1.4.0 Children aggregation returns empty buckets

[marekmalek]

I have been trying to test this feature with guide data as follow:

PUT /company
{
  "mappings": {
    "branch": {},
    "employee": {
      "_parent": {
        "type": "branch" 
      }
    }
  }
}

POST /company/branch/_bulk
{ "index": { "_id": "london" }}
{ "name": "London Westminster", "city": "London", "country": "UK" }
{ "index": { "_id": "liverpool" }}
{ "name": "Liverpool Central", "city": "Liverpool", "country": "UK" }
{ "index": { "_id": "paris" }}
{ "name": "Champs Élysées", "city": "Paris", "country": "France" }

POST /company/employee/_bulk
{ "index": { "_id": 2, "parent": "london" }}
{ "name": "Mark Thomas", "dob": "1982-05-16", "hobby": "diving" }
{ "index": { "_id": 3, "parent": "liverpool" }}
{ "name": "Barry Smith", "dob": "1979-04-01", "hobby": "hiking" }
{ "index": { "_id": 4, "parent": "paris" }}
{ "name": "Adrien Grand", "dob": "1987-05-11", "hobby": "horses" }

and execute the same query as here:
http://www.elasticsearch.org/guide/en/elasticsearch/guide/current/children-agg.html

GET /company/branch/_search?search_type=count
{
  "aggs": {
    "country": {
      "terms": { 
        "field": "country"
      },
      "aggs": {
        "employees": {
          "children": { 
            "type": "employee"
          },
          "aggs": {
            "hobby": {
              "terms": { 
                "field": "hobby"
              }
            }
          }
        }
      }
    }
  }
}

A response is:

{
   "took": 87,
   "timed_out": false,
   "_shards": {
      "total": 5,
      "successful": 5,
      "failed": 0
   },
   "hits": {
      "total": 3,
      "max_score": 0,
      "hits": []
   },
   "aggregations": {
      "country": {
         "doc_count_error_upper_bound": 0,
         "sum_other_doc_count": 0,
         "buckets": [
            {
               "key": "uk",
               "doc_count": 2,
               "employees": {
                  "doc_count": 2,
                  "hobby": {
                     "doc_count_error_upper_bound": 0,
                     "sum_other_doc_count": 0,
                     "buckets": []
                  }
               }
            },
            {
               "key": "france",
               "doc_count": 1,
               "employees": {
                  "doc_count": 1,
                  "hobby": {
                     "doc_count_error_upper_bound": 0,
                     "sum_other_doc_count": 0,
                     "buckets": []
                  }
               }
            }
         ]
      }
   }
}

As you can see countries are grouped correctly but buckets for hobbies are empty.

[clintongormley]

Hi @marekmalek

This is a bug in field resolution: the branch in the URL sets the default type, so with hobby, it looks only for branch.hobby. If you change that to employee.hobby then it works correctly.

This bug will be fixed by #4081

I've updated the example in the guide to use employee.hobby. Thanks for reporting.