CRII: NeTS: Scaling Distributed Storage with Programmable Switches

现代互联网服务，如搜索、社交网络和电子商务，严重依赖于高性能的分布式存储。随着这些服务扩展到数十亿用户，系统运营商越来越依赖内存存储来满足必要的吞吐量和延迟需求。扩展分布式存储的一个主要挑战是处理倾斜的动态工作负载，这会导致严重的负载不平衡和性能下降。传统的基于闪存的存储和基于磁盘的存储可以使用快速的内存缓存层进行平衡，但是基于服务器的缓存不适用于内存存储，因为缓存层和存储层之间的性能差别很小。该项目研究了一种新的分布式存储架构，该架构利用新一代可编程交换机的功能和灵活性来缓存网络中的数据。该项目的目标不仅是在实践中提高云系统的性能和可靠性，而且还为经典分布式系统主题提供新的架构和理论见解。该项目将促进网络和系统社区在共同设计具有可编程交换机的网络和系统的新领域的合作。该项目将开发一种新的架构，即使在高度倾斜和快速变化的工作负载下也能提供高总吞吐量和低延迟。有两个主要的技术推动力。第一种是在有限的交换机功能和资源下设计交换机缓存。该方法将利用现代开关设计的匹配动作表、寄存器数组和多管道、多阶段结构，有效地索引和打包可变长度对象到有限的开关表和内存资源中。第二个研究重点是对整个系统进行设计，使其具有可扩展性、一致性和容错性。虽然这些都是经典的分布式系统主题，但它们将在一种由快速交换缓存和通用存储服务器组成的新型异构系统中重新讨论。原型系统将使用可编程软件和硬件开关构建，并在广泛的现实和合成工作负载下进行广泛评估。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Modern Internet services, such as search, social networking and e-commerce, depend critically on high performance distributed storage. As these services scale to billions of users, system operators are increasingly relying on in-memory storage to meet the necessary throughput and latency demands. A major challenge in scaling distributed storage is coping with skewed, dynamic workloads, which can lead to severe load imbalance and performance degradations. While traditional flash-based and disk-based storage can be balanced using a fast in-memory caching layer, server-based caching does not work for in-memory storage, because there is little difference in performance between the caching and storage layers. This project investigates a new distributed storage architecture that leverages the power and flexibility of new generation programmable switches to cache data in the network. The project goal is to not only improve the performance and reliability of cloud systems in practice, but also provide new architectural and theoretical insights on classical distributed systems topics. This project will foster the collaboration between the networking and systems communities in the new area of co-designing networks and systems with programmable switches.The project will develop a new architecture to provide high aggregate throughput and low latency even under highly-skewed and rapidly-changing workloads. There are two major technical thrusts. The first one is to design the switch cache with limited switch functionalities and resources. The approach will be to exploit the match-action tables, register arrays, and multi-pipeline, multi-stage structure of modern switch designs to efficiently index and pack variable-length objects into limited switch table and memory resources. The second research thrust is to design the overall system to achieve scalability, consistency and fault-tolerance. While these are classical distributed systems topics, they will be revisited in a new type of heterogeneous system which consists of fast switch caches and general-purpose storage servers. A prototype system will be constructed using both programmable software and hardware switches, and extensively evaluated with a wide range of realistic and synthetic workloads.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.