CSR-PDOS: Exploring and Developing Improved Erasure Codes for Storage Systems

存储系统在规模、复杂性和受欢迎程度上呈爆炸式增长，随着它们的增长，它们暴露在各种各样的故障中。因此，支持这些系统的软件必须能够承受越来越多的故障。Erasure编码是一种技术，它允许存储节点丰富额外的编码信息，这样如果一个或多个节点失败，原始数据可以从幸存者恢复。虽然擦除码已经存在了几十年，但在理解允许多次失败的代码的结构、性能和属性方面存在相当大的差距。该项目的任务是探索、设计、评估和传播针对多种故障的擦除代码，从而显著提高当前代码的性能和故障覆盖率。研究部分集中在统一不同的技术从经典编码理论，磁盘阵列技术，和渐近图论。这项工作将影响到多个存储节点串联使用的所有应用程序，并且一个或多个节点故障的风险是显著的。新的，有效的代码将被开发和评估相对于目前最好的代码。此外，这些代码的实现将分发给需要它们的系统程序员社区，并且将开发教程材料，以便代码可能产生广泛的影响。这是一个严重的问题，因为大多数当前的代码都是以理论上的形式呈现的，这使得需要实现它们的程序员无法触及它们。最后，擦除码将作为田纳西州东部K-12学校数学和科学激励课程的基础。

Storage systems are exploding in size, complexity and popularity, andas they grow, they expose themselves to a variety of failures. Assuch, the software that supports these systems must be able totolerate a growing number of failures. Erasure coding is a techniquethat allows storage nodes to be enriched with extra codinginformation so that if one or more nodes fail, the original data maybe recovered from the survivors. While erasure codes have existedfor decades, there is a considerable gap in understandingconstructions, performance and properties of codes that toleratemultiple failures. This project's mission is explore, design,evaluate and disseminate erasure codes for multiple failures thatsignificantly improve the performance and failure coverage of currentcodes. The research component is centered around unifying disparatetechniques from classical coding theory, disk array technology, andasymptotic graph theory.This work will impact all applications where multiple storage nodesare used in tandem, and the risk of one or more nodes failing issignificant. New, efficient codes will be developed and evaluatedwith respect to the best currently known codes. Additionally, theimplementations of these codes will be disseminated to the communityof systems programmers that need them, and tutorial material will bedeveloped so that the codes may have wide impact. This is a seriousissue, as most current codes are presented in a theoretcially formalway that puts them beyond the reach of the programmers who need toimplement them. Finally, erasure codes will be used as the basis formotivational programs on math and science at K-12 schools in EastTennessee.