Getting the Tool Interface warning even though it is implemented
As your question pops really fast on the top of Google search for this warning, I'll give a proper answer here :
As user1797538 you said : (sorry about that)
user1797538: "The problem was the call to get a Job instance"
The superclass Configured must be used. As its name suggests, it is already configured, so the existing Configuration must be used by the Tester class and not set a new empty one.
If we extract the Job creation in a method :
private Job createJob() throws IOException { // On this line use getConf() instead of new Configuration() Job job = Job.getInstance(getConf(), Tester.class.getCanonicalName()); // Other job setter call here, for example job.setJarByClass(Tester.class); job.setMapperClass(TesterMapper.class); job.setCombinerClass(TesterReducer.class); job.setReducerClass(TesterReducer.class); job.setOutputKeyClass(Text.class); job.setOutputValueClass(IntWritable.class); // adapt this to your needs of course. return job;}Another example from the javadoc : org.apache.hadoop.util.Tool
And the Javadoc : Configured.getConf()