Book Image

ElasticSearch Cookbook

By : Alberto Paro
Book Image

ElasticSearch Cookbook

By: Alberto Paro

Overview of this book

ElasticSearch is one of the most promising NoSQL technologies available and is built to provide a scalable search solution with built-in support for near real-time search and multi-tenancy. This practical guide is a complete reference for using ElasticSearch and covers 360 degrees of the ElasticSearch ecosystem. We will get started by showing you how to choose the correct transport layer, communicate with the server, and create custom internal actions for boosting tailored needs. Starting with the basics of the ElasticSearch architecture and how to efficiently index, search, and execute analytics on it, you will learn how to extend ElasticSearch by scripting and monitoring its behaviour. Step-by-step, this book will help you to improve your ability to manage data in indexing with more tailored mappings, along with searching and executing analytics with facets. The topics explored in the book also cover how to integrate ElasticSearch with Python and Java applications. This comprehensive guide will allow you to master storing, searching, and analyzing data with ElasticSearch.
Table of Contents (19 chapters)
ElasticSearch Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Creating a query


Before search, a query must be built: ElasticSearch provides several ways to build these queries. In this recipe, will see how to create a query object via QueryBuilder and via simple strings.

Getting ready

You need a working ElasticSearch cluster and a working copy of Maven. The code of this recipe is in chapter_10/nativeclient in the code bundle of this book available on Packt's website and the referred class is QueryCreation.

How to do it...

For creating a query, we will perform the steps given as follows:

  1. There are several ways to define a query in ElasticSearch; they are interoperable.

    Generally a query can be defined as a:

    • QueryBuilder: This is a helper to build a query.

    • XContentBuilder: This is a helper to create JSON code. We discussed it in the Managing mapping recipe in this chapter. The JSON code to be generated is similar to the previous REST, but converted in programmatic code.

    • Array of bytes or string: In this case, it's usually the JSON to be executed as we have...