title: How EC2 (persistent) HDFS and EMR (transient) HDFS communicate
body: <p>I've set up a Hadoop cluster on Amazon EC2 with NameNode/DataNode and some other services. My ingestion job brings the data into the EC2 HDFS cluster (let's say <code>hdfs://ec2-hdfs/</code>).</p>
  
  <p>Now I'm having a pipeline which runs as a weekly batch. I'm launching a new Amazon EMR cluster for running my computation. Once the processing completes, I will terminate the EMR cluster.</p>
  
  <p>The input for my spark job that needs to run in EMR is in EC2 HDFS (<code>hdfs://ec2-hdfs/</code>). How can I access it from the newly created EMR cluster? I believe there should be some option (bootstrap/VPC/subnet) available during the EMR Cluster launch.</p>