EC2. As the spark documentation said </p>
  
  <blockquote>
    <p>"Each driver program has a web UI, typically on port 4040, that displays information about running tasks, executors, and storage usage. Simply go to http://:4040 in a web browser to access this UI"</p>
  </blockquote>
  
  <p>My question is: what is this "driver-node"? 
  I thought it's the public IP of the driver node xx.xx.xxx.xx. But I kept getting page not found error when I user <a href="http://xx.xx.xxx.xx:4040" rel="nofollow">http://xx.xx.xxx.xx:4040</a></p>
  
  <p>Please help.</p>