django channles channels.exceptions.Channels Full

Question

我是django-channels和python的新手，我用django-channels和django做了一个演示，主动地将数据从后台发送到前端。consumers.py中的代码如下：

websocket_clients = []

class WebsocketConsumer(AsyncWebsocketConsumer):       
    def __init__(self, *args, **kwargs):
    """
    initial a new thread when new websocket instance initialed.
    """
    super(WebsocketConsumer, self).__init__(self)
    self.index_websocket = GendataThread()


    async def connect(self):
        self.index_websocket.channels_name = self.channel_name
        print('channel_name', self.channel_name)
        self.index_websocket.start()
        websocket_clients.append(self.channel_name)
        await self.accept()


    async def disconnect(self, close_code):
        """disconnected a websocket instance, and stop the thread."""

        self.index_websocket.stop()
        time.sleep(2)
        index = websocket_clients.index(self.channel_name)
        websocket_clients.pop(index)


    async def receive(self, text_data):
        """receive message from connected client, wouldn't work in this project."""
        text_data = '{"message": "%s"}' % (text_data)
        text_data_json = json.loads(text_data)


    async def chat_message(self, event):
    """send message to websocket."""
        print('event', event)
        await self.send(text_data=json.dumps(
        {'message': event['message']}))


def websocket_send_data(data, channel_name):
    """
    send data to front in websocket protocol,
    :param data: data which will be sent,
    :param channel_name: a symbol to mark connected client.
    :return:
    """
    channel_layer = get_channel_layer()
    event = {
        "type": "chat.message",
        "message": data
    }
    async_to_sync(channel_layer.send)(channel_name, event)

如您所见，我创建了一个函数名: websocket_send_data(data，channel_name)，我可以在GendataThread()中调用它，如下所示：

class GendataThread(threading.Thread):
    """new thread
    thread for getting data from cluster, and send to front with websocket protocol.
    """
    def __init__(self, *args, **kwargs):
        super(GendataThread, self).__init__(*args, **kwargs)
        self.channels_name = None

    def run(self):
        while true:
          websocker_send_data('1', self.channels_name)

在这种情况下，当django项目运行时，我可以从后台向前端发送数据，我连接到url。

ws://127.0.0.1:8000/ws/intime_data

在routing.py中设置如下：

websocket_urlpatterns = [
    url(r'^ws/intime_data$', consumers.WebsocketConsumer),
] 

我可以在前面接收数据，但当它运行几分钟时，事情就出错了：

aioredis.errors.ReplyError: OOM command not allowed when used memory > 'maxmemory'.

我认为是因为redis通过保存数据而被填满，但我不想要这些数据，我尝试通过以下方式配置redis.conf：

maxmemory-policy allkeys-lru 

但是当使用maxmemory时，仍然会出现错误。有时会出现这样的错误：

channels.exceptions.Channels Full

我认为channels正在使用redis作为缓存，但我不知道为什么会出现错误，有人能帮我吗？提前谢谢。

Answer 1

将此代码添加到settings.py中

CHANNEL_LAYERS = {
    "default": {
        "BACKEND": "asgi_redis.RedisChannelLayer",
        "CONFIG": {
            "hosts": [(XXX, XXX)],
        },
        "ROUTING": "XXXXXchannel_routing"
    },
 }