Cryptographic Content-Addressed Version-Aware Distributed Mutual Exclusion

Distributed mutual exclusion mechanisms range from low-latency centralized systems (e.g., Redis-based locking) to strongly consistent consensus-based services (e.g., etcd and ZooKeeper). While consensus-based approaches provide linearizable guarantees, they incur coordination overhead, quorum latency, and operational complexity, making them inefficient for high-frequency, short-lived locking workloads. In contrast, Redis-based locks achieve low latency but rely on application-defined resource identifiers that are decoupled from execution context, providing no guarantees about the code version or invariants of a critical section. Additionally, systems that compute cryptographic identifiers at runtime introduce non-trivial overhead (10–50 μs per operation), which becomes significant at scale. We present SC-DKVL, a version-aware distributed mutual exclusion framework that defines lock identity as a deterministic function of code content rather than resource names. By reusing precomputed Git-derived hashes—available directly from the code-hosting layer where every version is already content-addressed—SC-DKVL eliminates runtime hashing and enables constant-time lock identification, while ensuring that distinct code versions map to distinct locks and cannot interfere during rolling deployments. To operationalize this, a lightweight build-time sidecar script extracts repository-native hashes and generates a header-only C++ mapping that binds code regions to lock identifiers. This establishes a direct bridge between build-time artifacts and runtime synchronization without introducing additional execution overhead. The framework's Redis backend uses atomic Lua scripting and fencing tokens to guarantee correctness under concurrency and failure, achieving 0.5–2 ms lock acquisition latency compared to 3–15 ms for etcd leases. SC-DKVL avoids consensus for identity management, requiring coordination only for shared state. It supports pluggable backends, including Redis for low-latency execution and consensus systems for durability when needed. By shifting synchronization from resource-level naming to code-level identity, SC-DKVL provides stronger semantic guarantees alongside improved performance, forming a practical foundation for version-aware distributed synchronization in modern microservice systems.