title: Spark Shell -how to find whether ID has appeared maximum times in file
body: <p>Find userID of user/s who has/have given maximum feedback to movies from textfile using Spark Shell</p>
  
  <pre><code>1:123
  1:212
  1:111
  1:212
  2:212
  2:125
  3:88
  </code></pre>
  
  <p>so I want to display use ID 1 who have given maximum feedback 
  how can I find whether ID 1 has appeared maximum times in file?</p>
  
  <pre><code>scala&gt;  val feedback = sc.textFile("/ratings.dat")     
  scala&gt;  val a = feedback.map(row =&gt; row.split("::")(0)).count     
  a: Long = 1000209
  </code></pre>