MapReduce


Top 60 MapReduce Interview Questions and Answers

Objective A Hadoop MapReduce is a software framework for easily writing Application for processing a large amount of data in parallel or on a large cluster of a commodity. As it deals with processing of data it is likely to be asked in Hadoop Interview. So in this section, we covered 60 MapReduce interview questions and answers framed by our company expert. These questions are as per the latest trend followed in an interview. A Proper care has been taken […]


50 MapReduce Interview Questions and Answers

Objective It is difficult to pass the Hadoop interview as it is fast and growing technology. To get you through this tough path the interview questions will serve as the backbone. this blog contains the commonly asked Hadoop MapReduce interview questions and answers. These 50 MapReduce Interview Questions are framed by keeping in mind the need of an era, and the trending pattern of the interview that is being followed by the companies. The interview questions of Hadoop MapReduce are dedicatedly […]


How Hadoop MapReduce Works – MapReduce Tutorial 2

1. Objective MapReduce is the core component of Hadoop that process huge amount of data in parallel by dividing the work into a set of independent tasks. In MapReduce data flow in step by step from Mapper to Reducer. In this tutorial, we are going to cover how Hadoop MapReduce works internally? This blog on Hadoop MapReduce data flow will provide you the complete MapReduce data flow chart in Hadoop. The tutorial covers various phases of MapReduce job execution such as Input Files, […]

Learn How Hadoop MapReduce works internally?

Types of Counters in Hadoop MapReduce

Hadoop Counters, Types of MapReduce Counters in Hadoop

1. Objective In this MapReduce tutorial, we will provide you the detailed description of MapReduce Counters in Hadoop. The tutorial covers an introduction to Hadoop MapReduce counters, Types of Hadoop Counters such as Built-in Counters and User-defined counters. In this tutorial, We will also discuss the FileInputFormat and FileOutputFormat of Hadoop MapReduce. 2. What is Hadoop MapReduce? Before we start with Hadoop Counters, let us first see the overview of Hadoop MapReduce. MapReduce is the core component of Hadoop which provides […]


Learn the Concept of Key-Value Pair in Hadoop MapReduce

1. Objective In this MapReduce tutorial, we are going to learn the concept of a key-value pair in Hadoop. The key Value pair is the record entity that MapReduce job receives for execution. By default, RecordReader uses TextInputFormat for converting data into a key-value pair. Here we will learn what is a key-value pair in MapReduce, how key-value pairs are generated in Hadoop using InputSplit and RecordReader and on what basis generation of key-value pairs in Hadoop MapReduce takes place? We […]

The concepts of key-value pair in Hadoop MapReduce.

Different types of OutputFormats in Hadoop MapReduce

Hadoop OutputFormat, Types of OutputFormat in Mapreduce

1. Objective The Hadoop OutputFormat checks the Output-Specification of the job. It determines how RecordWriter implementation is used to write output to output files. In this blog, we are going to see what is Hadoop OutputFormat, what is Hadoop RecordWriter, how RecordWriter is used in Hadoop? We will also discuss various types of OutputFormat in Hadoop like textOutputFormat, sequenceFileOutputFormat, mapFileOutputFormat, sequenceFileAsBinaryOutputFormat, DBOutputFormat, LazyOutputForma, and MultipleOutputs in this blog. Learn How to install Cloudera Hadoop CDH5 on CentOS. 2. What is Hadoop OutputFormat? […]


Map Only Job in Hadoop MapReduce with example

1. Objective In Hadoop, Map-Only job is the process in which mapper does all task, no task is done by the reducer and mapper’s output is the final output. In this tutorial on Map only job in Hadoop MapReduce, we will learn about MapReduce process, the need of map only job in Hadoop, how to set a number of reducers to 0 for Hadoop map only job. We will also learn what are the advantages of Map Only job in Hadoop […]

Introduction to Map Only Job in Hadoop MapReduce.

Shuffling & Sorting in Hadoop

Shuffling and Sorting in Hadoop MapReduce 1

1. Objective In Hadoop, the process by which intermediate output from mappers is transferred to the reducer is called Shuffling. Reducer gets 1 or more keys and associated values on the basis of reducers. Intermediated key-value generated by mapper is sorted automatically by key. In this blog, we will discuss in detail about shuffling and Sorting in Hadoop MapReduce. Here we will learn what is sorting in Hadoop, what is shuffling in Hadoop, what is the purpose of Shuffling and sorting […]


Hadoop Partitioner – Internals of MapReduce Partitioner 1

1. Objective In this MapReduce Tutorial, we are going to discuss what is Hadoop Partitioner. The Partitioner in MapReduce controls the partitioning of the key of the intermediate mapper output. By hash function, key (or a subset of the key) is used to derive the partition. A total number of partitions depends on the number of reduce task. Here we will also learn what is the need of Hadoop partitioner, what is the default Hadoop partitioner, how many practitioners are required in […]

Partitioner in Hadoop

Introduction to InputSplit in Hadoop MapReduce.

InputSplit in Hadoop MapReduce – Hadoop MapReduce Tutorial 1

1. Objective In this Hadoop MapReduce tutorial, we will provide you the detailed description of InputSplit in Hadoop. In this blog, we will try to answer What is Hadoop InputSplit, what is the need of inputSplit in MapReduce and how Hadoop performs InputSplit, How to change split size in Hadoop. We will also learn the difference between InputSplit vs Blocks in HDFS. 2. What is InputSplit in Hadoop? InputSplit in Hadoop MapReduce is the logical representation of data. It describes […]