Switch from get_client to get_sync_client : ConnectError('[Errno 111] Connection refused')

[arthberman]

Spend few hours to try to understand why the connection was refused from one of my graph to the LangGraph SDK deployment
The difference that I have from the template is that I try to use the get_sync_client from langgraph_sdk (and not get_client) to run in sync graph

On the template, it works with get_client but not get_sync_client

from langgraph_sdk import get_sync_client

memory_client = get_sync_client(url="http://localhost:52347")
memory_client.assistants.search()

but not in my node, even with the URL specified

Got the issue : ConnectError('[Errno 111] Connection refused')

How should I investigate this ?

ConnectError('[Errno 111] Connection refused')Traceback (most recent call last):


  File "/usr/local/lib/python3.12/site-packages/httpx/_transports/default.py", line 72, in map_httpcore_exceptions
    yield


  File "/usr/local/lib/python3.12/site-packages/httpx/_transports/default.py", line 236, in handle_request
    resp = self._pool.handle_request(req)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


  File "/usr/local/lib/python3.12/site-packages/httpcore/_sync/connection_pool.py", line 216, in handle_request
    raise exc from None


  File "/usr/local/lib/python3.12/site-packages/httpcore/_sync/connection_pool.py", line 196, in handle_request
    response = connection.handle_request(
               ^^^^^^^^^^^^^^^^^^^^^^^^^^


  File "/usr/local/lib/python3.12/site-packages/httpcore/_sync/connection.py", line 99, in handle_request
    raise exc


  File "/usr/local/lib/python3.12/site-packages/httpcore/_sync/connection.py", line 76, in handle_request
    stream = self._connect(request)
             ^^^^^^^^^^^^^^^^^^^^^^


  File "/usr/local/lib/python3.12/site-packages/httpcore/_sync/connection.py", line 122, in _connect
    stream = self._network_backend.connect_tcp(**kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


  File "/usr/local/lib/python3.12/site-packages/httpcore/_backends/sync.py", line 205, in connect_tcp
    with map_exceptions(exc_map):
         ^^^^^^^^^^^^^^^^^^^^^^^


  File "/usr/local/lib/python3.12/contextlib.py", line 158, in __exit__
    self.gen.throw(value)


  File "/usr/local/lib/python3.12/site-packages/httpcore/_exceptions.py", line 14, in map_exceptions
    raise to_exc(exc) from exc


httpcore.ConnectError: [Errno 111] Connection refused



The above exception was the direct cause of the following exception:



Traceback (most recent call last):


  File "/usr/local/lib/python3.12/site-packages/langgraph/utils/runnable.py", line 576, in astream
    async for chunk in aiterator:


  File "/usr/local/lib/python3.12/site-packages/langchain_core/runnables/base.py", line 1455, in atransform
    async for ichunk in input:


  File "/usr/local/lib/python3.12/site-packages/langchain_core/runnables/base.py", line 1455, in atransform
    async for ichunk in input:


  File "/usr/local/lib/python3.12/site-packages/langchain_core/runnables/base.py", line 1018, in astream
    yield await self.ainvoke(input, config, **kwargs)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


  File "/usr/local/lib/python3.12/site-packages/langgraph/utils/runnable.py", line 236, in ainvoke
    ret = await asyncio.create_task(coro, context=context)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


  File "/usr/local/lib/python3.12/site-packages/langchain_core/runnables/config.py", line 588, in run_in_executor
    return await asyncio.get_running_loop().run_in_executor(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


  File "/usr/local/lib/python3.12/concurrent/futures/thread.py", line 58, in run
    result = self.fn(*self.args, **self.kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


  File "/usr/local/lib/python3.12/site-packages/langchain_core/runnables/config.py", line 579, in wrapper
    return func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^


  File "/.....py", line 79, in node_exp
    print(memory_client.assistants.search())
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


  File "/usr/local/lib/python3.12/site-packages/langgraph_sdk/client.py", line 2791, in search
    return self.http.post(
           ^^^^^^^^^^^^^^^


  File "/usr/local/lib/python3.12/site-packages/langgraph_sdk/client.py", line 2327, in post
    r = self.client.post(path, headers=headers, content=content)
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


  File "/usr/local/lib/python3.12/site-packages/httpx/_client.py", line 1157, in post
    return self.request(
           ^^^^^^^^^^^^^


  File "/usr/local/lib/python3.12/site-packages/httpx/_client.py", line 837, in request
    return self.send(request, auth=auth, follow_redirects=follow_redirects)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


  File "/usr/local/lib/python3.12/site-packages/httpx/_client.py", line 926, in send
    response = self._send_handling_auth(
               ^^^^^^^^^^^^^^^^^^^^^^^^^


  File "/usr/local/lib/python3.12/site-packages/httpx/_client.py", line 954, in _send_handling_auth
    response = self._send_handling_redirects(
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


  File "/usr/local/lib/python3.12/site-packages/httpx/_client.py", line 991, in _send_handling_redirects
    response = self._send_single_request(request)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


  File "/usr/local/lib/python3.12/site-packages/httpx/_client.py", line 1027, in _send_single_request
    response = transport.handle_request(request)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


  File "/usr/local/lib/python3.12/site-packages/httpx/_transports/default.py", line 235, in handle_request
    with map_httpcore_exceptions():
         ^^^^^^^^^^^^^^^^^^^^^^^^^


  File "/usr/local/lib/python3.12/contextlib.py", line 158, in __exit__
    self.gen.throw(value)


  File "/usr/local/lib/python3.12/site-packages/httpx/_transports/default.py", line 89, in map_httpcore_exceptions
    raise mapped_exc(message) from exc


httpx.ConnectError: [Errno 111] Connection refused

Any ideas on that @rlancemartin ? Many thks!

[arthberman]

After investigation, it seems that using the LangGraph SDK from a graph to interact with the deployment works only in an async graph with the get_client method