I'm running a socketio server with a flask app using gevent. My namespace code is here:
class ConversationNamespace(BaseNamespace):
def __init__(self, *args, **kwargs):
request = kwargs.get('request', None)
if request:
self.current_app = request['current_app']
self.current_user = request['current_user']
super(ConversationNamespace, self).__init__(*args, **kwargs)
def listener(self):
r = StrictRedis(host=self.current_app.config['REDIS_HOST'])
p = r.pubsub()
p.subscribe(self.current_app.config['REDIS_CHANNEL_CONVERSATION_KEY'] + self.current_user.user_id)
conversation_keys = r.lrange(self.current_app.config['REDIS_CONVERSATION_LIST_KEY'] +
self.current_user.user_id, 0, -1)
# Reverse conversations so the newest is up top.
conversation_keys.reverse()
# Emit conversation history.
pipe = r.pipeline()
for key in conversation_keys:
pipe.hgetall(self.current_app.config['REDIS_CONVERSATION_KEY'] + key)
self.emit(self.current_app.config['SOCKETIO_CHANNEL_CONVERSATION'] + self.current_user.user_id, pipe.execute())
# Listen for new conversations..
for m in p.listen():
conversation = r.hgetall(self.current_app.config['REDIS_CONVERSATION_KEY'] + str(m['data']))
self.emit(self.current_app.config['SOCKETIO_CHANNEL_CONVERSATION'] +
self.current_user.user_id, conversation)
def on_subscribe(self):
self.spawn(self.listener)
What I'm noticing in my app is that when I first start the SocketIO server (code below), the clients are able to connect via a websocket in firefox and chrome
#!vendor/venv/bin/python
from gevent import monkey
monkey.patch_all()
from yellowtomato import app_instance
import werkzeug.serving
from socketio.server import SocketIOServer
app = app_instance('sockets')
@werkzeug.serving.run_with_reloader
def runServer():
SocketIOServer(('0.0.0.0', app.config['SOCKET_PORT']), app, resource='socket.io').serve_forever()
runServer()
After sometime (maybe an hour or so), when I try to connect to that namespace via the browser client, it no longer communicates with a websocket but rather xhr-polling. Moreover, it takes about 20 seconds before the first response comes from the server. It gives the end user the perception that things have become very slow (but its only when rendering the page on the first subscibe, the xhr polling happens frequently and events get pushed to clients in a timely fashion).
What is triggering this latency and how can I assure that clients connect quickly using websockets.
