Performance implementing ActionCable broadcasting in Rails 7 under heavy load
I'm refactoring my project and I'm experiencing important performance degradation with ActionCable when attempting to broadcast messages to multiple subscribers under heavy load... My application, built on Rails 7.1, uses Redis as the backend for ActionCable. When I try to broadcast messages to a large number of users (around 500), I notice that the response time increases sharply and some messages are even dropped or delayed. Here’s a snippet of how I’m currently broadcasting messages: ```ruby ActionCable.server.broadcast('chat_#{chat_id}', message: 'Hello everyone!') ``` To manage subscriptions, I’ve implemented a simple channel setup: ```ruby class ChatChannel < ApplicationCable::Channel def subscribed stream_from "chat_#{params[:chat_id]}" end def unsubscribed # Any cleanup needed when channel is unsubscribed end end ``` I’ve also tried increasing the thread pool size in `cable.yml`: ```yaml production: adapter: redis url: redis://localhost:6379/1 channel_prefix: my_app_production pool_size: 10 ``` Despite these changes, the performance scenario continues. I have monitored Redis and noticed spikes in memory usage during peak times. I suspect there might be a question with how I’m managing subscriptions or perhaps the way ActionCable handles multiple connections. Has anyone encountered similar issues, and what strategies did you employ to improve the performance of ActionCable under heavy load? Any insights on configuration tweaks or design patterns that could help would be greatly appreciated. How would you solve this? This is my first time working with Ruby LTS. Is there a simpler solution I'm overlooking?