Q&A

What is the difference between input split and HDFS block?

What is the difference between input split and HDFS block?

HDFS Blockis the physical part of the disk which has the minimum amount of data that can be read/write. While MapReduce InputSplit is the logical chunk of data created by theInputFormat specified in the MapReduce job configuration.

What is the difference between block and split?

Split is a logical division of the input data while block is a physical division of data. HDFS default block size is default split size if input split is not specified. Split is user defined and user can control split size in his Map/Reduce program.

What is the difference between input split and block size?

All HDFS blocks are the same size except the last block, which can be either the same size or smaller. Hadoop framework break files into 128 MB blocks and then stores into the Hadoop file system. InputSplit – InputSplit size by default is approximately equal to block size.

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How MapReduce is different from HDFS?

The main difference between HDFS and MapReduce is that HDFS is a distributed file system that provides high throughput access to application data while MapReduce is a software framework that processes big data on large clusters reliably.

What are the basic differences between relational database and HDFS?

The key difference between RDBMS and Hadoop is that the RDBMS stores structured data while the Hadoop stores structured, semi-structured, and unstructured data. The RDBMS is a database management system based on the relational model.

What is the role of HDFS in Hadoop?

HDFS is a distributed file system that handles large data sets running on commodity hardware. It is used to scale a single Apache Hadoop cluster to hundreds (and even thousands) of nodes. HDFS is one of the major components of Apache Hadoop, the others being MapReduce and YARN.

Can HDFS blocks be broken?

1 Answer. Your answer to this is inputsplit. As HDFS does not know the content of the file. While storing data into multiple blocks, last record of each block might be broken.

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What is relation between the size of splitting data and mapping data?

The number of Map Tasks for a job are dependent on the size of split. Bigger the size of split configured, lesser would be the number of Map Tasks. This is because each split would consist of more than one block. Hence, lesser number of Map Tasks would be required to process the data.

How MapReduce works on HDFS?

MapReduce assigns fragments of data across the nodes in a Hadoop cluster. The goal is to split a dataset into chunks and use an algorithm to process those chunks at the same time. The parallel processing on multiple machines greatly increases the speed of handling even petabytes of data.

Does Hdfs use MapReduce?

Mapreduce: MapReduce is a programming model that is used for processing and generating large data sets on clusters of computers….Difference Between Hadoop and MapReduce.

Based on Hadoop MapReduce
Pre-requisites Hadoop runs on HDFS (Hadoop Distributed File System) MapReduce can run on HDFS/GFS/NDFS or any other distributed system for example MapR-FS
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Where is the difference between traditional and HDFS storage system?

Hadoop has the ability to process and store all variety of data whether it is structured, semi-structured or unstructured. Although, it is mostly used to process large amount of unstructured data. Traditional RDBMS is used only to manage structured and semi-structured data.

Is HDFS a database?

It does have a storage component called HDFS (Hadoop Distributed File System) which stoes files used for processing but HDFS does not qualify as a relational database, it is just a storage model.