Simon Willison’s Weblog

Last Mile Redis (via) Fly.io article about running a local redis cache in each of their geographic regions—“Cache data overlaps a lot less than you assume it will. For the most part, people in Singapore will rely on a different subset of data than people in Amsterdam or São Paulo or New Jersey.” But then they note that Redis has the ability to act as both a replica of a primary AND a writable server at the same time (“replica-read-only no”), which actually makes sense for a cache—it lets you cache local data but send out cluster-wide cache purges if necessary.