Routing-Embedded Locking: Distributed Coordination Without a Lock Service

Live data migration across geographic regions in Internet-scale cloud services requires distributed locking—but dedicated lock services add infrastructure, latency on every request, and atomicity gaps between lock release and location cutover. We present an alternative: embedding lock metadata directly in the routing records that services already read on every user request. Deployed at a large-scale real-time messaging platform processing 6–10 million migrations per day, this approach makes lock enforcement free for the overwhelming majority of requests—lock checks piggyback on the routing lookup every request already performs—with a single extra point read only for the small, transient set of resources that carry an active lock. It also provides atomic cutover (location swap and lock release in a single database write) and deterministically correct lock propagation (passive cache expiry rather than active invalidation). Write-lock duration—the only user-impacting phase—holds at p99 under 20 seconds. We compare against Chubby, ZooKeeper, Redlock, and DynamoDB Lock Client, and discuss the broader applicability of infrastructure-embedded coordination for Internet-scale distributed systems.