[ES][WARN ][2020-02-21T14:53:03,646][o.e.d.s.f.s.DocValueFieldsFetchSubPhase][JEzmUW8] There are doc-value fields which are not using a format. The output will change in 7.0 when doc value fields get formatted based on mappings by default. It is recommended to pass [format=use_field_mapping] with a doc value field in order to opt in for the future behaviour and ease the migration to 7.0: [_entity_type]