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

Introduction


In ElasticSearch ecosystem, it can be immensely useful to monitor nodes and cluster to control and improve their performances and states. There are several scenarios involved in problems at cluster level such as the following:

  • Node overheads occur when some nodes can have too many shards allocated and become a bottleneck of all cluster.

  • Node shutdown can happen due to a lot of reasons, for example full disk, hardware problem and power problems.

  • Shard relocation problems or corruptions in which some shards are unable to become in online status may happen.

  • If a shard is too big, the index performance decreases due to Lucene massive segments merging.

  • Empty indices and shards only waste memory and storage, but because every shard has a lot of active thread, if there is a huge number of unused indices and shards, the general cluster performance is degraded.

Detecting malfunction or bad performances can be done via API or via some frontend plugins that can be activated in ElasticSearch...