fielddata shows how much heap memory is currently being used by fielddata
on every data node in the cluster.
GET /_cat/fielddata?v
Looks like:
id host ip node field size Nqk-6inXQq-OxUfOUI8jNQ 127.0.0.1 127.0.0.1 Nqk-6in body 544b Nqk-6inXQq-OxUfOUI8jNQ 127.0.0.1 127.0.0.1 Nqk-6in soul 480b
Fields can be specified either as a query parameter, or in the URL path:
GET /_cat/fielddata?v&fields=body
Which looks like:
id host ip node field size Nqk-6inXQq-OxUfOUI8jNQ 127.0.0.1 127.0.0.1 Nqk-6in body 544b
And it accepts a comma delimited list:
GET /_cat/fielddata/body,soul?v
Which produces the same output as the first snippet:
id host ip node field size Nqk-6inXQq-OxUfOUI8jNQ 127.0.0.1 127.0.0.1 Nqk-6in body 544b Nqk-6inXQq-OxUfOUI8jNQ 127.0.0.1 127.0.0.1 Nqk-6in soul 480b
The output shows the individual fielddata for the body and soul fields, one row per field per node.