Updating a document using scripts
Elasticsearch allows the updating of a document in-place. Updating a document via scripting reduces network traffic (otherwise, you need to fetch the document, change the field/fields, and send them back) and improves performance when you need to process a huge amount of documents.
Getting ready
You need an up-and-running Elasticsearch installation as we described in the Downloading and installing Elasticsearch recipe in Chapter 2, Downloading and Setup.
To execute curl via the command-line you need to install curl for your operating system.
To correctly execute the following commands, you need an index populated with the chapter_09/populate_for_scripting.sh script available in the online code and Javascript/Python language scripting plugins installed.
How to do it...
For updating using scripting, we will perform the following steps:
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...
