👀 Views: 2 💬 Answers: 1 📅 Created: 2025-06-06

ruby rails redis sessions

I'm trying to implement Redis as a session store in my Rails 7 application, but I'm running into intermittent `SessionStore::CookieOverflow` errors. This seems to happen when the session size exceeds the maximum allowed by cookies, which is around 4KB. I've configured my session store in `config/initializers/session_store.rb` like this: ```ruby Rails.application.config.session_store :redis_store, servers: [ { host: "localhost", port: 6379, db: 0 }, ], key: "_my_app_session", expire_after: 90.minutes, threadsafe: false ``` I often store user preferences and shopping cart items in the session, which can add up quickly. I’ve tried to clear the session before storing new data to ensure it doesn’t exceed the limit: ```ruby session.clear session[:cart] = @cart_items session[:user_preferences] = @user_preferences ``` However, this doesn’t seem to consistently resolve the issue, and I still see the error intermittently in production logs: ``` ActionDispatch::Cookies::CookieOverflow: Cookie overflow error: Session cookie too big. ``` I also noticed that when I inspect the session data, it sometimes contains unexpected entries, which might contribute to the overflow. I'm using the `redis` gem version 5.0.0 and `redis-rails` version 5.0.0. Any ideas on how to effectively manage session size or alternatively, configurations I might be missing? Is storing too much data in the session itself a bad practice? How can I ensure my application avoids these overflow errors?