GitHub Freno: A Cooperative Service to Prevent Database Replication Lag

GitHub Freno: cooperative, highly available throttler service

I built Freno, a highly available throttler service designed to protect MySQL clusters from excessive write loads. Instead of acting as a proxy, Freno cooperates with clients by answering simple queries about whether it is safe to write based on real-time replication lag. This lightweight system uses the Raft consensus protocol to ensure reliability, allowing bulk operations like schema migrations to proceed without overwhelming your database infrastructure.

"Freno is not a proxy between the client and the backend store; it merely observes the store and states you're good to write or you should stop writing."