CSR: Small: Improving Cloud Services by Exploiting Synchronized Clocks and Software Defined Flash

大型数据中心提供的计算基础设施是云服务(Amazon AWS、Microsoft Azure等)日益广泛使用的基础。今天的数据中心既表现出松散耦合的分布式系统的特性，又表现出紧密耦合的超级计算机的特性。例如，网络基础设施现在模仿早期的超级计算机，具有每条链路的低延迟和高带宽、高二分带宽胖树拓扑和远程存储器操作(例如，ROCE)。云计算的快速增长激发了人们投资于提高能力的愿望，而且趋势是进一步向超级计算类似的能力发展。然而，今天的系统和服务的规模要求许多分布式系统的特性仍然存在，例如相对较高的故障率和对用于事务处理的集成可靠存储系统的需求。该项目寻求通过结合使用IEEE精确时间协议和软件定义闪存来改进云服务，以开发高性能、可靠、经济高效的事务存储系统。该项目的一个关键方面是开发一个基于多版本Key-Value闪存存储系统的原型分布式事务系统。存储系统利用SSD写入行为来高效地维护多个密钥版本，这些密钥版本根据每个请求的全局(数据中心内)唯一时间戳进行时间排序，并使客户端能够做出本地提交或中止决策。所提出的方法利用具有1微秒偏差的紧密同步时钟和软件定义的闪存来消除或减少相对于其他系统的开销。

Large-scale data centers provide the computational infrastructure that underlies the increasing use of cloud services (Amazon AWS, Microsoft Azure, etc.). Today's data centers exhibit properties of both loosely coupled distributed systems and tightly coupled supercomputers. For example, networking infrastructure now mimics early supercomputers with low lantency and high bandwidth per link, high bisection bandwidth Fat-Tree topologies, and remote memory operations (e.g., RoCE). The rapid increase in cloud computing motivates the desire to invest in increasing capabilities, and that the trend is to move further toward supercomputing-like capabilities. Nonetheless, the scale of today's systems and services necessitates that many distributed systems properties remain, such as relatively high failure rates and the need for integrated reliable storage systems for transaction processing.This project seeks to improve cloud services through the combined use of the IEEE Precision Time Protocol and Software Defined Flash to develop a high performance, reliable, cost-effective, transactional storage system. A key aspect of this project is the development of a prototype distributed transactional system built on-top of a multi-version key-value Flash-based storage system. The storage system exploits SSD write behavior to efficiently maintain multiple key versions that are time ordered based on a globally (within the data center) unique timestamp for each request and enables clients to make a local commit or abort decision. The proposed approach exploits both tightly synchronized clocks with 1 microsecond skew and Software Defined Flash to eliminate or reduce overheads relative to other systems.