Support Questions
Find answers, ask questions, and share your expertise

If input directory is empty, then no mappers or Reducer will run?

If input directory is empty, then no mappers or Reducer will run?

1 REPLY 1

As a number of mappers depend upon the number of InputSplits , as no data no input splits hence no mappers. Without any mapper, a number of the reducer is also 0.

If we try to run map/reduce job on Hadoop cluster without specifying any input file it will throw following exception: java.io.IOException: No input paths specified in job.