我在heroku上运行一个服务器，在那里异步用户示例之间有间歇性的通道层通信。在本地运行heroku，我对redis通道连接没有问题，因为我可以拥有任意数量的redis通道，但是一旦我将服务器上传到heroku，它就给了我20个redis连接的限制。如果我使用了超过这个数，我的服务器就会出错，所以我会尽量降低到期时间，这样非活动的redis连接就会关闭。但是，如果redis连接过期，并且我尝试将通道名称与self.channel\u layer.send（）一起使用，我将得到下面的错误，如何从该错误中恢复，而不必通过外部调用来创建另一个asyncconsumer示例？

ERROR    Exception inside application: Reader at end of file
File "/app/.heroku/python/lib/python3.6/site-packages/channels/consumer.py", line 59, in __call__
[receive, self.channel_receive], self.dispatch
File "/app/.heroku/python/lib/python3.6/site-packages/channels/utils.py", line 51, in await_many_dispatch
await dispatch(result)
File "/app/.heroku/python/lib/python3.6/site-packages/channels/consumer.py", line 73, in dispatch
await handler(message)
File "./myapp/webhook.py", line 133, in http_request
await self.channel_layer.send(userDB.backEndChannelName,{"type": "device.query"})
File "/app/.heroku/python/lib/python3.6/site-packages/channels_redis/core.py", line 296, in send
if await connection.llen(channel_key) >= self.get_capacity(channel):
File "/app/.heroku/python/lib/python3.6/site-packages/aioredis/commands/list.py", line 70, in llen
return self.execute(b'LLEN', key)
File "/app/.heroku/python/lib/python3.6/site-packages/aioredis/commands/__init__.py", line 51, in execute
return self._pool_or_conn.execute(command, *args,**kwargs)
File "/app/.heroku/python/lib/python3.6/site-packages/aioredis/connection.py", line 322, in execute
raise ConnectionClosedError(msg)
Reader at end of file