New API namespace: features and endpoints features.get_features and snapshot.get_features.
cat.plugins adds parameter include_bootstrap: Include bootstrap plugins in the response.
Update in indices.close parameter wait_for_active_shards: Sets the number of active shards to wait for before the operation returns. Set to index-setting to wait according to the index setting index.write.wait_for_active_shards, or all to wait for all shards, or an integer. Defaults to 0.
actions.search adds parameter min_compatible_shard_node: The minimum compatible version that all shards involved in search should have for this request to be successful.