Part 2: Rethinking cache purge with a new architecture

What this post added

This post details the architecture of Cloudflare's new 'coreless' cache purge system. It describes the end-to-end flow of a purge request, including the roles of API Gateway workers, Purge Ingest workers (performing local validation and cache key generation), Purge Queue workers (Durable Objects for managing global purge queues and data center progress), and Purge Fanout workers (regional distributors). Key improvements include local validation to filter invalid purges, broadcasting cache keys instead of full purge requests, regional autoscaling for Durable Objects, and the use of fanout workers to reduce inter-region communication latency and improve throughput. The system is in production for purge-by-URL requests and benefits flexible purges through edge validation.