How YouTube Supports Billions of Users with MySQL and Vitess
YouTube scaled its backend to manage billions of users by implementing Vitess on top of MySQL. Vitess acts as a smart intermediary, enabling horizontal scaling, efficient query routing, and automated database management tasks. Key strategies included replication, sharding, vertical splitting, and enhancements like connection pooling, query safety mechanisms, and a specialized row cache. These measures addressed issues like replication lag, data consistency, and high write loads, ensuring YouTube's backend remained efficient and resilient.