> Extremely hard to scale in what sense? A single redis server running on fairly commodity hardware can serve some pretty intense loads (10s of thousands of ops

> Extremely hard to scale in what sense? A single redis server running on fairly commodity hardware can serve some pretty intense loads (10s of thousands of ops/sec). ~90k/sec on a single core of L5520. Scaling Redis is a premature optimization for 99.99% of the use cases. While it may be sexy to talk about millions of ops per second that one's project does in reality the number of projects that have that as a requirement is probably barely in triple digits globally.