Am ScyllaDB but Marc did completely independent work.
The client vcpus don't matter that much, the experiment compares
the server side, the client shouldn't suck.
When we test ScyllaDB or other DBs, we run benchmarks for hours and days. This is just a stateless, static http daemon, so short timing is reasonable.
The whole intent is to make it a learning experience, if you wish to reproduce, try it yourself. It's aligned with past measurements of ours and also with former Linux optimizations by Marc.