Reindexing an index

There are a lot of common scenarios that involve changing your mapping. Due to the limitations of Elasticsearch mapping, it not possible to delete a defined one, so you often need to reindex index data. The most common scenarios are as follows:

• Changing an analyzer for a mapping
• Adding a new subfield to a mapping, whereupon you need to reprocess all the records to search for the new subfield
• Removing an unused mapping
• Changing a record structure that requires a new mapping

Getting ready

You need an up-and-running Elasticsearch installation, as we described in the Downloading and installing Elasticsearch recipe in Chapter 1, Getting Started.

To execute these commands, HTTP clients can be used...