cat fielddata

edit

fielddata shows how much heap memory is currently being used by fielddata on every data node in the cluster.

% curl '192.168.56.10:9200/_cat/fielddata?v'
id                     host    ip            node          total   body    text
c223lARiSGeezlbrcugAYQ myhost1 10.20.100.200 Jessica Jones 385.6kb 159.8kb 225.7kb
waPCbitNQaCL6xC8VxjAwg myhost2 10.20.100.201 Adversary     435.2kb 159.8kb 275.3kb
yaDkp-G3R0q1AJ-HUEvkSQ myhost3 10.20.100.202 Microchip     284.6kb 109.2kb 175.3kb

Fields can be specified either as a query parameter, or in the URL path:

% curl '192.168.56.10:9200/_cat/fielddata?v&fields=body'
id                     host    ip            node          total   body
c223lARiSGeezlbrcugAYQ myhost1 10.20.100.200 Jessica Jones 385.6kb 159.8kb
waPCbitNQaCL6xC8VxjAwg myhost2 10.20.100.201 Adversary     435.2kb 159.8kb
yaDkp-G3R0q1AJ-HUEvkSQ myhost3 10.20.100.202 Microchip     284.6kb 109.2kb

% curl '192.168.56.10:9200/_cat/fielddata/body,text?v'
id                     host    ip            node          total   body    text
c223lARiSGeezlbrcugAYQ myhost1 10.20.100.200 Jessica Jones 385.6kb 159.8kb 225.7kb
waPCbitNQaCL6xC8VxjAwg myhost2 10.20.100.201 Adversary     435.2kb 159.8kb 275.3kb
yaDkp-G3R0q1AJ-HUEvkSQ myhost3 10.20.100.202 Microchip     284.6kb 109.2kb 175.3kb

The output shows the total fielddata and then the individual fielddata for the body and text fields.