Exception in ASGI application with uvicorn

[ghost]

Problem when we use channels v3, after some time in production, connection to establish websockets start to work more and more slowly, sometimes it take 1-3 seconds to accept websockets connection and with more time on prod time increases to 170 sec and more, and at the end nginx kill connections (in our setup it`s 300 sec) and you see 502 timeouts.

when we use --limit-max-requests=1000 and --proxy-headers we see errors [Exception in ASGI application],
but after we remove --limit-max-requests=1000 and --proxy-headers all works as expected (only in channels v3 in v4 nothing is working).

Django==4.0.6
daphne==3.0.2
asgiref==3.5.2
channels==3.0.5
channels-redis==3.3.0
websockets==10.4
uvicorn==0.19.0
uvloop==0.17.0
=========================
| ERROR:    Exception in ASGI application
| Traceback (most recent call last):
|   File "/usr/local/lib/python3.10/site-packages/uvicorn/protocols/websockets/websockets_impl.py", line 230, in run_asgi
|     result = await self.app(self.scope, self.asgi_receive, self.asgi_send)
|   File "/usr/local/lib/python3.10/site-packages/uvicorn/middleware/proxy_headers.py", line 78, in __call__
|     return await self.app(scope, receive, send)
|   File "/usr/local/lib/python3.10/site-packages/channels/routing.py", line 71, in __call__
|     return await application(scope, receive, send)
|   File "/usr/local/lib/python3.10/site-packages/channels/routing.py", line 150, in __call__
|     return await application(
|   File "/usr/local/lib/python3.10/site-packages/channels/consumer.py", line 94, in app
|     return await consumer(scope, receive, send)
|   File "/usr/local/lib/python3.10/site-packages/channels/consumer.py", line 58, in __call__
|     await await_many_dispatch(
|   File "/usr/local/lib/python3.10/site-packages/channels/utils.py", line 58, in await_many_dispatch
|     await task
| TypeError: An asyncio.Future, a coroutine or an awaitable is required

=========================
## uvicorn
uvicorn --host=0.0.0.0 --port=8002 --workers=4 --loop=uvloop --ws=websockets --limit-max-requests=1000 --proxy-headers --log-level=debug core.asgi:application

# simple test class that produce this error

```python
class TestWebSocket(AsyncJsonWebsocketConsumer):
    async def connect(self):
        try:
            await self.create_channel()
            await self.accept()
       except Exception as exc:
            logger.exception(exc)
            await self.close()

    @database_sync_to_async
    def create_channel(self):
         # some logic with database.
        return

Django==4.1.3
daphne==4.0.0
asgiref==3.5.2
channels==4.0.0
channels-redis==4.0.0
websockets==10.4
uvicorn==0.20.0
uvloop==0.17.0
=========================
| ERROR:    Exception in ASGI application
| Traceback (most recent call last):
|   File "/usr/local/lib/python3.10/site-packages/uvicorn/protocols/websockets/websockets_impl.py", line 230, in run_asgi
|     result = await self.app(self.scope, self.asgi_receive, self.asgi_send)
|   File "/usr/local/lib/python3.10/site-packages/uvicorn/middleware/proxy_headers.py", line 78, in __call__
|     return await self.app(scope, receive, send)
|   File "/usr/local/lib/python3.10/site-packages/channels/routing.py", line 71, in __call__
|     return await application(scope, receive, send)
|   File "/usr/local/lib/python3.10/site-packages/channels/routing.py", line 150, in __call__
|     return await application(
|   File "/usr/local/lib/python3.10/site-packages/channels/consumer.py", line 94, in app
|     return await consumer(scope, receive, send)
|   File "/usr/local/lib/python3.10/site-packages/channels/consumer.py", line 58, in __call__
|     await await_many_dispatch(
|   File "/usr/local/lib/python3.10/site-packages/channels/utils.py", line 58, in await_many_dispatch
|     await task
| AttributeError: 'list' object has no attribute 'decode'
=========================
uvicorn --host=0.0.0.0 --port=8002 --workers=4 --loop=uvloop --ws=websockets --limit-max-requests=1000 --proxy-headers --log-level=debug core.asgi:application

[ghost]

Problem was in CHANNEL_LAYERS config, for some reason old version 3 works with list setup example: "hosts": [["127.0.0.1", 6379]],
and migrating to v4 start raise "AttributeError: 'list' object has no attribute 'decode'".

it is very difficult to find and identify such a small mistake.

[carltongibson]

Duplicate of django/channels_redis#334