Book Image

Elasticsearch 8.x Cookbook - Fifth Edition

By : Alberto Paro
Book Image

Elasticsearch 8.x Cookbook - Fifth Edition

By: Alberto Paro

Overview of this book

Elasticsearch is a Lucene-based distributed search engine at the heart of the Elastic Stack that allows you to index and search unstructured content with petabytes of data. With this updated fifth edition, you'll cover comprehensive recipes relating to what's new in Elasticsearch 8.x and see how to create and run complex queries and analytics. The recipes will guide you through performing index mapping, aggregation, working with queries, and scripting using Elasticsearch. You'll focus on numerous solutions and quick techniques for performing both common and uncommon tasks such as deploying Elasticsearch nodes, using the ingest module, working with X-Pack, and creating different visualizations. As you advance, you'll learn how to manage various clusters, restore data, and install Kibana to monitor a cluster and extend it using a variety of plugins. Furthermore, you'll understand how to integrate your Java, Scala, Python, and big data applications such as Apache Spark and Pig with Elasticsearch and create efficient data applications powered by enhanced functionalities and custom plugins. By the end of this Elasticsearch cookbook, you'll have gained in-depth knowledge of implementing the Elasticsearch architecture and be able to manage, search, and store data efficiently and effectively using Elasticsearch.
Table of Contents (20 chapters)

Chapter 8: Scripting in Elasticsearch

Elasticsearch has a powerful way of extending its capabilities by using custom scripts, which can be written in several programming languages. The most common ones are Painless, Express, and Mustache. In this chapter, we will explore how it’s possible to create custom scoring algorithms, specially processed return fields, custom sorting, complex update operations on records, and ingest processors. The scripting concept of Elasticsearch is an advanced stored-procedure system in the NoSQL world; due to this, every advanced user of Elasticsearch should learn how to master it.

Elasticsearch natively provides scripting in Java (that is, Java code compiled in JAR files), Painless, Express, and Mustache; however, a lot of other interesting languages are also available as plugins, such as Kotlin and Velocity. In older Elasticsearch releases, prior to version 5.0, the official scripting language was Groovy. But, for better sandboxing and performance...