Thank you very much for clarifying - I wasn't exactly sure how to approach this, but your response makes sense.
Cheers! On Saturday, May 13, 2017 at 6:09:14 PM UTC-7, Andrew Godwin wrote: > > Hi Tristan, > > All messages sent from a consumer are delayed for sending until the > consumer exits to keep things atomic - long-running consumers is bad for > performance, as they'll hog an entire thread (they run synchronously) and > so you'll quickly run out of threads/processes as you'll end up using one > per connection. > > Instead, you should do your task and exit out of the consumer as quickly > as possible to free the worker space for something else to run. To achieve > repeated execution with delays, you can either look at the delay server ( > http://channels.readthedocs.io/en/stable/delay.html) or write your own > consumer code that talks to channels that uses an asynchronous framework > (asyncio, twisted) > > Andrew > > On Sat, May 13, 2017 at 11:29 AM, Tristan Barry <[email protected] > <javascript:>> wrote: > >> Hi - I'm working with Django Channels (1.1.3) on a Django project and I >> have some questions about how to send multiple messages from the same >> consumer. >> >> The idea is the consumer will receive a request to do some work, and will >> send incremental results back to user. I've attached a simplified example >> below with some questions. I'm hoping someone can steer me in the right >> direction. >> >> >> Django Channels: >> >>> >>> def do_some_work(message): >>> for i in range(3): >>> time.sleep(2) >>> message.reply_channel.send({"text": 'Finished work ' + str(i)}) >>> >>> def ws_connect(message): >>> message.reply_channel.send({"accept": True}) >>> >>> channel_routing = [ >>> route('websocket.connect', ws_connect), >>> route('websocket.receive', do_some_work, path=r'/todo') >>> ] >> >> >> Javascript (borrowed mostly from the docs): >> >> socket = new WebSocket("ws://" + window.location.host + "/todo/"); >>> socket.onmessage = function(e) { >>> console.log(e.data); >>> } >>> socket.onopen = function() { >>> socket.send("hello world"); >>> } >>> // Call onopen directly if socket is already open >>> if (socket.readyState == WebSocket.OPEN) socket.onopen(); >> >> >> >> Expected results: Every two seconds the browser would receive a reply >> from the consumer saying 'Finished work x'. >> >> What I observe is a delay for ~6 seconds and then all results returned at >> the same time. Are the response on the reply channel blocked somehow? Is >> there I way I can yield, or release the message before doing the next >> increment of work? >> >> I've also tried setting up a new consumer that *only* replies via a >> Group. So instead of *message.reply_channel.send, *I would >> *Channel('reply-channel').send({results: >> ...})* and have a new consumer defined on channel_routing for the >> *'reply-channel'*. But the results are the same - all the 'work' is >> completed before the browser receives a response. >> >> Any hints on how to send multiple message in the same consumer? >> >> Thanks in advance. >> >> -- >> 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 [email protected] <javascript:>. >> To post to this group, send email to [email protected] >> <javascript:>. >> 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/4bf7d2ce-9a13-4f85-9933-cb8496e1f59d%40googlegroups.com >> >> <https://groups.google.com/d/msgid/django-users/4bf7d2ce-9a13-4f85-9933-cb8496e1f59d%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 [email protected]. To post to this group, send email to [email protected]. 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/ff7db442-5444-4ff2-ae27-3abd18695b94%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
