CSR-DMSS, SM: A Holistic Approach to Reliable Pervasive Systems

可靠普适系统的整体方法本项目通过三个贡献提出了开发可靠普适系统的整体方法：(1)为调试目的提出了普适分布式系统的统一视图。这个视图克服了各种技术的异构需求。关键思想是将所有系统构件，系统范围的或局部的给定节点，静态的或临时的，独立于它们的粒度，形成关系。通过在这些关系上编写类似sql的查询来调试程序。开发了一个查询编译器，它将查询转换为系统级或节点级重放请求，同时使用应用程序代码填充相关关系。(2)提出编程语言支持，方便跟踪程序中重要事件之间的依赖关系。为此，建议在Java基础上构建一种简单的语言，并为高级应用程序事件及其依赖项提供注释。这是处理动态普及应用程序中大量事件的基础之一。此外，与编程语言的集成允许查询编译器验证引用特定于应用程序定义的部分查询。(3)通过特定的覆盖网络研究运行时和通信支持，以有效地跨节点传播事件和因果关系信息。在节点级别，使用一个安装了工具的Java虚拟机以一种可适应运行时的方式记录和跟踪本地事件。这种自适应事件日志/跟踪策略显著降低了资源需求。计算机科学学生组织的参与将专门用于促进本科生的研究。

Holistic Approach to Reliable Pervasive SystemsThis project proposes a holistic approach to developing reliable pervasive systems through three contributions: (1) A unified view of a pervasive distributed system is proposed for debugging purposes. This view overcomes the heterogeneous requirements for various technologies. The key idea is to formulate all system artifacts, system wide or local to a given node, static or temporal, independently of their granularity, into relations. Programs are debugged by writing SQL-like queries over these relations. A query compiler is developed that translates queries into system-level or node-level replay requests, and in the meantime, instruments application code to populate relevant relations. (2) Programming language support is proposed to facilitate the tracking of dependencies among essential events in the program. To that end, a simple language built on Java is proposed, with annotations for high-level application events and their dependencies. This represents one of the cornerstones for dealing with the large number of events in dynamic pervasive applications. In addition, the integration with a programming language allows the query compiler to verify parts of queries referring to application-specific definitions. (3) Runtime and communication support through specific overlay networks is investigated to efficiently propagate events as well as causality information across nodes. At the node level, an instrumented Java virtual machine is used to log and trace local events in a runtime-adaptable manner. Such an adaptive event logging/tracing strategy significantly reduces resource demands.Involvement in computer science student organizations will be specifically leveraged to promote undergraduate student research.