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

Controlling cluster health via API


In Understanding cluster, replication recipe, and sharding in Chapter 1, Getting Started, we discussed ElasticSearch cluster and how to manage in the case of red and yellow state.

ElasticSearch provides a convenient way to control the cluster state, which is one of the first things to control in case of problems.

Getting ready

You need a working ElasticSearch cluster.

How to do it…

For controlling the cluster health, we need to perform the following steps:

  1. To view the cluster health, the HTTP method is GET and the curl command is as follows:

    curl -XGET 'http://localhost:9200/_cluster/health'
  2. The result will be:

    {
      "cluster_name" : "elasticsearch",
      "status" : "green",
      "timed_out" : false,
      "number_of_nodes" : 2,
      "number_of_data_nodes" : 2,
      "active_primary_shards" : 5,
      "active_shards" : 10,
      "relocating_shards" : 0,
      "initializing_shards" : 0,
      "unassigned_shards" : 0
    }

How it works…

Every ElasticSearch node keeps the cluster status. The status can be...