Book Image

Elasticsearch 7 Quick Start Guide

By : Anurag Srivastava, Douglas Miller
Book Image

Elasticsearch 7 Quick Start Guide

By: Anurag Srivastava, Douglas Miller

Overview of this book

Elasticsearch is one of the most popular tools for distributed search and analytics. This Elasticsearch book highlights the latest features of Elasticsearch 7 and helps you understand how you can use them to build your own search applications with ease. Starting with an introduction to the Elastic Stack, this book will help you quickly get up to speed with using Elasticsearch. You'll learn how to install, configure, manage, secure, and deploy Elasticsearch clusters, as well as how to use your deployment to develop powerful search and analytics solutions. As you progress, you'll also understand how to troubleshoot any issues that you may encounter along the way. Finally, the book will help you explore the inner workings of Elasticsearch and gain insights into queries, analyzers, mappings, and aggregations as you learn to work with search results. By the end of this book, you'll have a basic understanding of how to build and deploy effective search and analytics solutions using Elasticsearch.
Table of Contents (10 chapters)

What is an analyzer?

Elasticsearch's analysis tool describes analysis as the process of converting text into tokens, which are then added to the inverted index and used for searching. Every analysis is performed by an analyzer. For example, an index time analysis built in English will convert a sentence into distinct words; these distinct words are the tokens. Take the example of the following sentence:

Hello World! This is my first program and these are my first lines.

This will be added to the inverted index as the following:

[hello, world, first, program, these, line]

The analyzer removes the most frequent words and reduces words to the word stem—so lines becomes line. An analyzer can be specified in the mapping in the text field, as shown in the following query:

PUT my_index 
"mappings": {
"_doc": {