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How many Reducers will the job Submit?

Question asked by pradeeshma on Jan 29, 2016
Latest reply on Feb 1, 2016 by keysbotzum
In a map reduce program assuming the default number of reducers are set to 1, if the mapper code emits 2 different types of keys, wont there be two reducers running ?

Im referring to Lesson 4 exercise for University data under Developing Hadoop applications where the mapper code emits two sets of keys for every invocation of map() function as below

public class UniversityMapper  extends Mapper  {

   public void map(LongWritable key, Text value, Context context) throws IOException,
               InterruptedException {


  //Processing logic....


  context.write(new Text("**satv**"), new IntWritable(satVerbal));

   context.write(new Text("**satm**"), new IntWritable(satMath));

}

I see there is only one reducer task submitted eventhough 2 keys are written by mapper. Please advise.


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