NOTE: You are looking at documentation for an older release. For the latest information, see the current release documentation.
This API is experimental and may be changed or removed completely in a future release. The underlying Upgrade Assistant concepts are stable, but the APIs for managing Upgrade Assistant are currently experimental.
The Upgrade Assistant API allows you to check the upgrade status of your Elasticsearch cluster and reindex indices that were created in the previous major version. The assistant helps you prepare for the next major version of Elasticsearch.