Quicksilver v2: evolution of a globally distributed key-value store (Part 1)

Cloudflare describes Quicksilver v1.5, an evolution of its globally replicated key-value store that introduces replica (full dataset) and proxy (persistent cache) roles to cut disk usage without sacrificing latency or sequential consistency. The design employs persistent RocksDB-backed caches with compaction-filter evictions and soft/hard space limits, MVCC to serve version-correct reads under asynchronous replication, a sliding window to retain recent writes on proxies, and key/value separation to accelerate negative lookups while keeping memory use practical. Service discovery and load balancing leverage a gossip-driven Network Oracle and Consul/DNS to find nearby replicas, yielding comparable (sometimes better) p99.9 latency to replicas and improved operational resilience.