CSR: Small: Client-Centric Consistency

存储系统提供的隔离保证调节多个并发执行的事务如何正确读写数据。类似地，当数据在不同的地理位置复制和更新时（如Facebook和Twitter），一致性保证指定哪些数据对访问不同副本的客户机是可见的。该项目将开发一种新的以程序员为中心的模型，用于在单一框架中严格表达地理复制存储系统提供的隔离和一致性保证。然后，它将利用新模式寻求更有效的方式来实施这些保证。该项目将沿着三个方向推进。首先，它将寻求将隔离和一致性保证表示为应用程序可以观察到的状态属性，而不是依赖于低级读/写操作的不可见历史。其次，它将寻求克服当前由缓慢或故障服务器引起的可伸缩性瓶颈，这些瓶颈迄今为止扼杀了行业对部署因果一致的地理复制数据存储的兴趣。第三，它将利用其对一致性和隔离的统一处理，首次在可扩展的一致数据存储之上支持通用的读/写事务。该项目直接解决了研究和行业对大规模事务性分布式系统日益增长的兴趣。通过面对可扩展性的主要障碍，它将有助于在20多年的因果一致性学术研究中取得工业成果。此外，通过建立一种共同的语言来讨论一致性和隔离性，它将使系统和数据库研究社区之间的交流更加富有成效，因为他们主要关注的是一致性和隔离性，他们经常各说各话。该项目紧密结合了理论和实验研究，非常适合研究生和本科生进行研究，并将为分布式计算研究生和本科生课程的一致性和隔离性教学提供一种新方法。项目成果（发表的论文、演示文稿以及用于展示项目成果的软件和工作负载的存储库）将在地址http://www.cs.utexas.edu/users/lorenzo/projects/CCC/上提供下载，这些成果将保存五年。

The isolation guarantees offered by a storage system regulate how multiple transactions executing concurrently read and write data correctly. Similarly, when data is replicated and updated at geographically-distinct locations (as do Facebook and Twitter), consistency guarantees specify which data is visible to clients that access different replicas. This project will develop a new programmer-centric model for expressing rigorously, in a single framework, the isolation and consistency guarantees offered by geo-replicated storage systems. It will then leverage the new model to seek more efficient ways to implement these guarantees.The project will proceed along three thrusts. First, it will seek to express isolation and consistency guarantees as properties of states that applications can observe, instead of relying on invisible histories of low-level read/write operations. Second, it will seek to overcome the current scalability bottlenecks that arise with slow or faulty servers, which have, to date, stifled industry's interest in deploying causally-consistent geo-replicated data stores. Third, it will leverage its unified treatment of consistency and isolation to support, for the first time, generic read/write transactions on top of a scalable consistent data store.The project directly addresses the growing interest in both research and industry towards large-scale, transactional distributed systems. By confronting key obstacles to scalability, it will contribute to bring to industrial fruition over two decades of academic research on causal consistency. Further, by establishing a common language to discuss consistency and isolation, it will enable more fruitful exchanges between the systems and database research communities, who, because of their primary focus on, respectively, consistency and isolation, have often been talking past each other. The project, with its tight integration of both theoretical and experimental research, is ideally suited to introducing graduate and undergraduate students to research, and will offer a new approach to teaching consistency and isolation in graduate and undergraduate courses in distributed computing.The project outcomes (papers published, presentations, and a repository of the software and workloads used to demonstrate the results of the project) will be made available for download at the address http://www.cs.utexas.edu/users/lorenzo/projects/CCC/, where they will be kept for five years.