CSR: Medium: Collaborative Research: Facets: Exploring Semantic Equivalence of Files to Improve Storage Systems

智力优势：该提案的重点是以有效和可伸缩的方式找到语义上等效的文件。如果两个文件相同，则可以对它们进行优化，以降低存储成本、提高性能并通常改进系统。传统上，两个文件只有在每个字节都相同的情况下才被认为是等价的——也就是说，字节等价。然而，该团队的初步研究表明，有许多其他文件本质上是等效的，即使它们包含的字节不相同。本提案将研究如何找到这样的情况，并执行优化，利用语义等价，而不是字节等价。这个项目将设计并实现一个框架，Facets，它通过对本质上彼此转换版本的文件应用优化来探索新的功能。许多优化和改进可以应用于语义等效的文件，包括：-确保语义等价文件的安全性-简化各种格式、保真度和版本的语义等价文件的备份和维护-使用语义等价文件来提高性能、可靠性、根据性能或能量限制选择访问哪些语义等效的文件。该团队的初步研究表明，典型用户机器上5%的文件是原创内容。其余的是来自其他地方的文件副本或原始内容的各种衍生品。虽然利用这一观察结果来获得优势并非微不足道，但如果能够找到这些关系并正确利用它们，就有可能实现许多重大改进。这些改进包括增强的安全性、更有效的备份和恢复、更好的文件缓存、更智能的性能与功耗权衡，以及许多其他可能性。更广泛的影响：开发的代码和技术将以开源的形式发布。该团队将采取措施（如申请补充REU资助）让本科生参与研究。他们将在拉美裔机构进行演讲和招聘。研究的材料和概念将被纳入其所在机构的主要研究人员的课程中。

Intellectual Merit:The focus of the proposal is on finding semantically equivalent files in an efficient and scalable manner. If two files are identical, they are candidates for optimizations to reduce storage costs, increase performance, and generally improve the system. Traditionally, two files are only considered equivalent if they are byte-by-byte identical - i.e., byte equivalence. However, this team's preliminary research shows that there are many other files that are essentially equivalent, even though the bytes they contain are not the same. This proposal will investigate how to find such cases and perform optimizations that make use of semantic equivalence, rather than byte equivalence.This project will design and implement a framework, Facets, which explores new capabilities by applying optimizations to files that are essentially transformed versions of each other. Many optimizations and improvements can be applied to semantically equivalent files, including: -Ensuring that the security of semantically equivalent files is preserved -Easing backup and maintenance of semantically equivalent files in various formats, fidelities, and versions -Using semantically equivalent files to improve performance, reliability, and availability -Regenerating semantically equivalent files to speed up recovery and network transfer -Selecting which semantically equivalent files to access according to performance or energy constraintsThis team's preliminary research shows that 5% of files on a typical user's machine are original content. The rest are copies of files from elsewhere or various derivatives of original content. While leveraging this observation to achieve advantages is not trivial, many significant improvements are possible if one can find these relationships and make proper use of them. These improvements include enhanced security, more efficient backup and restoration, better file caching, more intelligent tradeoffs in performance versus power use, and a host of other possibilities. Broader Impacts: The code and techniques developed will be released in open source form. The team will take steps (such as applying for supplemental REU grants) to involve undergraduates in the research. They will give talks and recruit at Hispanic-serving institutions. Materials and concepts from the research will be incorporated into classes taught by the principal investigators at their institutions.