Asked by: Anahit Shamov
technology and computing programming languages

What are the main configuration parameters that user need to specify to run MapReduce job?

Last Updated: 1st May, 2020

The main configuration parameters which users need to specify in “MapReduce” framework are:
  • Job's input locations in the distributed file system.
  • Job's output location in the distributed file system.
  • Input format of data.
  • Output format of data.
  • Class containing the map function.
  • Class containing the reduce function.

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Similarly one may ask, what are the main configuration parameters in a MapReduce program?

The main configuration parameters in “MapReduce” framework are:

  • Input location of Jobs in the distributed file system.
  • Output location of Jobs in the distributed file system.
  • The input format of data.
  • The output format of data.
  • The class which contains the map function.
  • The class which contains the reduce function.

Also Know, what are the parameters of mappers and reducers? The four parameters for mappers are:

  • LongWritable (input)
  • text (input)
  • text (intermediate output)
  • IntWritable (intermediate output)

Similarly, what are the main components of MapReduce job?

  • Main driver class which provides job configuration parameters.
  • Mapper class which must extend org. apache. hadoop. mapreduce. Mapper class and provide implementation for map () method.
  • Reducer class which should extend org. apache. hadoop. mapreduce. Reducer class.

What is partitioner and how it helps in MapReduce job process?

Partitioner in MapReduce job execution controls the partitioning of the keys of the intermediate map-outputs. With the help of hash function, key (or a subset of the key) derives the partition. Records as having the same key value go into the same partition (within each mapper).

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How do reducers communicate with each other?

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Which phase of MapReduce is optional?

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How many reducers run for a MapReduce job?

Using the command line: While running the MapReduce job, we have an option to set the number of reducers which can be specified by the controller mapred. reduce. tasks. This will set the maximum reducers to 20.

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How does Hadoop MapReduce work?

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When NameNode fails which node takes the responsibility of active node?

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What is MapReduce and how it works?

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What is the port number for Job Tracker?

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What are the two main components of Hadoop?

HDFS (storage) and MapReduce (processing) are the two core components of Apache Hadoop. The main components of HDFS are as described below: NameNode is the master of the system. It maintains the name system (directories and files) and manages the blocks which are present on the DataNodes.

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What do you mean by MapReduce?

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What are the four basic parameters of a mapper?

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What is optimal size of a file for distributed cache?

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Can we set the number of reducers to zero in MapReduce?

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