This is part two of a story about how we overcame the challenges of making a complex system more scalable. It is about how we made Quicksilver, our highly distributed key-value store, scalable with regard to its data size by evolving to a tiered caching architecture. https://blog.cloudflare.com/quicksilver-v2-evolution-of-a-globally-distributed-key-value-store-part-2-of-2/