Geo-distribution is essential for modern online applications to ensure service reliability and high availability. However, supporting high-performance serializable transactions in geo-replicated databases remains a significant challenge. This difficulty stems from the extensive over-coordination inherent in distributed atomic commitment, concurrency control, and fault-tolerance replication protocols under high network latency. To address these challenges, we introduce Minerva, a unified distributed concurrency control designed for highly scalable multi-leader replication. Minerva employs a novel epoch-based asynchronous replication protocol that decouples data propagation from the commitment process, enabling continuous transaction replication. Optimistic concurrency control is used to allow any replicas to execute transactions concurrently and commit without coordination. In stead of aborting transactions when conflicts are detected, Minerva uses deterministic re-execution to resolve conflicts, ensuring serializability without sacrificing performance. To further enhance concurrency, we construct a conflict graph and use a maximum weight independent set algorithm to select the optimal subset of transactions for commitment, minimizing the number of re-executed transactions. Our evaluation demonstrates that Minerva significantly outperforms state-of-the-art replicated databases, achieving over $3\times$ higher throughput in scalability experiments and $2.8\times$ higher throughput during a high network latency simulation with the TPC-C benchmark.

翻译：地理分布对于现代在线应用确保服务可靠性和高可用性至关重要。然而，在异地复制数据库中支持高性能可串行化事务仍然是一个重大挑战。这一困难源于高网络延迟下分布式原子提交、并发控制和容错复制协议固有的广泛过度协调问题。为应对这些挑战，我们提出了Minerva——一种为高可扩展多主复制设计的统一分布式并发控制方案。Minerva采用基于纪元的新型异步复制协议，将数据传播与提交过程解耦，实现持续的事务复制。系统通过乐观并发控制机制允许任意副本并行执行事务并在无协调情况下提交。当检测到冲突时，Minerva采用确定性重执行而非中止事务来解决冲突，在保证可串行化的同时不牺牲性能。为进⼀步提升并发度，我们构建冲突图并采用最大权独立集算法选择最优事务提交子集，从而最小化重执行事务数量。实验评估表明，Minerva显著优于现有先进复制数据库系统：在可扩展性实验中实现超过$3\times$的吞吐量提升，在TPC-C基准测试的高网络延迟模拟中达到$2.8\times$的吞吐量提升。