ElasticSearch custom sort, based on provided ids array order. Original code from here: http://damienalexandre.fr/post/elasticsearch-ids-query-order Rewritten to new "function_score" syntax Note: You need to remove \n new lines from "script" field in order to get it work.

elasticsearch.custom.sort.py

q = {
  "query": {
    "function_score": {
      "boost_mode": "replace",
      "query": {
        "ids": {
          "values": [
            50,
            80,
            44,
            12
          ]
        }
      },
      "script_score": {
        "params": {
          "ids": [
              50,
              80,
              44,
              12
          ]
        },
        "script": """
          count = ids.size();
          id    = org.elasticsearch.index.mapper.Uid.idFromUid(doc['_uid'].value);
          for (i = 0; i < count; i++) {
            if (id == ids[i]) { return count - i; }
           }""",
      }
    }
  },
  "size": 20,
  "from": 0
}

{
  "query": {
    "function_score": {
      "boost_mode": "replace",
      "query": {
        "ids": {
          "values":  [50, 80, 44, 12]
        }
      },
      "functions": [
         {  
          "filter": {
            "term": { "id": 50 }
          },
          "weight" : 4
     },
     {  
          "filter": {
            "term": { "id": 80 }
          },
          "weight" : 3
     },
     {  
          "filter": {
            "term": { "id": 44 }
          },
          "weight" : 1
     },
     {  
          "filter": {
            "term": { "id": 12 }
          },
          "weight" : 0
     }
       ]
    }
  },
  "_source": ["id"],
  "size": 20,
  "from": 0
}

@vi-hipvan
I used API which you told to get the results. It worked for the small set of numbers(till 100k) but if the array size is more than 500k then function block in API will increase and my ES server is going down.

I have following queries
Do we have any other way to solve this problem?
Can we use the script in ES API to solve this problem? if yes how to do that?

Please help me to solve this problem

Thanks in advance.

I have the similar problem, where I want to boost certain set of documents providing an array of id's. Is there a solution using functional score as asked above ?

Not 1:1 example, but you adjust to IDS as well, this is how I boosted certain items on top of others, while maintaining default sort as well (for ES 5.4+):

{
   "query": {
      "function_score": {
         "query": {
           "match_all": {}
         },
         "boost_mode": "replace",
         "script_score": {
            "script": {
               "params": {
                  "important_tags": ["tag1", "tag2, "tag3"]
               },
               "source": "params.important_tags.indexOf(doc['tag'].value) > -1 ? 10 : 0"
            }
         }
      }
   },
   "sort" : [
       "_score",
        { "defaultOrderField" : "desc" }
    ]
}

According with Elasticsearch Reference [6.6]

{
   "query":{
      "function_score":{
         "boost_mode":"replace",
         "query":{
            "bool":{
               "filter":{
                  "ids":{
                     "values":[
                        50,
                        80,
                        44,
                        12
                     ]
                  }
               }
            }
         },
         "script_score":{
            "script":{
               "params":{
                  "ids":[
                     50,
                     80,
                     44,
                     12
                  ]
               },
               "source":"params.ids.length - params.ids.indexOf(doc['_id'].value)"
            }
         }
      }
   },
   "size":20,
   "from":0
}

I am achieving my result using script but I want alternate solution for this. Please help....
I have the similar problem, but I want to boost certain set of documents using functional score :

My current code

{
.
.
.
"sort": [
    {
      "_script": {
        "type": "number",
        "script": {
          "lang": "painless",
          "source": "double pscore = 0;for(id in params.boost_ids){if(params._source.midoffice_master_id == id){pscore = -999999999;}}return pscore;",
          "params": {
            "boost_ids": [
              90,
              687,
              333,
              756
            ]
          }
        }
      }
    },
    {
      "_geo_distance": {
        "location": {
          "lat": -8.4095178,
          "lon": 115.188916
        },
        "order": "asc"
      }
    }
  ]
.
.
.
.
.
}

"script_score": {
  "params": {
    "ids": [
        50,
        80,
        44,
        12
    ]
  },
  "script": """
    count = ids.size();
    id    = org.elasticsearch.index.mapper.Uid.idFromUid(doc['_uid'].value);
    for (i = 0; i < count; i++) {
      if (id == ids[i]) { return count - i; }
     }""",
}

This doesn't work in my case.

I update it to:

sort: {
  _script: {
    type: 'number',
    script: {
      lang: 'painless',
      params: {
        ids: [4,8,2,4,8,16],
      },
      source: `
        int idsCount = params.ids.size();
        def id = doc['slug.keyword'].value;
        int foundIdx = params.ids.indexOf(id);
        return foundIdx > -1 ? foundIdx: idsCount + 1;
      `
    }
  }
}

hope it helps someone