elasticsearch - elasticsearch: how to get only documents whose normalized scores (_score divided by max_score) are above certain threshold

Question

While querying, I am trying to get only documents whose normalized scores(_score divided by max_score) are above a certain threshold. Is there any way to do that? I tried using function score, but I am getting a SearchPhaseExecutionException.

My query using the sense plugin:

POST my_index/my_type/_search
{
    "query": {
      "min_score": 0.4,

      "function_score" : {
         "query" :{
            "query_string": { "_all": "test"}
         },
         "functions": [
         {
            "script_score": {
                "script": "return _score / max_score;"
            }
         }
       ]
     }
   }
}

Exception trace: "error": "SearchPhaseExecutionException[Failed to execute phase [query], all shards failed; shardFailures