ReadOnlyError in Django application with Redis and DjangoCannels - django

Question

I have a Django app using DgangoChannels, Djangochannelrestframework. It establishes a websocket connection with ReactJS frontend. As channel layers I use Redis like that
CHANNEL_LAYERS = {
"default": {
"BACKEND": "channels_redis.core.RedisChannelLayer",
"CONFIG": {
"hosts": [("redis", 6379)],
},
},
}
Redis and Django runs in docker. My redis docker setup is
redis:
image: "redis:7.0.4-alpine"
command: redis-server
ports:
- "6379:6379"
networks:
- nginx_network
When I run my app on production server everything works for 5-8 hours. But after that period, if Django app trying to send a message via ws if falls with the error
ReadOnlyError at /admin/operations/operation/add/
READONLY You can't write against a read only replica.
Request Method: POST
Request URL: http://62.84.123.168/admin/operations/operation/add/
Django Version: 3.2.12
Exception Type: ReadOnlyError
Exception Value:
READONLY You can't write against a read only replica.
Exception Location: /usr/local/lib/python3.8/site-packages/channels_redis/core.py, line 673, in group_send
Python Executable: /usr/local/bin/python
Python Version: 3.8.13
Python Path:
['/opt/code',
'/usr/local/bin',
'/usr/local/lib/python38.zip',
'/usr/local/lib/python3.8',
'/usr/local/lib/python3.8/lib-dynload',
'/usr/local/lib/python3.8/site-packages']
Server time: Tue, 02 Aug 2022 08:23:18 +0300
I understand that it somehow connected with Redis replication, but no idea why if falls after period of time and how to fix it

Answer 1

I have the same error, the possible solution is here
Fix by adding command to docker and disable the replica-read-only config,
add this to your redis docker compose
​ command: redis-server --appendonly yes --replica-read-only no ​
then you could try to verify if the ​replica-read-only​ is disable using​redis-cli > config get replica-read-only​ command , if the result is no then it successful to disable.