In #54998 targeting 7.9.0, we introduced a new node.roles settings for configuring the roles that a node has. These supersede the legacy node settings such as node.data, node.master, etc., which were deprecated in the same release. For example, to configure a dedicated ML node, previously you would use node.ml: true and now you’d use node.roles: [ “ml” ].

We intend to remove the legacy node role settings in the 8.0.0 release of Elasticsearch. This issue is a placeholder for following that work.