Simon Willison’s Weblog

3 items tagged “cloudflare”


Details of the Cloudflare outage on July 2, 2019 (via) Best retrospective I’ve read in a long time. The outage was caused by a backtracking regex rule that was added to the Web Application Firewall project, which rolls out globally and skips most of Cloudflare’s regular graduar rollout process (delightfully animal themed, named DOG for the dogfooding PoP that their employees use, PIG for the Guinea Pig PoPs reserved for free customers, then Canary for the final step) so that they can deploy counter-measures to newly discovered vulnerabilities as quickly as possible—but the real value in the retro is that it provides an extremely deep insight into how Cloudflare organize, test and manage their changes. Really interesting stuff. # 12th July 2019, 5:36 pm


The Now CDN (via) Huge announcement from Zeit Now today: all deployments are now served through the Cloudflare CDN, which means they benefit from 150 worldwide CDN locations that obey HTTP caching headers. This is particularly relevant for Datasette, since it serves far-future cache headers by default and uses Cloudflare-compatible HTTP/2 push hints to accelerate 302 redirects. This means that both the “datasette publish now” CLI command and the Datasette Publish web app will now result in Cloudflare-accelerated deployments. # 12th July 2018, 3:34 am

Everyone can now run JavaScript on Cloudflare with Workers. This is such a brilliant piece of software design: Cloudflare took the service workers spec and used it as the basis for their edge-executed JacaScript feature. This means you can run server-side JavaScript in hundreds of edge locations worldwide, applying custom dynamic logic (including additional async cached fetch() calls) with only around 1ms if additional overhead. The pricing model is a steal: $0.50 per million requests with a $5/month minimum. # 13th March 2018, 4:36 pm