title: Running Hadoop MapReduce, is it possible to call external executables outside of HDFS
body: <p>Within my mapper I'd like to call external software installed on the worker node outside of the HDFS.  Is this possible?  What is the best way to do this?</p>
  
  <p>I understand that this may take some of the advantages/scalability of MapReduce away, but i'd like to interact both within the HDFS and call compiled/installed external software codes within my mapper to process some data.</p>