This section discusses the changes that you need to be aware of to migrate your application to 8.4.3. For more information about what’s new in this release, see the What’s new in 8.4 and Release notes.
As Elasticsearch introduces new features and improves existing ones, the changes sometimes make older settings, APIs, and parameters obsolete. We typically deprecate obsolete functionality as part of a release. If possible, we support the deprecated functionality for several subsequent releases before removing it. This enables applications to continue working unchanged while you prepare to migrate away from the deprecated functionality.
To get the most out of Elasticsearch and facilitate future upgrades, we strongly encourage migrating away from using deprecated functionality as soon as possible.
To give you insight into what deprecated features you’re using, Elasticsearch: