Book Image

Elasticsearch Server - Third Edition

By : Rafal Kuc
Book Image

Elasticsearch Server - Third Edition

By: Rafal Kuc

Overview of this book

ElasticSearch is a very fast and scalable open source search engine, designed with distribution and cloud in mind, complete with all the goodies that Apache Lucene has to offer. ElasticSearch’s schema-free architecture allows developers to index and search unstructured content, making it perfectly suited for both small projects and large big data warehouses, even those with petabytes of unstructured data. This book will guide you through the world of the most commonly used ElasticSearch server functionalities. You’ll start off by getting an understanding of the basics of ElasticSearch and its data indexing functionality. Next, you will see the querying capabilities of ElasticSearch, followed by a through explanation of scoring and search relevance. After this, you will explore the aggregation and data analysis capabilities of ElasticSearch and will learn how cluster administration and scaling can be used to boost your application performance. You’ll find out how to use the friendly REST APIs and how to tune ElasticSearch to make the most of it. By the end of this book, you will have be able to create amazing search solutions as per your project’s specifications.
Table of Contents (18 chapters)
Elasticsearch Server Third Edition
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Preface
Index

The Cat API


The Elasticsearch Admin API is quite extensive and covers almost every part of Elasticsearch architecture: from low-level information about Lucene to high-level ones about the cluster nodes and their health. All this information is available using the Elasticsearch Java API as well as the REST API. However, the returned data, even though it is a JSON document, is not very readable by a user, at least when it comes to the amount of information given.

Because of this, Elasticsearch provides us with a more human-friendly API – the Cat API. The special Cat API returns data in a simple text, tabular format and what's more – it provides aggregated data that is usually usable without any further processing.

The basics

The base endpoint for the Cat API is quite obvious: it is /_cat. Without any parameters, it shows all the available endpoints for this API. We can check this by running the following command:

curl -XGET 'localhost:9200/_cat'

The response returned by Elasticsearch should be...