Open Source Summit North America 2025

This presentation explores how to create a multi-threaded version of Valkey by employing userspace Read-Copy-Update (RCU) to achieve high performance. With fewer than 2,000 lines of code modifications, we introduce a coordinator-worker pattern, enabling key-value stores like Valkey and Redis to handle tasks concurrently across multiple threads while using a per-thread event loop for I/O operations. Userspace RCU facilitates lock-free data sharing between a writer thread and multiple reader threads, dramatically improving read performance.

Our experiments show that the multi-threaded Valkey can achieve over one million operations per second on a standard server.