Atomic Commit Problem (ACP) is a single-shot agreement problem similar to consensus, meant to model the properties of transaction commit protocols in fault-prone distributed systems. We argue that ACP is too restrictive to capture the complexities of modern transactional data stores, where commit protocols are integrated with concurrency control, and their executions for different transactions are interdependent. As an alternative, we introduce Transaction Certification Service (TCS), a new formal problem that captures safety guarantees of multi-shot transaction commit protocols with integrated concurrency control. TCS is parameterized by a certification function that can be instantiated to support common isolation levels, such as serializability and snapshot isolation. We then derive a provably correct crash-resilient protocol for implementing TCS through successive refinement. Our protocol achieves a better time complexity than mainstream approaches that layer two-phase commit on top of Paxos-style replication.

原子提交问题（ACP）是与共识相似的单发协议问题，旨在对易于出错的分布式系统中的事务提交协议的属性进行建模。我们认为，ACP太局限了，无法捕获现代事务数据存储的复杂性，因为提交协议与并发控制集成在一起，并且它们在不同事务中的执行是相互依赖的。作为替代方案，我们引入了交易认证服务（TCS），这是一个新的形式化问题，它捕获了具有集成并发控制的多发交易提交协议的安全保证。TCS由认证功能进行参数化，该认证功能可以实例化以支持常见的隔离级别，例如可序列化性和快照隔离。然后，我们通过逐次改进来推导可证明正确的防碰撞协议，以实现TCS。与在Paxos式复制之上分层两阶段提交的主流方法相比，我们的协议实现了更好的时间复杂性。