title: How to build and run Scala Spark locally
body: <p>I'm attempting to build Apache Spark locally. Reason for this is to debug Spark methods like reduce. In particular I'm interested in how Spark implements and distributes Map Reduce under the covers as I'm experiencing performance issues and I think running these tasks from source is best method of finding out what the issue is.</p>
  
  <p>So I have cloned the latest from Spark repo : </p>
  
  <pre><code>git clone https://github.com/apache/spark.git
  </code></pre>
  
  <p>Spark appears to be a Maven project so when I create it in Eclipse here is the structure : </p>
  
  <p><img src="https://i.stack.imgur.com/wvaf7.jpg" alt="enter image description here"></p>
  
  <p>Some of the top level folders also have pom files : </p>
  
  <p><img src="https://i.stack.imgur.com/bVtTy.jpg" alt="enter image description here"></p>
  
  <p>So should I just be building one of these sub projects ? Are these correct steps for running Spark against a local code base ?</p>