Hi, I’m getting the following error when using GPT-4.1 via Azure OpenAI with streaming=True in an async LangGraph workflow:
This happens intermittently — most of the time it works fine, but sometimes the connection drops in the middle of a streamed response, and the body isn’t fully received.
Is anyone else experiencing this, and how are you handling or resolving it?
log
RemoteProtocolError('peer closed connection without sending complete message body (incomplete chunked read)')Traceback (most recent call last):
File "/app/.venv/lib/python3.11/site-packages/httpx/_transports/default.py", line 101, in map_httpcore_exceptions
yield
File "/app/.venv/lib/python3.11/site-packages/httpx/_transports/default.py", line 271, in __aiter__
async for part in self._httpcore_stream:
File "/app/.venv/lib/python3.11/site-packages/httpcore/_async/connection_pool.py", line 407, in __aiter__
raise exc from None
File "/app/.venv/lib/python3.11/site-packages/httpcore/_async/connection_pool.py", line 403, in __aiter__
async for part in self._stream:
File "/app/.venv/lib/python3.11/site-packages/httpcore/_async/http11.py", line 342, in __aiter__
raise exc
File "/app/.venv/lib/python3.11/site-packages/httpcore/_async/http11.py", line 334, in __aiter__
async for chunk in self._connection._receive_response_body(**kwargs):
File "/app/.venv/lib/python3.11/site-packages/httpcore/_async/http11.py", line 203, in _receive_response_body
event = await self._receive_event(timeout=timeout)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/app/.venv/lib/python3.11/site-packages/httpcore/_async/http11.py", line 213, in _receive_event
with map_exceptions({h11.RemoteProtocolError: RemoteProtocolError}):
File "/usr/local/lib/python3.11/contextlib.py", line 155, in __exit__
self.gen.throw(typ, value, traceback)
File "/app/.venv/lib/python3.11/site-packages/httpcore/_exceptions.py", line 14, in map_exceptions
raise to_exc(exc) from exc
httpcore.RemoteProtocolError: peer closed connection without sending complete message body (incomplete chunked read)
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "/app/.venv/lib/python3.11/site-packages/langgraph/pregel/__init__.py", line 2274, in astream
async for _ in runner.atick(
File "/app/.venv/lib/python3.11/site-packages/langgraph/pregel/runner.py", line 444, in atick
await arun_with_retry(
File "/app/.venv/lib/python3.11/site-packages/langgraph/pregel/retry.py", line 123, in arun_with_retry
async for _ in task.proc.astream(task.input, config):
File "/app/.venv/lib/python3.11/site-packages/langgraph/utils/runnable.py", line 706, in astream
async for chunk in aiterator:
File "/app/.venv/lib/python3.11/site-packages/langchain_core/tracers/event_stream.py", line 181, in tap_output_aiter
first = await py_anext(output, default=sentinel)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/app/.venv/lib/python3.11/site-packages/langchain_core/utils/aiter.py", line 78, in anext_impl
return await __anext__(iterator)
^^^^^^^^^^^^^^^^^^^^^^^^^
File "/app/.venv/lib/python3.11/site-packages/langchain_core/runnables/base.py", line 1461, in atransform
async for ichunk in input:
File "/app/.venv/lib/python3.11/site-packages/langchain_core/runnables/base.py", line 1461, in atransform
async for ichunk in input:
File "/app/.venv/lib/python3.11/site-packages/langchain_core/runnables/base.py", line 1461, in atransform
async for ichunk in input:
File "/app/.venv/lib/python3.11/site-packages/langchain_core/runnables/base.py", line 1024, in astream
yield await self.ainvoke(input, config, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/app/.venv/lib/python3.11/site-packages/langgraph/utils/runnable.py", line 371, in ainvoke
ret = await asyncio.create_task(coro, context=context)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/app/.venv/lib/python3.11/site-packages/ddtrace/contrib/internal/asyncio/patch.py", line 50, in traced_coro
return await coro
^^^^^^^^^^
File "/app/app/llm/node.py", line 279, in __call__
response = await async_call_llm(prompt=prompt, payload=payload, run_name=self.__class__.__name__, tools=self.tools, model_name="gpt-4.1")
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/app/app/support/datadog_metric.py", line 21, in wrapper
return await func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/app/app/llm/support/llm_util.py", line 53, in async_call_llm
return await chain.ainvoke(payload, config=config)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/app/.venv/lib/python3.11/site-packages/langchain_core/runnables/base.py", line 3075, in ainvoke
input = await coro_with_context(part(), context, create_task=True)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/app/.venv/lib/python3.11/site-packages/ddtrace/contrib/internal/asyncio/patch.py", line 50, in traced_coro
return await coro
^^^^^^^^^^
File "/app/.venv/lib/python3.11/site-packages/langchain_core/runnables/base.py", line 5429, in ainvoke
return await self.bound.ainvoke(
^^^^^^^^^^^^^^^^^^^^^^^^^
File "/app/.venv/lib/python3.11/site-packages/langchain_core/language_models/chat_models.py", line 391, in ainvoke
llm_result = await self.agenerate_prompt(
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/app/.venv/lib/python3.11/site-packages/langchain_core/language_models/chat_models.py", line 957, in agenerate_prompt
return await self.agenerate(
^^^^^^^^^^^^^^^^^^^^^
File "/app/.venv/lib/python3.11/site-packages/langchain_core/language_models/chat_models.py", line 915, in agenerate
raise exceptions[0]
File "/app/.venv/lib/python3.11/site-packages/ddtrace/contrib/internal/asyncio/patch.py", line 50, in traced_coro
return await coro
^^^^^^^^^^
File "/app/.venv/lib/python3.11/site-packages/langchain_core/language_models/chat_models.py", line 1072, in _agenerate_with_cache
async for chunk in self._astream(messages, stop=stop, **kwargs):
File "/app/.venv/lib/python3.11/site-packages/langchain_openai/chat_models/base.py", line 1110, in _astream
async for chunk in response:
File "/app/.venv/lib/python3.11/site-packages/openai/_streaming.py", line 147, in __aiter__
async for item in self._iterator:
File "/app/.venv/lib/python3.11/site-packages/openai/_streaming.py", line 202, in __stream__
async for _sse in iterator:
File "/app/.venv/lib/python3.11/site-packages/openai/_streaming.py", line 151, in _iter_events
async for sse in self._decoder.aiter_bytes(self.response.aiter_bytes()):
File "/app/.venv/lib/python3.11/site-packages/openai/_streaming.py", line 302, in aiter_bytes
async for chunk in self._aiter_chunks(iterator):
File "/app/.venv/lib/python3.11/site-packages/openai/_streaming.py", line 313, in _aiter_chunks
async for chunk in iterator:
File "/app/.venv/lib/python3.11/site-packages/httpx/_models.py", line 997, in aiter_bytes
async for raw_bytes in self.aiter_raw():
File "/app/.venv/lib/python3.11/site-packages/httpx/_models.py", line 1055, in aiter_raw
async for raw_stream_bytes in self.stream:
File "/app/.venv/lib/python3.11/site-packages/httpx/_client.py", line 176, in __aiter__
async for chunk in self._stream:
File "/app/.venv/lib/python3.11/site-packages/httpx/_transports/default.py", line 270, in __aiter__
with map_httpcore_exceptions():
File "/usr/local/lib/python3.11/contextlib.py", line 155, in __exit__
self.gen.throw(typ, value, traceback)
File "/app/.venv/lib/python3.11/site-packages/httpx/_transports/default.py", line 118, in map_httpcore_exceptions
raise mapped_exc(message) from exc
httpx.RemoteProtocolError: peer closed connection without sending complete message body (incomplete chunked read)
Library version
- python = “^3.11”
- fastapi = “^0.115.6”
- uvicorn = “^0.34.0”
- langgraph = “^0.2.62”
- langchain = “^0.3.14”
- langchain-openai = “^0.3.0”