The cluster settings operation lets you check the current settings for your cluster, review default settings, and change settings. When you update a setting using the API, OpenSearch applies it to all nodes in the cluster.
flat_settings | Boolean | Whether to return settings in the flat form, which can improve readability, especially for heavily nested settings. For example, the flat form of `"cluster": { "max_shards_per_node": 500 }` is `"cluster.max_shards_per_node": "500"`.
include_defaults (GET only) | Boolean | Whether to include default settings as part of the response. This parameter is useful for identifying the names and current values of settings you want to update.
For more information about transient settings, persistent settings, and precedence, see [OpenSearch configuration]({{site.url}}{{site.baseurl}}/opensearch/configuration/).