ElasticSearch not sorting results

Question

I'm trying to sort the results based on a numeric field,

Here is my mapping:

{
  "elasticie": {
    "mappings": {
      "properties": {
        "name": {
          "type": "text",
          "fields": {
            "keyword": {
              "type": "keyword",
              "ignore_above": 256
            }
          }
        },
        "number": {
          "type": "long"
        }
      }
    }
  }
}

I'm using Python, and this is my testing data:

data = [
    {'name': 'sElwUYiLXGHaQCKbdxtnvVzqIehfFWkJcPSTurgNoRD', 'number': 8583},
    {'name': 'XJEtNsIFfcwHTMhqAvRkiygjbUGzZQPdS', 'number': 8127},
    {'name': 'ZIeAGosUKJbjOdylM', 'number': 5862},
    {'name': 'HYvcafoXkC', 'number': 7458},
    {'name': 'tATJCjNuizOlGckXBpyVqSQL', 'number': 530},
    {'name': 'TFYixotjhXzNZPvHnkraRDpAMEImJfqdcVGLC', 'number': 7052},
    {'name': 'JCEGfoKDHRrcIkPQSqiVgNshZOBaMdXjAlxwUzmeWLy', 'number': 6168},
    {'name': 'IpCTwUAQynSizJtcsuDmbX', 'number': 6492},
    {'name': 'fTrcoXSBJNFhAkzWpDMxsEiLmZRvgnC', 'number': 382},
    {'name': 'ulVNmqKTpPXfEIdiykhDjMrUGOYazLBFvgnWwsRtJoQbxSe', 'number': 2061}
]

Using following code, I'm creating the index and inserting the data:

from elasticsearch import Elasticsearch
from data import data  # the data I've shown above

INDEX = 'elasticie'
es = Elasticsearch('http://127.0.0.1:9200')

for _ in data:
    es.index(index=INDEX, body=_)

I'm trying to sort data based on number, asc or desc Here is what I tried so far:

es.search(index=INDEX, params={'sort': {'number': {'order': 'asc'}})
es.search(index=INDEX, params={'sort': {'number': 'asc'})
es.search(index=INDEX, params={'sort': [('number', 'asc')]})
es.search(index=INDEX, params={'sort': {'number': {'order': 'asc', 'ignore_unmapped': True}})
es.search(index=INDEX, params={'sort': {'number': {'order': 'asc', 'unmapped_type': 'integer'}})
es.search(index=INDEX, params={'sort': {'number': {'order': 'asc', 'unmapped_type': 'long'}})
es.search(index=INDEX, params={'sort': {'number.raw': 'asc'})

Not of the above methods worked for me, The result is the same as the inserted data, If I assign the above lines to a variable named search_result and print the result using the following code:

for index, result in enumerate(search_result['hits']['hits']):
    print(f'{index}. {result["_source"]["number"]}')

I'll get the following result:

0. 8583
1. 8127
2. 5862
3. 7458
4. 530
5. 7052
6. 6168
7. 6492
8. 382
9. 2061

Which is obviously not sorted using number field!!

I don't know what I'm doing wrong, I'm using ElasticSearch 7.6 and Python 3.8

How can I make the sorting results work?

Update

Based on debugging logs, Python is sending a GET request to the following URL using the first method: http://127.0.0.1:9200/elasticie/_search?sort={%27number%27%3A+{%27order%27%3A+%27asc%27}}

Answer 1

I am not familiar with python, but here is the Elasticsearch JSON query which would sort your documents according to the numbers in desc order. I've tried with your data set and it gives proper results.

Sort Search query

{
    "sort": [
        {
            "number": {
                "order": "desc"
            }
        }
    ]
}

Results

"hits": [
         {
            "_index": "so-60598395-sort",
            "_type": "_doc",
            "_id": "1",
            "_score": null,
            "_source": {
               "name": "sElwUYiLXGHaQCKbdxtnvVzqIehfFWkJcPSTurgNoRD",
               "number": 8583
            },
            "sort": [
               8583
            ]
         },
         {
            "_index": "so-60598395-sort",
            "_type": "_doc",
            "_id": "2",
            "_score": null,
            "_source": {
               "name": "XJEtNsIFfcwHTMhqAvRkiygjbUGzZQPdS",
               "number": 8127
            },
            "sort": [
               8127
            ]
         },
         {
            "_index": "so-60598395-sort",
            "_type": "_doc",
            "_id": "4",
            "_score": null,
            "_source": {
               "name": "HYvcafoXkC",
               "number": 7862
            },
            "sort": [
               7862
            ]
         },
         {
            "_index": "so-60598395-sort",
            "_type": "_doc",
            "_id": "3",
            "_score": null,
            "_source": {
               "name": "ZIeAGosUKJbjOdylM",
               "number": 5862
            },
            "sort": [
               5862
            ]
         }

EDIT:- Based on the OP comments, python library which he is using supports the POST method of search endpoint, using which he solved the issue. Refer to the comments on the question for more details.

Answer 2

My mistake, I read the documentation and the code functionality using help and dir functions

There is no parameter named sort defined on the Elasticsearch.search method, That's why I thought I should use it as a key within the params dict that it takes,

Thanks to @OpsterElasticSearchNinja and his comment, I realized there is something wrong with either the library or how I'm using it

Sending POST request with sort key as post body worked well, So I decided to read the whole source code and find out what's going wrong?

@query_params(
    #...
    "size",
    "sort",
    #...
)
def search(self, body=None, index=None, doc_type=None, params=None):
    # ...

This is how the sort parameter is defined, using a decorator on runtime!!

That's when I tried this code, and somehow it worked!

es.search(index=INDEX, sort=['number:asc'])