Add note in Changelog about parameter ordering changes 6.x -> 7.x

We recently upgrade to ES 7 and a script that’s worked for a long time started failing and we traced it back to the use .count() failing. Using the old elasticsearch 6.8.1 module works and we’ll use that as a workaround, but it would be nice to be able to use the ES 7 module to match our cluster

Elasticsearch version (bin/elasticsearch --version): Version: 7.9.1, Build: default/docker/083627f112ba94dffc1232e8b42b73492789ef91/2020-09-01T21:22:21.964974Z, JVM: 14.0.1

elasticsearch-py version (elasticsearch.__versionstr__): 7.9.1

Please make sure the major version matches the Elasticsearch server you are running.

Description of the problem including expected versus actual behavior:

Steps to reproduce:

1. Run .count(index) where index is the name of an index
2. Observe that an exception is raised

Traceback (most recent call last):
  File "test_es.py", line 104, in <module>
    sys.exit(main())
  File "test_es.py", line 74, in main
    total = es_conn.count(index)['count']
  File "/Users/dlj/.pyenv/versions/3.8.5/lib/python3.8/site-packages/elasticsearch/client/utils.py", line 152, in _wrapped
    return func(*args, params=params, headers=headers, **kwargs)
  File "/Users/dlj/.pyenv/versions/3.8.5/lib/python3.8/site-packages/elasticsearch/client/__init__.py", line 528, in count
    return self.transport.perform_request(
  File "/Users/dlj/.pyenv/versions/3.8.5/lib/python3.8/site-packages/elasticsearch/transport.py", line 392, in perform_request
    raise e
  File "/Users/dlj/.pyenv/versions/3.8.5/lib/python3.8/site-packages/elasticsearch/transport.py", line 358, in perform_request
    status, headers_response, data = connection.perform_request(
  File "/Users/dlj/.pyenv/versions/3.8.5/lib/python3.8/site-packages/elasticsearch/connection/http_urllib3.py", line 269, in perform_request
    self._raise_error(response.status, raw_data)
  File "/Users/dlj/.pyenv/versions/3.8.5/lib/python3.8/site-packages/elasticsearch/connection/base.py", line 300, in _raise_error
    raise HTTP_EXCEPTIONS.get(status_code, TransportError)(
elasticsearch.exceptions.RequestError: RequestError(400, 'parsing_exception', 'Failed to parse')

[daveisfera]

That’s all well and good, but having a list of breaking changes in the changelog would be very helpful and would have prevented us from running into this issue at all

[akramsystems]

I second this it would be helpful to know the changes required in updating from the 6.x -> 7.x really difficult figuring out what the breaking changes are. As i’m in the same situation as @itayB