What Happens When Reducers Are Set to Zero
If We Set the Number of Reducer to 0 (By Setting Job. setNumreduceTasks(0)), Then No Reducer Will Execute and No Aggregation Will Take Place. in Such Case, We...
If we set the number of Reducer to 0 (by setting job. setNumreduceTasks(0)), then no reducer will execute and no aggregation will take place. In such case, we will prefer “Map-only job” in Hadoop. In Map-Only job, the map does all task with its InputSplit and the reducer do no job.
What happens in a MapReduce job when you set number of reducers to zero?
What happens in a MapReduce job when you set the number of reducers to zero? No reducer executes, but the mappers generate no output. No reducer executes, and the output of each mapper is written to a separate file in HDFS.
Is it legal to set the number of reducer task to zero where the output will be stored in this case?
Is it legal to set the number of reducer task to zero? Where the output will be stored in this case? Yes, It is legal to set the number of reduce-tasks to zero if there is no need for a reducer. In this case the outputs of the map task is directly stored into the HDFS which is specified in the setOutputPath(Path).
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