WARNING: Version 2.1 of Elasticsearch has passed its EOL date.
This documentation is no longer being maintained and may be removed. If you are running this version, we strongly advise you to upgrade. For the latest information, see the current release documentation.
This section discusses the changes that you need to be aware of when migrating your application from one version of Elasticsearch to another.
As a general rule:
See Upgrading for more info.