The more like this (mlt) API allows to get documents that are "like" a specified document. Here is an example:
$ curl -XGET 'http://localhost:9200/twitter/tweet/1/_mlt?mlt_fields=tag,content&min_doc_freq=1'
The API simply results in executing a search request with
moreLikeThis query (http
parameters match the parameters to the
more_like_this query). This
means that the body of the request can optionally include all the
request body options in the search
API (aggs, from/to and so on). Internally, the more like this
API is equivalent to performing a boolean query of
queries, with one query per specified
Rest parameters relating to search are also allowed, including
mlt_fields are specified, all the fields of the document will
be used in the
more_like_this query generated.
By default, the queried document is excluded from the response (
set to false).
Note: In order to use the
mlt feature a
mlt_field needs to be either
source needs to be enabled.