AWS Elasticsearch TransportError(413, '') - elasticsearch

Question

We are using the python elasticsearch API version "elasticsearch-6.8.0"
With AWS Elasticsearch version 6.7
It only happens sometimes, on some machines (even when we make the queries within seconds of each other from different machines, one will succeed and the other will throw the error). Thus this is difficult to reproduce. We are using a paginated search like this:
def scrolled_search_query(self, index, query, size=es_config.ES_SIZE,
scroll=es_config.ES_SCROLL,
request_timeout=es_config.ES_TIMEOUT,
docs_only=False):
data = self.es_conn.search(index=index, size=size, scroll=scroll, body=query,
request_timeout=request_timeout)
while len(data['hits']['hits']) > 0:
for hit in data['hits']['hits']:
if docs_only:
yield hit['_source']
else:
yield hit
data = self.es_conn.scroll(scroll_id=data['_scroll_id'], scroll=scroll,
request_timeout=request_timeout)
The error message is utterly useless, just basically saying that there's a 413. like this:
TransportError: TransportError(413, '')
From looking around at forums, it seems the problem is because ES is attempting to return a large payload. However, since we're using scroll pagination, I don't know why this would be an issue because each payload should be well below the 100MB limit. Since the error message is so terrible, I can't really see what it's trying to do in the database. It seems like the database is calculating the total data for the query and rejecting it without taking into account pagination. It's normal for us to request large payloads, and paginate them.
The full exception looks like this, what else do you need?
---------------------------------------------------------------------------
TransportError Traceback (most recent call last)
<ipython-input-3-a3fd964bf999> in <module>
41 blah=blah,
42 blah=blah,
---> 43 start_date=start_date)
44
45 df = df.drop(['#blah', '#blah'], axis=1)
~/Documents/Repositories/blah/blah/downloader.py in get_data(self, data_type, blah, blah, device, blah, start_date, end_date)
186 return self.gatorEs.get_blah(es_requests=self.es_requests, blah=blah, blah=blah, blah=blah,
--> 188 start_date=start_date, end_date=end_date)
189
190 if data_type == 'blah':
~/Documents/Repositories/gator_access/gator_access/es_gator_api.py in get_blah(self, es_requests, blah, blah, blah, blah, blah, start_date, end_date)
180 logger=self.logger)
181 if not data: continue
--> 182 es_data += data
183
184 self.logger.info(" ".join(["Download took {t} seconds for p:'{p}' d:'{d}'",
~/Documents/Repositories/gator_core/gator_core/elasticsearch/es_requests.py in scrolled_search_query(self, index, query, size, scroll, request_timeout, docs_only)
144
145 data = self.es_conn.scroll(scroll_id=data['_scroll_id'], scroll=scroll,
--> 146 request_timeout=request_timeout)
147
148
~/anaconda3/envs/prognostic/lib/python3.6/site-packages/elasticsearch/client/utils.py in _wrapped(*args, **kwargs)
82 if p in kwargs:
83 params[p] = kwargs.pop(p)
---> 84 return func(*args, params=params, **kwargs)
85
86 return _wrapped
~/anaconda3/envs/prognostic/lib/python3.6/site-packages/elasticsearch/client/__init__.py in scroll(self, scroll_id, body, params)
1353 """
1354 return self.transport.perform_request(
-> 1355 "GET", _make_path("_search", "scroll", scroll_id), params=params, body=body
1356 )
1357
~/anaconda3/envs/prognostic/lib/python3.6/site-packages/elasticsearch/transport.py in perform_request(self, method, url, headers, params, body)
351 headers=headers,
352 ignore=ignore,
--> 353 timeout=timeout,
354 )
355
~/anaconda3/envs/prognostic/lib/python3.6/site-packages/elasticsearch/connection/http_requests.py in perform_request(self, method, url, params, body, timeout, ignore, headers)
139 raw_data,
140 )
--> 141 self._raise_error(response.status_code, raw_data)
142
143 self.log_request_success(
~/anaconda3/envs/prognostic/lib/python3.6/site-packages/elasticsearch/connection/base.py in _raise_error(self, status_code, raw_data)
160
161 raise HTTP_EXCEPTIONS.get(status_code, TransportError)(
--> 162 status_code, error_message, additional_info
163 )
TransportError: TransportError(413, '')