ITR: Scalable Non-Stop Blade-Based Servers

本项目提出了可扩展的不间断服务器(SNOPS)架构：一个可靠、可用和可服务(RAS)的硬件平台。通过使用通过可扩展网络和硬件分布式共享内存(DSM)互连的商用刀片组件，SNOPS提供了传统面向RAS的服务器无法比拟的成本和性能可扩展性。SNOPS通过对软/瞬时错误和/或单个处理器/内存组件故障的快速应用透明检测和恢复，以及在硬件组件故障时不丢失状态的模块热插拔来提供不间断服务。该项目提出了跨网络的内存屏障(膜)，这是一个规范处理器和内存模块之间内存数据传输的抽象层。对于来自处理器和内存端的错误数据，薄膜充当了一道难以逾越的屏障，只允许无错误的数据通过。在处理器端，膜相干协议通过比较它们的请求来检测并触发对源自组的冗余处理器的错误的恢复。在存储器方面，膜存储器冗余协议通过类似于RAID的分布式奇偶校验方案来检测和恢复源自存储器组件的错误。该原型将支持商用操作系统(如Linux)，并提供必要的性能，以允许针对商业级服务器应用对我们的想法进行全面评估。可扩展的服务器模拟基础设施也将可用于分布，从而实现快速、准确和全系统的服务器模拟。已经在工业和学术环境中建立了几个概念验证原型，特别是对于学生来说，这是一种无价的体验，但也有很高的潜力对工业研究和开发产生影响。

This project proposes the Scalable Non-stOP Server (SNOPS) architecture: a reliable, available, and serviceable (RAS) hardware platform. SNOPS offers both cost and performance scalability unparalleled by conventional RAS-oriented servers by using commodity blade components interconnected through a scalable network and hardware distributed shared memory (DSM). SNOPS offers non-stop service through fast application-transparent detection and recovery of soft/transient errors and/or single processor/memory component failure, and hot-swapping of a module upon hardware component failure without state loss.The project proposes the MEMory BaRrier Across the NEtwork (MEMBRANE), an abstraction layer to regulate memory data transfer between processor and memory modules. MEMBRANE serves as an impenetrable barrier for faulty data both from the processor and the memory sides, allowing only error-free data to transfer across. On the processor side, the MEMBRANE coherence protocols detect and trigger recovery for errors originating from redundant processors of a group by comparing their requests. On the memory side, the MEMBRANE memory redundancy protocols detect and recover from errors originating from the memory components via a RAID-like distributed parity scheme.This prototype will support a commodity OS (such as Linux) and deliver the necessary performance to permit full-scale evaluation of our ideas against commercial-grade server applications. Scalable server simulation infrastructure will be also be available for distribution, allowing for fast, accurate, and full-system simulation of servers. Several proof-of-concept prototypes have been built in industrial and academic settings and especially for students are an invaluable experience, but with a high potential to have impact on industrial research and development as well.