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.
You need an up-and-running Elasticsearch installation as we described in the Downloading and installing Elasticsearch recipe in Chapter 2, Downloading and Setup.
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