Channels 3 Memory Leak / Overconsumption

Every Django Channels project, including the Channels Tutorial project, has a memory leak.

Specifically, the MEM % used in a Docker image keeps rising, and it assumes you run them on Daphne.

To reproduce, I Dockerized the Tutorial project in this repo and the memory consumption issues are still present.

Steps to reproduce:

git clone https://github.com/alamorre/channels_3_leak.git
cd channels_3_leak
docker-compose build
docker-compose up -d
docker stats channels_3_leak_web_1

Stress test with the following command:

brew install chrome-cli
for i in {1..100}; do chrome-cli open http://127.0.0.1:8000/chat/lobby/; done

The MEM % will keep going up!

Personally, it starts around 2.5% and will go up to 4% with lots of tabs open. Then never goes back down once the tabs close.

Again, this project precisely follows the Tutorial and Deploying sections from the Docs. And it also seems like a popular discussion amongst users.

[alamorre]

Once these deps were upgraded the mem leak went away!

asgiref==3.5.0
daphne==3.0.2
Django==3.2.11

[Archmonger]

In my scenario, memory usage starts at around 260 MB for 3 Hypercorn workers and one miscellaneous subprocess (Huey). Over time, it inflates to ~600 MB and sits there (in a range of ±30 MB).

Seeing how it’s not exponential, this is probably Python doing some in-memory caching.