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

可靠普适系统的整体方法这个项目通过三个方面提出了一种开发可靠普适系统的整体方法：(1)为了调试目的，提出了普适系统的统一视图。该视图克服了各种技术的异构性需求。其关键思想是将所有系统构件，无论是系统范围的还是给定节点的本地构件，无论是静态的还是时态的，都独立于它们的粒度，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的重放请求，同时插入应用代码来填充相关关系。(2)提出了编程语言支持，以便于跟踪程序中关键事件之间的依赖关系。为此，提出了一种构建在Java上的简单语言，带有对高级应用程序事件及其依赖项的注释。这是处理动态普及应用程序中大量事件的基石之一。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的定义的部分查询。(3)研究了通过特定覆盖网络的运行时和通信支持，以有效地在节点之间传播事件和因果信息。在节点级，使用仪表化的Java虚拟机以运行时适应的方式记录和跟踪本地事件。这种自适应的事件记录/跟踪策略大大减少了对资源的需求。计算机科学学生组织的发展将被特别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.