title: Which files are ignored as input by mapper?
body: <p>I'm chaining multiple MapReduce jobs and want to pass along/store some meta information (e.g. configuration or name of original input) with the results. At least the file "_SUCCESS" and also anything in the directory "_logs" seams to be ignored.</p>
  
  <p>Are there any filename patterns which are by default ignored by the <code>InputReader</code>? Or is this just a fixed limited list?</p>