title: How to access Spark UI on EMR?
body: <p>I launched a EMR Spark cluster with 2 machines in interactive mode.</p>
  
  <p>with config sets:</p>
  
  <pre><code>cluster manager: yarn-client
  bootstrap: no
  IAM: all
  </code></pre>
  
  <p>and then open all the TCP ports of master to ANYWHERE.</p>
  
  <p>there is nothing at master:4040</p>
  
  <p>where/how can I find the Spark UI in this case ?</p>