micropython / micropython/micropython-lib

aiohttp - incorrect handling of connection pooling with web sockets.

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Python
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Description

Reading the official aiohttp documentation: https://docs.aiohttp.org/en/stable/client_reference.html

I optimized my code to have a single ClientSession within my app to take advantage of connection pooling

class My_class:
    _clientSession= aiohttp.ClientSession()

    async def my_method():
        async with self._clientSession.ws_connect(uri) as ws:
            await ws.receive_json()
            ...
            await ws.send_json(stuff)

my_method is invoked twice - to different web sockets, over TLS simultaneously.

I get randomly served with a Uncaught exception in callback: (-28928, 'MBEDTLS_ERR_SSL_BAD_INPUT_DATA').

Creating the ClientSession within my_method completely resolves the issue - but at the expense of connection pooling. I strongly suspect a racing condition tied to the pooling.

This is happening on a pico 2 w running 1.25.0

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Research direction

Start by reproducing the shared ClientSession example against two simultaneous TLS WebSocket connections on a pico 2 w running 1.25.0, then compare it with creating a session inside my_method. Done means connection pooling works for concurrent WebSocket connections without the MBEDTLS_ERR_SSL_BAD_INPUT_DATA exception.

Written by the indexing model from the issue text.

Assessment

Tech stack
python
Domain
networking
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

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