A test to demonstrate dropped messages when using WebSockets with Django Channels.
Simply fire up the test using Docker (instructions below), and navigate to http://localhost:8000/ in your favorite browser.
By default, the test will create 200 sockets (one at a time, in 50ms intervals). Each of these sockets will report their status in the JavaScript console.
Every 10 seconds, a celery process will send out a random UUID message to the "test" Group (which each socket is automatically subscribed to upon connecting). You can tell how many sockets actually received the message by looking at the number next to the message. Here's an example with two browsers running at the same time (Chrome left, Safari right):
Obviously, any number less than 200 means messages were lost. You can configure
the number of sockets to open in mass/static/js/app.js. Simply change the
value of targetSockets.
I'd recommend using separate browsers if you are going to run more than one instance of the test at once.
It's very easy once you have Docker! Simply:
docker-compose pull
docker-compose up -d
That's it! To view the logs from a certain service, run:
docker-compose logs -f service_name
So to view logs from daphne you'd run:
docker-compose logs -f web