Elasticsearch aggregation order by top hit score

Question

I want to order buckets by doc.score of top_hit. My current implementation is below.

  group_by_iid: {
    terms: {
      field: 'iid',
      order: { max_score: 'desc' },
      size: 0
    },
    aggs: {
      max_score: { max: { script: 'doc.score' } },
      top_hit: {
        top_hits: {
          sort: [{ source_priority: { order: 'desc' } }],
          size: 1
        }
      }
    }
  }

This is wrong because buckets are ordered by their top score, not their top source_priority document's score. Is there a way to solve this problem?

Solution

I had the same issue, and the way I resolved it was to introduce a sub-aggregation on the docs score. Then in my outer aggregation, I ordered by name of the max_score aggregation.

GET /my-index/my-type/_search
{
  "query": {
      "bool" : {
        "should" : [ {
          "match" : {
            "searchTerm" : {
              "query" : "style",
              "type" : "boolean"
            }
          }
        }, 
        {
          "flt_field" : {
            "searchTerm" : {
              "like_text" : "style"
            }
          }
        }]
      }
    },
    "aggs": {
        "group_by_target_url": {
          "terms": {
            "field": "targetUrl",
            "order": {
              "max_score": "desc"
            }
          },
          "aggs": {
            "max_score": {
              "max": {
                "script": "doc.score"
              }
            }
          }
    }
  }    
}

I followed the directions on this link:

http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-aggregations-bucket-terms-aggregation.html

Comments

[Shadocko]

If your documents happen to have a "score" field and you want a metrics aggregation like "max" to work with the score computed by elasticsearch rather than the document-defined one, the script in the aggregation should be "_score", not "doc.score".

[Darby]

@Shadocko yes! that's pretty misleading. Thanks for the comment. I'm trying out the same example and now it works.

[KingWu]

Do you know how to solve it with partitions? My question is here stackoverflow.com/questions/46484351/…

[rhitz]

@Roy, if you can update your answer to replace doc.score to _score. It will save few minutes for people who are not reading the comments. +1