ITR: Keyword Searching in Loosely Coupled Distributed Systems

松散耦合的分布式系统中，节点可以在没有集中控制的情况下以高速率加入、离开或失败，并且网络连接或拓扑结构可能非常不稳定。示例包括自组织覆盖网络、移动自组织网络（MANET）和传感器网络。本提案旨在解决在这些动态系统中支持关键字搜索的问题。关键字搜索对于覆盖网络中的信息检索和传感器网络中的生境监测等高级分布式服务来说是一种非常有效的工具。本提案旨在建立一个分布式关键字搜索框架，以达到理想的系统可伸缩性、搜索速度、内容过时性和搜索质量水平。所提出的设计的核心是一种称为摘要索引的分布式数据结构，它为更远的内容维护逐渐不那么精确的搜索索引，以实现可伸缩性。该项目包含三个主要内容：1。为松散耦合分布式系统创建健壮的基于“摘要索引”的关键字搜索框架；检查各种系统组件的设计，并研究性能指标之间的权衡；结合系统集成与应用研究。

Loosely coupled distributed systems are those in which nodes can join, leave, or fail at high rates without centralized control and network connections or topology can be highly unstable. Examples include self-organizing overlay networks, mobile ad hoc networks (MANET), and sensor networks. This proposal seeks to address issues in supporting key searching in these dynamic systems. Keyword searching is an extremely effective utility for many higher-level distributed services, such as information retrieval in overlay networks and habitat monitoring for sensor networks.This proposal seeks to build a distributed keyword searching framework that achieves a desirable level of system scalability, search speed, content staleness, and quality of search. The heart of the proposed design is a distributed data structure called a summary index, which maintains gradually less accurate search index for content farther away to achieve scalability. This project contains three main thrusts: 1. creating a robust "summary index"-based keyword searching framework for loosely coupled distributed systems, 2. examining the design of various system components and studying the tradeoffs among performance metrics, and 3. incorporating system integration and application studies.