Reads That Scale With Your Cores
· 5 min read
Redis is fast. It is also, by design, single-threaded on the data path: one event loop, one core, one command at a time. That's a genuinely good design — it makes Redis simple to reason about and removes a whole category of concurrency bugs. But it has a ceiling you can't buy your way out of. Give a single-event-loop engine a 4-core box, an 8-core box, a 32-core box, and read throughput lands in the same place. The extra cores sit idle.
Zaris takes the other road. Keys are partitioned and each partition has an owner, so reads for different keys land on different cores and run at the same time. The result is throughput that moves when you add cores — instead of a flat line, a slope.