title: How do I log to file in Scalding?
body: <p>In my Scalding map reduce code, I want to log out certain steps that are happening so that I can debug the map-reduce jobs if something goes wrong.</p>
  
  <p>How can I add logging to my scalding job?</p>
  
  <p>E.g.</p>
  
  <pre><code>import com.twitter.scalding._
  class WordCountJob(args: Args) extends Job(args) {
     //LOG: Starting job at time blah..
     TextLine( args("input") )
     .read
     .flatMap('line -&gt; 'word) {
        line: String =&gt;
        line.trim.toLowerCase.split("\\W+") 
     }
     .groupBy('word) { group =&gt; group.size('count) }
  }
  .write(Tsv(args("output")))
  //LOG - ending job at time...
  }
  </code></pre>