NeTS: Medium: Provisioning, Enforcing, and Pricing Temporal Service Differentiation in Virtualized Networked Environments

云计算改变了我们处理计算的方式。它的用途包括大规模科学计算、电子商务、数据密集型应用和网络托管。这种多样性是衡量其成功的标准，但也代表了它面临的主要挑战之一。云计算的实力是通过共享计算资源实现的，但共享必须是可控的。想象一下，金融交易或实时医疗成像处理由于（比如）大容量批处理应用程序而减慢。当前的解决方案在非常粗糙的级别上控制共享，例如，应用程序有权使用的处理器内核数量，或者它可以消耗多少内存或网络带宽。这种粗糙的控制已被证明不足以提供强有力的响应时间保证。该项目将设计和实现解决这一缺点的解决方案，并在此过程中将云计算的成本和性能优势扩展到具有实时需求的关键应用程序。该项目将提供对云计算资源（CPU、内存、网络带宽等）之间存在的依赖关系的全面理解，并设计考虑这些依赖关系的调度和资源管理解决方案，从而为云用户提供对响应时间的细粒度控制。将使用原型实现和测试平台来演示解决方案的适用性和可行性。该项目将探索云计算解决方案核心虚拟化技术中出现的复杂资源交互。重点是为虚拟化系统中的I/O操作实施服务保证，因为它们在提供端到端计算保证方面起着关键作用。具体来说，该项目将描述虚拟环境中I/O操作所涉及的资源依赖关系，并开发有效管理它们的机制。该项目将调查的示例问题包括I/O性能与分配给I/O操作的CPU内核数量之间的关系，为来自不同vm和流量类别的流量分配不同线程的开销，不同中断处理策略对性能的影响等。还将量化不同调度和资源管理机制的实现成本（开销），以便在效率和资源保证之间进行明智的权衡。原型实现将在Xen环境中进行，并在由8台16核计算机组成的本地测试平台上进行演示，网络连接范围从1Gbps到40Gbps。更广泛的影响：云计算已经在我们的现代社会中发挥了重要作用，但它在规模和范围上都有进一步发展的潜力（例如，优化电网的效率或控制交通流量，以最大限度地减少城市环境中的拥堵）。然而，要实现云的全部潜力，需要它不断发展，以提供可预测的保证。该项目将开发实现这一目标的解决方案，并在此过程中将云计算的好处扩展到对我们社会至关重要的新应用中。将这些解决方案转移到商业使用的云系统将通过面向开源Xen系统（Amazon EC2基于该系统）的模块交付来实现。该项目还旨在提高学生利用云计算的能力。它将开发教育实验室模块，让学生直接动手体验虚拟化环境中出现的复杂交互。该项目还将通过为本科生提供暑期研究机会，培养学生对云计算研究的兴趣。将特别强调征聘妇女和人数不足的少数民族。

Cloud computing has transformed how we approach computing. Its uses range from large-scale scientific computations, to e-commerce, to data-intensive applications, to web-hosting. This diversity is a measure of its success, but also represents one of the major challenges it faces. Cloud computing strength is through the sharing of computing resources, but sharing must be controlled. Imagine financial transactions or real-time medical imaging processing experiencing slow-downs because of, say, a high volume batch application. Current solutions control sharing at a very coarse level, e.g., the number of processor cores an application is entitled to, or how much memory or network bandwidth it can consume. This coarse control has been shown insufficient to offer strong response time guarantees. This project will design and implement solutions that address this short-coming, and in the process extend the cost and performance benefits of cloud computing to critical applications with real-time requirements. The project will provide a comprehensive understanding of the dependencies that exist among cloud computing resources (CPU, memory, network bandwidth, etc.), and devise scheduling and resource management solutions that account for those dependencies to provide fine grain control of the response time afforded to cloud users. A prototype implementation and a testbed will be used to demonstrate the applicability and feasibility of the solutions.The project will explore the complex resource interactions that arise in virtualization technologies at the core of cloud computing solutions. The focus is on enforcing service guarantees for I/O operations in virtualized systems, as they play a critical role in delivering end-to-end computing guarantees. Specifically, the project will characterize the resource dependencies involved in I/O operations in a virtualized environment, and develop mechanisms to manage them effectively. Sample questions the project will investigate include the relationship between I/O performance and the number of CPU cores allocated to I/O operations, the overhead of assigning different threads to traffic from different VMs and traffic classes, the impact on performance of different interrupt handling strategies, etc. The implementation cost (overhead) of different scheduling and resource management mechanisms will also be quantified to enable informed trade-offs between efficiency and resource guarantees. A prototype implementation will be carried out in the Xen environment, and demonstrated over a local testbed consisting of eight 16-core computers with network connectivity ranging from 1Gbps to 40Gbps.Broader Impacts: Cloud computing already plays a major role in our modern society, but it has the potential to grow even further in scale and scope (e.g., optimizing the efficiency of our electrical grid or controlling the flow of traffic to minimize congestion in urban settings). Realizing the cloud's full potential, however, requires that it evolves to offer predictable guarantees. This project will develop solutions towards realizing this goal, and in the process extend the benefits of cloud computing to new applications of vital importance to our society. Transfer of those solutions to commercially used cloud systems will be pursued through the delivery of modules aimed at the open-source Xen system (on which Amazon EC2 is based). The project will also target improving students' ability to leverage cloud computing. It will develop educational lab modules that give students direct hands-on experience with the complex interactions that arise in virtualized environments. The project will also be used to foster students' interest in cloud computing research by offering summer research opportunities to undergraduate students. Special emphasis will be given to recruiting women and under-represented minorities.