NeTS: Small: RDMA over Ethernet: A Control Theoretic Approach

数据中心应用程序——无论是云存储、大数据处理还是桌面虚拟化——都需要高带宽（每秒40千兆比特或更高）来满足不断增长的需求，以支持国家需求。传统的互联网协议栈不能在这样的速度下扩展，因为它们有非常高的处理需求。本项目将从控制理论的角度分析在该领域部署的新协议。行业和标准组织对这个话题非常感兴趣；研究者正在与工业界合作，并将利用他们的资源来实现和测试平台评估。基于融合以太网的远程直接内存访问（RDMA）技术正被部署在数据中心，以极低的CPU开销为应用程序提供超低延迟和高吞吐量。然而，初始设计缺乏任何正式的控制理论分析。该机制容易受到队列大小和流量波动的影响。如何为算法选择各种参数，以及参数选择如何随着流的数量或链路容量的变化而变化，并不是显而易见的。虽然现有部署使用40千兆位/秒的以太网链路，但在100千兆位/秒的以太网链路上的模拟显示队列不稳定、振荡和利用率损失。本计划旨在提供资料中心聚合乙太网路上RDMA协议拥塞控制的正式控制理论分析。该建议的主要智力优点是开发了在融合以太网上传输RDMA的拥塞控制协议的正式控制理论模型。研究人员将利用研究成果向哥伦比亚大学的学生提供创业培训，并正在制定一个试点项目，将创业培训扩大到高中生。

Datacenter applications -- be it cloud storage, big data processing, or desktop virtualization -- need high bandwidth (40 Gigabits/second or more) to meet rising demand in support of national needs. Traditional Internet Protocol stacks don't scale at such speeds, since they have very high processing demands. This project will analyze new protocols being deployed in the field from the point of view of control theory. The topic is of great interest to industry and standards bodies; the investigator is collaborating with industry and will be leveraging their resources for implementation and testbed evaluations. Remote Direct Memory Access (RDMA) over Converged Ethernet technology is being deployed in datacenters to provide ultra-low latency and high throughput to applications, with very low CPU overhead. However, initial designs lack any formal control theoretic analysis. The mechanisms are prone to oscillations in the queue size and fluctuating flow rates. It is not immediately obvious how to choose the various parameters for the algorithms, and how the parameter choices change with the number of flows or link capacities. While existing deployments operate with 40 Gigabit/second Ethernet links, simulations on 100Gigabit/second Ethernet links show instability of the queue, oscillations and loss of utilization. This project aims to provide a formal control theoretic analysis of congestion control in RDMA protocols over converged ethernet in the datacenter. The main intellectual merit of the proposal is to develop formal, control theoretic models of Congestion Control Protocols to transport RDMA over Converged Ethernet. The investigator will leverage the research efforts to deliver entrepreneurship training to Columbia University students, and is developing a pilot program to extend entrepreneurship training to high school students.