11/9/2023 0 Comments Reduce map filter javascript![]() ![]() The reducer performs a defined function on a list of values for unique keys, and Final output will be stored/displayed. An output of sort and shuffle sent to the reducer phase.This sort and shuffle acts on these list of pairs and sends out unique keys and a list of values associated with this unique key. Using the output of Map, sort and shuffle are applied by the Hadoop architecture.The keys will not be unique in this case. The map takes data in the form of pairs and returns a list of pairs.The reducer too takes input in key-value format, and the output of reducer is the final output. The reducer runs only after the Mapper is over. The output of the Mapper is fed to the reducer as input. In the Mapper, the input is given in the form of a key-value pair. The MapReduce is a paradigm which has two phases, the mapper phase, and the reducer phase. It was developed in 2004, on the basis of paper titled as "MapReduce: Simplified Data Processing on Large Clusters," published by Google. What is MapReduce?Ī MapReduce is a data processing tool which is used to process the data parallelly in a distributed form. Our MapReduce tutorial includes all topics of MapReduce such as Data Flow in MapReduce, Map Reduce API, Word Count Example, Character Count Example, etc. Our MapReduce tutorial is designed for beginners and professionals. MapReduce tutorial provides basic and advanced concepts of MapReduce. ![]()
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