We ran hundreds of machines (per cluster), and multiple clusters.
We don't use Scylla for dozens of reasons, including (but not limited to):
- The product was written before Scylla existed
- Our benchmarks didn't show Scylla as being 3x faster, let alone 10x faster
- Our machine count wasn't based on Cassandra limits, it was based on the amount of data we were comfortable storing on a given machine
- We don't throw shiny new tech into a critical stack just because someone says it's faster. I'd rather run code that's tested at scale. ONE of my Cassandra clusters there would have been 10x larger than any known Scylla deployment. At the same time, that deployment is at least 2 orders of magnitude smaller than other published Cassandra deployments (meaning largest known Cassandra deployments are 3 orders of magnitude larger than the largest known Scylla deployment)
The one thing I agree with the author: databases aren't where you want to have hipster tech. You want boring things that work. For me, Cassandra is the boring thing that works.