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

Updating with scripting


ElasticSearch allows updating a document in-place.

Updating a document via scripting reduces networking traffic (otherwise, you need to fetch the document, change the field, and send it back) and allows improving performance when you need to process a huge amount of documents.

Getting ready

You need a working ElasticSearch cluster and an index populated with the script used for facet processing, available in the online code.

How to do it...

For updating using a scripting, we will perform the following steps:

  1. We'll write an update action that adds a tag value to a list of tags available in the source of a document. It should look as shown in the following code:

     curl -XPOST 'http://127.0.0.1:9200/test-index/test-type/9/_update?&pretty=true' -d '{
        "script" : "ctx._source.tag += tag",
        "params" : {
            "tag" : "cool"
        }
    }'
  2. If everything is correct, the result returned by ElasticSearch should be:

    {
      "ok" : true,
      "_index" : "test-index",
      "_type" : "test-type...