`AIOKafkaProducer` appears to hang forever if Kafka is down for `send_and_wait` and `stop()`

[MrCreosote]

Describe the bug If the Kafka server is down, send()ing a message and awaiting the results has two effects:

1. A log is sent every retry_backoff_ms
   • This is pretty spammy at the default 100ms
2. The await hangs apparently forever

If the result is asyncio.wait_for()'d with a timeout so that the thread can eventually continue, and then stop() is called on the producer:

• The logs continue to be sent
• The stop() hangs apparently forever

Expected behaviour I would expect that both awaiting the result of a send() call (or awaiting a send_and_wait() call) and a stop() call eventually time out.

Environment (please complete the following information):

• aiokafka version: 0.12.0
• Kafka Broker version: Tested with 3.9.0 and 4.0.0
• Other information: n/a

Reproducible example

"""
Test what happens when kafka is down and the notifier sends a message.
"""

import asyncio
from aiokafka import AIOKafkaProducer
import traceback


async def main():
    ###
    # Kafka is running here
    ###
    kp = AIOKafkaProducer(
        bootstrap_servers=f"localhost:9092",
        enable_idempotence=True,
        acks='all',
        request_timeout_ms=5000,
        retry_backoff_ms=1000
    )
    await kp.start()
    print("sending 1st message")
    future = await kp.send("mytopic", b"foo1")
    print("done")
    await future

    ###
    # Kafka is stopped here
    ###
    print("sending 2nd message")
    future = await kp.send("mytopic", b"foo2")
    print("done")
    try:
        await asyncio.wait_for(future, 6)
    except TimeoutError as e:
        traceback.print_exception(e)
    print("stopping client")
    await kp.stop()
    print('done"')


if __name__ == "__main__":
    asyncio.run(main())

The above results in the output:

sending 1st message
Topic mytopic not found in cluster metadata
done
sending 2nd message
done
Unable connect to node with id 1: [Errno 111] Connect call failed ('127.0.0.1', 54301)
Got error produce response: NodeNotReadyError: Attempt to send a request to node which is not ready (node id 1).
Unable connect to node with id 1: [Errno 111] Connect call failed ('127.0.0.1', 54301)
Unable to update metadata from [1]
Unable connect to node with id 1: [Errno 111] Connect call failed ('127.0.0.1', 54301)
Got error produce response: NodeNotReadyError: Attempt to send a request to node which is not ready (node id 1).
Unable connect to node with id 1: [Errno 111] Connect call failed ('127.0.0.1', 54301)
Unable to update metadata from [1]
Unable connect to node with id 1: [Errno 111] Connect call failed ('127.0.0.1', 54301)
Got error produce response: NodeNotReadyError: Attempt to send a request to node which is not ready (node id 1).
Unable connect to node with id 1: [Errno 111] Connect call failed ('127.0.0.1', 54301)
Unable to update metadata from [1]
Unable connect to node with id 1: [Errno 111] Connect call failed ('127.0.0.1', 54301)
Got error produce response: NodeNotReadyError: Attempt to send a request to node which is not ready (node id 1).
Unable connect to node with id 1: [Errno 111] Connect call failed ('127.0.0.1', 54301)
Unable to update metadata from [1]
Unable connect to node with id 1: [Errno 111] Connect call failed ('127.0.0.1', 54301)
Got error produce response: NodeNotReadyError: Attempt to send a request to node which is not ready (node id 1).
Unable connect to node with id 1: [Errno 111] Connect call failed ('127.0.0.1', 54301)
Unable to update metadata from [1]
Unable connect to node with id 1: [Errno 111] Connect call failed ('127.0.0.1', 54301)
Got error produce response: NodeNotReadyError: Attempt to send a request to node which is not ready (node id 1).
Unable connect to node with id 1: [Errno 111] Connect call failed ('127.0.0.1', 54301)
Unable to update metadata from [1]
Traceback (most recent call last):
  File "/usr/lib/python3.11/asyncio/tasks.py", line 490, in wait_for
    return fut.result()
           ^^^^^^^^^^^^
asyncio.exceptions.CancelledError

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

Traceback (most recent call last):
  File "/home/<user>/test_manual/aiokafka_test.py", line 36, in main
    await asyncio.wait_for(future, 6)
  File "/usr/lib/python3.11/asyncio/tasks.py", line 492, in wait_for
    raise exceptions.TimeoutError() from exc
TimeoutError
stopping client
Unable connect to node with id 1: [Errno 111] Connect call failed ('127.0.0.1', 54301)
Got error produce response: NodeNotReadyError: Attempt to send a request to node which is not ready (node id 1).
Unable connect to node with id 1: [Errno 111] Connect call failed ('127.0.0.1', 54301)
Unable to update metadata from [1]
Unable connect to node with id 1: [Errno 111] Connect call failed ('127.0.0.1', 54301)
Got error produce response: NodeNotReadyError: Attempt to send a request to node which is not ready (node id 1).
Unable connect to node with id 1: [Errno 111] Connect call failed ('127.0.0.1', 54301)

*** continues seemingly forever ***

[jainal09]

+1 on this. Any way to stop or exit after not connecting certain amount of time

[shuckc]

I would agree this is a sensible suggestion - calling .stop() should cause exceptions to be raised on all outstanding futures and the stop call itself should return once the connection attempts are finished.