I-Corps: Flash in Action for High-Performance and Low-Energy Web Content Storage

这个项目解决了使用闪存作为多层存储系统的基础。数字内容（如文本、图像、声音、视频等）经历了爆炸式的增长。互联网媒体提供商（如Facebook、Flicker、YouTube、Hulu、Netflix等）在传送内容时面临着巨大的I/O需求。并且，由于web上视频流量的不断增加，后端存储服务器不仅需要增加存储容量，还需要增加存储带宽，以便及时地为web客户端提供服务。硬盘驱动器（hdd）的容量每美元有所提高，而主存储器（以DRAM的形式）的速度每美元有所提高。近年来，闪存技术因其显著降低成本而受到业界的关注。基于闪存的固态硬盘（ssd）现在的价格可以弥补hdd和DRAM之间的容量-速度差距。此外，闪存的能耗远低于这两种传统存储技术。该项目提出，多层存储架构是一种引人注目的工具，通过利用这三种技术的优势来优化存储的容量、速度和能耗。存储设备占典型数据中心能耗的近40%，因此，存储服务器不仅要具有高容量和高性能，而且要节能。从环境的角度来看，设计能够减少数据中心碳足迹的解决方案是极其重要的。使用闪存缓存的多层web存储系统在性能、容量和能效方面都是一个很有前途的解决方案。该项目的技术为CDN提供商和web服务提供商提供了优化其存储系统性能和能效的机会。虽然这项技术的主要客户将是运行大量web服务器的公司，但这些大型web公司运行的数据中心的碳排放减少对环境有好处。

This project addresses the use of flash memory as the foundation for multi-tiered storage systems. Digital content (e.g., text, image, sound, video, etc.) has experienced explosive growth. Internet media providers (e.g., Facebook, Flicker, YouTube, Hulu, Netflix, etc.) are facing huge I/O demand for delivering content. And, due to the increasing video traffic on the web, backend storage servers not only need increased storage capacity but also increased storage bandwidth to serve the web clients in a timely manner. Hard disk drives (HDDs) have advanced in capacity per dollar while main memory (in the form of DRAM) has advanced in speed per dollar. Recently, flash memory technology has been getting attention from industry due to its significant cost decrease. Flash-based Solid-State Drives (SSDs) are now at the price point where they can bridge the capacity-speed gap between HDDs and DRAM. In addition, energy consumption of flash memory is far less than the two traditional storage technologies. This project proposes that multi-tiered storage architecture is a compelling vehicle to optimize capacity, speed, and energy consumption of storage by exploiting the advantages of all three technologies Storage devices make up nearly 40% of the energy consumption of a typical data center -- consequently, storage servers should not only have high capacity and deliver high performance, but also be energy efficient. From an environmental perspective, it is extremely important to devise solutions that can reduce the carbon footprint of data centers. A multi-tiered, web storage system that uses flash memory for caching is a promising solution for performance, capacity, and energy efficiency. This project's technology presents an opportunity for CDN providers and web service providers to optimize the performance and energy efficiency of their storage systems. While the primary customers of this technology will be corporations that run a large number of web servers, there is an environmental benefit from the carbon emission reduction of the data centers run by such big web corporations.