🔗 Postgres postmaster does not scale

Every postgres server starts and ends with the postmaster process. It is responsible for spawning and reaping children to handle connections and parallel workers, amongst other things. The postmaster runs a single-threaded main loop. With high worker churn, this loop can consume an entire CPU core, slowing down connection establishment, parallel queries, signal handling and more. This caused a rare, hard-to-debug issue where some of our EC2 instances would get delayed by 10-15s, waiting on the postmaster to fork a new backend to handle the connection.