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)

Executing a scrolling query

Every time a query is executed, the results are calculated and returned to the user in real time. In Elasticsearch, there is no deterministic order for records—pagination on a big block of values can lead to inconsistency between results. This is due to added and deleted documents and also documents that have the same score.

The scrolling query tries to resolve this kind of problem by giving a special cursor that allows the user to uniquely iterate all of the documents. 

Getting ready

You will need an up-and-running Elasticsearch installation, as described in the Downloading and installing Elasticsearch recipe of Chapter 1Getting Started.

To execute these commands, any HTTP client can be used, such as Curl (https://curl.haxx.se/), Postman (https://www.getpostman.com/), or similar. I suggest using the Kibana console as it provides code completion and better character escaping for Elasticsearch.

To correctly execute...