I am facing update mapping errors on an ES (6.1) index because it seems we reached the limit
index.mapping.total_fields.limit. The error is:
Limit of total fields  in index [coin] has been exceeded
However, if I do:
$ curl -X GET "localhost:9200/coin/_mapping?pretty" | grep type | wc -l
I get only
I would like to properly monitor when we are getting close to the limit, but it's not clear how to fetch the value that is actually used by ES internally. Is there a way to do that?