One million connections

This post details a test where PlanetScale successfully maintained one million active MySQL connections by combining Vitess connection pooling at the VTTablet level with PlanetScale's Global Routing Infrastructure. It explains the challenges of database connection limits in serverless architectures, the role of `max_connections` in MySQL, and the limitations of application-side connection pools. The test involved using AWS Lambda with a fan-out pattern, where 1000 worker functions each established 1000 connections, demonstrating the scalability of the architecture to handle massive connection concurrency.