Database Traffic Control
PlanetScale introduced Database Traffic Control, a feature that provides fine-grained traffic management for databases, enabling users to route, shape, and control query traffic to optimize performance and reliability.
Background
PlanetScale is a serverless MySQL-compatible database platform built on Vitess (the same technology that scales YouTube's databases). The platform was already known for offering branching workflows (like developer branches for schema changes) and serverless scaling. This new "Database Traffic Control" feature lets developers inspect, reroute, or block individual queries going to their database—much like a network firewall or a reverse proxy for database traffic. Without such a tool, developers typically either let all queries through or take down the entire database to stop a bad query. Traffic Control enables surgical reactions to problematic queries (e.g., an accidental `DELETE FROM users`) without downtime, as well as A/B testing of database migrations, throttling expensive queries, and blocking traffic from specific applications or users. The feature leverages PlanetScale's position as a man-in-the-middle proxy architecture—every query already passes through its infrastructure, so adding inspection and control logic there is a natural extension.