Kenton Varda of Cloudflare introduces a new version of the Durable Object platform, now based on SQLite, offering zero-latency storage for high-performance applications. Courting controversy, this design aims to colocate application logic with data, resulting in efficient read and write speeds. The system handles scaling by creating multiple objects, each handling different units of state. For example, in a flight booking system, each flight can have its own Durable Object and SQLite database. The technical details are intricate, with constant streaming of WAL entries to object storage for point-in-time recovery. The Storage Relay Service powers this system, with plans for dynamic relocation of Durable Objects in the future.
https://simonwillison.net/2024/Oct/13/zero-latency-sqlite-storage-in-every-durable-object/