title: Unknown protocol to job tracker
body: <p>I'm attempting to run a Hadoop mapreduce job within DataStax 3.1 and getting this error. Any ideas on what's the cause?</p>
  
  <p>Caused by: org.apache.hadoop.ipc.RemoteException: java.io.IOException: Unknown protocol to job tracker: org.apache.hadoop.hdfs.protocol.ClientProtocol
      at org.apache.hadoop.mapred.JobTracker.getProtocolVersion(JobTracker.java:347)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcc</p>