How to do it...

The HTTP method that's used is POST. The URL format for optimizing one or more indices is as follows:

http://<server>/<index_name(s)>/_flush[?refresh=True]

The URL format for optimizing all the indices in a cluster is:

http://<server>/_flush[?refresh=True]

For optimizing, or to ForceMerge an index, we will perform the following steps:

1. If we consider the index we created in the Creating an index recipe, the call will be as follows:

POST /myindex/_forcemerge

1. The result returned by Elasticsearch should be as follows:

{
  "_shards" : {
    "total" : 2,
    "successful" : 1,
    "failed" : 0
  }
}

The result contains the shard operation status.