POST http://127.0.0.1:9200/_cache/clear?pretty=true&recycler=true HTTP/1.1
Accept: application/json
Content-Type: application/json
Host: 127.0.0.1:9200
Content-Length: 0

HTTP/1.1 400 Bad Request
content-type: application/json; charset=UTF-8
content-length: 348

{
  "error" : {
    "root_cause" : [
      {
        "type" : "illegal_argument_exception",
        "reason" : "request [/_cache/clear] contains unrecognized parameter: [recycler]"
      }
    ],
    "type" : "illegal_argument_exception",
    "reason" : "request [/_cache/clear] contains unrecognized parameter: [recycler]"
  },
  "status" : 400
}