I'm not sure why that would happen - the code that chooses what application instance to use is here: https://github.com/django/asgiref/blob/master/asgiref/server.py (under get_or_create_application_instance).
If you're always using a single channel name, which gets passed as scope_id (see here: https://github.com/django/channels/blob/master/channels/worker.py), it really should be returning the same instance. I recommend you poke around in there and do some debugging to figure out what's going on. Andrew On Fri, Jun 22, 2018 at 9:46 AM itsnate_b <nathan.blu...@gmail.com> wrote: > I am only using one channel name and my expectation is that only one > instance of the background worker class should be initiated/used. Instead, > I am seeing a new class being initiated for each call routed to the > background worker class. This is unexpected... > > > On Thursday, June 21, 2018 at 3:55:23 PM UTC-4, Andrew Godwin wrote: >> >> The worker server tries to keep one application instance open per >> incoming channel name, but that's no guarantee. It will always make a new >> instance for different channel names. What kind of behaviour are you >> expecting? >> >> Andrew >> >> On Tue, Jun 19, 2018 at 6:45 AM itsnate_b <nathan...@gmail.com> wrote: >> >>> I am using Django 2.0.5, Python 3.6.2, Django Channels 2.1.1, aiohttp >>> 3.1.3. >>> >>> I have created a background worker class which is initialized on a route >>> to the appropriate event/function. Problem is that it initializes a *new* >>> instance of the class on every triggered call, meaning that I cannot access >>> contextual variables (they don't persist). Is there a way to trigger the >>> same (i.e. first) and only class repeatedly on each routed call? I can >>> change it all to function calls with global variables stored for the >>> relevant asyncio futures and/or booleans, but would really prefer not to do >>> that....any suggestions? >>> >>> My (simplified) code: >>> >>> *consumers.py* >>> >>> from channels.generic.websocket import AsyncWebsocketConsumer >>> from channels.consumer import AsyncConsumer >>> from channels.layers import get_channel_layer >>> import json >>> import asyncio >>> import aiohttp >>> import datetime >>> >>> >>> class mainConsumer(AsyncWebsocketConsumer): >>> >>> async def connect(self): >>> await self.channel_layer.group_add('myGroup', self.channel_name) >>> await self.accept() >>> >>> async def disconnect(self, closeCode): >>> await self.channel_layer.group_discard('myGroup', >>> self.channel_name) >>> >>> async def receive(self, text_data): >>> eventData = json.loads(text_data) >>> print(eventData) >>> if eventData['toggle'] == 'on': >>> await self.channel_layer.send('myToggle',{"type": >>> "openConnection"}) >>> elif eventData['toggle'] == 'off': >>> await self.channel_layer.send('myToggle',{"type": >>> "closeConnection"}) >>> >>> async def myUpdate(self, data): >>> updateMsg = #some data processing here >>> await self.send(text_data=json.dumps(updateMsg)) >>> >>> >>> class backgroundConsumer(AsyncConsumer): >>> >>> def __init__(self, scope): >>> self.scope = scope >>> self.turnOnListener = True >>> self.channelLayer = get_channel_layer() >>> self.t1 = None >>> print('inside init') # this will print init on every >>> channel_layer.send to 'myToggle' in mainConsumer >>> >>> async def listen(self): >>> >>> async with aiohttp.ClientSession() as session: >>> async with session.ws_connect('...streaming url...', >>> ssl=False) as ws: >>> await ws.send_str('...some string...') >>> async for msg in ws: >>> if msg.type == aiohttp.WSMsgType.TEXT: >>> if msg.data.startswith('2'): >>> await ws.send_str('3') >>> else: >>> await self.parseListenData(msg) >>> >>> async def parseListenData(self, msgContent): >>> # process and create updateMsg dict with type: 'myUpdate' (so >>> that it gets to the myUpdate function in main Consumer) >>> await self.channelLayer.group_send('myGroup', updateMsg) >>> >>> async def openConnection(self, event): >>> if(self.turnOnListener): *# THIS IS ALWAYS TRUE BECAUSE THE >>> ROUTE INITIALIZES A NEW INSTANCE OF THIS CLASS!!* >>> await self.channelLayer.group_add( >>> 'myGroup', >>> self.channel_name, >>> ) >>> self.turnOnListener = False # This only changes it for the >>> current instance (obviously) >>> loop = asyncio.get_event_loop() >>> self.t1 = asyncio.run_coroutine_threadsafe(self.listen(), >>> loop=loop) >>> else: >>> print('already turned on listener') >>> >>> async def closeConnection(self, event): >>> loop = asyncio.get_event_loop() >>> loop.call_soon_threadsafe(self.t1.cancel) *# t1 is always None >>> because the route initialized a new instance of this class!!* >>> >>> *routing.py* >>> from channels.auth import AuthMiddlewareStack >>> from channels.routing import ProtocolTypeRouter, URLRouter, >>> ChannelNameRouter >>> import dashboard.routing >>> from dashboard.consumers import backgroundConsumer >>> >>> application = ProtocolTypeRouter({ >>> # (http->django views is added by default) >>> 'websocket': AuthMiddlewareStack( >>> URLRouter( >>> dashboard.routing.websocket_urlpatterns >>> ) >>> ), >>> 'channel': ChannelNameRouter({ >>> "myToggle": backgroundConsumer, >>> }), >>> }) >>> >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Django users" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to django-users...@googlegroups.com. >>> To post to this group, send email to django...@googlegroups.com. >>> Visit this group at https://groups.google.com/group/django-users. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/django-users/431ada54-74cb-4822-9b33-5dcb0326fb9c%40googlegroups.com >>> <https://groups.google.com/d/msgid/django-users/431ada54-74cb-4822-9b33-5dcb0326fb9c%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> For more options, visit https://groups.google.com/d/optout. >>> >> -- > You received this message because you are subscribed to the Google Groups > "Django users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to django-users+unsubscr...@googlegroups.com. > To post to this group, send email to django-users@googlegroups.com. > Visit this group at https://groups.google.com/group/django-users. > To view this discussion on the web visit > https://groups.google.com/d/msgid/django-users/541378d0-6e7d-43ea-9b08-016aefd38702%40googlegroups.com > <https://groups.google.com/d/msgid/django-users/541378d0-6e7d-43ea-9b08-016aefd38702%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Django users" group. 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